JP2011165930A - Power storage device, and method of manufacturing shared negative electrode of the same - Google Patents

Abstract

In a power storage device having a built-in structure of a lithium ion capacitor and a lithium battery and having a negative electrode in common and a negative electrode hole provided in the common negative electrode, even if a rapid charge / discharge cycle is repeated, short-circuiting or cycle characteristics An object of the present invention is to provide an electric power storage device that does not deteriorate.
The discharge capacity of the negative electrode layer on the lithium ion capacitor side is larger than the discharge capacity of the positive electrode layer on the lithium ion capacitor side, and the discharge capacity of the negative electrode layer on the lithium battery side is higher than that of the positive electrode layer on the lithium battery side. It was configured to be larger than the discharge capacity.
[Selection] Figure 1

Description

  The present invention relates to a power storage device having a built-in configuration of a lithium ion capacitor and a lithium secondary battery, and a manufacturing method thereof.

  The electric double layer capacitor is composed of a sheet-like positive and negative electrode made of a carbon material such as activated carbon and a binder, a porous separator that electrically insulates both electrodes, and an electrolytic solution impregnated therein. Since the ions in the electrolyte move between the electrodes due to the capacitance of the electric double layer generated at the interface between the two electrodes and the electrolyte, no electrochemical reaction occurs. For this reason, the electric double layer capacitor is excellent in charge / discharge rate characteristics and cycle characteristics, and is used as a backup power source for electronic devices and a power source for various transportation equipment including automobiles. However, there is a problem that the electric double layer capacitor has a lower energy density than the battery.

On the other hand, lithium secondary batteries use lithium-containing metal oxides such as LiCoO ₂ for the positive electrode and carbon materials such as graphite for the negative electrode, so that lithium is supplied from the lithium-containing metal oxide of the positive electrode to the negative electrode during charging. In the discharge, lithium ion insertion / desorption reaction of returning lithium in the negative electrode to the positive electrode is used. Since this battery has a high voltage and high energy density, it is widely used in power supplies for portable devices, electric tools, home appliances, and the like. However, while the lithium secondary battery has a high energy density, there are problems in terms of output characteristics, cycle characteristics, and safety.

  On the other hand, in recent years, lithium ion capacitors (LIC) in which lithium secondary batteries and electric double layer capacitors are combined have been actively developed. This LIC is a hybrid type capacitor using an activated carbon for an electric double layer capacitor as a positive electrode layer and a carbon material for a lithium battery as a negative electrode layer. In this LIC, the negative electrode potential can be lowered and a high cell voltage can be obtained by doping lithium ions in the negative electrode layer, so that the energy density can be improved as compared with the conventional electric double layer capacitor.

  In order to further improve the energy density of the LIC, those disclosed in Patent Document 1 and Patent Document 2 have been proposed as power storage devices incorporating the structure of the LIC and the lithium secondary battery. The power storage device disclosed in Patent Document 1 has a common negative electrode provided with a negative electrode layer on one side of a current collector foil having a through-hole, and a surface facing the side provided with the negative electrode layer is a lithium ion capacitor In this structure, a lithium secondary battery positive electrode is arranged on the other surface. By charging and discharging by connecting both positive electrodes of this device, an ideal power storage device that combines the output density of the LIC and the energy density of the lithium secondary battery is realized.

JP 2009-141181 (page 14, FIG. 1 and page 15, FIG. 12) Japanese Patent Laid-Open No. 11-9708

However, when the power storage device shown in Patent Document 1 was created and tested, if the rapid charge / discharge cycle is repeated, a short circuit may occur or the capacity may be greatly reduced in the initial stage, which is disclosed in Patent Document 1. It has been found that there is a problem that a practical power storage device cannot be obtained only by the developed technology.
This invention was made in order to solve the above-mentioned subject, and it aims at obtaining the electric power storage device which does not short-circuit even if it repeats a quick charge / discharge cycle, and a capacity | capacitance does not fall large initially. To do.

  The power storage device according to the present invention includes a capacitor positive electrode having a lithium ion capacitor positive electrode layer formed on one surface of the capacitor positive electrode current collector foil, and a lithium battery positive electrode layer formed on one surface of the battery positive electrode current collector foil. The lithium ion capacitor negative electrode layer is formed on one surface of the battery positive electrode and the negative electrode current collector foil, and the lithium battery negative electrode layer is formed on the other surface of the negative electrode current collector foil. A common negative electrode in which a layer is disposed opposite to the lithium ion capacitor positive electrode layer, and a lithium battery negative electrode layer is disposed opposite to the lithium battery positive electrode layer; a lithium ion capacitor positive electrode layer; and a lithium ion capacitor negative electrode layer A first separator provided between the lithium battery positive electrode layer and the lithium battery negative electrode layer. The common negative electrode has a plurality of negative electrode holes penetrating the negative electrode current collector foil from one side, and the discharge capacity of the lithium ion capacitor negative electrode layer is the discharge of the lithium ion capacitor positive electrode layer. It is larger than the capacity, and the discharge capacity of the lithium battery negative electrode layer is larger than the discharge capacity of the lithium battery positive electrode layer.

  According to the present invention, the electrochemical capacities of the lithium ion capacitor negative electrode layer and the lithium battery negative electrode layer are larger than the discharge capacities of the positive electrode layers facing each other, so there is no short circuit or rapid capacity drop due to the rapid charge / discharge cycle. Good cycle characteristics can be obtained.

It is sectional drawing which shows schematic structure of the cell of the power storage device by Embodiment 1 of this invention. It is a schematic diagram of the method of forming the negative electrode hole of the electric power storage device by Embodiment 1 of this invention. It is a schematic diagram of the method of forming the negative electrode hole of the electric power storage device by Embodiment 4 of this invention. It is sectional drawing which shows schematic structure of the electric power storage device by Embodiment 5 of this invention. It is sectional drawing which shows schematic structure of the electric power storage device by Embodiment 6 of this invention. It is sectional drawing which shows schematic structure of the electric power storage device by Embodiment 7 of this invention.

Embodiment 1 FIG.
The present inventors investigated and investigated the cause of the problem of the power storage device disclosed in Patent Document 1. In the case of the structure shown in FIG. 1 of Patent Document 1, metal lithium is deposited around the through hole. In the case of the structure shown in FIG. 12, the surface of the negative electrode layer facing the second separator (battery side separator) of the common negative electrode is formed. The presence of metallic lithium was confirmed. From this, because the electrochemical capacity of the negative electrode layer facing the second separator is insufficient, excess lithium ions that could not be inserted during charging were deposited on the copper foil or the negative electrode surface, breaking through the separator It has been found that this causes a short circuit, and the deterioration of the negative electrode layer is promoted to reduce the capacity. Accordingly, the present inventors prevent the formation of lithium metal around the through-holes and on the surface of the negative electrode layer facing the second separator, and realize a power storage device excellent in stability during rapid charge / discharge. I examined that.

  1 is a cross-sectional view showing a schematic configuration of a cell of a power storage device according to Embodiment 1 of the present invention. Although the figure shows a single unit, the structure of FIG. 1 may be laminated or a long electrode may be wound so as to reach the required capacity as a whole cell. In FIG. 1, reference numeral 1 denotes a lithium ion capacitor (LIC) positive electrode, and a lithium ion capacitor positive electrode layer 3 is formed on one surface of a positive electrode current collector foil (also referred to as a capacitor positive electrode current collector foil) 2 which is a smooth aluminum foil. It becomes the composition. Reference numeral 5 denotes a lithium battery positive electrode having a structure in which a lithium battery positive electrode layer 4 is formed on one surface of a positive electrode current collector foil (also referred to as battery current collector foil) 2. Reference numeral 6 denotes a common negative electrode having a structure in which a lithium ion capacitor negative electrode layer 8 and a lithium battery negative electrode layer 9 are formed on both surfaces of a negative electrode current collector foil 7 made of copper foil.

  The lithium ion capacitor positive electrode layer 3 and the lithium ion capacitor negative electrode layer 8 are opposed to each other via the first separator 11 to form a lithium ion capacitor portion 30, and the lithium battery positive electrode layer 4 and the lithium battery negative electrode layer 9 are The lithium battery unit 40 is configured to face each other with the second separator 12 interposed therebetween.

  The material of the lithium ion capacitor positive electrode layer 3 is a carbon material having a large surface area and a large capacitance. Examples of the carbon material include particulate activated carbon having a diameter of about 10 μm, and water vapor activated activated carbon, alkaline activated carbon, nanogate carbon, and the like can be used. The electrode layer is formed by binding all over one side of the binder by a rolling method, a coating method, a molding method, or the like. Therefore, the outer shape of the electrode layer is the same as that of the current collector foil except for the current terminal portion. For the binder, a fluororesin such as PTFE (polytetrafluoroethylene), SBR (styrene butadiene rubber), acrylic synthetic rubber, PVDF (polyvinylidene fluoride), or the like is used.

  The typical thickness of the electrode layer is 50 μm to 150 μm, but the optimum thickness differs depending on the type of carbon used, and the positive electrode layer is 100 μm here.

  As a material of the lithium battery positive electrode layer 4, a lithium metal compound generally used as a positive electrode layer of a lithium secondary battery such as lithium iron phosphate, lithium cobaltate, lithium manganate, or a composite thereof is desirable. However, it is not limited to these. In particular, when lithium iron phosphate having an olivine type crystal structure is used, the operating voltage range when a carbon material is used for the negative electrode is within the operating voltage range of the lithium ion capacitor, and the capacity of the lithium battery part is efficiently increased. Can be used.

  A typical thickness of the current collector foil 2 and the current collector foil 7 is 8 to 50 μm, and is selected according to a charge / discharge current when charging / discharging the power storage device. When the charge / discharge current is large, a thick current collector foil is used to reduce the internal resistance, and when the charge / discharge current is small, the thin one is used as much as possible from the viewpoint of improving the energy density.

  As a material for the negative electrode layer, a material capable of desorption / insertion of lithium by an electrochemical reaction is used. In this embodiment, graphite or hard carbon is used, but it is not limited thereto. For example, a negative electrode material used as a negative electrode of a lithium battery such as soft carbon, tin, or a silicon-based alloy can be used. In this case, it is desirable that the capacitance of the lithium ion capacitor negative electrode layer be sufficiently larger than the capacitance of the lithium ion capacitor positive electrode. This is because if the capacity of the negative electrode layer of the lithium ion capacitor is small, the potential change of the negative electrode during charging / discharging is large, and the cycle characteristics deteriorate.

In the present invention, the discharge capacity of the lithium ion capacitor negative electrode layer 8 is made larger than the discharge capacity of the lithium ion capacitor positive electrode layer 3, and the discharge capacity of the lithium battery negative electrode layer 9 is made larger than the discharge capacity of the lithium battery positive electrode layer 4. It is getting bigger. According to the analysis of the present inventors, if the electrochemical capacity of the negative electrode layer facing the second separator, that is, the negative electrode layer on the lithium battery side is insufficient, excess lithium ions that could not be inserted during charging are collected. Causes of partial deposition on the surface of the foil or the negative electrode, reaction distribution occurring inside the negative electrode surface or inside the negative electrode layer, acceleration of the deterioration of the negative electrode layer, lowering the capacity, or breaking through the separator and causing an internal short circuit Turned out to be. Therefore, as described above, in particular, by making the discharge capacity of the lithium battery negative electrode layer 9 larger than the discharge capacity of the lithium battery positive electrode layer 4, the lithium ion does not become excessive at the time of charging, and the negative electrode layer is sufficiently charged. It is inserted and lithium is no longer deposited on the surface of the current collector foil or the negative electrode, and internal short circuit and capacity reduction caused by lithium deposition are suppressed. Further, as for the lithium ion capacitor negative electrode layer, if the capacity of the lithium ion capacitor negative electrode layer is insufficient as in the case of the lithium battery part, an internal short circuit and a decrease in capacity are caused for the same reason as the lithium battery negative electrode layer. Also, since the lithium ion capacitor negative electrode layer performs input / output at a particularly high rate, it needs to have a capacity sufficiently larger than the discharge capacity of the lithium ion capacitor positive electrode layer.

The electrode after coating has a high porosity and a density that is too low, and in order to adjust this high porosity to an appropriate porosity, a smooth roll (calendar roll) press is performed at a predetermined temperature to pressurize the electrode layer. In the negative electrode, a large number of negative electrode holes 10 are formed as paths through which ions diffuse into the negative electrode current collector foil and the negative electrode layer in order to transmit lithium ions. FIG. 2 shows an example of a method for forming the negative electrode hole 10. In FIG. 2, the negative electrode hole is formed on one surface of a current collector foil material 70 that serves as a current collector foil between a protrusion mold 14 having a large number of needle-like protrusions and a smooth metal plate 15 having a smooth surface. A common negative electrode raw material 60 coated with a capacitor negative electrode layer material 80 serving as a capacitor negative electrode layer and a battery negative electrode material 90 serving as a battery negative electrode layer on the other surface is placed and pressed. Holes may be formed in the negative electrode layer after pressing, but the negative electrode layer material 60 before pressing is pressed at a predetermined temperature and pressure to simultaneously perform hole formation and porosity adjustment of the negative electrode layer. Is also possible. Further, after the perforating process is performed on the negative electrode layer material before pressing, the porosity may be adjusted by pressing at a predetermined temperature and pressure.
According to the method of FIG. 2, no shear force is applied to the common negative electrode original fabric, and damage to the common negative electrode in which the negative electrode hole is formed can be suppressed.

  The shape of the hole largely depends on the shape of the protrusion of the protrusion mold, but the size and opening ratio of the hole are the pressing force and the number of times of pressing, the material and thickness of the spacer 16 between the smooth metal plate 15 and the negative electrode material 60. Depends on the size. This pressing can be performed by a flat plate press, but if it is performed by a roll-type press, an electrode raw material having a larger area can be pressed efficiently. In any pressing method, the negative electrode surface and the negative electrode are controlled by adjusting the pressing pressure, temperature, the shape of the protrusions formed on the mold, the gap between the rolls, the number of presses, and the spacer 16 between the mold and the negative electrode layer material. It is possible to freely adjust the aperture ratio of the current collector foil.

  The separator separates the negative electrode from the positive electrode and allows lithium ions to pass through while ensuring insulation between the two electrodes. The first separator 11 and the second separator 12 are made of, for example, a microporous film made of polyethylene or polypropylene. Also suitable are cellulosic paper separators and non-woven fabrics made of polyester.

In the present embodiment, the electrolytic solution is not particularly limited. For example, LiPF ₆ , LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ and other electrolytes dissolved in an organic solvent. Examples of organic solvents include ether solvents such as dimethoxyethane and diethyl ether, and ester solvents such as ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (MEC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). Solvent, γ-butyrolactone (GBL), tetrahydrofuran (THF), tetrahydropyran (THP), 1,3-dioxane (DOX), ethyl dimethyl phosphate (EDMP), trimethyl phosphate (TMP), propyl dimethyl phosphate (PDMP) ) And the like, and these can be used alone or in combination of two or more. Furthermore, the electrolyte solution may contain other additives. Examples of combinations of electrolytes include LiPF ₆ / EC + DEC, LiBF ₄ / EC + DEC, LiN (CF ₃ SO ₂ ) ₂ / EC + DEC, LiN (C ₂ F5SO ₂ ) ₂ / EC + DEC, LiPF ₆ / EC + PC, LiPF ₆ / EC + GBL, LiBF _{4 / EC + PC, LiBF 4} / EC + GBL, LiBF 4 / EDMP, LiBF 4 / EC + EDMP, LiN (CF 3 SO 2) 2 / EC + GBL, LiN (C 2 F 5 SO 2) 2 / EC + GBL, LiN (CF 3 SO 2) ₂ / EC + EDMP, LiN (C ₂ F ₅ SO ₂ ) ₂ / EC + EDMP, and the like are exemplified, but not limited thereto. Further, in order to have ionic conductivity even at a high temperature of 100 ° C. or higher, the organic solvent desirably contains a high boiling point solvent such as EC, PC, GBL.

  Usually, such a power storage device is housed in a container. In the present embodiment, the container is not particularly limited, but may be a cylindrical or square container made of a metal such as stainless steel or aluminum, or a bag-like or box-shaped container made of a laminate film made of a metal and a resin. . The container made of this laminate film can be sealed by heat fusion (heat sealing), and any container that can prevent leakage of the electrolytic solution from the inside of the device and moisture from the outside of the device may be used. Although a resin film having heat-fusibility can be used for the seal portion, it is preferable to deposit a metal, coat with metal plating, or laminate a metal foil such as aluminum. When a metal is used as a container, it can be used alone as long as it has a sufficient thickness. Generally, however, a resin is laminated on a metal foil having a thickness of several microns to several tens of microns in order to reduce the weight. Used. And it is preferable to laminate | stack the polyethylene terephthalate and stretched nylon film for an intensity | strength improvement on the outer surface, and the polyethylene or polypropylene film for providing heat-fusibility.

  Various methods can be used for forming the bag-like container. For example, a film cut into a square shape is folded in half and heat-sealed in three directions, or both openings of the film formed in a cylindrical shape are heat-sealed. The method etc. can be mentioned. The container material may be used as it is cut, but it can also be used after pressing a recess corresponding to the electrode body. Excess container material may be cut or bent after heat sealing.

  The power storage device according to the present embodiment may have a structure in which a positive electrode is opposed to a negative electrode, and a separator impregnated with an electrolyte solution is present between the positive and negative electrodes. A laminated structure in which sheets are stacked, a wound structure in which strip-shaped electrodes are wound, a folded structure in which strip-shaped electrodes are folded while being folded, or a composite structure in which these are combined may be used. By reducing the area of the positive electrode facing the negative electrode slightly (about 1% to about 10%), the ion conductivity between the positive and negative electrodes can be improved.

  The current collector terminal connected to the current collector foil portion is not particularly limited as long as it is a conductive material that is stably present in the device, but the positive electrode is made of aluminum, the negative electrode is made of metal such as nickel or copper, or nickel plated. What formed by plating metal like copper and joined to current collection foil may be used. Moreover, it is good also considering the part near the edge part of current collection foil, and the electrode layer being not apply | coated as a current collection terminal.

  The example of the power storage device in this embodiment will be described with specific numerical values, and the results of the power storage device cell obtained will be compared with a plurality of comparative examples.

Example 1.
<Preparation of common negative electrode>
An electrode paste comprising graphite as a material for the negative electrode layer, polyvinylidene fluoride as a binder, and n-methylpyrrolidone as a solvent was prepared by mixing. Next, this paste was applied to both sides of a copper foil having a width of 300 mm and a thickness of 20 μm as a negative electrode current collector foil. This common negative electrode raw material was pressurized at 105 ° C. with a calender roll press to adjust the porosity of the electrode. The basis weight of the negative electrode layer was 10 mg / cm ² per side. In addition, the discharge capacity per unit weight of this negative electrode layer was 320 mAh / g. Accordingly, the discharge capacity per unit area is 3.2 mAh / cm ² per side.

The discharge capacity of the negative electrode layer was measured as follows. The negative electrode produced above is punched into φ12 mm to obtain a working electrode. Separately, a 0.15 mm thick lithium foil was punched out to φ14 mm as a counter electrode, a 40 μm thick cellulosic paper separator was sandwiched between them, and this electrode group was placed in a 2032 type coin cell. A coin-type cell was produced by injecting a mixed solvent of ethylene carbonate-diethyl carbonate containing LiPF ₆ . This cell was repeatedly charged and discharged at a current density of 100 mA / g and a voltage range of 0 V to 2 V at a constant temperature of 25 ° C., and the discharge capacity at the fifth time was taken as a measured value of the discharge capacity.

<Negative electrode drilling>
Next, a common negative electrode is placed between a metal mold with square pyramid projections with a base of 0.6 mm and a height of 0.7 mm spaced at intervals of 0.8 mm, and a metal plate with a smooth surface. The operation of placing the plate and pressing at a pressure of 0.3 MPa was repeated twice. A common negative electrode having negative electrode holes was prepared by shifting the position of the common negative electrode in the first time and the second time so that the positions of the holes were uniform without overlapping. The shape of the hole was the same quadrangular pyramid shape as the protrusion of the metal mold, and the side cross section was the shape shown as the negative electrode hole 10 in FIG. Observation of the negative electrode surface (perforated surface) after perforation revealed that square holes having a side of about 110 μm were formed at regular intervals. Moreover, no hole was observed on the back surface of the negative electrode (surface opposite to the perforated surface). When a part of the common negative electrode after perforation was cut out, immersed in an N-methylpyrrolidone solvent, and the electrode layer was peeled and removed, the aperture ratio of the negative electrode current collector foil was 1.3%.

<Negative electrode processing>
This common negative electrode was cut into a rectangle with a side of 30 mm × 43 mm, and the electrode layer having an end portion of 7 mm in the longitudinal direction was peeled off to form a current collecting tab. A part of the electrode layer on the short side was removed to form a current collecting tab. Thereafter, Ni-plated copper foil was connected to the negative electrode current collecting tab by ultrasonic welding to obtain a negative electrode current collecting terminal. Therefore, the discharge capacity of this negative electrode is calculated to be 34.6 mAh.

<Preparation of positive electrode for lithium ion capacitor>
An electrode paste made of activated carbon as a material for the positive electrode layer, an acrylic polymer as a binder, and water as a solvent was mixed and prepared. Next, this paste was applied to one side of an aluminum foil having a width of 300 mm and a thickness of 20 μm, and dried. This positive electrode original fabric was pressurized with a calender roll press to adjust the porosity of the electrode. The basis weight of the lithium ion capacitor positive electrode layer was 8.0 mg / cm ² . In addition, the discharge capacity per unit weight of this lithium ion capacitor positive electrode layer was 45 mAh / g. Accordingly, the discharge capacity per unit area is 0.36 mAh / cm ² . This lithium ion capacitor positive electrode was cut into a 29 mm × 42 mm rectangle, and the electrode layer of the end portion 7 mm in the longitudinal direction was peeled off to form a current collecting tab. Therefore, the discharge capacity of this lithium ion capacitor positive electrode is calculated to be 3.7 mAh.

The discharge capacity of the lithium ion capacitor positive electrode layer was measured as follows. The lithium ion capacitor positive electrode produced above is punched out to φ12 mm to obtain a working electrode. A 0.15 mm thick lithium foil is punched out to 14 mm to make a counter electrode, a 40 μm thick cellulose paper separator is sandwiched between them, and this electrode group is placed in a 2032 type coin cell, and 1.2 mol / l LiPF _{6 is} used as an electrolyte. A coin-type cell was prepared by injecting a mixed solvent of ethylene carbonate-diethyl carbonate containing With respect to this cell, charging and discharging were repeated at a current density of 100 mA / g and a voltage range of 0 V to 4.2 V at a constant temperature of 25 ° C., and the discharge capacity at the fifth time was taken as a measured value.

<Preparation of lithium battery positive electrode>
An electrode paste in which lithium iron phosphate as a material of a lithium battery positive electrode layer, acetylene black as a conductive material, and polyvinylidene fluoride as a binder are dispersed in an NMP solvent is formed on one surface of an aluminum foil having a thickness of 20 μm. And dried. This positive electrode was pressed with a calender roll press to adjust the porosity of the electrode. The basis weight of the lithium battery positive electrode layer was 12 mg / cm ² . In addition, the discharge capacity per unit weight of this lithium battery positive electrode layer was 150 mAh / g. Accordingly, the discharge capacity per unit area is 1.8 mAh / cm ² .

The discharge capacity of the lithium battery positive electrode layer was measured as follows. The lithium battery positive electrode produced above is punched out to φ12 mm to obtain a working electrode. A 0.15 mm thick lithium foil is punched out to 14 mm to make a counter electrode, a 40 μm thick cellulose paper separator is sandwiched between them, and this electrode group is placed in a 2032 type coin cell, and 1.2 mol / l LiPF _{6 is} used as an electrolyte. A coin-type cell was prepared by injecting a mixed solvent of ethylene carbonate-diethyl carbonate containing This cell was repeatedly charged and discharged at a current density of 100 mA / g and a voltage range of 2.7 V to 4.0 V at a constant temperature of 25 ° C., and the discharge capacity at the fifth time was taken as a measured value.

  This lithium battery positive electrode was cut into a rectangle of 29 mm × 42 mm, and the electrode layer of the end portion 7 mm in the longitudinal direction was peeled off to form a current collecting tab. Therefore, the discharge capacity of this lithium battery positive electrode layer is calculated to be 18.3 mAh.

<Production of cell>
The lithium ion capacitor positive electrode, the common negative electrode, and the lithium battery positive electrode are stacked in order so that the respective electrode layers face each other, and the thicknesses are respectively between the lithium ion capacitor positive electrode and the common negative electrode, and the lithium battery positive electrode and the common negative electrode. A 40 μm cellulosic paper separator was sandwiched (first separator and second separator). At this time, as shown in FIG. 1, the perforated surface of the common negative electrode was opposed to the lithium battery positive electrode. A lithium ion capacitor positive electrode current collector tab and a lithium battery positive electrode current collector tab were stacked, and an aluminum foil was connected thereto by ultrasonic welding to form a positive electrode current collector terminal.

This electrode laminate was housed in an aluminum laminate film exterior, and an ethylene carbonate-diethyl carbonate mixed solvent containing 1.2 mol / l LiPF ₆ was injected as an electrolyte, and finally the aluminum laminate exterior was sealed. . Then, the positive electrode terminal was connected to the + terminal of the charge / discharge device, the negative electrode terminal was connected to the-terminal, CC-CV charging up to 4 V was performed at 2 mA, and the negative electrode was doped with lithium ions to obtain a test cell.

Embodiment 2. FIG.
As described above, graphite, hard carbon, soft carbon, tin, a silicon alloy, or the like can be used as the material for the negative electrode layer. In the first embodiment, the same material is used for the lithium ion capacitor negative electrode layer 8 and the lithium battery negative electrode layer 9, but if different materials are used for the lithium ion capacitor negative electrode layer 8 and the lithium battery negative electrode layer 9, The negative electrode can be optimized according to the application. In particular, since it is possible to reduce the deterioration of the negative electrode layer of the lithium ion capacitor in which input / output (charge / discharge) is performed at a high rate, it is possible to configure a power storage device with good cycle characteristics and high reliability. For example, it is possible to use hard carbon that can provide a long life even when high-rate input / output is performed as the material of the lithium ion capacitor negative electrode layer 8, and graphite that has a large discharge capacity as the material of the lithium battery negative electrode layer 9. It is done. Examples using different materials for the lithium ion capacitor negative electrode layer 8 and the lithium battery negative electrode layer 9 are shown below.

Example 2
<Preparation of common negative electrode>
An electrode paste comprising graphite as a material for the negative electrode layer, polyvinylidene fluoride as a binder, and n-methylpyrrolidone as a solvent was prepared by mixing. Next, this paste was applied as a negative electrode current collector foil to one side of a copper foil having a width of 300 mm and a thickness of 20 μm. Further, an electrode paste comprising hard carbon as a material for the negative electrode layer, polyvinylidene fluoride as a binder, and n-methylpyrrolidone as a solvent was mixed and prepared. This paste was applied to the back surface of the negative electrode layer using graphite as an electrode layer material. This electrode fabric was pressed at 105 ° C. with a calender roll press to adjust the porosity of the electrode. The basis weight of the negative electrode layer using graphite was 10 mg / cm ^2, and the basis weight of the negative electrode layer using hard carbon was 11 mg / cm ² . In addition, the capacity | capacitance per unit weight at the time of using hard carbon as a negative electrode layer was 300 mAh / g. Therefore, the discharge capacity per unit area is 3.3 mAh / cm ² . The negative electrode was perforated from the negative electrode layer side using graphite.

<Production of cell>
A lithium ion capacitor positive electrode, a common negative electrode, and a lithium battery positive electrode were laminated in order so that the electrode layers face each other, and a cellulosic paper separator having a thickness of 40 μm was sandwiched between the electrode layers (first separator and Second separator). At this time, the negative electrode layer using the hard carbon of the common negative electrode was opposed to the lithium ion capacitor positive electrode. A lithium ion capacitor positive electrode current collector tab and a lithium battery positive electrode current collector tab were stacked, and an aluminum foil was connected thereto by ultrasonic welding to form a positive electrode current collector terminal. Other manufacturing methods were the same as those in Example 1.
As described above, in the power storage device of Example 2, as described in the first embodiment, the discharge capacity of the lithium ion capacitor negative electrode layer is larger than the discharge capacity of the lithium battery positive electrode layer, and the lithium battery negative electrode The discharge capacity of the layer is a power storage device that is greater than the discharge capacity of the positive electrode layer of the lithium ion capacitor.

Embodiment 3 FIG.
As described above, graphite, hard carbon, soft carbon, tin, a silicon alloy, or the like can be used as the material for the negative electrode layer. Moreover, what mixed several materials among these materials can also be used. The third embodiment is an embodiment in which such a mixed material is used for the negative electrode layer. In the cell of the power storage device having the configuration of FIG. 1, if materials having different mixing ratios of the lithium ion capacitor negative electrode layer 8 and the lithium battery negative electrode layer 9 are used, the negative electrode can be optimized according to the application. In particular, since it is possible to reduce the deterioration of the lithium ion capacitor negative electrode layer where input / output (charge / discharge) is performed at a high rate, it is possible to configure a power storage device with good cycle characteristics and high reliability. For example, graphite and hard carbon are used as materials to be mixed. As a material of the lithium ion capacitor negative electrode layer 8, a mixed material having a high ratio of hard carbon that can obtain a long life even when high rate input / output is performed, and a graphite having a large discharge capacity as a material of the lithium battery negative electrode layer 9 is used. It is conceivable to use a mixed material having a high ratio. Below, the Example using the material from which a mixing ratio differs by the lithium ion capacitor negative electrode layer 8 and the lithium battery negative electrode layer 9 is shown.

Example 3
<Preparation of common negative electrode>
Graphite and hard carbon as a material for the negative electrode layer were mixed at a ratio of 4: 6, and an electrode paste composed of polyvinylidene fluoride as a binder and n-methylpyrrolidone as a solvent was mixed and prepared. This paste was applied as a negative electrode current collector foil to one side of a copper foil having a width of 300 mm and a thickness of 20 μm to form a single-sided electrode. The basis weight of the negative electrode layer was 10 mg / cm ² . The capacity per unit weight of this negative electrode layer was 310 mAh / g. Therefore, the discharge capacity per unit area of this negative electrode layer is 3.1 mAh / cm ² . Next, graphite and hard carbon are mixed at a ratio of 2: 8 as a material for the negative electrode layer, and an electrode paste composed of polyvinylidene fluoride as a binder and n-methylpyrrolidone as a solvent is mixed and prepared. The coating was formed. The basis weight of the negative electrode layer on the back surface was 10 mg / cm ² . The capacity per unit weight of this negative electrode layer was 300 mAh / g. Therefore, the discharge capacity per unit area of the negative electrode layer is 3.0 mAh / cm ² . This electrode fabric was pressed at 105 ° C. with a calender roll press to adjust the porosity of the electrode. The basis weight of any negative electrode layer was also set to 10 mg / cm ² . The negative electrode was perforated from the electrode layer side in which the ratio of the negative electrode layer was larger in graphite. Other manufacturing methods were the same as those in Example 1.

<Production of cell>
The lithium ion capacitor positive electrode, the common negative electrode, and the lithium battery positive electrode were laminated in order so that the respective electrode layers face each other, and a cellulosic paper separator having a thickness of 40 μm was sandwiched between the electrode layers (the first separator and the first separator). Two separators). At this time, the negative electrode layer having a higher ratio of hard carbon and graphite: hard carbon of 2: 8 was opposed to the lithium ion capacitor positive electrode. A lithium ion capacitor positive electrode current collector tab and a lithium battery positive electrode current collector tab were stacked, and an aluminum foil was connected thereto by ultrasonic welding to form a positive electrode current collector terminal. Other manufacturing methods were the same as those in Example 1.

  As described above, in the power storage device of Example 3, as described in the first embodiment, the discharge capacity of the lithium ion capacitor negative electrode layer is larger than the discharge capacity of the lithium ion capacitor positive electrode layer, and the lithium battery negative electrode The discharge capacity of the electrode layer is a power storage device larger than the discharge capacity of the positive electrode layer of the lithium battery.

Embodiment 4 FIG.
The fourth embodiment relates to a perforation process in the method for manufacturing a common negative electrode. FIG. 3 shows a perforation processing method according to Embodiment 4 of the present invention. As shown in FIG. 3, a long common negative electrode raw material 60 is passed between a perforating roll 17 having needle-like protrusions 23 having a shape such as a large number of cones and quadrangular pyramids and a smooth roll 18 having a smooth surface. Thus, a common negative electrode 6 having a large number of negative electrode holes 10 can be formed by perforation. According to such a perforation process with a roll, a large number of negative electrode holes can be efficiently formed for a long common negative electrode, and a large number of negative electrodes can be easily manufactured. The example of the negative electrode produced with the roll shown in FIG.

Example 4
The prepared common negative electrode raw material 60 is passed between a perforation roll 17 in which conical projections having a bottom diameter of 0.7 mm and a height of 0.6 mm are formed at intervals of 0.8 mm and a smooth roll 18 having a smooth surface, Perforation was performed. When the surface of the negative electrode after drilling was observed, many circular holes having a diameter of about 160 μm were formed. Moreover, no hole was observed on the back surface of the negative electrode. When a part of the negative electrode after perforation was cut out and immersed in an N-methylpyrrolidone solvent and the electrode layer was peeled and removed, the aperture ratio of the negative electrode current collector foil was 1.2%. Other manufacturing methods were the same as those in Example 1.

Embodiment 5 FIG.
FIG. 4 is a cross-sectional view showing a schematic configuration of the structure of the power storage device according to the fifth embodiment of the present invention. As shown in FIG. 4, for example, a large-capacity device can be configured by stacking a plurality of power storage devices shown in FIG. A method for manufacturing the power storage device of FIG. 4 will be described below.

Example 5 FIG.
<Preparation of Negative Electrode><Pole Drilling Process><Processing of Negative Electrode> was prepared in the same manner as in Example 1.
<Preparation of Common Positive Electrode> In the case of a laminated structure, positive electrodes other than both ends are provided with a positive electrode layer 3 of a lithium ion capacitor on one surface of the current collector foil 2 and a positive electrode layer of a lithium battery on the other surface. The method for producing the common positive electrode 13 is as follows. An electrode paste made of activated carbon as a material of a positive electrode layer of a lithium ion capacitor, an acrylic polymer as a binder, and water as a solvent was mixed and prepared. Next, this paste was applied to one side of an aluminum foil having a width of 300 mm and a thickness of 20 μm. An electrode paste in which lithium iron phosphate, acetylene black, and PVDF, which are materials for a positive electrode layer of a lithium battery, are dispersed in NMP is applied and formed on the back surface of the electrode, dried at 100 ° C., and then roll pressed. The porosity was adjusted. It cut out into the rectangle of 29 mm x 42 mm, the electrode layer of the edge part 7mm of a elongate direction was peeled, and it was set as the current collection tab.
Further, the lithium ion capacitor positive electrode 1 serving as one end of the laminate and the lithium battery positive electrode 5 serving as the other end were manufactured in the same manner as in Example 1.

<Production of cell>
Nine sheets of the common negative electrode 6 and the common positive electrode 13 are alternately stacked on the lithium battery positive electrode 5 in this order, and then the common negative electrode 6 and the lithium ion capacitor positive electrode 1 are further disposed thereon so that the electrode layers thereof face each other. Laminated with the centers aligned, cellulosic paper separators 11 and 12 each having a thickness of 40 μm were sandwiched between positive and negative electrode layers. A lithium ion capacitor positive electrode current collecting tab, a lithium battery positive electrode current collecting tab, and a positive electrode current collecting tab were stacked, and an aluminum foil was connected thereto by ultrasonic welding to form a positive electrode terminal 19. Also, each negative electrode current collecting tab was overlapped, and Ni-plated copper foil was connected thereto by ultrasonic welding to form a negative electrode terminal 20.

This electrode laminate was housed in an aluminum laminate film exterior, and an ethylene carbonate-diethyl carbonate mixed solvent containing 1.2 mol / l LiPF ₆ was injected as an electrolyte, and finally the aluminum laminate exterior was sealed. . Then, the positive electrode terminal was connected to the + terminal of the charge / discharge device, the negative electrode terminal was connected to the-terminal, CC-CV charge up to 4 V was performed at 20 mA, and the negative electrode was doped with lithium ions to obtain a test cell.

Embodiment 6 FIG.
FIG. 5 is a cross-sectional view showing a schematic configuration of the power storage device according to the sixth embodiment of the present invention. As shown in FIG. 5, for example, the power storage device shown in FIG. 1 is manufactured in a large area, and a large-capacity device can be configured by winding it. A method for manufacturing the power storage device of FIG. 5 will be described below.

Example 6
<Preparation of Negative Electrode><Porosion treatment of negative electrode> was prepared in the same manner as in Example 1.
<Negative electrode processing>
The negative electrode after perforation was cut into 262 mm × 50 mm strips, the negative electrode layer having an end portion of 10 mm in the longitudinal direction was peeled only on one side, and the foil portion was exposed to form a current collecting tab. Thereafter, Ni-plated copper foil was connected to the negative electrode current collecting tab by ultrasonic welding to form a negative electrode terminal 22.

<Preparation of Common Positive Electrode> Also in the case of a wound structure, positive electrodes other than both ends are provided with a positive electrode layer 3 of a lithium ion capacitor on one surface of the current collector foil 2 and a positive electrode layer of a lithium battery on the other surface. The common positive electrode 13 was prepared by mixing and preparing an electrode paste made of activated carbon as a material for the positive electrode layer of a lithium ion capacitor, an acrylic polymer as a binder, and water as a solvent, as in Example 5. Next, this paste is 300 mm wide and 20 μm thick.
The coating was formed on one side of an aluminum foil of m. An electrode paste in which lithium iron phosphate, acetylene black, and PVDF, which are materials for the positive electrode layer of the lithium battery, are dispersed in NMP is applied and formed on the back surface of the electrode, dried at 100 ° C., and then roll pressed. The porosity was adjusted. This positive electrode was cut into a strip of 248 mm × 46 mm, the positive electrode layer and the lithium ion doped layer having an end portion of 10 mm in the longitudinal direction were peeled off, and the foil portion was exposed to form a current collecting tab. Thereafter, an aluminum foil was connected to the current collecting tab by ultrasonic welding to form a positive electrode terminal 21.

<Production of cell>
After each member was sufficiently dried, the positive electrode and the negative electrode were faced each other so that the positive electrode layer and the negative electrode layer were opposed to each other, and the separator was sandwiched between them, and then rolled around and fixed with a tape. At this time, the cell was fabricated so that the perforated surface of the negative electrode was opposed to the lithium battery positive electrode. This is put in an outer bag made of an aluminum laminate sheet, and an electrolyte solution containing 1.2 mol / l LiPF ₆ and a mixed solvent of ethylene carbonate-diethyl carbonate 3: 7 is injected into the outer bag. The laminate sheath was sealed to complete the power storage device cell in this embodiment. Thereafter, in order to promote the insertion of lithium ions into the common negative electrode, the positive electrode terminal is connected to the positive terminal of the charge / discharge device, the negative electrode terminal is connected to the negative terminal, and CC-CV charging is performed up to 4.0 V at 20 mA. A test cell was prepared by doping lithium ions into the cell.

Embodiment 7 FIG.
FIG. 6 is a cross-sectional view showing a schematic configuration of the power storage device according to the seventh embodiment of the present invention. In the embodiments so far, the perforated surface of the common negative electrode is opposed to the lithium battery positive electrode, but conversely, the perforated surface of the common negative electrode may be opposed to the lithium capacitor positive electrode. The power storage device of Example 7 has a configuration in which the perforated surface of the common negative electrode is opposed to the lithium capacitor positive electrode.

Example 7
A cell was produced in the same manner as in Example 6 except that the cell was produced such that the perforated surface of the negative electrode was opposed to the positive electrode of the lithium ion capacitor when the cell of Example 6 was produced.

Comparative example.
Below, the electric power storage device of the comparative example compared with the Examples 1-7 of the electric power storage device by the above this invention is shown.

  In the power storage device of the above embodiment, the discharge capacity of the lithium ion capacitor negative electrode layer is larger than the discharge capacity of the lithium ion capacitor positive electrode layer, and the discharge capacity of the lithium battery negative electrode layer is the discharge capacity of the lithium battery positive electrode layer. It is a larger power storage device. For comparison with the power storage devices of these examples, the negative electrode layer formed only on the lithium ion capacitor side (Comparative Example 1) and the discharge capacity of the lithium battery negative electrode layer were as follows. A material having less discharge capacity than the positive electrode layer (Comparative Example 2) was produced.

The power storage device according to the present invention has a through hole in the common negative electrode current collector foil. By having this through hole, ionic conductivity is ensured between the negative electrode layer 8 on the capacitor side and the negative electrode layer 9 on the battery side. That is, the lithium doped in the lithium battery negative electrode layer from the lithium battery positive electrode layer by the initial charging operation reaches the lithium ion capacitor negative electrode layer through this through hole. As a result, lithium ions are supplied to the negative electrode of the lithium ion capacitor and can function as a capacitor. Further, even during normal charge / discharge operation, lithium ions move through the through holes. When the opening ratio of the through hole is small, the lithium ion is not sufficiently doped during the initial charging, and a predetermined capacity cannot be obtained. When the aperture ratio increases, the capacity decreases due to a decrease in the reaction area of the negative electrode layer, and the capacity decreases due to partial peeling of the electrode layer from the current collector foil due to a decrease in strength.
Therefore, the present inventors made a power storage device of a common negative electrode current collector foil having an aperture ratio different from that of the power storage device of the above-described embodiment with respect to the aperture ratio of the through hole, and compared the characteristics (Comparative Example). 3 and 4). Below, the outline | summary of the power storage device of a comparative example is shown.

Comparative Example 1
In the production of the common negative electrode of Example 1, the negative electrode layer was applied only to the surface facing the lithium ion capacitor positive electrode. The basis weight of the negative electrode layer was 10 mg / cm ² . In the drilling of the negative electrode, perforation was performed from the surface of the copper foil on which the electrode layer was not applied.

Comparative Example 2
In the preparation of the common negative electrode of Example 1, the negative electrode layer was applied and formed on both sides of the copper foil, but the basis weight of the side facing the lithium ion capacitor positive electrode was 10 mg / cm ² and opposed to the lithium battery positive electrode. The basis weight on the side was 4 mg / cm ² . Therefore, the discharge capacity per unit area of the negative electrode layer facing the lithium ion capacitor positive electrode is 3.2 mAh / cm ² , and the discharge capacity per unit area of the negative electrode layer facing the lithium battery positive electrode is 1.28 mAh / cm ^2. And less than 2.1 mAh / cm ² of the lithium battery positive electrode.
For the perforation treatment of the negative electrode, perforation was performed from the negative electrode layer side that is the side facing the positive electrode of the lithium battery having a basis weight of 4 mg / cm ² .

Comparative Example 3 (Opening ratio of through holes is less than 1%)
<Negative electrode drilling>
A negative electrode is placed between a metal mold with quadrangular pyramid projections with a bottom of 0.5 mm and a height of 0.7 mm formed at 0.8 mm intervals and a metal plate with a smooth surface, and an acrylic plate is placed on it. The operation of pressing at a pressure of 0.3 MPa was repeated twice. The drilling process was performed by shifting the position of the negative electrode in the first time and the second time so that the positions of the holes were uniform without overlapping. When the surface of the negative electrode (perforated surface) after drilling was observed, square holes with a side of about 100 μm were formed at regular intervals. Moreover, no hole was observed on the back surface of the negative electrode (surface opposite to the perforated surface). When a part of the negative electrode after perforation was cut out and immersed in an N-methylpyrrolidone solvent and the electrode layer was peeled and removed, the aperture ratio of the negative electrode current collector foil was 0.9%. Others were the same as in Example 1.

Comparative Example 4 (Opening ratio of through holes is 15% or more)
<Negative electrode drilling>
A negative electrode is placed between a metal mold in which quadrangular pyramid projections with a base of 0.5 mm and a height of 0.7 mm are formed at intervals of 0.8 mm, and a metal plate with a smooth surface, and a silicon rubber sheet and The operation of placing an acrylic plate and pressing at a pressure of 0.5 MPa was repeated 8 times. Observation of the negative electrode surface (perforated surface) after perforation revealed that many square holes each having a side of about 160 μm were formed. Moreover, no hole was observed on the back surface of the negative electrode (surface opposite to the perforated surface). When a part of the negative electrode after perforation was cut out, immersed in an N-methylpyrrolidone solvent, and the electrode layer was peeled and removed, the aperture ratio of the negative electrode current collector foil was 16%. Other manufacturing methods were the same as those in Example 1.

Summary.
For the power storage device cells of the examples and comparative examples shown in each embodiment, Table 1 shows the discharge capacity per unit weight of the positive and negative electrode layers, the basis weight when forming the electrode layers, and the discharge determined from the electrode area. Indicates capacity. In the cells of Examples 1 to 7, both the lithium ion capacitor part and the lithium battery part had a larger negative electrode discharge capacity than the positive electrode discharge capacity. Since the layer is formed only on the lithium ion capacitor portion, there is no discharge capacity of the lithium battery negative electrode, and in the cell of Comparative Example 2, the discharge capacity of the lithium battery negative electrode is less than the discharge capacity of the lithium battery positive electrode. .

比較例３および比較例４の各電極の放電容量は実施例１と同じで、負極孔の開口率が実施例１と異なる。

The discharge capacity of each electrode of Comparative Example 3 and Comparative Example 4 is the same as that of Example 1, and the aperture ratio of the negative electrode hole is different from that of Example 1.

  The above power storage device cell was subjected to a charge / discharge test in a range of a lower limit voltage of 2.0 V and an upper limit voltage of 4.0 V under a 25 ° C. environment. The charge / discharge current was 20 mA for Examples 1 to 4 and Comparative Examples 1 to 4, and 200 mA for Examples 5 to 7. Next, these cells were subjected to a cycle test in which charging / discharging was repeated at 150 mA for Examples 1 to 4 and Comparative Examples 1 to 4 and 1500 mA for Examples 5 to 7 in the range of 4V-2V.

Table 2 shows the discharge capacity at 20 mA discharge in each cell and the capacity maintenance rate after 5000 cycles in the cycle test. From Table 2, the cells of Examples 1 to 7 have good discharge capacity and cycle time because the discharge capacity of the negative electrode is larger than the discharge capacity of each positive electrode part and the lithium battery part. The capacity retention rate was obtained. However, the cell of Comparative Example 1 has no lithium battery negative electrode layer facing the lithium battery positive electrode of the common negative electrode, and the negative electrode that can contribute to charging and discharging is part of the negative electrode layer of the lithium ion capacitor part through the opening of the current collector foil. Therefore, the reaction area was extremely small and the discharge capacity was small. In addition, lithium metal is generated around the hole in a high-rate cycle test, and the lithium metal grown in a dendritic state breaks through the separator, causing an internal short circuit at 3200 cycles and functioning as a power storage device. lost. Moreover, since the capacity | capacitance of the lithium battery negative electrode layer of the battery of the comparative example 2 is smaller than the lithium battery positive electrode which opposes the cell of the comparative example 2, sufficient discharge capacity cannot be obtained, and there are few electrode layers in a negative electrode also in a cycle test Since the electrode layer was abused, the electrode layer was significantly deteriorated, and the capacity retention rate after 5000 cycles was as low as 51%.

  As described above, the discharge capacity of the negative electrode layer is increased compared to the discharge capacity of each positive electrode layer in both the lithium ion capacitor part and the lithium battery part, so that a good discharge capacity and capacity maintenance during cycling can be maintained. It can be seen that

  In Comparative Example 3, since the aperture ratio of the common negative electrode current collector foil was as low as 0.9%, the doping amount of lithium ions was small, so that the capacity of the lithium ion capacitor portion could not be obtained and the discharge capacity was small. Moreover, compared with Example 1, the effect of the lithium ion capacitor part in the cycle test was reduced, and the capacity retention rate after 2000 cycles and 5000 cycles was also low.

Further, in Comparative Example 4, since the aperture ratio of the common negative electrode current collector foil was as high as 16%, lithium ion doping was sufficient, but the negative electrode layer became brittle and partially lost due to multiple perforations. A phenomenon occurred. Further, the capacity retention rate after 2000 cycles was good, but the capacity retention rate after 5000 cycles was low. This is because there is little capacity deterioration because part of the negative electrode layer on the positive electrode side of the lithium ion capacitor is used for charging and discharging the lithium battery part during cycling, but current tends to concentrate on the negative electrode layer around the hole. Since the deterioration of the battery was promoted, the capacity retention rate suddenly decreased from around 3000 cycles.
From the above, it was found that the aperture ratio of the common negative electrode current collector foil, that is, the aperture ratio of the negative electrode hole, is preferably 1% to 15%.

1: lithium ion capacitor positive electrode 2: positive electrode current collector foil 3: lithium ion capacitor positive electrode layer 4: lithium battery positive electrode layer 5: lithium battery positive electrode 6: common negative electrode 7: negative electrode current collector foil 8: lithium ion capacitor negative electrode layer 9: Negative electrode layer of lithium battery 10: Negative electrode hole 11: First separator 12: Second separator 13: Common positive electrode 14: Projection die 15: Smooth metal plate 16: Spacer 17: Perforated roll 18: Smooth roll 19, 21: Positive terminal 20, 22: Negative terminal 23: Needle-shaped protrusion 30: Lithium ion capacitor part 40: Lithium battery part 60: Common negative electrode raw material

Claims (12)

A capacitor positive electrode having a lithium ion capacitor positive electrode layer formed on one surface of the capacitor positive electrode current collector foil;
A lithium battery positive electrode having a lithium battery positive electrode layer formed on one surface of the battery positive electrode current collector foil, and a lithium ion capacitor negative electrode layer formed on one surface of the negative electrode current collector foil, the other of the negative electrode current collector foils A lithium battery negative electrode layer is formed on the surface, the lithium ion capacitor negative electrode layer is disposed opposite to the lithium ion capacitor positive electrode layer, and the lithium battery negative electrode layer is disposed on the lithium battery positive electrode layer. A common negative electrode arranged oppositely,
A first separator provided between the lithium ion capacitor positive electrode layer and the lithium ion capacitor negative electrode layer;
A second separator provided between the lithium battery positive electrode layer and the lithium battery negative electrode layer,
The common negative electrode has a plurality of negative electrode holes penetrating the negative electrode current collector foil from one side, the discharge capacity of the lithium ion capacitor negative electrode layer is larger than the discharge capacity of the lithium ion capacitor positive electrode layer, A power storage device, wherein a discharge capacity of the battery negative electrode layer is larger than a discharge capacity of the lithium battery positive electrode layer.   2. The power storage device according to claim 1, wherein the material of the negative electrode layer of the lithium ion capacitor and the material of the negative electrode layer of the lithium battery are the same material.   2. The power storage device according to claim 1, wherein the material of the lithium ion capacitor negative electrode layer is different from the material of the lithium battery negative electrode layer.   The material of the lithium ion capacitor negative electrode layer and the material of the lithium battery negative electrode layer are a mixed material of a plurality of types of materials, and the material of the lithium ion capacitor negative electrode layer and the material of the lithium battery negative electrode layer The power storage device according to claim 1, wherein the mixing ratio of the plurality of materials is different.   The power storage device according to claim 1, wherein an opening ratio of the negative electrode holes of the negative electrode current collector foil is 1% or more and less than 15%.   The power storage device according to claim 1, wherein the material of the lithium battery positive electrode layer is olivine type lithium iron phosphate.   The power storage device according to claim 1, wherein the surface with the negative electrode hole formed therein is a surface of a lithium battery negative electrode layer.   The power storage device according to claim 1, wherein the surface with the negative electrode hole formed therein is a surface of a lithium ion capacitor negative electrode layer. A common positive electrode in which a lithium ion capacitor positive electrode layer is formed on one surface of the positive electrode current collector foil and a lithium battery positive electrode layer is formed on the other surface of the positive electrode current collector foil;
A common negative electrode in which a lithium ion capacitor negative electrode layer is formed on one surface of the negative electrode current collector foil, and a lithium battery negative electrode layer is formed on the other surface of the negative electrode current collector foil;
A first separator;
A plurality of second separators,
The first separator, the common negative electrode, the second separator, and the common positive electrode are sequentially arranged so that the second separator is sandwiched between the lithium battery negative electrode layer and the lithium battery positive electrode layer. The first separator is sandwiched between the positive electrode layer and the lithium ion capacitor negative electrode layer, and one outermost surface is the first separator, and the other outermost surface is the second separator. Laminated so that
A positive electrode having a lithium ion capacitor positive electrode layer formed on one side of the positive electrode current collector foil is disposed outside the first outermost separator, and the lithium ion capacitor positive electrode layer is disposed on the outermost first separator side. Arrange to be
A lithium battery positive electrode having a lithium battery positive electrode layer formed on one side of the positive electrode current collector foil on the outer side of the second separator on the outermost surface, and the lithium battery positive electrode layer on the second separator side on the outermost surface. In a power storage device arranged to be
The common negative electrode has a plurality of negative electrode holes penetrating the negative electrode current collector foil from one surface, and the lithium ion capacitor negative electrode layer and the lithium ion capacitor positive electrode layer facing each other, The discharge capacity of the lithium battery negative electrode layer in the lithium battery negative electrode layer and the lithium battery positive electrode layer facing each other is larger than the discharge capacity of the lithium ion capacitor positive electrode layer. A power storage device having a discharge capacity larger than that of the power storage device. In the manufacturing method of the common negative electrode of the electric power storage device of Claim 1 or Claim 9,
Power storage characterized by forming perforations that penetrate from the negative electrode layer formed on one surface of the negative electrode current collector foil to the negative electrode layer formed on the other surface through the negative electrode current collector foil A method for manufacturing a common negative electrode of a device.   A negative electrode current collector foil having a lithium ion capacitor negative electrode layer formed on one surface and a lithium battery negative electrode layer formed on the other surface is formed of a common negative electrode original plate having a plurality of needle-like protrusions and a smooth surface. The method for manufacturing a common negative electrode for a power storage device according to claim 10, wherein the negative electrode hole is formed by pressing between a common negative electrode raw material and a flat plate.   A negative electrode current collector foil having a lithium ion capacitor negative electrode layer formed on one surface and a lithium battery negative electrode layer formed on the other surface of a common negative electrode raw material having a plurality of needle-shaped protrusions and a smooth roll The method for producing a common negative electrode for a power storage device according to claim 10, wherein the negative electrode hole is formed by roll pressing between the two.

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