JP2005093158A - Lithium ion secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery using an electrode having a short ion diffusion distance. <P>SOLUTION: In the lithium ion secondary battery, the thickness of an electrode layer of at least either a positive electrode or a negative electrode is the same as the diameter of activator particle of the electrode. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lithium ion secondary battery that can be stably charged even at a high current rate, an assembled battery using the battery, and a vehicle equipped with the same.

  When a lithium ion secondary battery is used as a vehicle power source, a battery that can be stably charged even at a high current rate is desired. Conventional lithium ion secondary batteries used for mobile phones do not need to flow current at a high rate, and have become capacity-oriented batteries so that they can be used for a long time with a single charge (for example, (See Patent Document 1).

  The reaction means that ions are exchanged at the interface, and the ion concentration near the electrode changes. Along with this, diffusion of ions occurs from the electrolyte side or from the electrolyte side so as to reduce the concentration change.

  When a current lithium ion battery is charged and discharged at a high current rate, the reaction on the electrode surface proceeds quickly, so that the ion concentration in the vicinity of the electrode rapidly decreases during charging or discharging. Thereby, the diffusion of ions from the electrolyte side cannot catch up, and the charge / discharge performance decreases. The resistance component that occurs because this diffusion is rate-limiting is called diffusion resistance. The diffusion resistance increases as the viscosity of the medium carrying ions increases and the diffusion distance increases.

As a technique for reducing the diffusion resistance, for example, there is a method of reducing the viscosity of the electrolyte. In order to reduce the viscosity, a method of using a solvent containing a chain carbonate has been proposed (see, for example, Patent Document 2).
JP-A-9-306547 Japanese Patent Laid-Open No. 2002-8721

  However, in the method described in Patent Document 2, since the boiling point of the solvent is low, it cannot be put in a large amount, and since these solvents have a weak ability to dissociate ions, the ions are rather difficult to conduct if they are not included. Performance is reduced.

  Other methods for reducing the diffusion resistance include a method of reducing the ion concentration and a method of shortening the ion diffusion distance. However, it has been found that the former has a problem that the ionic conductivity is lowered.

  Further, as a method for shortening the diffusion distance, the electrode may be thinned to shorten the distance between the bulk electrolyte layer and the active material. In order to make the electrode thin, it is necessary to use an active material having a small particle diameter. However, when an active material having a small particle size is used, the contact between the active materials and between the active material and the conductive auxiliary agent is deteriorated. As a result, particles that do not participate in the reaction are formed, and the capacity is reduced. Therefore, it is necessary to put a large amount of conductive aid in the electrode. As a result, it has been found that there is a new problem that the active material density in the electrode is lowered and the capacity per electrode volume is lowered.

  Therefore, an object of the present invention is to provide a lithium ion secondary battery using an electrode having reduced ion diffusion resistance without reducing the active material density in the electrode, and an assembled battery using the battery. A vehicle equipped with these is provided.

  The present invention can be achieved by a lithium ion secondary battery in which at least one of the positive electrode and the negative electrode has the same particle diameter of the active material particles of the electrode and the thickness of the electrode layer.

  According to the lithium ion secondary battery of the present invention, an electrode having only one active material particle on the current collector foil is used. By using one layer, all active materials are in contact with the bulk electrolyte, and the ion diffusion distance can be shortened. Since the diffusion distance is short, the diffusion resistance can be made very small. As a result, a high output can be obtained. In addition, a battery that can be stably charged and discharged even at a high current rate can be provided. In addition, since no conductive assistant is required, the active material density in the electrode is increased. In the present invention, the battery capacity is not reduced by making the electrodes thinner. By making the electrode thinner than before, the capacity of a single cell (single battery) decreases, but if compared without changing the size (volume) of the battery, more single cells are stacked (contained) than before. This is equivalent when viewed as a whole battery. In other words, the present invention can provide a battery that can stably charge and discharge even at a high current rate, with a high output without losing the battery capacity.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 and 2 are cross-sectional schematic views schematically showing one electrode structure of the best mode of the lithium ion secondary battery according to the present invention.

  As shown in FIGS. 1 and 2, in one of the best modes of the lithium ion secondary battery according to the present invention (hereinafter also referred to as the first mode), at least one of the positive electrode and the negative electrode is active in the electrode 1. The particle diameter of the material particles 3 and the thickness T of the electrode layer (electrode active material layer) are the same. Here, making the particle diameter of the active material particles 3 of the electrode 1 and the thickness T of the electrode layer the same means that each active material 3 is applied to both the current collector (current collector foil) 5 and the electrolyte layer 7. Since they are in contact with each other, a conductive aid is not necessary. Further, since the active material 3 is always in contact with the bulk electrolyte 7, the diffusion distance is short, and the ion diffusion resistance can be kept small.

  On the other hand, high-rate characteristics, that is, performance when charging / discharging at a high current (specifically, 100% of the actual discharge capacity with respect to 100% of the theoretical capacity) depends on the size of the diffusion resistance. To do. In other words, if the diffusion resistance can be kept small, the high rate characteristics will be considerably improved. Therefore, in the first embodiment, since the diffusion resistance is small, it is possible to provide a lithium ion secondary battery with improved high rate characteristics and very high output and electrical resistance.

  Here, “the particle diameter of the active material particles and the thickness of the electrode layer (electrode active material layer) are the same” means the average particle diameter Ra of the active material particles and the thickness of the electrode layer (electrode active material layer). It suffices if the average value Ta is within the range where the average values Ta substantially match. Specifically, when the thickness of the active material particles and the electrode layer is determined by a measuring means described later, the average particle diameter Ra of the active material particles Ra = Ta ± 20% If it is within the range, it shall satisfy the above regulations. Preferably, the average particle diameter Ra of the active material particles is within the range of Ta = Ta ± 10%. This is because, as shown in FIG. 1, as the electrode layer becomes thinner, the thickness of the binder on the surface of the active material particles may not be negligible. In addition, the number of samples of each average value shall be 10 or more. The particle diameter of the active material particles and the thickness of the electrode layer (electrode active material layer) can be measured by, for example, a scanning electron microscope. However, regarding the average particle diameter of the active material particles, the average particle diameter of the active material used in the production may be used. Similarly, the electrode layer thickness may be the electrode thickness measured in the manufacturing stage. Moreover, when measuring the particle diameter of the active material particle in an electrode layer, the particle diameter of the thickness direction of an electrode layer shall be measured. Moreover, the thickness of the electrode layer here is the thickness of the electrode layer formed on one surface of the current collector, as shown in FIGS.

  The constituent components of the electrode layer in the first embodiment are not particularly limited, and may contain a binder, an electrolyte, an additive, etc. in addition to the active material, as will be described later. In addition, a conductive additive may be included. That is, by using the electrode structure of the first form, as described above, the conductive auxiliary agent is not necessary, but even if the conductive auxiliary agent is included, the electrode structure of the present invention can be taken, As long as the effect of the present invention that the diffusion distance is short and the diffusion resistance of ions can be kept small can be effectively expressed, it can be included in the technical scope of the present invention. Preferably, as described above, the conductive auxiliary agent is not necessary, and it is needless to say that it is desirable that the conductive auxiliary agent is not contained in terms of increasing the active material density in the electrode. More preferably, only the active material and the binder are desirable as in the third embodiment to be described later. In addition, about description of these each component etc., since it mentions later, description here is abbreviate | omitted.

  The electrode structure of the first form in which the particle diameter of the active material particles and the thickness of the electrode layer (electrode active material layer) are the same may be either a positive electrode or a negative electrode, preferably a positive electrode, More preferably, both the positive electrode and the negative electrode are used.

  1 and 2 are also schematic cross-sectional views schematically showing another electrode structure of the best mode of the lithium ion secondary battery according to the present invention.

  That is, as another one of the best modes of the lithium ion secondary battery according to the present invention (also referred to as the second mode), as shown in FIGS. 1 and 2, at least one of the positive electrode and the negative electrode is active. The electrode 1 is composed of only a single layer of substance particles 3. Even in such an electrode structure, since the active material particles 3 are a single layer, each active material 3 is in contact with both the current collector (current collector foil) 5 and the electrolyte layer 7. This eliminates the need for a conductive aid. Further, since the active material 3 is always in contact with the bulk electrolyte 7, the diffusion distance is short, and the ion diffusion resistance can be kept small. Therefore, in the second embodiment as well, since the diffusion resistance is small, it is possible to provide a lithium ion secondary battery with improved high rate characteristics and high output / electric resistance.

  Here, the “electrode composed only of a single layer of active material particles” means that a single layer is formed without laminating two or more layers of active material particles in the electrode layer as shown in FIGS. What is necessary is just to be comprised by (1 layer). However, it is sufficient that the active material particles are formed in a substantially single layer on the entire surface of the current collector. When observed by the method described later, a very small number of active material particles are locally (partially) multilayered. In such cases, it shall be included in the above rules. Specifically, when the active material particles are composed of only a single layer in 80% or more of the entire observed region when observed by the method described later, the above-mentioned rule is satisfied. Preferably, the active material particles are composed of only a single layer in 90% or more of the entire observed region when observed by means described later. Moreover, in the said 2nd form, it does not restrict | limit at all regarding the structure of other structural components other than the active material particle in an electrode layer.

  In addition, it can be observed with a scanning electron microscope that the active material particles in the electrode layer are a single layer.

  Further, the constituent components of the electrode layer in the second embodiment are not particularly limited, and may contain a binder, an electrolyte, an additive and the like in addition to the active material, as will be described later. In addition, a conductive additive may be included. That is, the electrode structure of the second embodiment eliminates the need for a conductive aid as described above, but the electrode structure of the present invention can be used even if a conductive aid is included, and diffusion is achieved. As long as the effect of the present invention that the distance is short and the diffusion resistance of ions can be suppressed can be effectively expressed, it can be included in the technical scope of the present invention. Preferably, as described above, the conductive auxiliary agent is not necessary, and it is needless to say that it is desirable that the conductive auxiliary agent is not contained in terms of increasing the active material density in the electrode. More preferably, only the active material and the binder are desirable as in the third embodiment to be described later. In addition, about description of these each component etc., since it mentions later, description here is abbreviate | omitted.

  In addition, although the electrode structure of the 2nd form assumed to be comprised only by the active material particle single layer may be at least any one of a positive electrode or a negative electrode, Preferably it is a positive electrode, More preferably, it is both a positive electrode and a negative electrode.

  FIG. 1 is also a schematic cross-sectional view schematically showing still another electrode structure (also referred to as a third embodiment) of the best mode of the lithium ion secondary battery according to the present invention. It is drawing showing the best form in case the thickness T (= active material particle 3) of an electrode layer is larger than 1 micrometer. Similarly, FIG. 2 is a schematic cross-sectional view schematically showing the electrode structure according to the third embodiment of the present invention, and the best when the thickness T (= active material particle 3) of the electrode layer is less than 1 μm. It is drawing which represented the form.

  As shown in FIGS. 1 and 2, the third embodiment is characterized in that at least one of the positive electrode and the negative electrode is composed of only the active material 3 and the binder 9. In such an electrode structure, an electrode 1 that does not use a conductive auxiliary agent can be obtained. Thereby, the compounding ratio of the active material 3 can be increased by several percent.

  In particular, in the third embodiment, as shown in FIG. 2, when the thickness T (active material particles 3) of the electrode layer becomes 1 μm or less, the active material is applied loosely when applied by a normal application method. As a result, problems such as a decrease in electrode density occur. Therefore, when the electrode 1 is produced by using the active material 3 and the binder 9 without using any conductive aid by the method as in Example 1, the active material 3 is closely arranged even if the thickness T of the electrode layer is 1 μm or less. , A decrease in volumetric efficiency is suppressed. As a result, a diffusion resistance can be reduced, a high rate characteristic can be improved, and a lithium ion secondary battery with a very high output and electrical resistance can be provided.

  Here, “consisting only of an active material and a binder” means that the constituent components in the electrode layer constituting the electrode are composed of only the active material and the binder, as in the first and second embodiments described above. In addition, other components such as a conductive additive and an electrolyte are not included. However, as shown in FIG. 2, depending on the electrode manufacturing method, when the binder is used only in a part of the electrode layer, the gap between the active material particles is formed from the electrolyte layer to the electrolyte, particularly the electrolyte solution. Needless to say, it may be in a state of being penetrated. Even in such a state, the requirement of the third aspect of the present invention is satisfied. From this point of view, it can be said that the third embodiment of the present invention only needs to include a conductive additive as a constituent component in the electrode layer. In addition, about description of these each component etc., since it mentions later, description here is abbreviate | omitted.

  In the third embodiment, it is not always necessary to satisfy the requirements of the first and second embodiments. However, as shown in FIGS. That is, in order to provide a lithium ion secondary battery that can be stably charged even at a high current rate in the electrode structure of the third embodiment that does not include a conductive additive, as shown in FIGS. It can be said that it is desirable that at least one of the requirements of the second form is satisfied.

  In the present invention, it is sufficient if it satisfies any one of the requirements of the first to third embodiments. However, as described above, these two or more embodiments may be satisfied at the same time. That is, the lithium ion secondary battery of the present invention is not particularly limited as long as it has an electrode that satisfies any one of the above requirements. Hereinafter, the lithium ion secondary battery of the present invention will be specifically described including other components.

  The lithium ion secondary battery that is the subject of the present invention is not particularly limited. For example, when distinguished by the structure and form of the lithium ion secondary battery, a stacked (flat) battery, It is not particularly limited, such as a wound (cylindrical) battery, and can be applied to any conventionally known structure. In the present invention, a flat (stacked) battery structure is preferable. In the case of a wound (cylindrical) battery structure, it may be difficult to improve the sealing performance at the location where the positive electrode and negative electrode lead terminals are taken out, and the high energy density mounted on the electric vehicle or hybrid electric vehicle, High-power-density batteries may not be able to ensure long-term reliability of the sealing performance of the lead terminal extraction site, but by adopting a flat structure, long-term reliability is ensured by simple sealing technology such as thermocompression bonding. This is because it is advantageous in terms of cost and workability.

  Similarly, when distinguishing by the type of electrolyte layer of a lithium ion secondary battery, there is no particular limitation, and a liquid electrolyte type battery (liquid battery) in which a separator (including a nonwoven fabric separator) is impregnated with an electrolytic solution. It can be applied to both a gel polymer battery using a polymer gel electrolyte, also called a polymer battery, and an intrinsic polymer battery using a solid polymer electrolyte (all solid electrolyte). Of these electrolyte layers, for polymer batteries using polymer gel electrolytes and solid polymer electrolytes (all solid electrolytes), these polymer gel electrolytes and solid polymer electrolytes (all solid electrolytes) may be used alone. The polymer gel electrolyte or solid polymer electrolyte (all solid electrolyte) can be used by impregnating or supporting the separator (including a nonwoven fabric separator), and is not particularly limited.

  In this invention, it can be said that it is suitable when the lithium ion secondary battery is a gel polymer battery. A gel polymer battery using a polymer gel electrolyte has a large diffusion resistance because ions are less likely to move than a liquid battery. For this reason, the high rate characteristic is remarkably improved by shortening the diffusion distance and reducing the resistance.

  The gel polymer battery is a battery using a polymer gel electrolyte in the electrolyte layer as described above. The polymer gel electrolyte is a solid polymer electrolyte having ion conductivity containing an electrolyte used in a conventionally known lithium ion secondary battery. Those in which the same electrolyte solution is held in the molecular skeleton are also included.

The electrolyte solution (electrolyte salt and plasticizer) is not particularly limited, and various conventionally known electrolyte solutions can be appropriately used. For example, inorganic acid anion salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiTaF ₆ , LiAlCl ₄ , Li ₂ B ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N or an organic acid anion salt selected from at least one lithium salt (electrolyte salt), cyclic carbonates such as propylene carbonate and ethylene carbonate; dimethyl carbonate; Chain carbonates such as methyl ethyl carbonate and diethyl carbonate; ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dibutoxyethane; γ-butyrolactone, etc. Lactones; Nitriles such as acetonitrile Esters such as methyl propionate; amides such as dimethylformamide; plasticizers such as aprotic solvents (organic solvents) mixed with at least one selected from methyl acetate and methyl formate ) Can be used. However, it is not necessarily limited to these.

  Examples of the solid polymer electrolyte having ion conductivity include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof. This is also used as an intrinsic (all solid) polymer electrolyte.

  Examples of the polymer having no lithium ion conductivity used in the polymer gel electrolyte include polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyacrylonitrile (PAN), and polymethyl methacrylate (PMMA). Can be used. However, it is not necessarily limited to these. Note that PAN, PMMA, etc. are in a class that has almost no ionic conductivity, and therefore can be a polymer having the above ionic conductivity, but here, they are used for a polymer gel electrolyte. This is exemplified as a polymer having no lithium ion conductivity.

  Moreover, in this invention, it can be said that it is more suitable when a lithium ion secondary battery is an intrinsic polymer battery. Intrinsic polymer batteries have a very high diffusion resistance because ions are less likely to move than liquid batteries or gel polymer batteries. For this reason, the high rate characteristic is remarkably improved by shortening the diffusion distance and reducing the resistance.

  An intrinsic polymer battery is a battery using a solid polymer electrolyte having ion conductivity in an electrolyte layer. Examples of the solid polymer electrolyte having ion conductivity include known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

  In addition, regarding the lithium ion secondary battery that is the subject of the present invention, when viewed from the electrical connection form (electrode structure) in the battery, it is not a bipolar type (internal parallel connection type) battery and a bipolar type (internal series connection) It can be applied to any type of battery. A bipolar battery (also simply referred to as a bipolar battery) is preferable. A bipolar battery is a battery in which a plurality of unit batteries each having a positive electrode layer on one side and a negative electrode layer on the opposite side are stacked with a current collector (foil) interposed therebetween. In the case of stacking batteries that are not bipolar batteries, lead wires are taken from each of the positive electrode and the negative electrode and connected to the adjacent battery via the lead wires. For this reason, the path of electron conduction corresponding to the length of the lead wire becomes long, and the output of the battery becomes low. On the other hand, since current flows in the vertical direction through the current collector in the bipolar battery, the path of electron conduction is remarkably shortened, and the output is increased accordingly.

  In the following description, a bipolar polymer lithium ion secondary battery, which is one of the optimum forms of the present invention, will be described as an example, but the present invention should not be limited to these.

  FIG. 3 is a schematic sectional view schematically showing the entire structure of the bipolar polymer lithium ion secondary battery. As shown in FIG. 3, in the bipolar polymer battery 21, a positive electrode (also referred to as a positive electrode active material layer) 25 is provided on one side of a current collector 23 composed of one or more sheets, and the other side is provided. The bipolar electrode 29 provided with the negative electrode (also referred to as negative electrode active material layer) 27 of the present invention is configured so that the electrode layers 25 and 27 of the bipolar electrode 29 adjacent to each other with the solid electrolyte layer 31 interposed therebetween. That is, in the bipolar polymer lithium ion secondary battery 21, the bipolar electrode (electrode layer) 29 having the positive electrode layer 25 on one surface of the current collector 23 and the negative electrode layer 27 on the other surface is provided as an electrolyte layer. The electrode stack (bipolar battery main body) 33 has a structure in which a plurality of layers are stacked via 31. Further, the uppermost layer and the lowermost layer electrodes 25a and 27a of the electrode laminate 33 in which a plurality of such bipolar electrodes 29 and the like are laminated may not have a bipolar electrode structure, and are necessary for the current collector 23 (or terminal plate). A structure in which electrode layers only on one side (the positive electrode active material layer 25a and the negative electrode active material layer 27a) may be arranged. In the bipolar polymer lithium ion secondary battery 21, positive and negative electrode leads 35 and 37 are joined to current collectors 23 at both upper and lower ends, respectively. The number of stacked bipolar electrodes is adjusted according to the desired voltage. In the bipolar polymer battery 21, sufficient output can be secured even if the battery is made as thin as possible, and therefore the number of laminations of the bipolar electrode 29 may be reduced. Further, in the bipolar polymer lithium ion secondary battery 21 of the present invention, the electrode laminate 33 portion is sealed under reduced pressure in a battery exterior material (exterior package) 39 in order to prevent external impact and environmental degradation during use. The electrode leads 35 and 37 are preferably taken out of the battery exterior member 39. From the viewpoint of weight reduction, a conventionally known battery exterior material such as a polymer-metal composite laminate film in which a metal (including an alloy) such as aluminum, stainless steel, nickel, or copper is covered with an insulator such as a polypropylene film is used. A structure in which the electrode laminate is stored and sealed (sealed) under reduced pressure by joining a part or all of the peripheral part thereof by heat fusion, and the electrode leads 35 and 37 are taken out of the battery exterior material 39. It is preferable to do this. The basic configuration of the bipolar polymer lithium ion secondary battery 21 can be said to be a configuration in which a plurality of stacked single battery layers (single cells) are connected in series.

  Hereinafter, the components of the bipolar polymer lithium ion secondary battery of the present invention will be mainly described.

[Current collector]
The current collector that can be used in the present invention is not particularly limited, and conventionally known current collectors can be used. For example, aluminum foil, stainless steel (SUS) foil, titanium foil, nickel-aluminum clad material, copper-aluminum clad material, SUS-aluminum clad material, or a plating material of a combination of these metals can be preferably used. Further, a current collector in which a metal surface is coated with aluminum may be used. Moreover, you may use the electrical power collector which bonded 2 or more metal foil depending on the case. When the composite current collector is used, as a material for the positive electrode current collector, for example, a conductive metal such as aluminum, an aluminum alloy, SUS, or titanium can be used, and aluminum is particularly preferable. On the other hand, as a material of the negative electrode current collector, for example, conductive metals such as copper, nickel, silver, and SUS can be used, and copper and the like are particularly preferable. Further, in the composite current collector, the positive electrode current collector and the negative electrode current collector may be electrically connected to each other directly or via a conductive intermediate layer made of a third material.

  Each thickness of the positive electrode current collector and the negative electrode current collector in the composite current collector may be as usual, and both current collectors are, for example, about 1 to 100 μm. Preferably, the thickness of the current collector (including the composite current collector) may be about 1 to 100 μm, but the active layer in the electrode layer is reduced in thickness to the particle size of the electrode active material particles. Since it is desirable that the current collector is made thin corresponding to the electrode structures of the first to third embodiments in which the material particles are composed of a single layer or are composed of only the active material and the binder, The thickness is preferably in the range of 1 to 50 μm.

[Positive electrode layer (positive electrode active material layer)]
Here, the constituent material of the positive electrode layer only needs to contain a positive electrode active material, and if necessary, a conventionally known binder that binds the positive electrode active material particles to each other, and an electrolyte supporting salt for increasing ion conductivity. (Lithium salts), polymer electrolytes, additives and the like may be included. In particular, by employing the electrode structures of the first to third embodiments, a conductive auxiliary agent that has been conventionally used as a constituent material of the positive electrode layer is not necessary. However, when the electrode structure of the present invention is adopted only for the negative electrode, or when the first or second embodiment is adopted for the electrode structure of the positive electrode layer, the constituent material of the positive electrode layer may be the same as the conventional material. In addition, when a polymer gel electrolyte is used for the electrolyte layer, it only needs to contain a binder binder and a conductive auxiliary agent, and does not include a host polymer, an electrolytic solution or a lithium salt as a raw material of the polymer electrolyte. Also good.

As said positive electrode active material, the composite oxide (lithium-transition metal composite oxide) of a transition metal and lithium can be used conveniently. Specifically, Li—Mn composite oxides such as LiMnO ₂ and LiMn ₂ O ₄ , Li—Co composite oxides such as LiCoO ₂ , Li—Cr such as Li ₂ Cr ₂ O ₇ and Li ₂ CrO _4. Li-Ni composite oxides such as LiNiO ₂ , Li-Fe composite oxides such as Li _x FeO _y and LiFeO _2, and Li-V composite oxides such as Li _x V _y O _z And selected from Li metal oxides such as those obtained by substituting a part of these transition metals with other elements (for example, LiNi _x Co _1-x O ₂ (0 <x <1), etc.) However, the present invention is not limited to these materials. These lithium-transition metal composite oxides are excellent in reactivity and cycle durability and are low-cost materials. Therefore, using these materials for the electrodes is advantageous in that a battery having excellent output characteristics can be formed. In addition, transition metal and lithium phosphate compounds and sulfate compounds such as LiFePO ₄ ; transition metal oxides and sulfides such as V ₂ O ₅ , MnO ₂ , TiS ₂ , MoS ₂ , and MoO ₃ ; PbO ₂ , AgO, NiOOH etc. are mentioned.

  Among the positive electrode active materials, a Li—Mn composite oxide is desirable. This is because by using the Li—Mn-based composite oxide, the profile can be tilted, and the reliability at the time of abnormality is improved. Specifically, the voltage-SOC profile can be tilted by making the positive electrode active material Li-Mn based composite oxide. As a result, the state of charge (SOC) of the battery can be determined by measuring the voltage, so that the battery can detect and deal with a particularly unstable overcharge / overdischarge state. It becomes possible to improve the property. In addition, the Li—Mn-based composite oxide has a mild reaction even when the battery fails due to overcharge or overdischarge, and can be said to have high reliability in an abnormal state. As a result, it becomes easy to detect the voltage of each single cell layer and the entire bipolar.

  The average particle diameter of the positive electrode active material particles is 0.1 to 500 μm, preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm. In particular, when the electrode structures of the first to third embodiments are employed, the thickness of the electrode layer is the same as the particle diameter of the positive electrode active material particles. It is desirable to use one having a uniform particle size.

  Examples of the conductive aid include acetylene black, carbon black, graphite, various carbon fibers, and carbon nanotubes. However, it is not necessarily limited to these.

  As the binder, polyvinylidene fluoride (PVDF), SBR, polyimide, or the like can be used. However, it is not necessarily limited to these.

  Regarding the polymer gel electrolyte among the polymer electrolytes, since the polymer gel electrolyte described in the gel polymer battery can be used, description thereof is omitted here.

  The ratio (mass ratio) between the host polymer and the electrolytic solution in the polymer gel electrolyte may be determined according to the purpose of use, but is in the range of 2:98 to 90:10. That is, the leakage of the electrolyte from the electrolyte material in the battery electrode can be effectively sealed by forming an insulating layer. Therefore, it is possible to give priority to battery characteristics relatively with respect to the ratio (mass ratio) between the host polymer and the electrolytic solution in the polymer gel electrolyte.

  Examples of the additive include trifluoropropylene carbonate for enhancing battery performance and life, and various fillers as reinforcing materials.

  The thickness of the positive electrode layer (positive electrode active material film thickness) is the thickness of the positive electrode layer = the particle diameter (average particle diameter) of the positive electrode active material particles when the first to third electrode structures are employed. If it is the same. Further, when the electrode structures of the first to third embodiments are not adopted, there is no particular limitation, and it should be determined in consideration of the purpose of use of the battery (emphasis on output, importance on energy, etc.) and ion conductivity. is there. Therefore, although the thickness of the positive electrode layer (positive electrode active material film thickness) is about 0.1 to 500 μm, it is preferably in the range of 0.1 to 50 μm because an electrode structure with a short ion diffusion distance is desirable.

  Regarding the compounding amount of the positive electrode active material, binder, polymer electrolyte (host polymer, electrolytic solution, etc.), lithium salt, and conductive additive in the positive electrode layer, the intended use of the battery (emphasis on output, emphasis on energy, etc.) It should be determined in consideration of ionic conductivity. In particular, when the thickness of the positive electrode layer exceeds 1 μm, a conventional coating method can be applied, and the thickness can be arbitrarily adjusted. On the other hand, as explained in the third embodiment, since it was difficult to make the thickness of the positive electrode layer 1 μm or less in the conventional method, in this case, a novel manufacturing method shown in an example described later is used. It is necessary to adopt.

[Negative electrode layer (negative electrode active material layer)]
The negative electrode layer includes a negative electrode active material active material. In addition to this, a conductive auxiliary agent for increasing electronic conductivity, a conventionally known binder for linking negative electrode active material particles, a polymer electrolyte (host polymer, electrolytic solution, etc.), a lithium salt for increasing ion conductivity, Additives and the like can be included. In particular, the use of the electrode structures of the first to third embodiments eliminates the need for a conductive additive that has been conventionally used as a constituent material for the negative electrode layer. However, when the electrode structure of the present invention is employed only for the positive electrode or when the first or second embodiment is employed for the electrode structure of the negative electrode layer, the constituent material of the negative electrode layer may be the same as that of the conventional material. When a polymer gel electrolyte is used for the polymer electrolyte layer, it only needs to contain a binder, a conductive auxiliary agent, etc., and does not contain a host polymer, electrolyte solution, lithium salt, or the like as a raw material of the polymer electrolyte. Also good. Except for the type of the negative electrode active material, the contents are basically the same as those described in the section “Positive electrode layer”, and thus the description thereof is omitted here.

As the negative electrode active material, a negative electrode active material that is also used in a solution-type lithium ion battery can be used. Specifically, carbon, metal compounds, metal oxides, Li metal compounds, Li metal oxides (including lithium-transition metal composite oxides), boron-added carbon, graphite, and the like can be used. These may be used alone or in combination of two or more. Examples of the carbon include conventionally known carbon materials such as graphite, hard carbon, and soft carbon. Examples of the metal compound include LiAl, LiZn, Li ₃ Bi, Li ₃ Cd, Li ₃ Sd, Li ₄ Si, Li _4.4 Pb, Li _4.4 Sn, Li _0.17 C (LiC ₆ ), and the like. It is done. The metal _{oxides, SnO, SnO 2, GeO,} GeO 2, In 2 O, In 2 O 3, PbO, PbO 2, Pb 2 O 3, Pb 3 O 4, Ag 2 O, AgO, Ag 2 O ₃ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , SiO, ZnO, CoO, NiO, FeO and the like. Examples of the Li metal compound include Li ₃ FeN ₂ , Li _2.6 Co _0.4 N, Li _2.6 Cu _0.4 N, and the like. Examples of the Li metal oxide (lithium-transition metal composite oxide) include a lithium-titanium composite oxide represented by Li _x Ti _y O _z such as Li ₄ Ti ₅ O ₁₂ . Examples of the boron-added carbon include boron-added carbon and boron-added graphite. However, in this invention, it should not be restrict | limited to these but a conventionally well-known thing can be utilized suitably. The boron content in the boron-added carbon is preferably in the range of 0.1 to 10% by mass, but should not be limited to this.

  Among the negative electrode active materials, those selected from a crystalline carbon material and an amorphous carbon material are preferable. By using these, the profile can be tilted. Specifically, the voltage-SOC profile can be tilted by selecting the negative electrode active material from a crystalline carbon material or an amorphous carbon material. As a result, the state of charge (SOC) of the battery can be determined by measuring the voltage, so that the battery can detect and deal with a particularly unstable overcharge / overdischarge state. It becomes possible to improve the property. This effect is particularly remarkable in amorphous carbon and is effective but not particularly limited. As a result, the voltage of each single cell layer and the entire bipolar battery can be easily detected. The crystalline carbon material here refers to a graphite-based carbon material, and includes the above-described graphite carbon and the like. The non-crystalline carbon material refers to a hard carbon-based carbon material, and includes the hard carbon and the like.

  The average particle diameter of the negative electrode active material particles is 0.1 to 500 μm, preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm. In particular, when the electrode structures of the first to third embodiments are employed, the thickness of the electrode layer is the same as the particle diameter of the negative electrode active material particles. It is desirable to use one having a uniform particle size.

  The thickness of the negative electrode layer (negative electrode active material film thickness) is the thickness of the negative electrode layer = the particle diameter (average particle diameter) of the negative electrode active material particles when the first to third electrode structures are employed. If it is the same. Further, when the electrode structures of the first to third embodiments are not adopted, there is no particular limitation, and it should be determined in consideration of the purpose of use of the battery (emphasis on output, importance on energy, etc.) and ion conductivity. is there. Therefore, although the thickness of the negative electrode layer (negative electrode active material film thickness) is about 0.1 to 500 μm, it is preferably in the range of 0.1 to 50 μm because an electrode structure with a short ion diffusion distance is desirable.

  Regarding the compounding amount of the negative electrode active material, binder, polymer electrolyte (host polymer, electrolyte solution, etc.), lithium salt, and conductive additive in the negative electrode layer, the intended use of the battery (emphasis on output, emphasis on energy, etc.) It should be determined in consideration of ionic conductivity. In particular, when the thickness of the negative electrode layer exceeds 1 μm, a conventional coating method can be applied and can be arbitrarily adjusted. On the other hand, as explained in the third embodiment, since it was difficult to make the thickness of the negative electrode layer 1 μm or less in the conventional method, in this case, a novel manufacturing method shown in the examples described later is used. It is necessary to adopt.

[Electrolyte layer]
In the present invention, it is applicable to any of (a) a polymer gel electrolyte, (b) a polymer solid electrolyte, or (c) a separator (including a nonwoven fabric separator) impregnated with these polymer electrolytes, depending on the purpose of use. It is possible.

(A) Polymer gel electrolyte Since the polymer gel electrolyte demonstrated in the said gel polymer battery can be used, description here is abbreviate | omitted.

  The ratio of the electrolytic solution in the gel electrolyte in the present invention is not particularly limited, but is preferably about several mass% to 98 mass% from the viewpoint of ionic conductivity.

  In the present invention, the amount of the electrolyte contained in the gel electrolyte may be substantially uniform inside the gel electrolyte, or may be decreased in an inclined manner from the central portion toward the outer peripheral portion. . The former is preferable because reactivity can be obtained in a wider range, and the latter is preferable in that the sealing property of the all solid polymer electrolyte portion in the outer peripheral portion with respect to the electrolytic solution can be improved. When decreasing gradually from the central part toward the outer peripheral part, polyethylene oxide (PEO), polypropylene oxide (PPO) and copolymers thereof having lithium ion conductivity are used as the host polymer. It is desirable.

(B) Polymer solid electrolyte Since the solid polymer electrolyte described in the intrinsic polymer battery can be used, the description thereof is omitted here. The solid polymer electrolyte contains the lithium salt in order to ensure ionic conductivity. Polyalkylene oxide polymers such as PEO and PPO can dissolve lithium salts such as LiBF ₄ , LiPF ₆ , LiN (SO ₂ CF ₃ ) ₂ , and LiN (SO ₂ C ₂ F ₅ ) ₂ well. Moreover, excellent mechanical strength is exhibited by forming a crosslinked structure.

(C) Separator (including non-woven fabric separator) impregnated (or supported) with the polymer electrolyte
As the polymer electrolyte that can be impregnated into the separator, the same as those already described (a) and (b) can be used, and the description thereof is omitted here.

  The separator is not particularly limited, and a conventionally known separator can be used. For example, a porous sheet made of a polymer that absorbs and holds the electrolyte (for example, a polyolefin microporous separator). Etc.) can be used. The polyolefin microporous separator having the property of being chemically stable to an organic solvent has an excellent effect that the reactivity with the electrolyte (electrolytic solution) can be kept low.

  Examples of the polymer material include polyethylene (PE), polypropylene (PP), a laminate having a three-layer structure of PP / PE / PP, and polyimide.

  The thickness of the separator cannot be unambiguously defined because it varies depending on the intended use. However, in the case of a secondary battery for driving a motor such as an electric vehicle (EV) or a hybrid electric vehicle (HEV), a single layer is used. Or it is desirable that it is 4-60 micrometers in a multilayer. The mechanical strength in the thickness direction is desirable because the thickness of the separator is within such a range, and it is desirable to narrow the gap between the electrodes for high output and prevention of short-circuiting caused by fine particles entering the separator. And there is an effect of ensuring high output performance. In addition, when a plurality of batteries are connected, the electrode area increases, so that it is desirable to use a thick separator in the above range in order to increase the reliability of the battery.

  The fine pore diameter of the separator is desirably 1 μm or less (usually a pore diameter of about several tens of nm). Due to the fact that the average diameter of the micropores in the separator is within the above range, the “shutdown phenomenon” that the separator melts due to heat and the micropores close quickly occurs, resulting in higher reliability during abnormalities, resulting in heat resistance. Has the effect of improving. In other words, when the battery temperature rises due to overcharging (in an abnormal state), the “shutdown phenomenon” that the separator melts and closes the micropores occurs quickly, so that the positive electrode (+) of the battery (electrode) Li ions cannot pass through to the negative electrode (−) side, and no further charge is possible. As a result, overcharging cannot be performed and overcharging is eliminated. As a result, the heat resistance (safety) of the battery is improved, and it is possible to prevent gas from being released and the heat fusion part (seal part) of the battery exterior material from being opened. Here, the average diameter of the micropores of the separator is calculated as an average diameter obtained by observing the separator with a scanning electron microscope or the like and statistically processing the photograph with an image analyzer or the like.

  The separator preferably has a porosity of 20 to 50%. The separator's porosity is within the above range, preventing output from being reduced due to the resistance of the electrolyte (electrolyte), and preventing the short circuit caused by fine particles penetrating the separator's pores (micropores). It has the effect of securing both sexes. Here, the porosity of the separator is a value obtained as a volume ratio from the density of the raw material resin and the density of the separator of the final product.

  The amount of the polymer electrolyte impregnated into the separator may be impregnated up to the separator holding capacity range, but the separator may be impregnated beyond the holding capacity range. This can be impregnated as long as it can be retained in the electrolyte layer because a seal portion is provided in the electrolyte and the electrolyte solution can be prevented from exuding from the electrolyte layer.

  The nonwoven fabric separator used for holding the electrolyte is not particularly limited, and can be manufactured by entwining the fibers into a sheet. Moreover, the spun bond etc. which are obtained by fusing fibers by heating can also be used. In other words, it may be in the form of a sheet formed by arranging fibers in a web (thin cotton) shape or mat shape by an appropriate method, and joining them using an appropriate adhesive or the fusing force of the fibers themselves. The adhesive is not particularly limited as long as it has sufficient heat resistance at the temperature during manufacture and use, and is stable without any reactivity or solubility with respect to the gel electrolyte. In addition, conventionally known ones can be used. In addition, the fiber used is not particularly limited, and for example, conventionally known fibers such as cotton, rayon, acetate, nylon, polyester, polypropylene, polyethylene such as polyethylene, polyimide, and aramid can be used. Depending on (such as mechanical strength required for the electrolyte layer), they are used alone or in combination. Further, the bulk density of the nonwoven fabric is not particularly limited as long as sufficient battery characteristics can be obtained by the impregnated polymer gel electrolyte. That is, if the bulk density of the nonwoven fabric is too large, the proportion of the non-electrolyte material in the electrolyte layer becomes too large, which may impair the ionic conductivity in the electrolyte layer.

  The porosity of the nonwoven fabric separator is preferably 50 to 90%. If the porosity is less than 50%, the electrolyte retention deteriorates, and if it exceeds 90%, the strength is insufficient. Furthermore, the thickness of the nonwoven fabric separator may be the same as that of the electrolyte layer, preferably 1 to 200 μm, and particularly preferably 1 to 50 μm. When the thickness is less than 1 μm, the electrolyte retention deteriorates, and when it exceeds 200 μm, the resistance increases.

  In addition, you may use together the electrolyte layer of said (1)-(3) in one battery.

  In addition, the polymer electrolyte may be contained in the electrolyte layer, the positive electrode active material layer, and the negative electrode active material layer, but the same polymer electrolyte may be used, or different polymer electrolytes may be used depending on the layer.

  By the way, a host polymer for a polymer electrolyte that is preferably used at present is a polyether polymer such as PEO and PPO. For this reason, the oxidation resistance on the positive electrode side under high temperature conditions is weak. Therefore, when using a positive electrode agent having a high oxidation-reduction potential that is generally used in a solution-type lithium ion battery, the capacity of the negative electrode is preferably smaller than the capacity of the positive electrode facing through the polymer electrolyte layer. . If the capacity of the negative electrode is less than the capacity of the opposing positive electrode, it is possible to prevent the positive electrode potential from rising excessively at the end of charging. In addition, the capacity | capacitance of a positive electrode and a negative electrode can be calculated | required from manufacturing conditions as theoretical capacity | capacitance at the time of manufacturing a positive electrode and a negative electrode. You may measure the capacity | capacitance of a finished product directly with a measuring device.

  However, if the capacity of the negative electrode is smaller than the capacity of the opposing positive electrode, the negative electrode potential will be too low and the durability of the battery may be impaired, so it is necessary to pay attention to the charge / discharge voltage. For example, care should be taken not to lower the durability by setting the average charge voltage of one cell (single cell layer) to an appropriate value for the oxidation-reduction potential of the positive electrode active material.

  The thickness of the electrolyte layer constituting the battery is not particularly limited. However, in order to obtain a compact bipolar polymer lithium ion secondary battery, it is preferable to make it as thin as possible as long as the function as an electrolyte can be secured. In particular, when using an unprecedented thin electrode, it is desirable to adopt a thin electrolyte layer corresponding to this. Therefore, the thickness of the electrolyte layer is 1 to 200 μm, preferably 1 to 50 μm.

[Insulation layer]
Insulating layers are used around the electrodes in order to prevent liquid junctions due to electrolytes, contact between adjacent current collectors in the battery, and short-circuiting due to slight irregularities at the ends of the laminated electrodes. It is formed. In the present invention, in the case of a bipolar battery, if necessary, an insulating layer may be provided around the electrode. This means that when used as a vehicle drive or auxiliary power source, even if a solid electrolyte is used to completely prevent a short circuit due to the electrolyte (liquid drop), the vibration and impact on the battery will last for a long time. Be loaded. Therefore, from the viewpoint of prolonging battery life, it is desirable to install an insulating layer in order to ensure longer-term reliability and safety, and to provide a high-quality, large-capacity power supply. .

  As the insulating layer, any insulating layer may be used as long as it has insulating properties, sealing performance against falling off of the solid electrolyte, sealing performance against moisture permeation from the outside (sealing performance), heat resistance under battery operating temperature, etc. Epoxy resin, rubber, polyethylene, polypropylene, polyimide and the like can be used, but epoxy resin is preferable from the viewpoint of corrosion resistance, chemical resistance, ease of production (film forming property), economy and the like.

[Positive electrode and negative electrode terminal plate]
The positive electrode and the negative electrode terminal plate may be used as necessary. That is, depending on the stacking or winding structure of the battery, the positive electrode and the negative electrode tab (electrode terminal) may be taken out from the outermost current collector directly or through the electrode lead. It is not necessary to use it.

  When using positive and negative terminal plates, in addition to having a function as a terminal, it is better to be as thin as possible from the viewpoint of thinning, but the laminated electrode, electrolyte and current collector all have mechanical strength. Since it is weak, it is desirable to have strength to sandwich and support these from both sides. Furthermore, from the viewpoint of suppressing the internal resistance from the electrode terminal plate to the electrode tab, it can be said that the thickness of the positive electrode and the negative electrode terminal plate is usually preferably about 0.1 to 2 mm.

  As the material of the positive electrode and the negative electrode terminal plate, a material used in a lithium ion secondary battery which is not a normal bipolar type can be used. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used.

  The material of the positive electrode terminal plate and the negative electrode terminal plate may be the same material or different materials. Furthermore, the positive electrode and the negative electrode terminal plate may be a laminate of different materials. In these positive electrode and negative electrode terminal plates, since they may be close to or in close contact with the battery outer packaging material, if necessary, the high resistance layer is provided on the outer surface of the electrode terminal plate as in the case of the electrode tabs. Needless to say, it may be provided appropriately.

[Positive electrode and negative electrode lead]
The positive electrode and the negative electrode lead may be used as necessary. As the positive electrode and the negative electrode lead, a well-known electrode lead used in an ordinary lithium ion secondary battery which is not a bipolar type can be used. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. The material of the positive electrode lead and the negative electrode lead may be the same material or different materials. Furthermore, the positive electrode and the negative electrode lead may be a laminate of different materials. In addition, since these positive and negative electrode leads may also be close to or in close contact with the battery outer packaging material, if necessary, a high resistance layer is appropriately applied to a required portion on the surface of the electrode lead as in the case of the electrode tab. Needless to say, it may be provided.

[Positive electrode and negative electrode tab]
The positive and negative electrode tabs used in the present invention may be connected between the positive and negative electrode leads connected to the current collector of the outermost layer electrode (or the electrode terminal plate connected thereto). It may be connected to the positive / negative electrode terminal plate or positive / negative electrode lead connected to the current collector of the outer layer electrode, or may be formed by extending a part of the current collector of the outermost electrode, etc. There is no particular limitation. In addition, the part taken out from the battery exterior material to the outside of the battery is not heat-resistant so that it does not affect products (for example, automobile parts, especially electronic devices) by contacting with peripheral devices or wiring and leaking electricity. It may be covered with an insulating heat-shrinkable tube.

  Moreover, the tab used for this invention can use the well-known electrode tab used with the normal lithium ion secondary battery which is not an existing bipolar type. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. The materials of the positive electrode tab and the negative electrode tab may be the same material or different materials. Furthermore, the positive electrode and the negative electrode tab may be formed by stacking multiple layers of metals (including alloys) of different materials.

  The thickness of the tab is preferably thinner from the viewpoint of improving the airtightness and waterproofness of the portion sandwiched between the exterior material seal portions, whereas the thickness of the tab is desirable from the viewpoint of reducing electrical resistance. Although it may be determined appropriately according to the purpose of use, it is usually in the range of 1 to 500 μm, preferably 1 to 100 μm.

  Also, as a method of taking out the tab from the battery, the positive electrode tab and the negative electrode tab may be taken out separately from the opposite sides, the positive electrode tab and the negative electrode tab may be taken out from the same side, or the positive electrode tab. The negative electrode tab and the negative electrode tab may be separately taken out from adjacent sides, but there is no particular limitation. However, in order to form a battery pack by connecting a plurality of these batteries, the positive electrode tab and negative electrode It can be said that it is desirable to take out the tab separately from the opposite side. Moreover, you may provide a high resistance layer also in the tab metal surface as needed.

[Voltage detection tab]
In the case of bipolar batteries, each cell has a voltage detection tab that detects the voltage of each cell (single cell layer) in the battery and bypasses overcharged or overdischarged cells for charging and discharging. It is desirable to have it. It is desirable that one end of the voltage detection tab is connected to the current collector of the cell, the other end is taken out to the outside of the battery, and these tabs are connected to a voltage detection / bypass control circuit or the like. As a result, in order to ensure the high voltage required for the vehicle power supply, it is possible to suppress the deterioration of the battery performance due to the capacity variation of each single battery layer inside the battery containing tens to hundreds of tens of cells (single battery layer). , Battery life can be increased. In particular, when a bipolar battery is used as a power source for a vehicle, reliability and stability are required, so that each bipolar battery and each single battery layer (cell) in the battery function normally. It is necessary to constantly monitor whether or not. For this reason, the voltage of all bipolar batteries (usually an assembled battery in which a plurality of bipolar batteries are connected and mounted in a vehicle as a composite battery in which a plurality of bipolar batteries are connected) and the cells in the battery are constantly monitored and deteriorated. This is because it is desirable to be able to detect the bipolar battery and the cells within the battery.

  In addition, it is convenient to take out the positive electrode tab and the negative electrode tab, which are electrode tabs, and the voltage detection tab from different sides of the battery for the convenience of wiring and the like, and it is desirable from the viewpoint of ensuring the airtightness of the seal portion. .

  Furthermore, since only the voltage for each cell (about 4.2 V) is applied to the voltage detection tab, it is not necessary to form a high resistance layer like the electrode tab.

  The same material as that of the electrode tab can be used for the voltage detection tab. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. Although it is desirable to use the same material for each voltage detection tab, different materials may be used. Furthermore, the voltage detection tab may be a laminate of metals (including alloys) made of different materials.

[Battery exterior materials]
In the present invention, in the same manner as in the past, the waterproof and sealing properties of the battery are ensured, the battery is further reduced in weight, and from the viewpoint of preventing external impact and environmental degradation during use, the battery stack as the battery body is used. A polymer metal composite film is used as a battery exterior material for housing the entire body (or battery winding body). The polymer metal composite film is not particularly limited, and any conventionally known one can be appropriately applied. For example, a metal (including alloy) layer such as aluminum, stainless steel, nickel, copper, or the like. A polymer metal composite film having both surfaces covered with a resin layer (skin resin layer, metal layer-between-tab resin layer) of an insulator (preferably heat resistant insulator) such as a polypropylene film can be used. Examples of the resin layer of the insulator (preferably heat-resistant insulator) include, for example, a polyethylene tetraphthalate film (heat-resistant insulating film), a nylon film (heat-resistant insulating film), a polyethylene film (heat-bonding insulating film), Examples thereof include a polypropylene film (heat fusion insulating film), and these may be applied to the skin resin layer side and the metal layer-tab resin layer side according to the purpose.

  As the metal layer, aluminum is required because it requires heat resistance rather than insulation against high voltage, a high barrier property against external oxygen, water vapor and light (such as ultraviolet rays), and a soft material with excellent strength against bending. desirable. The film thickness of the metal layer is not particularly limited as long as the above characteristics can be sufficiently exhibited, and is in the range of 1 to 100 μm, preferably 5 to 50 μm.

  The above-mentioned skin resin layer does not require heat fusibility, and is required to have external insulation, weather resistance, abrasion resistance, barrier properties against external oxygen and water vapor, heat resistance, etc. A desired material such as an insulating film) or a nylon film (heat-resistant insulating film) may be selected. Moreover, the film thickness of a skin resin layer should just be able to fully express the said characteristic, and is 1-50 micrometers, Preferably it is the range of 5-30 micrometers.

  In the resin layer between the metal layer and the tub, internal insulation, heat-fusibility, chemical resistance (resistance to electrolytic solution, etc.), barrier property against oxygen and water vapor, gas generated by charging / discharging, heat resistance, etc. Therefore, a desired material such as a polyethylene film (heat-fusing insulating film), a polypropylene film (heat-fusing insulating film) or the like may be selected. Moreover, the film thickness of the resin layer between a metal layer and a tab should just be able to fully express the said characteristic, and is 1-100 micrometers, Preferably it is the range of 5-50 micrometers.

  The film thickness of the entire polymer metal composite film is not particularly limited as long as it can exhibit the above-described functions required for battery exterior materials, but is usually in the range of 20 to 150 μm, preferably 50 to 120 μm. It is.

  In addition, these metal layers, skin resin layers, and metal layer-tab resin layers may be formed by laminating layers of different materials. In addition, when two upper and lower polymer metal composite films are used by heat-sealing, the material of each layer in these two polymer metal composite films may be the same or different. May be used.

  In the present invention, a polymer metal composite film is used to form a seal part by joining a part or all of its peripheral part by thermal fusion, and the battery stack is housed and sealed. In this case, the positive electrode and the negative electrode tab are sandwiched between the seal portions (heat fusion portions), and the insulation is ensured to expose the leading end of the positive electrode and the negative electrode tab to the outside of the battery exterior material. What is necessary is just a structure. In addition, it is preferable to use a polymer metal composite film having excellent thermal conductivity in that heat can be efficiently transmitted from a heat source of an automobile and the inside of the battery can be quickly heated to the battery operating temperature.

  Next, as a use of the lithium ion secondary battery of the present invention, for example, as a large-capacity power source such as an electric vehicle (EV), a hybrid electric vehicle (HEV), a fuel cell vehicle and a hybrid fuel cell vehicle, a high energy density, It can be suitably used for a vehicle driving power source and an auxiliary power source that require high power density. In this case, it is desirable that the assembled battery is constructed by connecting a plurality of lithium ion secondary batteries of the present invention. That is, using at least two lithium ion secondary batteries of the present invention, particularly bipolar polymer lithium ion secondary batteries, at least one connection method of parallel connection, series connection, parallel-series connection, and series-parallel connection. By using the assembled battery and the combined assembled battery, a high-capacity, high-output power source can be formed. Therefore, it becomes possible to respond to the demand for battery capacity and output for each purpose of use at a relatively low cost. These will be described later.

  Next, as a manufacturing method of the lithium ion secondary battery of the present invention, the conventional application method, and further the method employed in the examples (a binder is applied to the surface of the current collector, so as to have the electrode structure described above, A method in which the active material particles are carefully adhered to form a single layer and then the binder is solidified (see the examples for details), etc. Instead, various conventionally known methods can be used as appropriate. Hereinafter, a bipolar polymer lithium ion secondary battery will be described as an example.

(1) Application of positive electrode composition or binder composition (i) Application of positive electrode composition (when the thickness of the positive electrode layer exceeds 1 μm)
First, an appropriate current collector is prepared. The positive electrode composition is usually obtained as a slurry (positive electrode slurry) and applied to one surface of the current collector.

  The positive electrode slurry is a solution containing a positive electrode active material. Other optional components include conductive additives, binders, polymerization initiators, electrolyte raw materials (polymers or host polymers for solid electrolytes, electrolytes, etc.), supporting salts (lithium salts), other additives, and slurry viscosity adjusting solvents. Included. That is, the positive electrode slurry contains, in addition to the positive electrode active material, a conductive additive, an electrolyte raw material, a supporting salt (lithium salt), a slurry viscosity adjusting solvent, a polymerization initiator, etc., in the same manner as a non-bipolar lithium ion secondary battery. It can be made by mixing the materials optionally contained in a predetermined ratio.

  When a polymer gel electrolyte is used for the electrolyte layer, a polymer gel electrolyte may be used as long as it contains a conventionally known binder that binds the positive electrode active material fine particles, a conductive aid for increasing electronic conductivity, a solvent, and the like. The raw material host polymer, electrolyte, lithium salt, etc. may not be contained. The same applies when a separator impregnated with an electrolytic solution is used as the electrolyte layer.

  Examples of the electrolyte polymer raw material (the host polymer of the polymer gel electrolyte raw material or the polymer raw material of the polymer solid electrolyte) include PEO, PPO, and copolymers thereof, and a crosslinkable functional group ( It preferably has a carbon-carbon double bond). By cross-linking the polymer electrolyte using this cross-linkable functional group, the mechanical strength is improved.

  With respect to the positive electrode active material, the conductive additive, the binder, and the lithium salt, the above-described compounds can be used.

  The polymerization initiator needs to be selected according to the compound to be polymerized. For example, benzyl dimethyl ketal (BDK) is used as a photopolymerization initiator, and azobisisobutyronitrile, t-hexylperoxypiparate, etc. are mentioned as thermal polymerization initiators, but these are not limited thereto. is not.

  The slurry viscosity adjusting solvent such as NMP is selected according to the type of slurry for positive electrode.

  The addition amount of the positive electrode active material, the lithium salt, and the conductive additive may be adjusted according to the purpose of the bipolar battery, and may be added in a commonly used amount. The addition amount of the polymerization initiator is determined according to the number of crosslinkable functional groups contained in the polymer raw material. Usually, it is about 0.01-1 mass% with respect to a polymeric raw material.

(Ii) Application of binder composition for positive electrode (when the thickness of the positive electrode layer is 1 μm or less; however, it is also applicable when the thickness exceeds 1 μm)
Prepare an appropriate current collector. The positive electrode binder composition is obtained as a slurry (binder slurry) and applied to one surface of the current collector.

  The binder slurry is a solution in which the positive electrode active material is removed from the positive electrode composition. As the components, a binder, a polymerization initiator, an electrolyte raw material (polymer or host polymer for solid electrolyte, electrolytic solution, etc.), supporting salt (lithium salt), other additives, slurry viscosity adjusting solvent, and the like are optionally included. That is, the binder slurry can be prepared by mixing, in addition to the binder, materials including an electrolyte raw material, a supporting salt (lithium salt), a slurry viscosity adjusting solvent, a polymerization initiator, and the like at a predetermined ratio.

  When a polymer gel electrolyte is used for the electrolyte layer, it only needs to contain a conventionally known binder, solvent, or the like that binds the positive electrode active material particles to each other. The host polymer, electrolyte solution, or lithium salt as a raw material for the polymer gel electrolyte Etc. may not be included. The same applies when a separator impregnated with an electrolytic solution is used as the electrolyte layer.

  Examples of the electrolyte polymer raw material (the host polymer of the polymer gel electrolyte raw material or the polymer raw material of the polymer solid electrolyte) include PEO, PPO, and copolymers thereof, and a crosslinkable functional group ( It preferably has a carbon-carbon double bond). By cross-linking the polymer electrolyte using this cross-linkable functional group, the mechanical strength is improved.

  With respect to the binder and the lithium salt, the aforementioned compounds can be used.

  The polymerization initiator needs to be selected according to the compound to be polymerized. For example, examples of the photopolymerization initiator include benzyl dimethyl ketal, and examples of the thermal polymerization initiator include azobisisobutyronitrile, t-hexylperoxypiparate, and the like. is not.

  The slurry viscosity adjusting solvent such as NMP is selected according to the type of slurry for positive electrode.

  The addition amount of the lithium salt may be adjusted according to the purpose of the bipolar battery, and may be an amount usually used. The addition amount of the polymerization initiator is determined according to the number of crosslinkable functional groups contained in the polymer raw material. Usually, it is about 0.01-1 mass% with respect to a polymeric raw material.

(2) Formation of positive electrode layer (i) When the thickness of the positive electrode layer exceeds 1 μm The current collector coated with the positive electrode slurry is dried to remove the contained solvent. At the same time, depending on the positive electrode slurry, the cross-linking reaction may be advanced to increase the mechanical strength of the polymer solid electrolyte. For drying, a vacuum dryer or the like can be used. The drying conditions are determined according to the applied positive electrode slurry and cannot be uniquely defined, but are usually 40 to 150 ° C. and 5 minutes to 20 hours.

(Ii) When the thickness of the positive electrode layer is 1 μm or less (applicable even when the thickness exceeds 1 μm)
The current collector coated with the binder slurry is brought into contact with positive electrode active material particles having a uniform particle size while confirming with a micromanipulator, for example, as shown in Examples. Further, while confirming with a micromanipulator, the current collector and the active material are dried and dried to remove the solvent contained. At the same time, depending on the binder slurry, the cross-linking reaction may be advanced to increase the mechanical strength of the polymer solid electrolyte. For drying, a hot air blower, a blower or the like can be used. The drying conditions are determined according to the applied binder slurry and cannot be uniquely defined, but are usually 40 to 150 ° C. and 5 minutes to 20 hours.

  However, the present invention is not limited to the above-described method, and any method can be used as long as a single-layer active material particle layer can be formed.

(3) Application of negative electrode composition or binder composition (i) Application of negative electrode composition (when the thickness of the negative electrode layer exceeds 1 μm)
The negative electrode composition (negative electrode slurry) containing the negative electrode active material is applied to the surface opposite to the surface on which the positive electrode layer is formed.

  The negative electrode slurry is a solution containing a negative electrode active material. As other components, a binder, a polymerization initiator, (a polymer or host polymer for a solid electrolyte, an electrolytic solution, etc.), a supporting salt (lithium salt), a slurry viscosity adjusting solvent, and a conductive additive are optionally included. Since the raw materials used and the amount added are the same as those described in the section “(1) (i) Application of positive electrode composition”, the description is omitted here.

(Ii) Application of binder composition for negative electrode (when the thickness of the negative electrode layer is 1 μm or less; however, it is also applicable when the thickness exceeds 1 μm)
A negative electrode binder composition (binder slurry) is applied to the surface opposite to the surface on which the positive electrode layer is formed.

  The binder slurry is a solution in which the positive electrode active material is removed from the positive electrode composition. As the components, a binder, a polymerization initiator, an electrolyte raw material (polymer or host polymer for solid electrolyte, electrolytic solution, etc.), supporting salt (lithium salt), other additives, slurry viscosity adjusting solvent, and the like are optionally included. Since the raw materials used and the amount added are the same as those described in the section “(1) (ii) Application of Negative Electrode Binder Composition”, the description is omitted here.

(4) Formation of negative electrode layer (i) When the thickness of the negative electrode layer exceeds 1 μm The current collector coated with the slurry for negative electrode is dried to remove the contained solvent. At the same time, depending on the slurry for the negative electrode, the crosslinking reaction may be advanced to increase the mechanical strength of the polymer gel electrolyte. This work completes the bipolar electrode. For drying, a vacuum dryer or the like can be used. The drying conditions are determined according to the applied slurry for negative electrode and cannot be uniquely defined, but are usually 40 to 150 ° C. and 5 minutes to 20 hours. By this drying treatment, a negative electrode layer is formed on the current collector.

(Ii) When the thickness of the negative electrode layer is 1 μm or less (applicable even when the thickness exceeds 1 μm)
The surface of the current collector on which the negative electrode binder slurry has been applied is brought into contact with negative electrode active material particles having a uniform particle size while being confirmed with a micromanipulator, for example, as shown in the Examples. Further, while confirming with a micromanipulator, the current collector and the negative electrode active material are dried while being pressed, and the contained solvent is removed. At the same time, depending on the binder slurry, the cross-linking reaction may be advanced to increase the mechanical strength of the polymer solid electrolyte. For drying, a hot air blower, a blower or the like can be used. The drying conditions are determined according to the applied binder slurry and cannot be uniquely defined, but are usually 40 to 150 ° C. and 5 minutes to 20 hours.

  However, the present invention is not limited to the above-described method, and any method can be used as long as a single-layer active material particle layer can be formed.

(5) Formation of electrolyte layer When a polymer solid electrolyte layer is used, for example, by curing a solution prepared by dissolving a polymer solid electrolyte raw material polymer, lithium salt, etc. in a solvent such as NMP. Manufactured. In the case of using a polymer gel electrolyte layer, for example, as a raw material for the polymer gel electrolyte, a pregel solution composed of a host polymer and an electrolytic solution, a lithium salt, a polymerization initiator and the like is simultaneously heated and dried in an inert atmosphere. It is produced by polymerizing (accelerating the crosslinking reaction). Further, when using a polymer gel electrolyte layer in which a polymer gel electrolyte is held in a nonwoven fabric separator, for example, as a raw material for the polymer gel electrolyte, a host polymer and an electrolytic solution, a lithium salt, a polymerization initiator are used in the separator. It is produced by impregnating a pregel solution composed of, etc., and polymerizing (accelerating the crosslinking reaction) simultaneously with heat drying in an inert atmosphere. In the case of using a polymer solid electrolyte layer in which a solid polymer electrolyte is held in a nonwoven fabric separator, for example, as a raw material for the polymer solid electrolyte, a host polymer and an electrolytic solution, a lithium salt, a polymerization initiator, etc. It is produced by impregnating a solution obtained by dissolving in a viscosity modifier and polymerizing (accelerating the crosslinking reaction) simultaneously with heat drying in an inert atmosphere.

  For example, the prepared solution or pregel solution is applied onto the positive electrode layer and / or the negative electrode layer of the electrode, and an electrolyte layer having a predetermined thickness or a part thereof (an electrolyte film having about half the electrolyte layer thickness) Form. Then, the electrode on which the electrolyte layer (film) is laminated is cured or heated and dried in an inert atmosphere and polymerized (accelerating the crosslinking reaction), thereby increasing the mechanical strength of the electrolyte and producing the electrolyte layer (film). A film is formed (completed).

  Alternatively, an electrolyte layer laminated between the electrodes or a part thereof (an electrolyte membrane having about half the electrolyte layer thickness) is prepared. The polymer gel electrolyte layer (membrane) in which the polymer gel electrolyte is held in an electrolyte layer (membrane) or separator is prepared by applying the above solution or pregel solution on a suitable film such as a polyethylene terephthalate (PET) film. It is produced by polymerizing (accelerating the crosslinking reaction) simultaneously with curing or heat drying in an active atmosphere, or impregnated with the above-mentioned solution or pregel solution in a suitable non-woven separator such as polypropylene (PP) It is produced by polymerizing (accelerating the crosslinking reaction) simultaneously with curing or heat drying in an atmosphere.

  For curing or heat drying, a vacuum dryer (vacuum oven) or the like can be used. The conditions for heat drying are determined according to the solution or the pregel solution and cannot be uniquely defined, but are usually 30 to 110 ° C. and 0.5 to 12 hours.

  The thickness of the electrolyte layer (film) can be controlled using a spacer or the like. In the case of using a photopolymerization initiator, it is poured into a light transmissive gap, irradiated with ultraviolet rays using an ultraviolet irradiation device capable of drying and photopolymerization, and the polymer in the electrolyte layer is photopolymerized to carry out a crosslinking reaction. It is good to advance and form a film. However, it is needless to say that the method is not limited to this. Depending on the type of polymerization initiator, radiation polymerization, electron beam polymerization, thermal polymerization, etc. are used properly.

  In addition, since the film used above may be heated to about 80 ° C. in the production process, it has sufficient heat resistance at the temperature and has no reactivity with the solution or the pregel solution, and the production process. For example, polyethylene terephthalate (PET) or polypropylene film can be used, but it should not be limited to these.

  The width of the electrolyte layer is often slightly smaller than the current collector size of the bipolar electrode.

  About the composition component of the said solution or pregel solution, its compounding quantity, etc., it should be suitably determined according to the intended purpose.

(6) Lamination of bipolar electrode and electrolyte layer (i) In the case of a bipolar electrode in which the electrolyte layer (membrane) is formed on one or both sides, the electrolyte layer (membrane) is sufficiently heated and dried under high vacuum. A plurality of the electrodes formed with is cut into a suitable size, and the cut out electrodes are directly bonded together to produce a bipolar battery body (electrode laminate).

    (Ii) When bipolar electrodes and electrolyte layers (membranes) are separately produced, after sufficiently heating and drying under high vacuum, a plurality of bipolar electrodes and electrolyte layers (membranes) are cut into appropriate sizes. . A predetermined number of the cut bipolar electrodes and electrolyte layers (membranes) are bonded together to produce a bipolar battery body (electrode laminate).

  The number of stacked electrode laminates is determined in consideration of battery characteristics required for the bipolar battery. Moreover, the electrode which formed only the positive electrode layer on the electrical power collector is arrange | positioned at the outermost layer by the side of a positive electrode. In the outermost layer on the negative electrode side, an electrode in which only the negative electrode layer is formed on the current collector is disposed. The step of obtaining a bipolar battery by laminating a bipolar electrode and an electrolyte layer (film) or by laminating an electrode having an electrolyte layer (film) is not effective from the viewpoint of preventing moisture from entering the battery. It is preferable to carry out in an active atmosphere. For example, the bipolar battery may be manufactured in an argon atmosphere or a nitrogen atmosphere.

(7) Formation of Insulating Layer In the present invention, for example, the periphery of the electrode forming portion of the electrode laminate is immersed in epoxy resin (precursor solution) or the like with a predetermined width, or the resin is injected or impregnated. In either case, the voltage detection tab, the electrode terminal plate, the electrode lead, the electrode tab, or the current collector portion to which these need to be connected are masked in advance using a releasable masking material or the like. . Thereafter, the epoxy resin is cured to form an insulating portion, and then the masking material is peeled off.

(8) Connection of terminal plate, electrode lead, and tab (terminal) A positive electrode terminal plate and a negative electrode terminal plate are respectively installed on and connected to the current collectors on both outermost layers of the bipolar battery body (battery stack). The positive electrode terminal plate and the negative electrode terminal plate are joined (electrically connected) to the positive electrode lead and the negative electrode lead, and the positive electrode tab and the negative electrode tab are further joined (electrically connected). As a method for joining these terminal plates, leads, and tabs, ultrasonic welding having a low joining temperature can be suitably used, but it should not be limited to this, and a conventionally known joining method is appropriately used. can do. Further, in the present invention, the voltage of the single cell layer is detected, and a voltage detection tab that can be bypassed if overcharged or overdischarged is connected to each current collector, and these are connected to the outside of the battery. It is desirable to take out and connect these tabs to a voltage detection and bypass control circuit. Thereby, the fall of the battery performance by the capacity | capacitance variation of each single battery layer inside a battery can be suppressed, and battery life can be extended.

(9) Packing (Battery completion)
Finally, in order to prevent external impact and environmental degradation, the entire battery stack is sealed with a battery exterior material to complete a bipolar battery. When sealing, the positive electrode tab, the negative electrode tab, and one end of the voltage detection tab are taken out of the battery.

  Next, in the present invention, a plurality of the above bipolar batteries can be formed into a battery pack using at least one of a parallel connection, a series connection, a parallel-series connection, or a series-parallel connection. This makes it possible to meet the demands for capacity and voltage for various vehicles with a combination of basic bipolar batteries. As a result, it becomes possible to facilitate the design selectivity of required energy and output. Therefore, it is not necessary to design and produce different bipolar batteries for various vehicles, and the basic bipolar battery can be mass-produced, and the cost can be reduced by mass production. Hereinafter, typical embodiments of the assembled battery will be briefly described with reference to the drawings.

  FIG. 4 shows a schematic diagram of an assembled battery (42V1Ah) in which the bipolar battery (24V, 50 mAh) of the present invention is connected in two lines and 20 lines. The tabs in the parallel part were connected by copper bus bars 56 and 58, and the serial part was connected by vibration welding the tabs 11 and 13. The ends of the series part are connected to the terminals 42 and 44 to constitute positive and negative terminals. On both sides of the battery, detection tabs 12 for detecting the voltage of each layer of the bipolar battery 1 are taken out, and their detection lines 53 are taken out at the front part of the assembled battery 50. Specifically, in order to form the assembled battery 50 shown in FIG. 4, five bipolar batteries 1 are connected in parallel by a bus bar 56, and five bipolar batteries 1 connected in parallel are further connected to each other by electrode tabs in series. These are stacked in four layers and connected in parallel by a bus bar 58 and housed in a metal assembled battery case 55. In this way, by connecting an arbitrary number of bipolar batteries 1 in series and parallel, an assembled battery 50 that can handle a desired current, voltage, and capacity can be provided. In the assembled battery 50, a positive electrode terminal 42 and a negative electrode terminal 44 are formed at the front side of a metal assembled battery case 55. After the batteries are connected in series and parallel, for example, each bus bar 56 and each positive electrode terminal 42 are connected. The negative terminal 44 is connected to the terminal lead 59. Further, the assembled battery 50 includes a detection tab terminal 54 for monitoring a battery voltage (a voltage of each single cell layer and further a bipolar battery), and a positive electrode terminal 42 and a negative electrode terminal of a metal assembled battery case 55. It is installed in the front part of the side surface in which 44 is provided. All the voltage detection tabs 12 of each bipolar battery 1 are connected to the detection tab terminal 54 via the detection line 53. In addition, an external elastic body 52 is attached to the bottom of the assembled battery case 55, and when a plurality of assembled batteries 50 are stacked to form a composite assembled battery, the distance between the assembled batteries 50 is maintained to prevent vibration. , Impact resistance, insulation, heat dissipation, etc. can be improved.

  The assembled battery 50 may be provided with various measuring devices and control devices in addition to the detection tab terminal 54, depending on the intended use. Furthermore, in order to connect the electrode tabs (11, 13) of the bipolar battery 1 or the detection tab 12 and the detection line 53, ultrasonic welding, heat welding, laser welding, electron beam welding, or a rivet is used. You may make it connect using the bus-bars 56 and 58, or using the crimping method. Furthermore, in order to connect the bus bars 56, 58 and the terminal leads 59, etc., ultrasonic welding, heat welding, laser welding, or electron beam welding may be used.

  The external elastic body 52 may be made of the same material as that of the resin group used in the battery of the present invention, but is not limited thereto.

  Further, in the assembled battery of the present invention, the bipolar battery of the present invention and the battery having the same voltage by making the bipolar battery and the positive and negative electrode materials the same and by arranging the number of structural units of the bipolar battery in series (preferably the present invention) And a non-bipolar lithium ion secondary battery (hereinafter also referred to as a general lithium ion secondary battery) may be connected in parallel. That is, the battery forming the assembled battery may be a mixture of the bipolar battery of the present invention and the non-bipolar lithium ion secondary battery of the present invention. As a result, an assembled battery that compensates for each other's weaknesses can be made by combining a bipolar battery that focuses on output and a general lithium ion secondary battery that focuses on energy, and the weight and size of the assembled battery can be reduced. The proportion of each bipolar battery and non-bipolar lithium-ion secondary battery mixed depends on the safety performance and output performance required for the assembled battery.

  FIG. 5 shows an assembled battery in which a bipolar battery A (42 V, 50 mAh) and a general lithium ion secondary battery B (4.2 V, 1 Ah) 10 series (42 V) are connected in parallel. The general lithium ion secondary battery B and the bipolar battery A have the same voltage, and a parallel connection is formed at that portion. The assembled battery 50 ′ has a structure in which the bipolar battery A has an output sharing and the general lithium ion secondary battery B has an energy sharing. This is a very effective means in an assembled battery in which it is difficult to achieve both output and energy. In this assembled battery 50 ', the tabs of the parallel portion and the portion of the general lithium ion secondary battery B adjacent in the horizontal direction in the figure connected in series are connected by the copper bus bar 56, and the general battery adjacent in the vertical direction of the drawing. The parts connecting B in series were connected by vibration welding the tabs 11 and 13. The ends of the portion where the general lithium ion secondary battery B and the bipolar battery A are connected in parallel are connected to the terminals 42 and 44 to constitute positive and negative terminals. 4 except that the detection tabs 12 for detecting the voltage of each layer of the bipolar battery A are taken out on both sides of the bipolar battery A and the detection lines (not shown) are taken out to the front of the assembled battery 50. Since it is the same as that of the assembled battery 50, the same code | symbol was attached | subjected to the same member. Specifically, in order to form the assembled battery 50 ′ shown in FIG. 5, 10 general lithium ion secondary batteries B were sequentially welded from the end to the bus bar 56 and connected in series. Furthermore, the general lithium ion secondary battery B at both ends connected in series with the bipolar battery A is connected in parallel by the bus bar 56 and accommodated in a metal assembled battery case 55. In this way, by connecting an arbitrary number of bipolar batteries A in series and parallel, an assembled battery 50 ′ that can handle a desired current, voltage, and capacity can be provided. Also in the assembled battery 50 ′, a positive electrode terminal 42 and a negative electrode terminal 44 are formed at the front side of a metal assembled battery case 55. After connecting the batteries A and B in series and parallel, for example, Each positive terminal 42 and negative terminal 44 are connected by a terminal lead 59. The assembled battery 50 'has a detection tab terminal 54 for monitoring the battery voltage (the voltage of each single cell layer of the bipolar battery A, and the voltage between the terminals of the bipolar battery A and the general lithium ion secondary battery B). It is installed in the front part of the side surface in which the positive electrode terminal 42 and the negative electrode terminal 44 of the metal assembled battery case 55 are provided. And all the detection tabs 12 of each bipolar battery A (and also general lithium ion secondary battery B) are connected to the detection tab terminal 54 via the detection line (not shown). In addition, an external elastic body 52 is attached to the lower part of the assembled battery case 55, and when a plurality of assembled batteries 50 ′ are stacked to form a composite assembled battery, the distance between the assembled batteries 50 ′ is maintained. In addition, vibration resistance, impact resistance, insulation, heat dissipation, and the like can be improved.

  In the assembled battery of the present invention, the above-mentioned bipolar battery is further connected in series and parallel to form a first assembled battery unit, and the voltage between the terminals of the first assembled battery unit is the same as that of the other two batteries other than the bipolar battery. There is no particular limitation such as forming a second assembled battery unit in which the secondary batteries are connected in series and parallel, and connecting the first assembled battery unit and the second assembled battery unit in parallel. .

  The other constituent requirements of the assembled battery are not limited at all, and the same constituent requirements as the assembled battery using the existing non-bipolar lithium ion secondary battery can be applied as appropriate. However, since the conventionally known constituent members and manufacturing techniques for assembled batteries can be used, the description thereof is omitted here.

  Next, the above-mentioned assembled battery is a composite assembled battery in which at least two or more assembled batteries are connected in series, in parallel, or in series and in parallel. It is possible to cope with a relatively low cost without manufacturing a battery. That is, the composite assembled battery of the present invention includes at least two or more assembled batteries (including those composed of only the bipolar battery of the present invention and those composed of the bipolar battery of the present invention and other non-bipolar batteries) in series. It is characterized in that it is connected in parallel or in series and parallel, and a standard assembled battery is manufactured and combined to form a composite assembled battery, whereby the specifications of the assembled battery can be tuned. Thereby, since it is not necessary to manufacture many assembled battery types with different specifications, the composite assembled battery cost can be reduced.

  As a composite assembled battery, for example, FIG. 6 is a schematic diagram of a composite assembled battery (42V, 6Ah) connected in parallel with an assembled battery (42V, 1Ah) 6 using the bipolar battery shown in FIG. Each assembled battery constituting the composite assembled battery is integrated by a connecting plate and a fixing screw, and an anti-vibration structure is formed by installing an elastic body between the assembled batteries. The tabs of the assembled battery are connected by a plate-like bus bar. That is, as shown in FIG. 6, in order to connect the six assembled batteries 50 in parallel to form the composite assembled battery 60, the tabs of the assembled batteries 50 provided on the lid of each assembled battery case 55 ( The positive electrode terminal 42 and the negative electrode terminal 44) are electrically connected using an external positive electrode terminal portion that is a plate-shaped bus bar, an assembled battery positive electrode terminal connecting plate 62 having an external negative electrode terminal portion, and an assembled battery negative electrode terminal connecting plate 64, respectively. To do. Further, a connecting plate 66 having an opening corresponding to the fixing screw hole is fixed to each screw hole (not shown) provided on both side surfaces of each assembled battery case 55 with a fixing screw 67, and each set is assembled. The batteries 50 are connected to each other. Further, the electrode terminal 42 and the negative electrode terminal 44 of each assembled battery 50 are protected by a positive electrode and a negative electrode insulating cover, respectively, and are identified by color-coding them into appropriate colors, for example, red and blue. Further, an anti-vibration structure is formed by installing an external elastic body 52 between the assembled batteries 50, specifically, at the bottom of the assembled battery case 55.

  In this way, a composite assembled battery in which a plurality of assembled batteries are connected in series and parallel can be repaired by simply replacing the failed part even if some of the batteries or the assembled battery fail.

  The vehicle according to the present invention is characterized in that the assembled battery and / or the composite assembled battery is mounted. This makes it possible to meet a large vehicle demand for space by using a light and small battery. By reducing the battery space, the weight of the vehicle can be reduced.

  As shown in FIG. 7, in order to mount the composite battery pack 60 on a vehicle (for example, an electric vehicle or the like), it is mounted under a seat (seat) in the center of the vehicle body of the electric vehicle 70. This is because if it is installed under the seat, the interior space and the trunk room can be widened. The place where the battery is mounted is not limited to under the seat, but may be under the floor of the vehicle, behind the seat back, under the rear trunk room, or in the engine room in front of the vehicle.

  In the present invention, not only the composite battery pack 60 but also the battery pack 50 may be mounted on a vehicle depending on the intended use, or the composite battery pack and the battery pack may be mounted in combination. Good. Further, as the vehicle on which the composite assembled battery or the assembled battery of the present invention can be mounted as a driving power source or an auxiliary power source, the above-described electric vehicle, fuel cell vehicle and hybrid vehicle thereof are preferable, but are not limited thereto. It is not a thing. In addition, as a vehicle on which the assembled battery and / or the composite assembled battery of the present invention can be mounted as, for example, a driving power source or an auxiliary power source, an electric vehicle, a hybrid electric vehicle, a fuel cell vehicle, a hybrid fuel cell vehicle, etc. However, it is not limited to these.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples.

Example 1: Experiment using the electrode structure of the present invention for the negative electrode and the gel electrolyte for the electrolyte layer FIGS. 8A to 8C show the test cell, test electrode and counter electrode produced in this example, respectively. Show. Specifically, FIG. 8A shows a schematic perspective view schematically showing the configuration of the test cell produced in this example, and FIG. 8B shows the test of FIG. FIG. 8C shows an enlarged view of the counter electrode used in FIG. 8A.

<Preparation of gel precursor solution>
The gel precursor solution was obtained by mixing the following materials.

  That is, 1 g of polyethylene oxide, 9 g of a lithium salt LiBETI dissolved to 1.0 M in an electrolyte EC + PC (volume ratio 1: 1), and a gel precursor solution (pregel) consisting of 5 mg of BDK as a photopolymerization initiator Solution).

<Formation of test cell>
1.2 pieces of platinum wires 71 and 73 having a diameter of 10 μm were sealed with glass 75, and the tips were shaved to expose a platinum surface having a diameter of 10 μm.

  2. Among them, PVdF77 as a binder is applied to the tip of one platinum wire 71, and while confirming it with a micromanipulator, hard carbon particles 79 having an average particle diameter of 0.8 μm, which is an amorphous carbon material, are used as a negative electrode active material. Made contact.

  3. While confirming with a micromanipulator, the platinum wire 71 and the active material 79 were pressed, PVdF77 was hardened with a drier, and the test electrode 87 was obtained. In the test electrode 87, as shown in FIG. 8 (b), the particle diameter of the active material particles and the thickness of the electrode layer are the same on the tip surface of the platinum wire 71 functioning as a current collector. It was confirmed that an electrode (negative electrode) composed only of the particle single layer was formed.

  4). Lithium 81 was previously deposited on the surface of platinum by electrolytic plating at the tip of the other platinum wire 73 to form a counter electrode (positive electrode) 89 (see FIG. 8C).

  5). The gel precursor solution was placed in a bipolar cell 83 as shown in FIG. 7A, and a test electrode 87 with an active material 79 and an electrode (counter electrode) 89 with lithium 81 were set. The distance between the test electrode 87 and the electrode (counter electrode) 89 corresponding to the thickness of the electrolyte layer was 100 μm.

  6. Photopolymerization was performed by irradiating the bipolar cell 83 with ultraviolet rays to gel the gel precursor solution (pregel solution) (form the gel electrolyte 85), and a test cell 91 was produced.

<Charging / discharging test of test cell (negative electrode performance)>
1. Constant current charging: The test cell obtained as described above was charged with a predetermined current to a predetermined voltage. Thereafter, the voltage was maintained for 15 hours.

  2. Pause: Pause for 10 minutes.

  3. Constant voltage discharge: Discharged to a predetermined voltage with a predetermined current.

  4). Pause: Paused for 10 minutes.

  The charge / discharge conditions were as follows.

・ Charging current: 0.5C
-Charging voltage: 10 mV vs. Li / Li ⁺
Discharge current: 0.5C, 1C, 5C, 10C, 100C (per sample)
-Discharge voltage: 3V vs. Li / Li ⁺
Here, 1C is a current value at which the battery is fully charged (100% charged) when charged at that current value for 1 hour. For example, 2C is a current value that is twice that of 1C, and is a current value that can fully charge the battery in 30 minutes.

  The results (discharge efficiency) obtained by the charge / discharge test are shown in Table 1.

Reference example 1
<Formation of reference test electrode (negative electrode)>
A material composed of 27 g of hard carbon having an average particle diameter of 0.8 μm, which is an amorphous carbon material, as a negative electrode active material, 3 g of PVdF as a binder, and 30 g of N-methyl-2-pyrrolidone (NMP) as a slurry viscosity adjusting solvent in the above mixing ratio. And mixed to prepare a negative electrode slurry.

  The negative electrode slurry was uniformly applied on a Cu current collector by a coater. The thin film formed by coating was heated at 120 ° C. for 10 minutes to evaporate NMP to form a negative electrode having a dry thickness of 40 μm.

  The negative electrode was cut into 16 mmφ with a punch and used as a reference test electrode (negative electrode).

<Production of test cell>
A coin-type test cell having the following configuration was manufactured and tested.

  Li metal foil (16 mmφ) was used for the counter electrode. For the gel electrolyte layer, a glass separator having a thickness of 150 μm cut into 18 mmφ and a gel precursor solution similar to that in Example 1 was soaked and photopolymerized was used. As the negative electrode, a hard carbon electrode (16 mmφ), which is the reference test electrode (negative electrode), was used.

  The charge / discharge test of the obtained test cell was performed under the same charge / discharge test conditions as the test single cell of Example 1. The obtained results (discharge efficiency) are shown in Table 1.

  Values other than the film thickness in the table represent discharge efficiency. The discharge efficiency is 100% of the actual discharge capacity when the theoretical capacity of the battery is 100%.

Example 2: Experiment using the electrode structure of the present invention for the negative electrode and the gel electrolyte for the electrolyte layer In Example 1, the hard carbon particles having an average particle diameter of 0.8 μm, which is an amorphous carbon material, were used as the negative electrode active material. A test cell was prepared in the same manner as in Example 1 except that hard carbon particles having an average particle diameter of 2 μm were used. Also in this example, in the test electrode, as shown in FIG. 8B, the particle diameter of the active material particles and the thickness of the electrode layer are the same on the tip surface of the platinum wire that functions as a current collector. It was confirmed that an electrode (negative electrode) composed only of a single active material particle layer was formed.

  The charge / discharge test of the test cell was performed under the same conditions as in Example 1. The obtained results (discharge efficiency) are shown in Table 2.

  Further, in Reference Example 1, hard carbon particles having an average particle diameter of 2 μm are used instead of hard carbon particles having an average particle diameter of 0.8 μm, which is an amorphous carbon material, as the negative electrode active material, so that the dry thickness is 2 μm. A test cell was prepared in the same manner as in Reference Example 1 except that a negative electrode was formed by using a coater so that the thickness of the coating film was the same as the particle diameter of the active material particles and was applied uniformly. . Even in such a manufacturing method, since the average particle diameter exceeds 1 μm (2 μm), the active material is arranged densely without being loosely applied, and in the test electrode, the particle diameter of the active material particles and the Cu current collector It was confirmed that an electrode (negative electrode) composed of only a single active material particle layer can be formed with the same electrode layer thickness. Moreover, as a result of performing the charge / discharge test of this test cell on the same conditions as Example 1, it has confirmed that the discharge efficiency obtained the favorable result close | similar to Example 2 of Table 2 below.

Reference example 2
In Reference Example 1, the same procedure as in Reference Example 1 was used, except that the hard carbon particles having an average particle diameter of 2 μm were used instead of the hard carbon particles having an average particle diameter of 0.8 μm as the negative electrode active material. A test electrode for reference (negative electrode) was formed to prepare a test cell.

  The charge / discharge test conditions of the obtained test cell were the same charge / discharge test conditions as the test cell of Example 1. The obtained results (discharge efficiency) are shown in Table 2.

  Values other than the film thickness in the table represent discharge efficiency.

Example 3 Experiment Using Electrode Structure of Present Invention for Negative Electrode and Gel Electrolyte for Electrolyte Layer In Example 1, hard carbon particles having an average particle diameter of 0.8 μm, which is an amorphous carbon material, are used as the negative electrode active material. A test cell was prepared in the same manner as in Example 1 except that hard carbon particles having an average particle diameter of 8 μm were used. Also in this example, in the test electrode, as shown in FIG. 8B, the particle diameter of the active material particles and the thickness of the electrode layer are the same on the tip surface of the platinum wire that functions as a current collector. It was confirmed that an electrode (negative electrode) composed only of the active material particle single layer was formed.

  The charge / discharge test conditions of the test cell were the same as those in Example 1. The obtained results (discharge efficiency) are shown in Table 3.

  In Reference Example 1, hard carbon particles having an average particle size of 8 μm are used as the negative electrode active material instead of hard carbon particles having an average particle size of 0.8 μm, which is an amorphous carbon material, and the dry thickness is 8 μm. A test cell was prepared in the same manner as in Reference Example 1 except that a negative electrode was formed by using a coater so that the thickness of the coating film was the same as the particle diameter of the active material particles and was applied uniformly. . Even in such a manufacturing method, since the average particle diameter exceeds 1 μm (8 μm), the active material is arranged densely without being sparsely applied, and in the test electrode, the particle diameter of the active material particles and the Cu current collector It was confirmed that an electrode (negative electrode) composed of only a single active material particle layer can be formed with the same electrode layer thickness. Moreover, as a result of performing the charge / discharge test of this test cell on the same conditions as Example 1, it has confirmed that the discharge efficiency obtained the favorable result close | similar to Example 3 of Table 3 below.

Reference example 3
In Reference Example 1, the same procedure as in Reference Example 1 was used, except that the hard carbon particles having an average particle diameter of 8 μm were used as the negative electrode active material instead of the amorphous carbon material having an average particle diameter of 0.8 μm. A test electrode for reference (negative electrode) was formed to prepare a test cell.

  The charge / discharge test conditions of the obtained test cell were the same charge / discharge test conditions as the test cell of Example 1. The obtained results (discharge efficiency) are shown in Table 3.

  Values other than the film thickness in the table represent discharge efficiency.

Example 4: Experiment using the electrode structure of the present invention for the negative electrode and the solid polymer electrolyte for the electrolyte layer <Preparation of raw material solution for solid polymer electrolyte>
The raw material solution was obtained by mixing the following materials.

  That is, it was set as the raw material solution which consists of polyethylene oxide 5g, lithium salt LiBETI2.5g, NMP5g, and BDK0.025g as a photoinitiator.

<Formation of test cell>
In Example 1, the raw material solution was used instead of the gel precursor solution (pregel solution), and the hard carbon particles having an average particle diameter of 0.8 μm, which is an amorphous carbon material, were used as the negative electrode active material, and the average particle diameter was 5 μm. A test cell was formed in the same manner as in Example 1 except that hard carbon particles were used.

  1.2 pieces of 10 μmφ platinum wire were sealed with glass, and the tip was shaved to expose a 10 μm diameter platinum surface.

  2. Hard carbon particles with an average particle diameter of 5 μm, which is an amorphous carbon material, are used as the negative electrode active material while applying PVdF as a binder to the tip of one of the platinum wires in the glove box and checking it with a micromanipulator. Contact.

  3. While confirming with a micromanipulator, a platinum wire and an active material were pressed, and PVdF was hardened with a dryer to obtain a test electrode. In the test electrode, an electrode composed of only a single active material particle layer (negative electrode) on the surface of the tip of a platinum wire acting as a current collector, the particle diameter of the active material particles and the thickness of the electrode layer are the same. Has been confirmed (see FIG. 8B).

  4). Lithium was deposited in advance on the surface of platinum by electrolytic plating at the tip of the other platinum wire to obtain a counter electrode (positive electrode) (see FIG. 8C).

  5). The raw material solution was placed in a bipolar cell as shown in FIG. 8A, and a test electrode with an active material and an electrode (counter electrode) with lithium were set. The distance between the test electrode and the electrode (counter electrode) corresponding to the thickness of the electrolyte layer was 50 μm.

  6. Photopolymerization was performed by applying ultraviolet light to the bipolar cell, solidifying the raw material solution (forming a solid polymer electrolyte), and producing a test cell.

  The charge / discharge test conditions of the test cell were the same as those in Example 1. Table 4 shows the obtained results (discharge efficiency).

Reference example 4
5 g of hard carbon having an average particle size of 5 μm, which is an amorphous carbon material as a negative electrode active material, 5 g of polyethylene oxide as a raw material polymer for a polymer solid electrolyte, 2.5 g of LiBETI as a lithium salt, and N-methyl-2 as a slurry viscosity adjusting solvent A negative electrode slurry was prepared by mixing 5 g of pyrrolidone (NMP) and 0.025 g of AIBN as a thermal polymerization initiator at the above blending ratio.

  The negative electrode slurry was uniformly applied on a Cu current collector by a coater. The thin film formed by coating was heated at 120 ° C. for 10 minutes to evaporate NMP to form a negative electrode having a dry thickness of 25 μm.

  The negative electrode was cut into 16 mmφ with a punch and used as a reference test electrode (negative electrode).

<Production of test cell>
A coin-type test cell having the following configuration was manufactured and tested.

  Li metal foil (16 mmφ) was used for the counter electrode. In the solid polymer electrolyte layer, a Teflon (registered trademark) sheet having a clearance of 50 μm in thickness is placed at both ends of the plate glass, the same raw material solution as in Example 4 is applied on the plate glass, and a plate glass is further placed from above. A photopolymerized product cut out to 18 mmφ in a state of being sandwiched and fixed with a clip was used. As the negative electrode, a hard carbon electrode (16 mmφ), which is the reference test electrode (negative electrode), was used.

  The charge / discharge test conditions of the obtained test cell were the same charge / discharge test conditions as the test cell of Example 1. Table 4 shows the obtained results (discharge efficiency).

  Values other than the film thickness in the table represent discharge efficiency.

  Moreover, in Reference Example 4, the coating thickness was changed to a dry thickness of 5 μm by changing to a dry thickness of 25 μm, and the coating film thickness was uniformly adjusted by using a slit so that the particle diameter of the active material particles was the same. A test cell was prepared in the same manner as in Reference Example 4 except that the negative electrode was formed by coating the film. Even in such a manufacturing method, since the average particle diameter exceeds 1 μm (5 μm), the active material is densely arranged without being loosely applied, and in the test electrode, the particle diameter of the active material particles and the Cu current collector It was confirmed that an electrode (negative electrode) composed of only a single active material particle layer can be formed with the same electrode layer thickness. Moreover, as a result of performing the charge / discharge test of this test cell on the same conditions as Example 1, it has confirmed that the discharge efficiency obtained the favorable result close | similar to Example 4 of Table 4 below.

1 is a schematic cross-sectional view schematically showing one electrode structure of the best mode of a lithium ion secondary battery according to the present invention, and the best when the thickness T (= active material particles) of the electrode layer is larger than 1 μm. It is drawing showing the form of. 1 is a schematic cross-sectional view schematically showing one electrode structure of the best mode of a lithium ion secondary battery according to the present invention, in which the thickness T (= active material particles 3) of an electrode layer is 1 μm or less. It is drawing showing the best form. It is the cross-sectional schematic which represented typically the basic structure of the bipolar polymer lithium ion secondary battery which is one of the more suitable aspects of the lithium ion secondary battery of this invention. It is a schematic diagram which shows an example of the assembled battery which connected the bipolar battery of this invention in 2 series 20 parallel. FIG. 4A is a plan view of the assembled battery, FIG. 4B is a front view of the assembled battery, and FIG. 4C is a right side view of the assembled battery. In (c), all show the inside of the assembled battery through the outer case so that it can be seen that the bipolar batteries are connected in series and in parallel. It is a figure which shows an example of the assembled battery which connected in parallel the bipolar battery A of this invention and the lithium ion secondary battery B10 which is not the bipolar type of this invention. 5 (a) is a plan view of the assembled battery, FIG. 5 (b) is a front view of the assembled battery, and FIG. 5 (c) is a right side view of the assembled battery. In (c), the inside of the assembled battery is shown through the outer case so that it can be seen that the bipolar battery A and the non-bipolar lithium ion secondary battery B are connected in series and parallel mixing. . It is a figure which shows an example of the composite assembled battery of this invention. 6A is a plan view of the composite assembled battery, FIG. 6B is a front view of the composite assembled battery, and FIG. 6C is a right side view of the composite assembled battery. It is a schematic diagram which shows the electric vehicle of the state which mounted the composite assembled battery. FIGS. 8A to 8C show a test cell, a test electrode, and a counter electrode produced in this example, respectively. Specifically, FIG. 8A shows a schematic perspective view schematically showing the configuration of the test cell produced in this example, and FIG. 8B shows the test of FIG. FIG. 8C shows an enlarged view of the counter electrode used in FIG. 8A.

Explanation of symbols

1 electrode,
3 active material particles,
5 Current collector,
7 electrolyte layer (bulk electrolyte),
9 Binder,
21 Bipolar polymer lithium ion secondary battery,
23 current collector,
25 positive electrode (positive electrode active material layer),
25a Lowermost positive electrode active material layer,
27a ... uppermost negative electrode active material layer,
27 negative electrode (negative electrode active material layer),
29 bipolar electrodes,
31 electrolyte layer,
33 electrode laminate (bipolar battery body),
35 positive lead,
37 Negative lead,
39 Battery exterior materials,
42 positive terminal,
44 negative terminal,
50, 50 'battery pack,
52 external elastic body,
53 detection lines,
54 detection tab terminal,
55 battery pack case,
56, 58 Busbar,
59 Terminal lead,
60 composite battery pack,
62 composite battery positive electrode terminal connecting plate,
64 composite battery negative electrode terminal plate,
66 connecting plate,
67 fixing screws,
70 electric car,
71, 73 platinum wire,
75 glass,
77 Binder (PVdF),
79 negative electrode active material particles (hard carbon particles),
81 lithium (counter electrode active material),
83 Bipolar cell,
85 Gel electrolyte,
87 test electrodes,
89 Counter electrode,
91 test cell,
A bipolar battery,
B Lithium ion secondary battery that is not bipolar
T The thickness of the electrode layer.

Claims (11)

  A lithium ion secondary battery characterized in that at least one of the positive electrode and the negative electrode has the same particle diameter of the active material particles of the electrode and the thickness of the electrode layer.   A lithium ion secondary battery, wherein at least one of a positive electrode and a negative electrode is an electrode composed of only a single active material particle layer.   At least one of a positive electrode or a negative electrode consists only of an active material and a binder, The lithium ion secondary battery characterized by the above-mentioned.   At least one of a positive electrode or a negative electrode comprises the requirements of at least 2 or more of Claims 1-3, The lithium ion secondary battery characterized by the above-mentioned.   The lithium ion secondary battery according to any one of claims 1 to 4, wherein the lithium ion secondary battery is a gel polymer battery.   The lithium ion secondary battery according to any one of claims 1 to 4, wherein the lithium ion secondary battery is an intrinsic polymer battery.   The lithium ion secondary battery according to any one of claims 1 to 6, wherein the lithium ion secondary battery is a bipolar battery.   A battery pack using at least one of a plurality of the bipolar batteries in parallel connection, series connection, parallel-series connection, or series-parallel connection. A bipolar battery according to claim 7;
Batteries having the same positive electrode material as the bipolar battery, and the same voltage by serially connecting the number of structural units of the bipolar battery,
Are connected in parallel.   A composite assembled battery comprising at least two or more assembled batteries according to claim 8 and / or 9 connected in series, in parallel, or in series and parallel.   A vehicle using the assembled battery and / or the composite assembled battery.

Images