JP2019160543A - Secondary battery, electronic device, and manufacturing method of secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery having improved rigidity, a method for manufacturing the secondary battery, and an electronic device equipped with the secondary battery. A lithium battery (100) as a secondary battery includes a first battery cell (10) having a first positive electrode (13) and a first negative electrode (15) arranged with a first electrolyte portion (14) sandwiched between the first battery cell (10) and a second battery cell (10). The second battery cell 20 having the second positive electrode 23 and the second negative electrode 25 arranged with the electrolyte part 24 interposed therebetween, and the first negative electrode 15 and the second negative electrode 25 are electrically connected to each other. The second battery cell 20 is arranged so as to overlap the first battery cell 10 so as to be connected to the first battery cell 10, and the first electrolyte part 14 protruding to the side of the first positive electrode 13 and the second positive electrode The second electrolyte portion 24 protruding to the side of 23 is connected to form a connecting portion 101. [Selection diagram] Figure 2

Description

  The present invention relates to a secondary battery, an electronic device including the secondary battery, and a method for manufacturing the secondary battery.

  As a secondary battery, a lithium battery (including a primary battery and a secondary battery) is used as a power source for many electronic devices including a portable information device. In recent years, lithium batteries using a solid electrolyte capable of achieving both high energy density and safety have attracted attention.

  In the lithium battery, there is a possibility that a short circuit between the negative electrode and the positive electrode occurs inside the battery due to dendrites generated by the growth of lithium deposited on the negative electrode side during charging. Such lithium dendrites have a correlation with the current density during charging, and are said to appear prominently at the periphery of the negative electrode.

  For example, in Patent Document 1, an electrolyte layer includes a positive electrode active material layer formed on at least one surface of a first current collector and a negative electrode active material layer formed on at least the other surface of a second current collector. A non-aqueous electrolyte secondary battery including a power generation element in which a plurality of unit cell layers laminated with a battery sandwiched therebetween is disclosed. In the non-aqueous electrolyte secondary battery, at least one of the positive electrode active material layer and the negative electrode active material layer has an electrode reaction portion effective for an electrochemical reaction and a resin infiltration portion formed by impregnating a non-ion permeable resin. The resin permeation portion is disposed on the outer periphery of the electrode reaction portion in the surface direction of the positive electrode active material layer or the negative electrode active material layer, and the outer peripheral edge of the electrode reaction portion in the positive electrode active material layer is the electrode in the negative electrode active material layer It is assumed that it is coincident with or located in the inner peripheral edge of the reaction part.

  According to the nonaqueous electrolyte secondary battery of Patent Document 1, since the resin infiltration portion is disposed on the outer peripheral side of the electrode reaction portion, lithium dendrite is generated at the end portion of the electrode reaction portion that functions as the positive electrode. It can be easily adjusted to a difficult state.

JP 2010-92696 A

  In the non-aqueous electrolyte secondary battery of Patent Document 1, a structure in which a power generation element formed by laminating a plurality of single battery layers is further enclosed with a laminate film and sealed is proposed. However, if the pressure applied to the negative electrode is small or non-uniform when sealed with the laminate film, the current density varies during charging on the negative electrode side, and lithium may be deposited non-uniformly. The uneven deposition of lithium affects the charge / discharge characteristics. In addition, lithium dendrite grows locally and tends to cause a short circuit between the positive electrode and the negative electrode.

  In order to avoid such a problem, it is necessary to seal the power generation element in a state where a sufficient pressure is applied from the outside. For this purpose, there has been a problem that it is necessary to increase the rigidity of the power generation element so that the unit cell layer constituting the power generation element is not damaged by the applied pressure.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  The secondary battery according to the present application includes a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte portion interposed therebetween, and a second battery disposed with a second electrolyte portion interposed therebetween. A second battery cell having a positive electrode and a second negative electrode, wherein the second battery cell is electrically connected to the second battery cell so that the first negative electrode and the second negative electrode are electrically connected to each other. The battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. To do.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode, wherein the first battery cell is electrically connected to the first battery cell so that the first positive electrode and the second positive electrode are electrically connected to each other. The second battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. It is characterized by that.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode, wherein the first battery cell is electrically connected to the first battery cell so that the first negative electrode and the second positive electrode are electrically connected to each other. The second battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. It is characterized by that.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode formed, and a third battery cell having a third positive electrode and a third negative electrode arranged with a third electrolyte portion interposed therebetween, And the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected to each other with respect to the first battery cell. The second battery cell and the third battery cell are overlapped, and a first electrolyte part protruding to the side of the first positive electrode, and a second electrolyte part protruding to the side of the second positive electrode, The third electrolyte portion protruding from the side of the third positive electrode is connected to the third positive electrode.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode formed, and a third battery cell having a third positive electrode and a third negative electrode arranged with a third electrolyte portion interposed therebetween, And the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected to each other with respect to the first battery cell. The second battery cell and the third battery cell are overlapped, and a first electrolyte part protruding to the side of the first positive electrode, and a second electrolyte part protruding to the side of the second positive electrode, Are connected.

  In the above secondary battery, it is preferable to include an outer package that encloses and seals the stacked first battery cells and second battery cells.

  The secondary battery preferably includes an outer package that encloses and seals the stacked first battery cell, second battery cell, and third battery cell.

  An electronic apparatus according to the present application includes any one of the above secondary batteries.

  The method for manufacturing a secondary battery according to the present application includes a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte portion interposed therebetween, and a second electrolyte portion interposed therebetween. And a second battery cell having a second positive electrode and a second negative electrode, wherein the first negative electrode and the second negative electrode are electrically connected to each other. In addition, the step of stacking the second battery cell on the first battery cell, the first electrolyte part protruding to the side of the first positive electrode, and the second of the second electrolyte protruding to the side of the second positive electrode And heating and melting the electrolyte part, and solidifying the part of the melted first electrolyte part and part of the second electrolyte part.

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A method of manufacturing a secondary battery comprising: a second battery cell having a second positive electrode and a second negative electrode arranged sandwiched between the first positive electrode and the second positive electrode. A step of stacking the second battery cell on the first battery cell so as to connect to the first battery cell, a first electrolyte portion protruding to the side of the first positive electrode, and a side of the second positive electrode. And the second electrolyte part is heated and melted, and solidified in a state where a part of the melted first electrolyte part and a part of the second electrolyte part are combined. And

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A method of manufacturing a secondary battery comprising a second battery cell having a second positive electrode and a second negative electrode arranged sandwiched between the first negative electrode and the second positive electrode. A step of stacking the second battery cell on the first battery cell so as to connect to the first battery cell, a first electrolyte portion protruding to the side of the first positive electrode, and a side of the second positive electrode. And the second electrolyte part is heated and melted, and solidified in a state where a part of the melted first electrolyte part and a part of the second electrolyte part are combined. And

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A third battery cell having a second battery cell having a second positive electrode and a second negative electrode disposed therebetween, and a third battery having a third positive electrode and a third negative electrode disposed with the third electrolyte portion interposed therebetween. And a first negative electrode and a second negative electrode are electrically connected to each other, and a second positive electrode and a third positive electrode are electrically connected to each other. The second battery cell and the third battery cell are stacked on the first battery cell, and the first electrolyte part, the second electrolyte part, and the third electrolyte part, The first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are heated and melted, and the melted first electrolyte part To a portion of the electrolyte part and the part of the second electrolyte portion a step is solidified in a state bound, comprising the.

  In the above secondary battery manufacturing method, the heating body is brought into contact with the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode. It is preferable to melt.

  In the above secondary battery manufacturing method, the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are irradiated with laser light. And may be melted.

  In the above secondary battery manufacturing method, the first electrolyte part, the second electrolyte part, and the third electrolyte part, the first electrolyte part protruding to the side of the first positive electrode, and the first electrolyte part, The second electrolyte part protruding to the side of the second positive electrode and the third electrolyte part protruding to the side of the third positive electrode are heated and melted, and a part of the melted first electrolyte part is It is preferable to include a step of solidifying in a state where a part of the second electrolyte part and a part of the third electrolyte part are combined.

The schematic perspective view which shows the external appearance of the lithium battery as a secondary battery of 1st Embodiment. The schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 1st Embodiment. The flowchart which shows the manufacturing method of the lithium battery of 1st Embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. 1 is a schematic cross-sectional view showing a method for manufacturing a lithium battery according to a first embodiment. The graph which shows the weight ratio change accompanying the thermal decomposition of LCBO. The schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 2nd Embodiment. The schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 3rd Embodiment. The schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 4th Embodiment. The schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 5th Embodiment. The schematic sectional drawing which shows the manufacturing method of the lithium battery of 5th Embodiment. FIG. 4 is a schematic cross-sectional view showing the structure of a lithium battery as a secondary battery of Example 3. The perspective view which shows the structure of the wearable apparatus as an electronic device of 6th Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In this embodiment, a lithium battery using a solid electrolyte containing lithium will be described as an example of a secondary battery. Further, the secondary battery of the present embodiment is configured by stacking two or more battery cells.

(First embodiment)
<Secondary battery>
A lithium battery as a secondary battery of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic perspective view showing the appearance of a lithium battery as a secondary battery of the first embodiment, and FIG. 2 is a schematic cross-sectional view showing the structure of the lithium battery as a secondary battery of the first embodiment.

  As shown in FIG. 1, the lithium battery 100 of the present embodiment has a plurality of battery cells sandwiched and sealed between two laminate films 51 and 52 constituting an exterior (package) 50. The battery cell has a disk shape, for example, and a plurality of battery cells are stacked inside the exterior 50. Two leads 41 and 42 are connected to the battery cell stack, and are pulled out from the exterior 50. In the lithium battery 100, the lead 41 is a positive lead (+), and the lead 42 drawn from the opposite side to the lead 41 is a negative lead (−). Note that the method of pulling out the leads 41 and 42 from the exterior 50 is not limited to this, and the leads 41 and the leads 42 can be pulled out from the exterior 50 close to each other.

  Although a detailed configuration of the battery cell will be described later, the laminate films 51 and 52 for sealing with a plurality of battery cell laminates sandwiched between the laminates prevent the intrusion of moisture and the like from the outside. A laminated film in which a resin film and a metal foil are laminated is used. In the laminated film, a polyethylene film having a thickness of, for example, 80 μm, an aluminum foil having a thickness of, for example, 7 μm, a polyethylene film having a thickness of, for example, 15 μm, and a PET film having a thickness of, for example, 12 μm are laminated. Things can be mentioned. In addition, the battery cell enclosed in the exterior | packing 50 is not limited to disk shape, For example, a sheet form may be sufficient.

  As shown in FIG. 2, the lithium battery 100 includes a first battery cell 10 and a second battery cell 20 that are enclosed in an exterior 50. The first battery cell 10 includes a first positive electrode 13, a first negative electrode 15, and a first electrolyte part 14 provided between the first positive electrode 13 and the first negative electrode 15. ing. In this embodiment, the 1st positive electrode 13 is comprised by the electrical power collector 11 and the active material part 12 which functions as a positive electrode. The first electrolyte part 14 is sandwiched between the active material part 12 and the first negative electrode 15.

  The second battery cell 20 includes a second positive electrode 23, a second negative electrode 25, and a second electrolyte part 24 provided between the second positive electrode 23 and the second negative electrode 25. ing. In the present embodiment, the second positive electrode 23 includes a current collector 21 and an active material portion 22 that functions as a positive electrode. The second electrolyte part 24 is sandwiched between the active material part 22 and the second negative electrode 25. That is, the second battery cell 20 basically has the same configuration as the first battery cell 10.

  In the present embodiment, the second battery cell 20 is disposed so as to overlap the first battery cell 10 with the lead 42 interposed therebetween so that the first negative electrode 15 and the second negative electrode 25 are electrically connected. Has been. In the first battery cell 10, the first positive electrode 13 and the first negative electrode 15 are disposed to face each other with the first electrolyte portion 14 interposed therebetween. In the first positive electrode 13, the active material portion 12 is larger than the current collector 11. The first electrolyte part 14 is disposed so as to cover the surface opposite to the one surface of the active material part 12 in contact with the current collector 11, and protrudes laterally from the outer peripheral end of the active material part 12. It is provided as follows. In other words, the outer peripheral end of the active material portion 12 is covered with the first electrolyte portion 14. The first negative electrode 15 is disposed in contact with the first electrolyte part 14. The area where the current collector 11 is in contact with the active material portion 12 and the area where the first negative electrode 15 is in contact with the first electrolyte portion 14 are the same. That is, the current collector 11 and the first negative electrode 15 are disposed to face each other with the active material portion 12 and the first electrolyte portion 14 interposed therebetween.

  The structure of the second battery cell 20 is also the same as the structure of the first battery cell 10, and the second electrolyte part 24 is opposite to one surface of the active material part 22 in contact with the current collector 21. It arrange | positions so that the surface of a side may be coat | covered, and it protrudes to the side from the outer peripheral end of the active material part 22, and is provided so that an outer peripheral end may be covered. And the 1st electrolyte part 14 which protruded to the side from the outer periphery end of the active material part 12 and the 2nd electrolyte part 24 which protruded to the side from the outer periphery end of the active material part 22 are connected. The portion where the first electrolyte part 14 and the second electrolyte part 24 are connected and located on the outer peripheral side of the stacked first battery cell 10 and second battery cell 20 is hereinafter referred to as the connection part 101. Call.

  The first lead is connected to the current collector 11 on the positive electrode side of the first battery cell 10 with respect to the stacked body of the first battery cell 10 and the second battery cell 20 electrically connected in parallel as described above. 41 a is connected, and the second lead 41 b is connected to the current collector 21 on the same positive electrode side of the second battery cell 20. The lead 41 is configured by overlapping the end portion of the first lead 41a and the end portion of the second lead 41b.

  The first battery cell 10 and the second battery cell 20 that are stacked by the two laminate films 51 and 52 are sandwiched so that the positive lead 41 and the negative lead 42 are exposed to the outside, respectively. The two laminated films 51 and 52 are thermocompression-bonded at the outer peripheral ends, and the resin films constituting each of the laminated films 51 and 52 are thermally fused to be sealed.

  In addition, it is good also as a structure which apply | coats an adhesive agent inside the outer peripheral edge of the laminate films 51 and 52, adhere | attaches, and seals.

  Such a lithium battery 100 is connected because the first electrolyte part 14 of the first battery cell 10 and the second electrolyte part 24 of the second battery cell 20 are connected on the outer peripheral side. Compared with the case where there is not, the rigidity of the laminated body of the 1st battery cell 10 and the 2nd battery cell 20 improves. Although it is desirable from the viewpoint of improving rigidity that the first electrolyte part 14 and the second electrolyte part 24 are connected to form the connecting part 101 over the outer periphery of the laminate, the first negative electrode located on the inner side The lead 42 sandwiched between the first negative electrode 25 and the second negative electrode 25 is pulled out to the outside of the connecting portion 101, so that the first electrolyte portion 14 and the second electrolyte portion are partially formed on the outer periphery of the laminate. There may be a portion where 24 is not connected.

  Further, although a detailed manufacturing method of the lithium battery 100 will be described later, if the space 102 generated on the negative electrode side inside the connecting portion 101 is filled with the electrolyte, the first negative electrode 15 and the lead 42 are not connected. And the electrolyte may enter between the second negative electrode 25 and the lead 42, and electrical connection between the first negative electrode 15 and the second negative electrode 25 and the lead 42 is obstructed. 102 is preferably not completely filled with electrolyte.

  Moreover, when sealing the laminated body of the 1st battery cell 10 and the 2nd battery cell 20 with the laminate films 51 and 52, it is preferable to carry out under reduced pressure. Therefore, the space 103 formed between the bonding portion of the two laminate films 51 and 52 and the laminate is in a reduced pressure state, but a filler is disposed on the outer peripheral side of the laminate to make the space 103 It is good also as a structure sealed so that it may fill with a filler. In this way, when pressure is applied to the laminate from the outside of the laminate films 51 and 52 by sealing under reduced pressure, it is not necessary to apply an excessive load to the leads 41 and 42 and the like. Disconnection of the leads 41 and 42 can be prevented.

<Configuration of each part of the battery cell>
Next, each part of the 1st battery cell 10 is demonstrated. Since the 1st battery cell 10 and the 2nd battery cell 20 have the same structure, description of each part of the 2nd battery cell 20 is abbreviate | omitted.

[Active material part]
The active material portion 12 that electrically functions as a positive electrode includes a positive electrode active material. Examples of the positive electrode active material include a lithium composite metal compound. The lithium composite metal compound is preferably a compound such as an oxide containing lithium and containing two or more metal elements as a whole and in which the presence of oxo acid ions is not observed.

Examples of such a lithium composite metal compound include lithium (Li), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper A composite metal compound containing at least one element of (Cu) is exemplified. Specifically, LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O ₃ , LiCr _0.5 Mn _0.5 O ₂ , LiFePO ₄ , Li ₂ FeP ₂ O ₇ , LiMnPO ₄ , LiFeBO ₃ , Li ₃ V _{2 (PO 4) 3, Li 2} CuO 2, Li 2 FeSiO 4, Li 2 MnSiO 4, NMC (Li a (Ni x Mn y Co 1-xy) O 2), NCA (Li (Ni x Co y Al 1- Examples thereof include oxides such as _xy ) O ₂ ) and fluorides such as LiFeF ₃ . In this embodiment, a solid solution in which some atoms in the crystals of these lithium composite metal compounds are substituted with other transition metals, typical metals, alkali metals, alkali rare earths, lanthanoids, chalcogenides, halogens, etc. is also lithium. These solid solutions can be used as a positive electrode active material.

  Although the detailed formation method of the active material part 12 is mentioned later, in this embodiment, the active material part 12 is formed by agglomerating and sintering positive electrode active material particles having an average particle diameter of 500 nm to 30 μm. ing. Such an active material portion 12 is a porous sintered body having voids between the positive electrode active material particles in contact with each other and the voids communicating with each other. In the present embodiment, the active material portion 12 has an outer shape of, for example, φ10 mm. However, the thickness is not particularly limited as long as it can be molded. If thin, the thickness is about 50 μm from the viewpoint of moldability. It is estimated from the viewpoint of lithium ion conductivity of the electrolyte, and if it is too thick up to about 300 μm, the utilization efficiency of the active material is lowered.

[Electrolyte part]
The first electrolyte portion 14 is made of a crystalline or amorphous solid electrolyte made of lithium oxide, sulfide, halide, nitride, hydride, boride, or the like.

Examples of oxide crystals include Li _0.35 La _0.55 TiO ₃ , Li _0.2 La _0.27 NbO ₃ , and some of the elements of these crystals include N, F, Al, Sr, Sc, Nb, Ta, Sb, and lanthanoid elements A perovskite type crystal or a perovskite-like crystal substituted with, Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₅ La ₃ Nb ₂ O ₁₂ , Li ₅ BaLa ₂ TaO ₁₂ , and some of the elements of these crystals are substituted with N, F, Garnet-type crystals or garnet-like crystals substituted with Al, Sr, Sc, Nb, Ta, Sb, lanthanoid elements, etc., Li _1.3 Ti _1.7 Al _0.3 (PO ₄ ) ₃ , Li _1.4 Al _0.4 Ti _1.6 (PO ₄ ) ₃ , Li _1.4 Al _0.4 Ti _1.4 Ge _0.2 (PO ₄ ) ₃ , and a portion of these crystals substituted with N, F, Al, Sr, Sc, Nb, Ta, Sb, lanthanoid elements, etc. Other crystalline materials such as ASICON type crystals, LISICON type crystals such as Li ₁₄ ZnGe ₄ O ₁₆ , Li _3.4 V _0.6 Si _0.4 O ₄ , Li _3.6 V _0.4 Ge _0.6 O ₄ can be mentioned.

Examples of the sulfide crystal may include Li ₁₀ GeP ₂ S ₁₂ , Li _9.6 P ₃ S ₁₂ , Li _9.54 Si _1.74 P _1.44 S _11.7 Cl _0.3 , Li ₃ PS _{4 and the} like.

Also. Examples of other amorphous materials include Li ₂ O—TiO ₂ , La ₂ O ₃ —Li ₂ O—TiO ₂ , LiNbO ₃ , LiSO ₄ , Li ₄ SiO ₄ , Li ₃ PO ₄ —Li ₄ SiO ₄ , Li ₄ GeO ₄ —Li ₃ VO ₄ , Li ₄ SiO ₄ —Li ₃ VO ₄ , Li ₄ GeO ₄ —Zn ₂ GeO ₂ , Li ₄ SiO ₄ —LiMoO ₄ , Li ₃ PO ₄ —Li ₄ SiO ₄ , Li _{4 SiO 4 -Li 4 ZrO 4, SiO} 2 -P 2 O 5 -Li 2 O, SiO 2 -P 2 O 5 -LiCl, Li 2 O-LiCl-B 2 O 3, LiI, LiI-CaI 2, LiI- _{CaO, LiAlCl 4, LiAlF 4,} LiF-Al 2 O 3, LiBr-Al 2 O 3, LiI-Al 2 O 3, Li 2.88 PO 3.73 N 0.14, Li 3 NI 2, Li 3 N-LiI-LiOH, Li _{3 N-LiCl, Li 6 NBr} 3, L _{2 S-SiS 2, Li 2} S-SiS 2 -LiI, and the like _{Li 2 S-SiS 2 -P 2} S 5. Among these, in consideration of the formation of the first electrolyte portion 14, Li _{2 + x} which is a lithium composite oxide containing carbon (C) and boron (B) whose melting point is lower than that of the active material portion 12 described above. Similar materials such as C _1-x B _x O ₃ and Li ₃ BO ₃ are particularly preferably used.

  From the viewpoint of preventing a short circuit between the active material portion 12 functioning as the positive electrode and the first negative electrode 15, the thickness of the portion of the first electrolyte portion 14 sandwiched between the active material portion 12 and the first negative electrode 15 is It is preferable that it is 2 micrometers or more.

[Negative electrode]
The first negative electrode 15 includes a negative electrode active material. Examples of the negative electrode active material include niobium pentoxide (Nb ₂ O ₅ ), vanadium pentoxide (V ₂ O ₅ ), titanium oxide (TiO ₂ ), indium oxide (In ₂ O ₃ ), zinc oxide (ZnO), Tin oxide (SnO ₂ ), nickel oxide (NiO), indium oxide (ITO) added with tin (Sn), zinc oxide (AZO) added with aluminum (Al), oxide added with gallium (Ga) Zinc (GZO), antimony (Sb) added tin oxide (ATO), fluorine (F) added tin oxide (FTO), TiO ₂ anatase phase, Li ₄ Ti ₅ O ₁₂ , Li ₂ Ti ₃ lithium composite oxides such as O _7, lithium (Li), silicon (Si), tin (Sn), silicon - manganese alloy (Si-Mn), silicon - cobalt alloy (Si-Co), silicon - nickel Alloy (Si-Ni), indium (In), metals and alloys, carbon materials such as gold (Au), lithium ions, and the like inserted material between layers of the carbon material. In the present embodiment, lithium (Li; also referred to as metallic lithium) is used in consideration of battery capacity.

  The thickness of the first negative electrode 15 is preferably about 50 nm to about 100 μm, but can be arbitrarily designed according to desired battery capacity and material characteristics. In the present embodiment, the lead 42 sandwiched between the first negative electrode 15 and the second negative electrode 25 functions also as a current collector on the negative electrode side, but more than the first negative electrode 15. A low resistance current collector may be provided separately, and the current collector and the first negative electrode 15 may form the first negative electrode of the present invention.

[Current collector]
The current collector 11 on the positive electrode side and the current collector on the negative electrode side described above do not cause an electrochemical reaction with the active material portion 12 and the first negative electrode 15 that function as the positive electrode, and have electronic conductivity. Any forming material can be suitably used. Examples of the material for forming the current collector on the positive electrode side and the negative electrode side include copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), and zinc (Zn). ), Aluminum (Al), germanium (Ge), indium (In), gold (Au), platinum (Pt), silver (Ag), and palladium (Pd), one kind of metal (metal simple substance) ), Alloys containing at least one metal element selected from the above group, ITO (Tin-doped Indium Oxide), ATO (Antimony-doped Tin Oxide), and FTO (Fluorine-doped Tin Oxide) Examples include metal oxides, metal nitrides such as titanium nitride (TiN), zirconium nitride (ZrN), and tantalum nitride (TaN).

  The current collector can be selected according to the purpose, such as a thin film of the above-mentioned forming material having electron conductivity, a metal foil, a plate, or a paste prepared by kneading fine conductive powder with a binder. It is. Further, the current collector may have a multilayer structure composed of a plurality of layers using these forming materials. The thickness of such a current collector is not particularly limited, but in the present embodiment, a gold (Au) thin film having a thickness of about 5 μm or less is used as the current collector 11 on the positive electrode side.

  Note that an aluminum foil having a thickness of approximately 20 μm is used as the first lead 41 a and the second lead 41 b on the positive electrode side, and a copper foil having a thickness of approximately 20 μm is also used as the lead 42 on the negative electrode side.

<Method for producing secondary battery>
Next, the manufacturing method of the lithium battery 100 as a manufacturing method of the secondary battery of this embodiment is demonstrated with reference to FIGS. FIG. 3 is a flowchart showing a method for manufacturing a lithium battery according to the first embodiment, and FIGS. 4 to 9 are schematic cross-sectional views showing a method for manufacturing the lithium battery according to the first embodiment.

  As shown in FIG. 3, the manufacturing method of the lithium battery 100 as the manufacturing method of the secondary battery of the present embodiment includes an active material part forming step (step S1), an electrolyte part forming step (step S2), A negative electrode forming step (step S3), a current collector forming step (step S4), a battery cell stacking step (step S5), a lead attaching step (step S6), and an electrolyte portion connecting step (step). S7) and a sealing step (step S8).

In step S1, first, a molded body having voids therein is formed using the positive electrode active material powder. Specifically, in this embodiment, LiCoO ₂ (lithium cobaltate; hereinafter referred to as LCO) was used as the positive electrode active material. Then, as shown in FIG. 4, for example, 150 mg of LCO particles 12p are weighed using a molding apparatus having a die (molding die) 61 and a pressurizing part 62, and filled into a φ10 mm die (molding die) 61, Uniaxial pressing was performed for 2 minutes at a pressure of 50 kgN to produce pellets having a thickness of approximately 100 μm. The pellet is placed on a substrate and fired using, for example, an electric muffle furnace. The firing temperature is preferably 850 ° C. or higher and lower than the melting point of the positive electrode active material. In this case, since the LCO particles 12p are used as the positive electrode active material, the firing temperature is preferably 875 ° C. or higher and 1000 ° C. or lower. As a result, the LCO particles 12p are sintered together to obtain the active material portion 12 that is an integrated porous sintered body. By setting the firing temperature to 850 ° C. or higher, sintering proceeds sufficiently and electron conductivity between the LCO particles 12p is ensured. By setting the firing temperature below the melting point of the positive electrode active material, it is possible to suppress excessive volatilization of lithium in the crystals of the LCO particles 12p and to maintain lithium ion conductivity. That is, the capacity of the active material portion 12 can be secured. Therefore, an appropriate output and capacity can be provided in the lithium battery 100 using the active material portion 12.

  In addition, although the said pellet may be formed including organic substances, such as a binder (binder) which joins LCO particle | grains 12p, and a pore expanding material for adjusting the porosity of a molded object, after baking, these pellets may be formed. If the organic substance remains, the charge conductivity is affected. Therefore, it is preferable that the organic substance is surely burned off by baking. In other words, it is desirable to form the pellet without containing an organic substance such as a binder or a pore expanding material. Further, the porosity in the molded body can be controlled by adjusting the average particle diameter of the LCO particles 12p, that is, the positive electrode active material particles, and the sintering conditions such as the pressure and the firing temperature when forming the pellets. In the present embodiment, in order to achieve sufficient contact between the electrolyte filled thereafter and the positive electrode active material particles, the porosity of the molded body was adjusted to be 40% or more and 60% or less.

  The firing time is preferably, for example, 5 minutes or more and 36 hours or less. More preferably, it is 4 hours or more and 14 hours or less. The porous active material part 12 is obtained by the above process. The material of the substrate used at the time of firing is not particularly limited, but it is preferable to use a material such as magnesium oxide that hardly reacts with the LCO particles 12p. Then, the process proceeds to step S2.

In step S <b> 2, the first electrolyte part 14 is formed in the active material part 12. Specifically, Li _{2 + x} C _1-x B _x O ₃ (hereinafter referred to as LCBO) having a melting point lower than that of the positive electrode active material (in this case, LCO) was used as the electrolyte. First, as shown in FIG. 5, the active material portion 12 is placed in the crucible 65. Subsequently, a predetermined amount of LCBO powder 14p is weighed on the surface of the active material portion 12 and uniformly disposed. Further, for example, a stainless steel weight 66 is placed on the powder 14p. Since the melting point of LCBO is approximately 700 ° C., the crucible 65 is heated to approximately 800 ° C. in an atmosphere containing carbon dioxide (CO ₂ ) gas to melt the LCBO powder 14 p on the active material portion 12. Part of the melt of the powder 14p soaks into the porous active material portion 12. Further, the weight 66 pushes the melt to the outer peripheral side of the active material portion 12. Thereafter, the crucible 65 is cooled to room temperature, and the melt that has soaked into the active material portion 12 or has spread out is solidified. Thereby, a part of the first electrolyte part 14 is filled in the void inside the active material part 12, and the first electrolyte part 14 covering one surface and the end face of the active material part 12 is formed. . When the LCBO melt is solidified, the first electrolyte part 14 made of amorphous LCBO is obtained.

Since the LCBO, which is an electrolyte, is melted in a carbon dioxide (CO ₂ ) gas atmosphere, even if the crucible 65 is heated to 800 ° C., it is possible to prevent carbon (C) from escaping from the LCBO and changing the composition. .

Since a part of the amorphous first electrolyte portion 14 is filled in the gap of the active material portion 12, the area where the active material portion 12 and the first electrolyte portion 14 are in contact with each other substantially increases. The conductivity (ion conductivity) of lithium ions is improved. From the viewpoint of ensuring high ionic conductivity, before forming the first electrolyte part 14, a crystalline electrolyte having an ionic conductivity superior to the electrolyte constituting the first electrolyte part 14 is used as an active material. It may be included in the part 12. As such a crystalline electrolyte, a lithium composite metal of a garnet type crystal such as Li ₇ La ₃ Zr ₂ O ₁₂ (hereinafter referred to as LLZ) or a garnet-like type crystal selected from the electrolytes described above. An oxide is mentioned. Specifically, a liquid phase method in which LLZ crystals are precipitated in the voids of the active material portion 12 by impregnating the active material portion 12 with a solution in which LLZ is dissolved in a solvent and heating the solution. Further, the positive electrode active material particles (LCO particles) constituting the active material portion 12 and the LLZ crystal particles are mixed and pressure-molded to form pellets as shown in FIG. The substance portion 12 may be used. Then, the process proceeds to step S3.

  In step S <b> 3, the first negative electrode 15 is formed on the first electrolyte portion 14. As described above, in the present embodiment, the first negative electrode 15 is formed using metallic lithium. Specifically, by masking a portion of the first electrolyte portion 14 other than the region where the first negative electrode 15 is to be formed and depositing metal lithium by a sputtering method, a vacuum evaporation method, or the like, the film thickness is, for example, A first negative electrode 15 having a thickness of 50 nm to 100 μm was formed. Then, the process proceeds to step S4.

  In step S4, the current collector 11 is formed. Specifically, a portion other than the region where the current collector 11 is formed on one surface of the active material portion 12 is masked, and the thickness of the gold (Au) is about 5 μm or less by, for example, a sputtering method or a vacuum deposition method. The current collector 11 is formed by forming a film so that As a result, as shown in FIG. 6, the first electrolyte portion 14 is sandwiched between the first positive electrode 13 and the first negative electrode 15 formed of the current collector 11 and the active material portion 12. A first battery cell 10 in which a part of the electrolyte portion 14 protrudes laterally from the first positive electrode 13 is completed.

  When lithium deposits and grows on the first negative electrode 15 when the first battery cell 10 is charged, it becomes a dendrite. From the viewpoint of preventing the active material part 12 functioning as the positive electrode and the first negative electrode 15 from being short-circuited via lithium dendrite, the first electrolyte part 14 between the active material part 12 and the first negative electrode 15 is used. The thickness of the portion 14a is preferably 2 μm or more. In other words, in step S2, the first electrolyte part is filled in the active material part 12 with a part of the first electrolyte part 14 so that the film thickness of the part 14a of the first electrolyte part 14 is 2 μm or more. When forming 14, the amount of electrolyte to be melted is adjusted. If it is still difficult to secure the film thickness of the portion 14a of the first electrolyte part 14, an additional film of the electrolyte is formed by, for example, sputtering before forming the first negative electrode 15 in step S3. Is preferred.

  Thereafter, the end portion 14b of the first electrolyte portion 14 covering the outer peripheral end of the active material portion 12 is heated and melted to be connected to the end portion 24b of the second electrolyte portion 24 in the second battery cell 20. Therefore, the length from the outer peripheral end of the active material portion 12 to the surface of the end portion 14b of the first electrolyte portion 14 (the thickness of the end portion 14b in the surface direction of the first electrolyte portion 14) is 0.5 mm or more. It is preferable that In other words, the amount of the electrolyte to be melted in step S2 is adjusted so as to be the end portion 14b of the first electrolyte portion 14 as described above.

  The formation method of the second battery cell 20 is the same as that of the first battery cell 10. Therefore, the second battery cell 20 is formed by repeating the above steps S1 to S4. Then, the process proceeds to step S5.

  In step S5, as shown in FIG. 7, the second battery is connected to the first battery cell 10 via the lead 42 so that the first negative electrode 15 and the second negative electrode 25 are electrically connected. The cells 20 are arranged in an overlapping manner. Then, the process proceeds to step S6.

  In step S6, the lead 41 (the first lead 41a and the second lead 41b) on the positive electrode side is attached to the stacked body of the first battery cell 10 and the second battery cell 20 shown in FIG. Specifically, as shown in FIG. 2, the first lead 41 a made of aluminum foil is overlapped and pressed on the current collector 11, and the second lead 41 b also made of aluminum foil is overlapped on the current collector 21. Press. As a method for connecting the lead 41, a method such as welding or soldering can be used in addition to the pressure welding. Then, the process proceeds to step S7.

  In the step of connecting the electrolyte part in step S7, the first electrolyte part 14 that protrudes to the side of the first positive electrode 13 and the second electrolyte part 24 that protrudes to the side of the second positive electrode 23 are heated. And a step of solidifying the molten first electrolyte part 14 and a part of the second electrolyte part 24 in a combined state. Specifically, as shown in FIG. 8, a stacked body of the first battery cell 10 and the second battery cell 20 is placed on a table 81, and the stacked body is pressed to a predetermined pressure by a pressurizing unit 82. Pressurized with. Then, a tip 83 as a heating body heated by a heater or the like is brought into contact with the end portion 14b of the first electrolyte portion 14 and the end portion 24b of the second electrolyte portion 24, and each end portion 14b, 24b. Is melted locally, and the melt is made to conform to the tip surface of the tip 83 and bonded. When it is confirmed that the melt is bonded, the melt is cooled and solidified by, for example, applying cold air to the tip 83. By performing such a connection operation involving melting and cooling along the outer periphery of the first electrolyte part 14 and the second electrolyte part 24, as shown in FIG. In the stacked body of the second battery cells 20, a connecting portion 101 is formed in which the end portion 14 b of the first electrolyte portion 14 and the end portion 24 b of the second electrolyte portion 24 are connected. As shown in FIG. 9, the first negative electrode 15 and the first negative electrode 15 are connected to the electrolyte portion so that the melt of the electrolyte portion does not penetrate between the lead 42 and the first negative electrode 15 and the second negative electrode 25. It is preferable to perform the connecting operation so that the space 102 is formed on the negative electrode 25 side of the two. Then, the process proceeds to step S8.

  In step S8, as shown in FIG. 2, the laminated body of the first battery cell 10 and the second battery cell 20 in which the first electrolyte part 14 and the second electrolyte part 24 are connected by the connecting part 101. Is sandwiched between the two laminate films 51 and 52 under reduced pressure, and the ends of the two laminate films 51 and 52 are overlapped and bonded by thermocompression bonding. Thereby, the lithium battery 100 encapsulating the two battery cells 10 and 20 electrically connected in parallel to the exterior 50 is completed. Note that the ends of the two laminate films 51 and 52 are bonded together in a state in which the lead 41 on the positive electrode side and the lead 42 on the negative electrode side are drawn out from the exterior 50.

Next, technical contents relating to the formation of the connecting portion 101 will be described with reference to FIG.
FIG. 10 is a graph showing the change in weight ratio accompanying the thermal decomposition of LCBO.
The connecting portion 101 is formed by locally heating and melting the end portion 14 b of the first electrolyte portion 14 and the end portion 24 b of the second electrolyte portion 24. In this embodiment, since the first electrolyte part 14 and the second electrolyte part 24 are formed using LCBO, in order to melt LCBO, the melting point is 720 ° C. or higher, and the active material part Heat at a temperature of 1000 ° C. or less at which 12 does not melt. The thermal decomposition reaction of LCBO by such heat is shown as the following reaction formula.
Li _2.2 C _0.8 B _0.2 O ₃ → _0.8 CO ₂ +0.8 Li ₂ O + _0.2 Li ₃ BO ₃
That is, carbon dioxide gas (CO ₂ ), lithium oxide (Li ₂ O), and lithium borate (Li ₃ BO ₃ ) are generated by heating LCBO. Since carbon dioxide gas is released by the pyrolysis reaction, the weight of LCBO decreases.
Specifically, when all 1 mol (mol), that is, 75.04 g of LCBO is pyrolyzed, 0.8 mol, that is, 35.21 g of CO ₂ is generated, and the remaining mass is 39.83 g.

FIG. 10 shows the relationship between the heating time and the weight ratio when LCBO is pyrolyzed at 720 ° C. In the present embodiment, the heating conditions are set so that the LCBO is decomposed by 1% or more (weight is reduced by 1% or more) when the connecting portion 101 is formed. The heating conditions are, for example, 720 ° C. and about 1 minute. This ensures that lithium oxide is present in the formed connecting portion 101. As shown in the following reaction formula, when lithium oxide reacts with water, it becomes lithium hydroxide.
Li ₂ O + H ₂ O → 2LiOH
That is, by enclosing the laminated body of the first battery cell 10 and the second battery cell 20 in which the connecting portion 101 is formed in the exterior 50, even if moisture enters from the outside, the absorbing portion is absorbed by the connecting portion 101. Therefore, the lithium battery 100 having high durability quality can be realized.

According to the lithium battery 100 and its manufacturing method of the first embodiment, the following effects can be obtained.
(1) The laminated body of the first battery cell 10 and the second battery cell 20 included in the outer package 50 includes an end portion 14b of the first electrolyte part 14 of the first battery cell 10, and a second battery. The end portion 24b of the second electrolyte portion 24 of the cell 20 is locally heated and has a connecting portion 101 formed by bonding. Therefore, the rigidity of the laminate is improved as compared with the case where the connecting portion 101 is not formed. Further, the first battery cell 10 and the second battery cell 20 are overlapped and pressurized, and the first negative electrode 15 and the second negative electrode 25 are connected in a state of being electrically connected via the lead 42. Since the portion 101 is formed, even after the connection portion 101 is formed, the first negative electrode 15 is pressed against the first electrolyte portion 14, and the second electrolyte portion 24 is The state where the negative electrode 25 is in pressure contact is maintained. Therefore, when the lithium battery 100 is charged, variation in current density in the first negative electrode 15 and the second negative electrode 25 is suppressed, and lithium is easily deposited uniformly. That is, it becomes difficult for the lithium dendrite to grow locally on the negative electrode side. That is, the parallel type lithium battery having high reliability quality in which the rigidity of the laminated body of the first battery cell 10 and the second battery cell 20 is improved and short-circuiting due to local growth of dendrites is unlikely to occur. 100 can be provided or manufactured.

  (2) Since the laminate of the first battery cell 10 and the second battery cell 20 with improved rigidity is enclosed and sealed in the exterior 50 under reduced pressure, pressure is applied to the laminate after sealing from the outside. Even if added, it is possible to provide or manufacture the parallel type lithium battery 100 in which the laminate is not easily damaged.

  (3) The connection portion 101 formed by locally heating and melting the end portion 14b of the first electrolyte portion 14 and the end portion 24b of the second electrolyte portion 24 causes the LCBO to be thermally decomposed by heating. Lithium oxide produced as a result. Therefore, even if moisture enters the exterior 50 from the outside, lithium oxide contained in the connecting portion 101 and the infiltrated water react to form lithium hydroxide, so that the battery characteristics are hardly affected. A parallel type lithium battery 100 having quality can be provided or manufactured.

(Second Embodiment)
Next, the secondary battery of the second embodiment will be described with reference to FIG. 11 by taking a lithium battery as an example, as in the first embodiment. FIG. 11 is a schematic cross-sectional view showing the structure of a lithium battery as a secondary battery of the second embodiment. The lithium battery of the second embodiment is obtained by changing the way of stacking the first battery cell 10 and the second battery cell 20 with respect to the lithium battery 100 of the first embodiment. Therefore, the same components as those of the lithium battery 100 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 11, a lithium battery 100 </ b> B as a secondary battery of the present embodiment includes a first battery cell 10 and a second battery cell 20 that are included in an exterior 50. The first battery cell 10 includes a first positive electrode 13, a first negative electrode 15, a first positive electrode 13, a first positive electrode 13 and a first positive electrode 13 formed by laminating a current collector 11 and an active material portion 12 that functions as a positive electrode. The first electrolyte part 14 is provided between the negative electrode 15 and the first electrolyte part 14.

  The second battery cell 20 includes a second positive electrode 23 in which a current collector 21 and an active material portion 22 that functions as a positive electrode are stacked, a second negative electrode 25, a second positive electrode 23, and a second positive electrode 23. The second electrolyte portion 24 is provided between the negative electrode 25 and the second electrolyte portion 24. The first battery cell 10 and the second battery cell 20 basically have the same configuration.

  In the present embodiment, the current collector 11 of the first positive electrode 13 and the current collector 21 of the second positive electrode 23 are electrically connected to the first battery cell 10 via the leads 41. The second battery cells 20 are arranged so as to overlap each other.

  Then, the first electrolyte portion 14 that protrudes laterally from the outer peripheral end of the active material portion 12 of the first battery cell 10 and the outer periphery end of the active material portion 22 of the second battery cell 20 protrudes laterally. The second electrolyte part 24 is connected. A portion where the first electrolyte portion 14 and the second electrolyte portion 24 are connected to each other and located on the outer peripheral side of the stacked first battery cell 10 and second battery cell 20 will be referred to as a connecting portion 101B hereinafter. Call.

  The first lead 42a is provided on the first negative electrode 15 of the first battery cell 10 with respect to the stacked body of the first battery cell 10 and the second battery cell 20 electrically connected in parallel as described above. The second lead 42 b is connected to the second negative electrode 25 of the second battery cell 20. The lead 42 on the negative electrode side is configured by overlapping the end of the first lead 42a and the end of the second lead 42b.

  The first battery cell 10 and the second battery cell 20 that are stacked by the two laminate films 51 and 52 are sandwiched so that the positive lead 41 and the negative lead 42 are exposed to the outside, respectively. The two laminated films 51 and 52 are sealed by thermocompression bonding at the outer peripheral ends. At the outer peripheral ends of the two laminate films 51 and 52, the lead 41 on the positive electrode side and the lead 42 on the negative electrode side are sealed.

  The outer peripheral ends of the laminate films 51 and 52 are not limited to sealing by thermocompression bonding, and sealing is performed by placing an adhesive on the outer peripheral ends of the laminated laminate films 51 and 52 and bonding them. It is good also as a structure.

  Such a lithium battery 100B is connected because the first electrolyte part 14 of the first battery cell 10 and the second electrolyte part 24 of the second battery cell 20 are connected on the outer peripheral side. Compared with the case where there is not, the rigidity of the laminated body of the 1st battery cell 10 and the 2nd battery cell 20 improves.

  The manufacturing method of the lithium battery 100B is the same as the manufacturing method of the lithium battery 100 of the first embodiment, except that the battery cell stacking method in step S5 is different. In step S7, the end 14b of the first electrolyte part 14 of the first battery cell 10 and the end 24b of the second electrolyte part 24 of the second battery cell 20 are locally heated and melted. Then, the connecting portion 101B is formed by solidifying after bonding.

According to the lithium battery 100B of the second embodiment and the manufacturing method thereof, the same effect as the effect (3) of the first embodiment is obtained, and the following effect is obtained.
(4) The laminated body of the first battery cell 10 and the second battery cell 20 enclosed in the exterior 50 includes the end portion 14b of the first electrolyte part 14 of the first battery cell 10 and the second battery. The end part 24b of the second electrolyte part 24 of the cell 20 is locally heated and has a connecting part 101B formed by bonding. Therefore, the rigidity of the laminate is improved as compared with the case where the connecting portion 101B is not formed. Since the laminated body of the first battery cell 10 and the second battery cell 20 with improved rigidity is enclosed and sealed in the exterior 50 under reduced pressure, it is assumed that pressure is applied to the laminated body from the outside after sealing. However, the laminate is difficult to break. Since the laminate is sealed in a state where pressure is applied from the outside, variation in current density is suppressed in each of the first negative electrode 15 and the second negative electrode 25 during charging of the lithium battery 100B, Lithium precipitates uniformly, making it difficult to locally grow lithium dendrites. That is, the parallel type lithium battery having high reliability quality in which the rigidity of the laminated body of the first battery cell 10 and the second battery cell 20 is improved and short-circuiting due to local growth of dendrites is unlikely to occur. 100B can be provided or manufactured.

(Third embodiment)
Next, the secondary battery according to the third embodiment will be described with reference to FIG. 12, taking a lithium battery as an example, as in the first embodiment. FIG. 12 is a schematic cross-sectional view showing the structure of a lithium battery as a secondary battery of the third embodiment. The lithium battery of the third embodiment is obtained by changing the way of stacking the first battery cell 10 and the second battery cell 20 with respect to the lithium battery 100 of the first embodiment. Therefore, the same components as those of the lithium battery 100 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 12, the lithium battery 100 </ b> C as the secondary battery of the present embodiment includes a first battery cell 10 and a second battery cell 20 enclosed in an exterior 50. The first battery cell 10 includes a first positive electrode 13, a first negative electrode 15, a first positive electrode 13, a first positive electrode 13 and a first positive electrode 13 formed by laminating a current collector 11 and an active material portion 12 that functions as a positive electrode. The first electrolyte part 14 is provided between the negative electrode 15 and the first electrolyte part 14.

  The second battery cell 20 includes a second positive electrode 23 in which a current collector 21 and an active material portion 22 that functions as a positive electrode are stacked, a second negative electrode 25, a second positive electrode 23, and a second positive electrode 23. The second electrolyte portion 24 is provided between the negative electrode 25 and the second electrolyte portion 24. The first battery cell 10 and the second battery cell 20 basically have the same configuration.

  In the present embodiment, the second battery is connected to the first battery cell 10 via the conductor 43 so that the first negative electrode 15 and the current collector 21 of the second positive electrode 23 are electrically connected. The cells 20 are arranged so as to overlap each other. The conductor 43 is, for example, a copper foil having a thickness of 20 μm.

  Then, the first electrolyte portion 14 that protrudes laterally from the outer peripheral end of the active material portion 12 of the first battery cell 10 and the outer periphery end of the active material portion 22 of the second battery cell 20 protrudes laterally. The second electrolyte part 24 is connected. A portion where the first electrolyte portion 14 and the second electrolyte portion 24 are connected to each other and located on the outer peripheral side of the stacked first battery cell 10 and second battery cell 20 will be referred to as a connecting portion 101C hereinafter. Call.

  The lead 41 is superimposed on the positive electrode current collector 11 and pressed against the stacked body of the first battery cell 10 and the second battery cell 20 that are electrically connected in series as described above. A lead 42 is stacked and pressed against the second negative electrode 25 of the battery cell 20.

  The first battery cell 10 and the second battery cell 20 that are stacked by the two laminate films 51 and 52 are sandwiched so that the positive lead 41 and the negative lead 42 are exposed to the outside, respectively. The two laminated films 51 and 52 are sealed by thermocompression bonding at the outer peripheral ends. At the outer peripheral ends of the two laminate films 51 and 52, the lead 41 on the positive electrode side and the lead 42 on the negative electrode side are sealed.

  Note that the outer peripheral ends of the laminate films 51 and 52 are not limited to thermo-compression sealing, and an adhesive is placed on the outer peripheral ends of the laminated laminate films 51 and 52 and sealed. May be.

  Such a lithium battery 100C is connected because the first electrolyte part 14 of the first battery cell 10 and the second electrolyte part 24 of the second battery cell 20 are connected on the outer peripheral side. Compared with the case where there is not, the rigidity of the laminated body of the 1st battery cell 10 and the 2nd battery cell 20 improves.

  The manufacturing method of the lithium battery 100C is the same as the manufacturing method of the lithium battery 100 of the first embodiment, except that the battery cell stacking method in step S5 is different. In step S7, the end 14b of the first electrolyte part 14 of the first battery cell 10 and the end 24b of the second electrolyte part 24 of the second battery cell 20 are locally heated and melted. Then, the connecting portion 101C is formed by solidifying after bonding.

According to the lithium battery 100C of the third embodiment and the manufacturing method thereof, the same effect as the effect (3) of the first embodiment is obtained, and the following effect is obtained.
(5) The stacked body of the first battery cell 10 and the second battery cell 20 included in the outer package 50 includes an end portion 14b of the first electrolyte part 14 of the first battery cell 10, and a second battery. The end part 24b of the second electrolyte part 24 of the cell 20 is locally heated and has a connecting part 101C formed by bonding. Therefore, the rigidity of the laminate is improved as compared with the case where the connecting portion 101C is not formed. Since the laminated body of the first battery cell 10 and the second battery cell 20 with improved rigidity is enclosed and sealed in the exterior 50 under reduced pressure, it is assumed that pressure is applied to the laminated body from the outside after sealing. However, the laminate is difficult to break. Since the laminate is sealed in a state in which pressure is applied from the outside, variation in current density is suppressed in each of the first negative electrode 15 and the second negative electrode 25 when the lithium battery 100C is charged, Lithium precipitates uniformly, making it difficult to locally grow lithium dendrites. That is, the series lithium battery having high reliability quality in which the rigidity of the laminated body of the first battery cell 10 and the second battery cell 20 is improved and short-circuiting due to local growth of dendrites is unlikely to occur. 100C can be provided or manufactured.

(Fourth embodiment)
The secondary battery according to the fourth embodiment will be described with reference to FIG. 13 by taking a lithium battery as an example as in the first embodiment. FIG. 13: is a schematic sectional drawing which shows the structure of the lithium battery as a secondary battery of 4th Embodiment. The lithium battery according to the fourth embodiment is different from the lithium battery 100C according to the third embodiment in the exterior configuration. Accordingly, the same components as those of the lithium battery 100C of the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 13, a lithium battery 100 </ b> D as a secondary battery of the present embodiment includes a first battery cell 10 and a second battery cell 20 enclosed in an exterior (package) 90. The first battery cell 10 and the second battery cell 20 are stacked via a conductor 43 so that the first negative electrode 15 and the current collector 21 of the second positive electrode 23 are electrically connected. Has been placed. That is, the first battery cell 10 and the second battery cell 20 are electrically stacked in series. The end portion of the first electrolyte portion 14 that protrudes to the side of the active material portion 12 that functions as the positive electrode of the first battery cell 10, and the side of the active material portion 22 that functions as the positive electrode of the second battery cell 20. The protruding end portion of the second electrolyte portion 24 is connected to form a connecting portion 101C.

The exterior 90 includes a metal case 91, a metal lid 92, an insulating member 93, and a spring 94.
The case portion 91 has a cylindrical shape, and a stacked body of the first battery cell 10 and the second battery cell 20 is inserted from the opening 91 a of the case portion 91 and placed in the case portion 91. . The bottom surface inside the case portion 91 is in contact with the current collector 11 on the positive electrode side of the first battery cell 10. A current collector 44 is laminated on the second negative electrode 25 of the second battery cell 20, and a spring 94 is placed on the current collector 44. A lid portion 92 is disposed so as to be in contact with the current collector 44 via the spring 94. The lid 92, the first battery cell 10, and the second battery cell 20 are not in contact with the case portion 91, and between the lid portion 92 and the case portion 91 in the opening 91 a and the first battery cell 10. An insulating member 93 is laid between the outer periphery of the stacked body of the battery cell 20 and the inner wall of the case portion 91. The current collector 44 is, for example, a copper foil having a thickness of approximately 20 μm.

  The lithium battery 100D of this embodiment is a so-called coin-type secondary battery in which the case portion 91 is a positive electrode (+) and the lid portion 92 is a negative electrode (−), and the case portion 91 has a plurality of battery cells. Since it is enclosed, it has a relatively large battery capacity. Further, the laminated body of the first battery cell 10 and the second battery cell 20 is pressed toward the bottom surface of the case portion 91 by the spring 94. According to such a lithium battery 100D, since the first battery cell 10 and the second battery cell 20 are connected by the connecting portion 101C, the rigidity is improved and the first battery cell 10 and the second battery cell 20 are pressed evenly by the spring 94. The lithium battery 100D in which the stacked body of the battery cell 10 and the second battery cell 20 is not easily damaged can be provided.

(Fifth embodiment)
Next, the secondary battery of the fifth embodiment will be described with reference to FIG. 14 by taking a lithium battery as an example, as in the first embodiment. FIG. 14 is a schematic cross-sectional view showing the structure of a lithium battery as a secondary battery of the fifth embodiment. The lithium battery of the fifth embodiment is obtained by increasing the number of battery cells included in the exterior 50 with respect to the lithium battery 100 of the first embodiment. Therefore, the same components as those of the lithium battery 100 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 14, a lithium battery 200 as a secondary battery of the present embodiment includes a first battery cell 10, a second battery cell 20, and a third battery cell 30 that are included in an exterior 50. And have. The first battery cell 10 includes a first positive electrode 13, a first negative electrode 15, a first positive electrode 13, a first positive electrode 13 and a first positive electrode 13 formed by laminating a current collector 11 and an active material portion 12 that functions as a positive electrode. The first electrolyte part 14 is provided between the negative electrode 15 and the first electrolyte part 14.

  The second battery cell 20 includes a second positive electrode 23 in which a current collector 21 and an active material portion 22 that functions as a positive electrode are stacked, a second negative electrode 25, a second positive electrode 23, and a second positive electrode 23. The second electrolyte portion 24 is provided between the negative electrode 25 and the second electrolyte portion 24.

  The third battery cell 30 includes a third positive electrode 33 in which a current collector 31 and an active material part 32 functioning as a positive electrode are stacked, a third negative electrode 35, a third positive electrode 33, and a third positive electrode 33. The third electrolyte part 34 is provided between the negative electrode 35 and the third electrolyte part 34. The first battery cell 10, the second battery cell 20, and the third battery cell 30 basically have the same configuration.

  In the present embodiment, the first negative electrode 15 and the second negative electrode 25 are electrically connected, and the current collector 21 of the second positive electrode 23 and the current collector 31 of the third positive electrode 33 are electrically connected. The second battery cell 20 is arranged so as to overlap with the first battery cell 10 via the first lead 42a on the negative electrode side so as to be connected to the first battery cell 10, and on the positive electrode side with respect to the second battery cell 20 The third battery cell 30 is disposed so as to overlap with the second lead 41b.

  Then, the first electrolyte portion 14 that protrudes laterally from the outer peripheral end of the active material portion 12 of the first battery cell 10 and the outer periphery end of the active material portion 22 of the second battery cell 20 protrudes laterally. The second electrolyte part 24 is connected to the third electrolyte part 34 that protrudes laterally from the outer peripheral end of the active material part 32 of the third battery cell 30. Located on the outer peripheral side of the stacked first battery cell 10 and second battery cell 20 and third battery cell 30, the first electrolyte part 14, the second electrolyte part 24, and the third electrolyte part 34. Hereinafter, the portion where is connected is referred to as a connecting portion 201.

  The current collector on the positive electrode side of the first battery cell 10 with respect to the stacked body of the first battery cell 10, the second battery cell 20, and the third battery cell 30 thus electrically connected in parallel. 11, the first lead 41a is connected (pressure contact), and the second lead 42b is connected (pressure contact) to the third negative electrode 35 of the third battery cell 30. The end of the first lead 41a and the end of the second lead 41b are overlapped to form the positive-side lead 41, and the end of the first lead 42a and the end of the second lead 42b are overlapped. Thus, a lead 42 on the negative electrode side is configured.

  The first battery cell 10, the second battery cell 20, and the third battery stacked by the two laminate films 51 and 52 so that the positive electrode side lead 41 and the negative electrode side lead 42 are respectively exposed to the outside. The cell 30 is sandwiched, and the two laminate films 51 and 52 are sealed by thermocompression bonding at the outer peripheral ends under reduced pressure. At the outer peripheral ends of the two laminate films 51 and 52, the first lead 41a and the second lead 41b on the positive electrode side are overlapped and sealed. Similarly, at the outer peripheral ends of the two laminate films 51 and 52, the first lead 42a and the second lead 42b on the negative electrode side are overlapped and sealed.

  Note that the outer peripheral ends of the laminate films 51 and 52 are not limited to thermo-compression sealing, and an adhesive is placed on the outer peripheral ends of the laminated laminate films 51 and 52 and sealed. May be.

  Such a lithium battery 200 includes a first electrolyte part 14 of the first battery cell 10, a second electrolyte part 24 of the second battery cell 20, and a third electrolyte part of the third battery cell 30. 34 is connected on the outer peripheral side, the rigidity of the stacked body of the first battery cell 10, the second battery cell 20, and the third battery cell 30 is improved as compared with the case where they are not connected. .

The manufacturing method of the lithium battery 200 is basically the same as the manufacturing method of the lithium battery 100 of the first embodiment, and the number of battery cells stacked in step S5 is different.
FIG. 15 is a schematic cross-sectional view showing the method for manufacturing the lithium battery of the fifth embodiment. In step S7, as shown in FIG. 15, the first battery cell 10, the second battery cell 20, and the third battery cell 30 including the leads 41a, 41b, 42a, and 42b are stacked on the table 81. The body is placed, and the pressurizing unit 82 pressurizes the laminated body with a predetermined pressure. Then, the tip 83 as a heating body heated by a heater or the like is applied to the end portion 14b of the first electrolyte portion 14, the end portion 24b of the second electrolyte portion 24, and the end portion 34b of the third electrolyte portion 34. The end portions 14b, 24b, and 34b are locally melted by being brought into contact with each other, and the melt is adapted to the tip surface of the iron tip 83 and bonded. When it is confirmed that the melt is bonded, the melt is cooled and solidified by, for example, applying cold air to the tip 83. By performing such a connection operation involving melting and cooling along the outer periphery of the first electrolyte part 14, the second electrolyte part 24, and the third electrolyte part 34, as shown in FIG. In the stacked body of the first battery cell 10, the second battery cell 20, and the third battery cell 30, the end portion 14b of the first electrolyte section 14, the end section 24b of the second electrolyte section 24, and the third electrolyte A connecting portion 201 is formed by connecting the end portions 34 b of the portion 34. As shown in FIG. 14, the above connecting operation is performed so that a space 202 is provided on the first negative electrode 15 side and the second negative electrode 25 side of the connecting portion 201. Moreover, it is preferable to perform the connection operation so as to have the space 203 closer to the second positive electrode 23 and the third positive electrode 33 than the connection portion 201. In addition, since the laminated body of the 1st battery cell 10, the 2nd battery cell 20, and the 3rd battery cell 30 is enclosed in the exterior 50 under pressure reduction, the space 204 which arose on the outer peripheral side of this laminated body Is in a decompressed state. The space 204 may be filled with a filler as described in the first embodiment.

According to the lithium battery 200 of the fifth embodiment and the manufacturing method thereof, the same effect as the effect (3) of the first embodiment is obtained, and the following effect is obtained.
(6) The laminated body of the first battery cell 10, the second battery cell 20, and the third battery cell 30 included in the exterior 50 is an end portion of the first electrolyte part 14 of the first battery cell 10. 14b, the end 24b of the second electrolyte part 24 of the second battery cell 20, and the end 34b of the third electrolyte part 34 of the third battery cell 30 are locally heated and combined. It has the connecting part 201 formed. Therefore, the rigidity of the laminate is improved as compared with the case where the connecting portion 201 is not formed. Since the laminated body of the first battery cell 10, the second battery cell 20, and the third battery cell 30 with improved rigidity is enclosed and sealed in the exterior 50 under reduced pressure, the laminated body is sealed after sealing. Even if pressure is applied from the outside, the laminate is hardly damaged. Since the laminate is sealed in a state where pressure is applied from the outside, the current density in each of the first negative electrode 15, the second negative electrode 25, and the third negative electrode 35 is charged when the lithium battery 200 is charged. Variation is suppressed, lithium is deposited uniformly, and lithium dendrite is difficult to grow locally. That is, the rigidity of the laminated body of the first battery cell 10, the second battery cell 20, and the third battery cell 30 is improved, and a high reliability quality that is unlikely to cause a short circuit due to local lithium dendrite growth. It is possible to provide or manufacture a lithium battery 200 having a large electric capacity as compared with the lithium battery 100 of the first embodiment.

  Hereinafter, the effects of the examples will be described in detail with reference to examples and comparative examples according to the embodiment.

Example 1
The secondary battery of Example 1 is the lithium battery 100 of the first embodiment described above, and as shown in FIG. 2, the first battery cell is mounted on the exterior 50 composed of two laminate films 51 and 52. The second battery cells 20 are arranged so as to be electrically connected in parallel to each other and sealed. In the first battery cell 10 and the second battery cell 20, the first electrolyte part 14 and the second electrolyte part 24 are connected on the outer peripheral side to form a connection part 101. Inside the connecting portion 101, the first negative electrode 15 and the second negative electrode 25 are in a state of being electrically connected via the lead 42.

  The first positive electrode 13 in the first battery cell 10 has a current collector 11 made of a gold (Au) thin film with a film thickness of about 5 μm or less, and a sintered body of LCO particles filled with LCBO as an electrolyte. The active material part 12 is comprised. The active material portion 12 has a disk shape with a thickness of approximately 100 μm and an outer shape of φ10 mm. The first electrolyte part 14 is formed so as to cover the active material part 12 side of the first positive electrode 13 and protrude about 0.5 mm to the side of the active material part 12. The first electrolyte part 14 is made of LCBO, and the thickness between the active material part 12 and the first negative electrode 15 is approximately 2 μm. Furthermore, the first negative electrode 15 is formed by forming and patterning metallic lithium on the first electrolyte portion 14 so as to have a thickness of about 2 μm. The configuration of the second battery cell 20 is the same as the configuration of the first battery cell 10.

(Comparative Example 1)
The secondary battery of Comparative Example 1 is a laminate type, and the first electrolyte part 14 and the second electrolyte part 24 are not connected to the lithium battery 100 of Example 1 on the outer peripheral side. Other configurations are the same as those of the first embodiment.

(Example 2)
The secondary battery of Example 2 is the lithium battery 100D of the fourth embodiment described above, and in the coin-type exterior 90, inside the case portion 91, the conductor 43 is interposed with respect to the first battery cell 10. The second battery cells 20 are stacked and electrically connected in series. The configurations of the first battery cell 10 and the second battery cell 20 are the same as those in the first embodiment.

(Comparative Example 2)
The secondary battery of Comparative Example 2 is a coin type, and is configured such that the first electrolyte part 14 and the second electrolyte part 24 are not connected on the outer peripheral side with respect to the lithium battery 100D of Example 2. Other configurations are the same as those of the second embodiment.

(Example 3)
FIG. 16 is a schematic cross-sectional view showing the structure of a lithium battery as a secondary battery of Example 3.
As shown in FIG. 16, the lithium battery 100 </ b> E as the secondary battery of Example 3 has a coin-type exterior 90 and a conductor 46 with respect to the first battery cell 10 inside the case portion 91. The second battery cell 20 is arranged in an overlapping manner. The structure of the 1st battery cell 10 and the 2nd battery cell 20 is the same as Example 1, and the 1st electrolyte part 14 of the 1st battery cell 10 and the 2nd electrolyte of the 2nd battery cell 20 are the same. The connecting portion 101 is connected to the portion 24 on the outer peripheral side.

  The current collector 11 of the first positive electrode 13 of the first battery cell 10 and the bottom surface inside the case portion 91 are electrically connected via a conductor 45. The conductor 45 is an aluminum foil having a thickness of 20 μm, is folded back outside the connecting portion 101, and is in pressure contact with the current collector 21 in the second positive electrode 23 of the second battery cell 20.

  The conductor 46 disposed between the first negative electrode 15 of the first battery cell 10 and the second negative electrode 25 of the second battery cell 20 is a copper foil having a thickness of 20 μm and includes a connecting portion 101. It is pulled out outside and folded back to the second battery cell 20 side. The folded conductor 46 is disposed so as to overlap the conductor 45 pressed against the current collector 21 of the second positive electrode 23 with an insulating member 95 interposed therebetween. Further, a spring 94 is placed on the folded conductor 46, and a lid portion 92 is disposed so as to contact the conductor 46 via the spring 94. The laminated body of the first battery cell 10 and the second battery cell 20 is pressed toward the bottom surface inside the case portion 91 by the spring 94.

  That is, the lithium battery 100E of Example 3 has a coin-type exterior 90 and a first battery cell 10 and a second battery that are basically the same as those of Example 1 with respect to the lithium battery 100D of the fourth embodiment. The battery cell 20 is included in a state of being electrically connected in parallel.

(Comparative Example 3)
The secondary battery of Comparative Example 3 is a coin type, and is configured such that the first electrolyte part 14 and the second electrolyte part 24 are not connected on the outer peripheral side with respect to the lithium battery 100E of Example 3. Other configurations are the same as those of the third embodiment.

  The evaluation method of each lithium battery of Examples 1 to 3 and Comparative Examples 1 to 3 is as follows.

[Evaluation methods]
For each of the lithium batteries of Examples 1 to 3 and Comparative Examples 1 to 3, charging at 20 μA (microampere) and discharging at 10 μA, the first discharge amount is 100, The number of charge / discharge cycles until the discharge capacity became 80 or less in the subsequent charge / discharge was taken as one of the evaluation items. Specifically, the number of charge / discharge cycles was ranked into three from A to C as follows.
A: 10 times or more, B: 3 times or more and less than 10 times, C: less than 3 times The state where the number of charge / discharge cycles until the discharge capacity becomes 80 or less indicates a decrease in charge / discharge characteristics of the secondary battery. It is considered that the current density on the negative electrode side varies and lithium dendrite grows unevenly.

  Furthermore, after charging and discharging 10 times or more, it was confirmed whether or not the battery cells in the exterior (package) were damaged such as cracks. Table 1 shown below shows the evaluation results of the lithium batteries of Examples 1 to 3 and Comparative Examples 1 to 3.

  As shown in Table 1, in the lithium battery of Comparative Example 1 of the laminate type, although no damage was observed in the battery cell after charge / discharge, the number of charge / discharge cycles where the discharge capacity was 80 or less was less than 3 times C. Met. On the other hand, in the coin type lithium batteries of Comparative Example 2 and Comparative Example 3, the number of charge / discharge cycles with a discharge capacity of 80 or less was 3 or more and less than 10 times of B, but the battery cells after charge / discharge were damaged. Was recognized. That is, in the lithium batteries of Comparative Example 2 and Comparative Example 3, the electrolyte part is not connected in the stacked body of the first battery cell 10 and the second battery cell 20 enclosed in the coin-shaped exterior 90. The rigidity was insufficient, and damage was caused by pressurization by the spring 94.

  On the other hand, in the lithium batteries of Examples 1 to 3 in which the electrolyte part is connected, the number of charge / discharge cycles at which the discharge capacity is 80 or less is 10 times or more of A regardless of the exterior type, No damage after discharge was observed. That is, the rigidity in the laminated body of the plurality of battery cells included in the exterior was improved, and excellent charge / discharge characteristics were obtained. In particular, even a coin-type exterior could sufficiently withstand the pressure applied by the spring 94.

(Sixth embodiment)
<Electronic equipment>
Next, the electronic device of the present embodiment will be described using a wearable device as an example. FIG. 17 is a perspective view illustrating a configuration of a wearable device as an electronic device according to the sixth embodiment.

  As shown in FIG. 17, a wearable device 300 as an electronic device according to the present embodiment is an information device that is attached to a human body, for example, a wrist WR like a wristwatch and can obtain information about the human body, , Sensor 302, display unit 303, processing unit 304, and battery 305.

  The band 301 is a band shape using a flexible resin such as rubber so as to be in close contact with the wrist WR when worn, and has a coupling portion whose coupling position can be adjusted at the end of the band. .

  The sensor 302 is an optical sensor, for example, and is disposed on the inner surface side (the wrist WR side) of the band 301 so as to touch the wrist WR when worn.

  The display unit 303 is, for example, a light-receiving type liquid crystal display device, and on the outer surface side of the band 301 (on the opposite side to the inner surface to which the sensor 302 is attached) so that the wearer can read information displayed on the display unit 303. Has been placed.

  The processing unit 304 is an integrated circuit (IC), for example, and is built in the band 301 and is electrically connected to the sensor 302 and the display unit 303. The processing unit 304 performs arithmetic processing for measuring a pulse, a blood glucose level, and the like based on the output from the sensor 302. Further, the display unit 303 is controlled to display the measurement result and the like.

  The battery 305 is built in a detachable state with respect to the band 301 as a power supply source for supplying power to the sensor 302, the display unit 303, the processing unit 304, and the like. As the battery 305, the lithium battery 100 of the first embodiment is used.

  According to the wearable device 300 of this embodiment, the sensor 302 electrically detects information related to the wearer's pulse, blood sugar level, and the like from the wrist WR, and after performing arithmetic processing in the processing unit 304, the display unit 303 The pulse and blood sugar level can be displayed. The display unit 303 can display not only the measurement result but also information indicating the state of the human body predicted from the measurement result, time, and the like.

  In addition, since the lithium battery 100 having excellent charge / discharge characteristics and durability is used as the battery 305, the wearable device 300 is light and thin and can withstand repeated use over a long period of time. be able to. In addition, since the lithium battery 100 is a solid-state secondary battery, it can be used repeatedly by charging, and there is no fear of leakage of the electrolyte, so that the wearable device 300 that can be used safely for a long time is provided. it can.

  In the present embodiment, the watch-type wearable device 300 is illustrated, but the wearable device 300 may be worn on, for example, an ankle, a head, an ear, or a waist. Note that the battery 305 may be the lithium battery 100B of the second embodiment, the lithium battery 100C of the third embodiment, the lithium battery 100D of the fourth embodiment, or the lithium battery 200 of the fifth embodiment. Effects can be obtained.

  In addition, the electronic device to which the lithium battery of each of the above embodiments as a power supply source is applied is not limited to the wearable device 300. For example, a head-mounted display, a head-up display, a mobile phone, a portable information terminal, a notebook computer, a digital camera, a video camera, a music player, wireless headphones, a game machine, and the like can be given. Moreover, it is applicable not only to such consumer (general consumer) devices but also to industrial devices. The electronic device of the present invention may have other functions such as a data communication function, a game function, a recording / playback function, and a dictionary function.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope or spirit of the invention that can be read from the claims and the entire specification. The manufacturing method of the secondary battery and electronic equipment to which the secondary battery is applied are also included in the technical scope of the present invention. Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

  (Modification 1) In the above embodiment, the method of connecting the electrolyte part protruding to the side of the active material part of the plurality of stacked battery cells is obtained by bringing a heating body into contact with the end of the electrolyte part and melting it. It is not limited to the method of solidifying from. For example, the end portion of the electrolyte portion may be heated and melted by irradiating laser light.

  (Modification 2) In the lithium battery 200 of the fifth embodiment, the end 14b of the first electrolyte part 14 of the first battery cell 10 and the end of the second electrolyte part 24 of the second battery cell 20 are shown. The connecting portion 201 is formed by joining the portion 24b and the end portion 34b of the third electrolyte portion 34 of the third battery cell 30 by locally heating and melting them, but is not limited thereto. In a state where the first negative electrode 15 and the second negative electrode 25 are electrically connected via the first lead 42a, the end portion 14b of the first electrolyte portion 14 of the first battery cell 10, and the second The connection part 201 may be formed by joining the end part 24b of the second electrolyte part 24 of the battery cell 20 by locally heating and melting the part 24b. According to this, since the first battery cell 10 and the second battery cell 20 can be connected in a state where the first negative electrode 15 and the second negative electrode 25 are pressurized inside the connecting portion 201, It is possible to prevent lithium dendrite from growing unevenly on the negative electrode side.

  (Modification 3) In the lithium battery as the secondary battery of each of the above embodiments, when a plurality of battery cells are connected in parallel or in series, at least one of the two current collectors in an electrically connected state is collected. Electrical objects can be deleted. For example, in the lithium battery 100B as the secondary battery of the second embodiment, even if one of the current collector 11 and the current collector 21 arranged with the lead 41 on the positive electrode side interposed is deleted, Good. The lead 41 can also function as a current collector. In that case, both the current collector 11 and the current collector 21 may be deleted.

(Modification 4) In each of the above embodiments, LCBO is used as the electrolyte constituting the electrolyte part. However, the present invention is not limited to this. For example, Li ₃ BO ₃ as an electrolyte; can use the (LBO lithium borate) constitutes the electrolyte portion, linking the electrolyte portion over a plurality of battery cells. In this case, the electrolyte part is locally melted and connected in an inert gas atmosphere such as nitrogen or argon or in a dry air atmosphere. The melting point of LBO is said to be 760 ° C to 880 ° C, but since it does not thermally decompose even when heated at 800 ° C, the electrolyte part is connected to form a compositionally stable connection part. Can do.

  The contents derived from the embodiment and the modification are described below.

  The secondary battery according to the present application includes a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte portion interposed therebetween, and a second battery disposed with a second electrolyte portion interposed therebetween. A second battery cell having a positive electrode and a second negative electrode, wherein the second battery cell is electrically connected to the second battery cell so that the first negative electrode and the second negative electrode are electrically connected to each other. The battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. To do.

  According to this configuration, since the first electrolyte part and the second electrolyte part are connected to each other, the stacked body of the first battery cell and the second battery cell is compared with the case where they are not connected. , The rigidity is improved. In addition, since the first negative electrode and the second negative electrode are electrically connected and pressurized inside the connected portion, the first battery cell and the second battery cell are connected. The first negative electrode is pressed against the first electrolyte portion, and the second electrolyte portion is pressed against the second negative electrode. Therefore, since force is uniformly applied to the first negative electrode and the second negative electrode, respectively, when lithium is contained as an active material in the electrolyte portion, variation in current density on the negative electrode side during charging can be suppressed, and lithium can be evenly distributed. Precipitate. That is, it is possible to provide a parallel type secondary battery in which defects such as a short circuit are unlikely to occur due to dendrite generated locally due to uneven growth of lithium.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode, wherein the first battery cell is electrically connected to the first battery cell so that the first positive electrode and the second positive electrode are electrically connected to each other. The second battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. It is characterized by that.

  According to this configuration, since the first electrolyte part and the second electrolyte part are connected to each other, the stacked body of the first battery cell and the second battery cell is compared with the case where they are not connected. , The rigidity is improved. Moreover, since the rigidity of the laminated body of the 1st battery cell and the 2nd battery cell is improving, this laminated body can be enclosed by the exterior in the state pressurized firmly. Therefore, since force is uniformly applied to the first negative electrode and the second negative electrode, respectively, when lithium is contained as an active material in the electrolyte portion, variation in current density on the negative electrode side during charging can be suppressed, and lithium can be evenly distributed. Precipitate. That is, it is possible to provide a parallel type secondary battery in which defects such as a short circuit are unlikely to occur due to dendrite generated locally due to uneven growth of lithium.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode, wherein the first battery cell is electrically connected to the first battery cell so that the first negative electrode and the second positive electrode are electrically connected to each other. The second battery cells are arranged in an overlapping manner, and the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. It is characterized by that.

  According to this configuration, since the first electrolyte part and the second electrolyte part are connected to each other, the stacked body of the first battery cell and the second battery cell is compared with the case where they are not connected. , The rigidity is improved. Moreover, since the rigidity of the laminated body of the 1st battery cell and the 2nd battery cell is improving, this laminated body can be enclosed by the exterior in the state pressurized firmly. Therefore, since force is uniformly applied to the first negative electrode and the second negative electrode, respectively, when lithium is contained as an active material in the electrolyte portion, variation in current density on the negative electrode side during charging can be suppressed, and lithium can be evenly distributed. Precipitate. That is, it is possible to provide a series-type secondary battery in which defects such as a short circuit are unlikely to occur due to dendrite generated locally due to uneven growth of lithium.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode formed, and a third battery cell having a third positive electrode and a third negative electrode arranged with a third electrolyte portion interposed therebetween, And the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected to each other with respect to the first battery cell. The second battery cell and the third battery cell are overlapped, and a first electrolyte part protruding to the side of the first positive electrode, and a second electrolyte part protruding to the side of the second positive electrode, The third electrolyte portion protruding from the side of the third positive electrode is connected to the third positive electrode.

  In addition, another secondary battery of the present application is arranged with a first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part sandwiched therebetween, and a second electrolyte part in between. A second battery cell having a second positive electrode and a second negative electrode formed, and a third battery cell having a third positive electrode and a third negative electrode arranged with a third electrolyte portion interposed therebetween, And the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected to each other with respect to the first battery cell. The second battery cell and the third battery cell are overlapped, and a first electrolyte part protruding to the side of the first positive electrode, and a second electrolyte part protruding to the side of the second positive electrode, May be connected.

  According to these configurations, since at least the first electrolyte part and the second electrolyte part are connected, in the stacked body of the first battery cell, the second battery cell, and the third battery cell, the connection is made. Rigidity is improved compared to the case where it is not. In addition, since the first negative electrode and the second negative electrode are electrically connected and pressurized inside the connected portion, the first battery cell and the second battery cell are connected. The first negative electrode is pressed against the first electrolyte portion, and the second electrolyte portion is pressed against the second negative electrode. Therefore, since force is uniformly applied to the first negative electrode and the second negative electrode, respectively, when lithium is contained as an active material in the electrolyte portion, variation in current density on the negative electrode side during charging can be suppressed, and lithium can be evenly distributed. Precipitate. That is, it is possible to provide a parallel type secondary battery having a larger battery capacity in which defects such as a short circuit are hardly caused by dendrite generated locally due to uneven growth of lithium.

  In the above secondary battery, it is preferable to include an outer package that encloses and seals the stacked first battery cells and second battery cells.

  The secondary battery preferably includes an outer package that encloses and seals the stacked first battery cell, second battery cell, and third battery cell.

  According to these secondary batteries, since the rigidity of the stacked body of the plurality of battery cells is improved, the plurality of battery cells can be included in a state where the outer battery is firmly pressed by the exterior. Therefore, a secondary battery having excellent durability can be provided. The number of the plurality of battery cells included in the exterior is not limited to two or three.

  An electronic apparatus according to the present application includes any one of the above secondary batteries. Therefore, a stable power supply can be obtained from the secondary battery, and an electronic device having excellent durability can be provided.

  The method for manufacturing a secondary battery according to the present application includes a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte portion interposed therebetween, and a second electrolyte portion interposed therebetween. And a second battery cell having a second positive electrode and a second negative electrode, wherein the first negative electrode and the second negative electrode are electrically connected to each other. In addition, the step of stacking the second battery cell on the first battery cell, the first electrolyte part protruding to the side of the first positive electrode, and the second of the second electrolyte protruding to the side of the second positive electrode And heating and melting the electrolyte part, and solidifying the part of the melted first electrolyte part and part of the second electrolyte part.

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A method of manufacturing a secondary battery comprising: a second battery cell having a second positive electrode and a second negative electrode arranged sandwiched between the first positive electrode and the second positive electrode. A step of stacking the second battery cell on the first battery cell so as to connect to the first battery cell, a first electrolyte portion protruding to the side of the first positive electrode, and a side of the second positive electrode. And the second electrolyte part is heated and melted, and solidified in a state where a part of the melted first electrolyte part and a part of the second electrolyte part are combined. And

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A method of manufacturing a secondary battery comprising a second battery cell having a second positive electrode and a second negative electrode arranged sandwiched between the first negative electrode and the second positive electrode. A step of stacking the second battery cell on the first battery cell so as to connect to the first battery cell, a first electrolyte portion protruding to the side of the first positive electrode, and a side of the second positive electrode. And the second electrolyte part is heated and melted, and solidified in a state where a part of the melted first electrolyte part and a part of the second electrolyte part are combined. And

  According to these methods, in the stacked body in which the first battery cell and the second battery cell are stacked, the first electrolyte portion protruding from the side of the first positive electrode and the side of the second positive electrode A parallel or series secondary battery with improved rigidity can be manufactured by connecting to the second electrolyte portion protruding to the side.

  In another method for manufacturing a secondary battery of the present application, a first battery cell having a first positive electrode and a first negative electrode disposed with a first electrolyte part interposed therebetween, and a second electrolyte part are provided. A third battery cell having a second battery cell having a second positive electrode and a second negative electrode disposed therebetween, and a third battery having a third positive electrode and a third negative electrode disposed with the third electrolyte portion interposed therebetween. And a first negative electrode and a second negative electrode are electrically connected to each other, and a second positive electrode and a third positive electrode are electrically connected to each other. The second battery cell and the third battery cell are stacked on the first battery cell, and the first electrolyte part, the second electrolyte part, and the third electrolyte part, The first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are heated and melted, and the melted first electrolyte part To a portion of the electrolyte part and the part of the second electrolyte portion a step is solidified in a state bound, comprising the.

  According to this method, in the stacked body in which the first battery cell, the second battery cell, and the third battery cell are stacked, the first electrolyte portion that protrudes to the side of the first positive electrode, The second electrolyte part protruding to the side of the positive electrode 2 is connected to improve rigidity, and a parallel type secondary battery having a large battery capacity can be manufactured.

  In the above secondary battery manufacturing method, the heating body is brought into contact with the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode. It is preferable to melt.

  According to this method, the end portion of the first electrolyte portion that protrudes to the side of the first positive electrode and the end portion of the second electrolyte portion that protrudes to the side of the second positive electrode are locally heated. it can. In other words, the first electrolyte part and the second electrolyte part can be melted and connected in a state in which other parts are hardly altered by heating.

  In the above secondary battery manufacturing method, the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are irradiated with laser light. And may be melted.

  In the above secondary battery manufacturing method, the first electrolyte part, the second electrolyte part, and the third electrolyte part, the first electrolyte part protruding to the side of the first positive electrode, and the first electrolyte part, The second electrolyte part protruding to the side of the second positive electrode and the third electrolyte part protruding to the side of the third positive electrode are heated and melted, and a part of the melted first electrolyte part is It is preferable to include a step of solidifying in a state where a part of the second electrolyte part and a part of the third electrolyte part are combined.

  According to this method, in the stacked body in which the first battery cell, the second battery cell, and the third battery cell are stacked, the first electrolyte portion that protrudes to the side of the first positive electrode, The second electrolyte portion that protrudes to the side of the positive electrode 2 and the third electrolyte portion that protrudes to the side of the third positive electrode are connected to each other, further improving rigidity and having a large battery capacity. A secondary battery can be manufactured.

  DESCRIPTION OF SYMBOLS 10 ... 1st battery cell, 11 ... Current collector, 12 ... Active material part, 13 ... 1st positive electrode, 14 ... 1st electrolyte part, 15 ... 1st negative electrode, 20 ... 2nd battery cell, DESCRIPTION OF SYMBOLS 21 ... Current collector, 22 ... Active material part, 23 ... 2nd positive electrode, 24 ... 2nd electrolyte part, 25 ... 2nd negative electrode, 30 ... 3rd battery cell, 31 ... Current collector, 32 ... Active material part, 33 ... third positive electrode, 34 ... third electrolyte part, 35 ... third negative electrode, 50 ... exterior, 90 ... exterior, 100, 100B, 100C, 100D, 100E ... lithium as a secondary battery Batteries, 300 ... Wearable devices as electronic devices.

Claims (15)

A first battery cell having a first positive electrode and a first negative electrode disposed with the first electrolyte portion interposed therebetween;
A second battery cell having a second positive electrode and a second negative electrode arranged with the second electrolyte part interposed therebetween,
The second battery cell is placed on top of the first battery cell so that the first negative electrode and the second negative electrode are electrically connected;
A secondary battery in which the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. A first battery cell having a first positive electrode and a first negative electrode disposed with the first electrolyte portion interposed therebetween;
A second battery cell having a second positive electrode and a second negative electrode arranged with the second electrolyte part interposed therebetween,
The second battery cell is disposed so as to overlap the first battery cell so that the first positive electrode and the second positive electrode are electrically connected.
A secondary battery in which the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. A first battery cell having a first positive electrode and a first negative electrode disposed with the first electrolyte portion interposed therebetween;
A second battery cell having a second positive electrode and a second negative electrode arranged with the second electrolyte part interposed therebetween,
The second battery cell is placed on top of the first battery cell so that the first negative electrode and the second positive electrode are electrically connected;
A secondary battery in which the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected. A first battery cell having a first positive electrode and a first negative electrode disposed with the first electrolyte portion interposed therebetween;
A second battery cell having a second positive electrode and a second negative electrode disposed across the second electrolyte part;
A third battery cell having a third positive electrode and a third negative electrode disposed with the third electrolyte portion interposed therebetween,
With respect to the first battery cell, the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected. The second battery cell and the third battery cell are arranged to overlap,
The first electrolyte part protruding to the side of the first positive electrode, the second electrolyte part protruding to the side of the second positive electrode, and the side of the third positive electrode The secondary battery with which the 3rd electrolyte part is connected. A first battery cell having a first positive electrode and a first negative electrode disposed with the first electrolyte portion interposed therebetween;
A second battery cell having a second positive electrode and a second negative electrode disposed across the second electrolyte part;
A third battery cell having a third positive electrode and a third negative electrode disposed with the third electrolyte portion interposed therebetween,
With respect to the first battery cell, the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected. The second battery cell and the third battery cell are arranged to overlap,
A secondary battery in which the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are connected.   The secondary battery as described in any one of Claims 1 thru | or 3 provided with the exterior | packing which encloses and seals the said 1st battery cell and the said 2nd battery cell which were piled up.   6. The secondary battery according to claim 4, further comprising an outer package that encloses and seals the stacked first battery cell, second battery cell, and third battery cell. 7.   An electronic device comprising the secondary battery according to claim 6. A first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part interposed therebetween, and a second positive electrode and a second negative electrode arranged with a second electrolyte part in between A second battery cell comprising: a method for manufacturing a secondary battery comprising:
Stacking the second battery cell on the first battery cell so that the first negative electrode and the second negative electrode are electrically connected;
The first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are heated and melted to melt the first electrolyte And a step of solidifying in a state where a part of the electrolyte part and a part of the second electrolyte part are bonded to each other. A first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part interposed therebetween, and a second positive electrode and a second negative electrode arranged with a second electrolyte part in between A second battery cell comprising: a method for manufacturing a secondary battery comprising:
Stacking the second battery cell on the first battery cell such that the first positive electrode and the second positive electrode are electrically connected;
The first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are heated and melted to melt the first electrolyte And a step of solidifying in a state where a part of the electrolyte part and a part of the second electrolyte part are bonded to each other. A first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part interposed therebetween, and a second positive electrode and a second negative electrode arranged with a second electrolyte part in between A second battery cell comprising: a method for manufacturing a secondary battery comprising:
Stacking the second battery cell on the first battery cell so that the first negative electrode and the second positive electrode are electrically connected;
The first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode are heated and melted to melt the first electrolyte And a step of solidifying in a state where a part of the electrolyte part and a part of the second electrolyte part are bonded to each other. A first battery cell having a first positive electrode and a first negative electrode arranged with a first electrolyte part interposed therebetween, and a second positive electrode and a second negative electrode arranged with a second electrolyte part in between And a third battery cell having a third positive electrode and a third negative electrode arranged with a third electrolyte portion interposed therebetween, in a method for manufacturing a secondary battery. There,
With respect to the first battery cell, the first negative electrode and the second negative electrode are electrically connected, and the second positive electrode and the third positive electrode are electrically connected. Stacking the second battery cell and the third battery cell;
Of the first electrolyte part, the second electrolyte part, and the third electrolyte part, the first electrolyte part that protrudes to the side of the first positive electrode and the side of the second positive electrode Heating and melting the protruding second electrolyte part, and solidifying the molten part of the first electrolyte part and the part of the second electrolyte part combined with each other. A manufacturing method of a secondary battery provided.   The heating body is brought into contact with the first electrolyte part protruding to the side of the first positive electrode and the second electrolyte part protruding to the side of the second positive electrode to be melted. The manufacturing method of the secondary battery as described in any one of thru | or 12.   10. The first electrolyte part that protrudes to the side of the first positive electrode and the second electrolyte part that protrudes to the side of the second positive electrode are melted by irradiation with laser light. The manufacturing method of the secondary battery as described in any one of thru | or 12.   Of the first electrolyte part, the second electrolyte part, and the third electrolyte part, the first electrolyte part that protrudes to the side of the first positive electrode and the side of the second positive electrode The second electrolyte part that protrudes and the third electrolyte part that protrudes to the side of the third positive electrode are heated and melted, and a part of the melted first electrolyte part and the first electrolyte part are heated. The method for producing a secondary battery according to claim 12, further comprising a step of solidifying the second electrolyte part and a part of the third electrolyte part in a coupled state.

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