Energy Storage Devices

Abstract

To provide a power storage device capable of improving yield and durability by shortening the time required for manufacture.SOLUTION: In a power storage device 10, a positive electrode plate 11 in which positive electrode mixture layers 11b are formed on both surfaces of a positive electrode collector 11a, a negative electrode plate 12 in which negative electrode mixture layers 12b are formed on both surfaces of a negative electrode collector 12a, and a solid electrolyte layer 13 held between the positive electrode plate 11 and the negative electrode plate 12 are provided inside of a sheath body 14. In the power storage device 10, a joint member 16 is further provided inside of the sheath body 14 in such a manner that a first space 15A in contact with the positive electrode plate 11 and the solid electrolyte layer 13 is separated from a second space 15B in contact with the negative electrode plate 12 and the solid electrolyte layer 13. In the power storage device 10, the first space 15A is filled with a first electrolyte and the second space 15B is filled with a second electrolyte.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electricity storage device. [Background technology]

[0002] In light of climate-related disasters, there is a need to reduce CO2 emissions, so there is growing interest in electric vehicles equipped with secondary batteries.

[0003] Patent Document 1 describes a secondary battery including a partition wall separating a first space and a second space from each other and allowing metal ions to pass between the first space and the second space, a negative electrode disposed in the first space and absorbing and releasing metal ions, and a positive electrode disposed in the second space and absorbing and releasing metal ions. Here, a first aqueous electrolyte solution containing metal ions is accommodated in the first space, and a second aqueous electrolyte solution containing metal ions and having a pH lower than that of the first aqueous electrolyte solution is accommodated in the second space. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 218456 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the structure of accommodating the first aqueous electrolyte solution and the second aqueous electrolyte solution in the first space in which the negative electrode is disposed and the second space in which the positive electrode is disposed, respectively, is complicated, the time required for manufacturing the secondary battery is increased. In addition, during the manufacturing process of the secondary battery, the possibility that either the first aqueous electrolyte solution or the second aqueous electrolyte solution will be mixed into the other electrolyte solution increases, resulting in a decrease in yield. Furthermore, due to the thermal cycle during charging and discharging of the secondary battery, the partition wall is likely to peel off, and the components contained in either the first space or the second space are likely to be mixed into the other space, resulting in a decrease in durability.

[0006] An object of the present invention is to provide an electricity storage device that can be manufactured in a shorter time and with improved yield and durability. [Means for solving the problem]

[0007] In one aspect of the present invention, in an electricity storage device, a positive electrode plate having a positive electrode mixture layer formed on both sides of a positive electrode current collector, a negative electrode plate having a negative electrode mixture layer formed on both sides of a negative electrode current collector, and a solid electrolyte layer sandwiched between the positive electrode plate and the negative electrode plate are provided within an exterior body, a bonding member is further provided within the exterior body so as to isolate a first space in contact with the positive electrode plate and the solid electrolyte layer from a second space in contact with the negative electrode plate and the solid electrolyte layer, a first electrolyte composition is disposed in the first space, and a second electrolyte composition is disposed in the second space.

[0008] The first electrolyte composition may be different from the second electrolyte composition.

[0009] The above-mentioned electricity storage device may have a plurality of the positive electrode plates and / or the negative electrode plates and the solid electrolyte layers, and adjacent solid electrolyte layers may be joined via the joining member such that the positive electrode plates do not contact the second space and the negative electrode plates do not contact the first space.

[0010] The above-mentioned electricity storage device may further include an end member within the exterior body, the end member having a positive electrode composite layer formed on one surface of a positive electrode collector and a retaining plate formed on the other surface, the solid electrolyte layer being sandwiched between the end member and the negative electrode plate adjacent to the end member, the solid electrolyte layer sandwiched between the end member and the negative electrode plate adjacent to the end member being joined to the retaining plate via the joining member so that the positive electrode collector and the positive electrode composite layer constituting the end member do not come into contact with the second space, and the retaining plate being joined to the exterior body via the joining member.

[0011] The above-mentioned electricity storage device may further include an end member within the exterior body, the end member having a negative electrode composite layer formed on one surface of a negative electrode collector and a retaining plate formed on the other surface, the solid electrolyte layer being sandwiched between the end member and the positive electrode plate adjacent to the end member, the solid electrolyte layer sandwiched between the end member and the positive electrode plate adjacent to the end member being joined to the retaining plate via the joining member so that the negative electrode collector and the negative electrode composite layer constituting the end member do not come into contact with the first space, and the retaining plate being joined to the exterior body via the joining member.

[0012] In the above-described electricity storage device, at least a part of a region of the solid electrolyte layer that is not in contact with the first space and the second space may be joined to the exterior body via the joining member.

[0013] In the above-described electricity storage device, the joining member may be provided in a region of the solid electrolyte layer that is not sandwiched between the positive electrode plate and the negative electrode plate.

[0014] In the above-mentioned power storage device, the positive electrode plate, the negative electrode plate, and the solid electrolyte layer may be substantially rectangular in a plan view, and the regions in which the joining members are provided may overlap with at least a portion of two sides of the adjacent solid electrolyte layers other than the sides in contact with the first space and the second space. Effect of the Invention

[0015] According to the present invention, it is possible to provide an electricity storage device that can be manufactured in a shorter time and with improved yield and durability. [Brief description of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view illustrating an example of an electricity storage device according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view of the electricity storage device of FIG. 1 taken along the ZZ′ line. [Diagram 3] 2A to 2C are diagrams illustrating an example of a method for manufacturing the electricity storage device in FIG. [Figure 4] 2 is a diagram showing a solid electrolyte layer used in a modified example of the electricity storage device in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] FIG. 1 shows an example of the electricity storage device of this embodiment.

[0019] In the electricity storage device 10, a positive electrode plate 11 having a positive electrode mixture layer 11b formed on both sides of a positive electrode current collector 11a, a negative electrode plate 12 having a negative electrode mixture layer 12b formed on both sides of a negative electrode current collector 12a, and a solid electrolyte layer 13 sandwiched between the positive electrode plate 11 and the negative electrode plate 12 are provided in an exterior body 14. In the electricity storage device 10, a joining member 16 is further provided in the exterior body 14 so as to separate a first space 15A in contact with the positive electrode plate 11 and the solid electrolyte layer 13 from a second space 15B in contact with the negative electrode plate 12 and the solid electrolyte layer 13. In this case, the positive electrode plate 11 has a positive electrode tab lead 11c extending from the positive electrode current collector 11a to the first space 15A side, and the negative electrode plate 12 has a negative electrode tab lead 12c extending from the negative electrode current collector 12a to the second space 15B side. Furthermore, in the electricity storage device 10, the first space 15A is filled with a first electrolyte solution as a first electrolyte composition, and the second space 15B is filled with a second electrolyte solution as a second electrolyte composition. This shortens the time required to manufacture the electricity storage device 10. In addition, during the manufacturing process of the electricity storage device 10, the possibility that either the first electrolyte solution or the second electrolyte solution will be mixed into the other electrolyte solution is reduced, improving the yield. Furthermore, due to a thermal cycle during charging and discharging of the electricity storage device 10, the joining member 16 is less likely to peel off, and the components contained in either the first space 15A or the second space 15B are less likely to be mixed into the other space, improving durability.

[0020] The exterior body 14 is not particularly limited, but examples thereof include a laminate film.

[0021] Examples of materials constituting the laminate film include aluminum and stainless steel.

[0022] The thickness of the exterior body 14 is not particularly limited, but is, for example, not less than 50 μm and not more than 500 μm.

[0023] The material constituting the joining member 16 is not particularly limited as long as it is capable of joining corresponding members so as to isolate the first space 15A and the second space 15B, but examples thereof include polyolefin resin, epoxy resin, polyurethane resin, acrylic resin, silicone resin, etc.

[0024] In the electricity storage device 10, an end member 17 having a negative electrode mixture layer 17b formed on one surface of a negative electrode collector 17a and a holding plate 17c formed on the other surface is further provided in the exterior body 14, and a solid electrolyte layer 13 is sandwiched between the end member 17 and a positive electrode plate 11 adjacent to the end member 17. In this case, a negative electrode tab lead 17d of the end member 17 extends from the negative electrode collector 17a to the second space 15B side. In the electricity storage device 10, the solid electrolyte layer 13 sandwiched between the end member 17 and the positive electrode plate 11 adjacent to the end member 17 and the holding plate 17c are joined via a joining member 16 so that the negative electrode collector 17a and the negative electrode mixture layer 17b do not come into contact with the first space 15A. In the electricity storage device 10, the holding plate 17c is joined to the exterior body 14 via a joining member 16.

[0025] Here, negative electrode current collector 17a and negative electrode mixture layer 17b may be the same as negative electrode current collector 12a and negative electrode mixture layer 12b, or may be different.

[0026] The material constituting the retaining plate 17c is not particularly limited as long as it is capable of retaining the upper and lower surfaces of the electricity storage device 10 and is chemically stable with respect to the first electrolyte solution and the second electrolyte solution, but examples of the material include stainless steel, copper, nickel, polyolefin resin, epoxy resin, polyurethane resin, acrylic resin, silicone resin, etc.

[0027] The thickness of the holding plate 17c is not particularly limited, but is, for example, not less than 100 μm and not more than 1000 μm.

[0028] Instead of the end member 17, an end member having a positive electrode composite layer formed on one surface of a positive electrode current collector and a retaining plate formed on the other surface may be used. In this case, a solid electrolyte layer 13 is sandwiched between the end member and the negative electrode plate 12 adjacent to the end member, and the solid electrolyte layer 13 sandwiched between the end member and the negative electrode plate 12 adjacent to the end member and the retaining plate are joined via a joining member 16 so that the positive electrode current collector and the positive electrode composite layer constituting the end member do not come into contact with the second space 15B.

[0029] In the electricity storage device 10, adjacent solid electrolyte layers 13 are joined via joining members 16 so that the positive electrode plate 11 does not contact the second space 15B and the negative electrode plate 12 does not contact the first space 15A. This improves the vibration resistance and volumetric energy density of the electricity storage device 10.

[0030] As shown in FIG. 2, in the electricity storage device 10, a region of the solid electrolyte layer 13 that is not in contact with the first space 15A and the second space 15B is joined to the exterior body 14 via a joining member 16.

[0031] The electricity storage device 10 can be manufactured, for example, as shown in Fig. 3, by welding and joining the outer periphery of an electrode group obtained by stacking a solid electrolyte layer 13 having a substantially rectangular shape in plan view, a positive electrode plate 11, a solid electrolyte layer 13, a negative electrode plate 12, and the like, to an exterior body 14 via a joining member 16, and then filling the first space 15A and the second space 15B with a first electrolytic solution and a second electrolytic solution, respectively. At this time, the joining member 16 is provided in an area of ​​the solid electrolyte layer 13 that is not sandwiched between the positive electrode plate 11 and the negative electrode plate 12. Specifically, the solid electrolyte layer 13 on which the positive electrode plate 11 is stacked has the joining member 16 provided on the side on which the positive electrode tab lead 11c extends, i.e., on the side on which the positive electrode plate 11 is stacked on three sides other than the side in contact with the first space 15A. Furthermore, the solid electrolyte layer 13 on which the negative electrode plate 12 is laminated is provided with a bonding member 16 on the side on which the negative electrode tab lead 12c extends, i.e., on the three sides on which the negative electrode plate 12 is laminated other than the side in contact with the second space 15B. For this reason, in the electricity storage device 10, the regions on which the bonding members 16 are provided overlap on two sides of the adjacent solid electrolyte layers 13 other than the sides in contact with the first space 15A and the second space 15B.

[0032] The width of the bonding members 16 provided on the solid electrolyte layer 13 is not particularly limited, but is, for example, not less than 1 mm and not more than 10 mm.

[0033] In addition, the solid electrolyte layer 13 on which the positive electrode plate 11 is laminated may have a bonding member 16 provided on the side on which the positive electrode plate 11 is not laminated, and the solid electrolyte layer 13 on which the negative electrode plate 12 is laminated may have a bonding member 16 provided on the side on which the negative electrode plate 12 is not laminated.

[0034] In addition, as shown in FIG. 4, the electricity storage device 10 may have overlapping areas in which the bonding members 16 are provided on parts of two sides other than the sides in contact with the first space 15A and the second space 15B of the adjacent solid electrolyte layer 13.

[0035] The length L of the overlap between the regions of adjacent solid electrolyte layers 13 where bonding members 16 are provided is preferably 5 mm or more, and more preferably 10 mm or more. When L is 5 mm or more, the yield and durability of the electricity storage device 10 are improved.

[0036] Note that the electricity storage device 10 has two positive electrode plates 11, one negative electrode plate 12, and four solid electrolyte layers 13, but the numbers of the positive electrode plates 11, the negative electrode plates 12, and the solid electrolyte layers 13 are not particularly limited.

[0037] Furthermore, when the electricity storage device 10 has a plurality of positive electrode plates 11, negative electrode plates 12, and solid electrolyte layers 13, the plurality of positive electrode plates 11, negative electrode plates 12, and solid electrolyte layers 13 may be the same or different.

[0038] The electricity storage device 10 is not particularly limited as long as it is a device that can repeatedly store and release electrical energy, and examples of the electricity storage device 10 include a lithium ion secondary battery, a lithium air battery, a lithium ion capacitor, and a redox flow battery.

[0039] The following describes the case where the power storage device 10 is a lithium ion secondary battery.

[0040] The positive electrode current collector 11a is not particularly limited, but examples thereof include metal foils such as aluminum foils.

[0041] The thickness of the positive electrode current collector 11a is not particularly limited, but is, for example, not less than 5 μm and not more than 15 μm.

[0042] Positive electrode mixture layer 11b contains a positive electrode active material, and may further contain a solid electrolyte, a conductive assistant, a binder, and the like, as necessary.

[0043] The positive electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions. For example, LiCoO2, Li(Ni 5 / 10 Co 2 / 10 Mn3 / 10 )O 2、 Li(Ni) 6 / 10 Co 2 / 10 Mn 2 / 10 )O 2、 Li(Ni) 8 / 10 Co 1 / 10 Mn 1 / 10 )O 2、 Li(Ni) 0.8 Co 0.15 Al 0.05 )O 2、 Li(Ni) 1 / 6 Co 4 / 6 Mn 1 / 6 )O 2、 Li(Ni) 1 / 3 Co 1 / 3 Mn 1 / 3 )O 2、 Examples of the positive electrode active material include LiCoO4, LiMn2O4, LiNiO2, LiFePO4, lithium sulfide, sulfur, etc. These positive electrode active materials may be used alone or in combination.

[0044] The content of the positive electrode active material in positive electrode mixture layer 11b is not particularly limited, but is, for example, not less than 75 mass % and not more than 95 mass %.

[0045] The thickness of positive electrode mixture layer 11b is not particularly limited, but is, for example, not less than 20 μm and not more than 1000 μm.

[0046] The negative electrode current collector 12a is not particularly limited, but examples thereof include metal foils such as copper foils.

[0047] The thickness of the negative electrode current collector 12a is not particularly limited, but is, for example, not less than 5 μm and not more than 15 μm.

[0048] Negative electrode mixture layer 12b contains a negative electrode active material, and may further contain a solid electrolyte, a conductive assistant, a binder, and the like, as necessary.

[0049] The content of the negative electrode active material in negative electrode mixture layer 12b is not particularly limited, but is, for example, not less than 60 mass % and not more than 95 mass %.

[0050] The negative electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions, and examples thereof include metallic lithium, lithium alloys, metal oxides, metal sulfides, metal nitrides, Si, SiO, carbon materials, etc. These negative electrode active materials may be used alone or in combination.

[0051] Examples of the carbon material include artificial graphite, natural graphite, hard carbon, and soft carbon.

[0052] The thickness of negative electrode mixture layer 12b is not particularly limited, but is, for example, not less than 10 μm and not more than 500 μm.

[0053] The solid electrolyte constituting the solid electrolyte layer 13 is not particularly limited, but examples thereof include lithium ion conductive oxides and lithium ion conductive sulfides.

[0054] The thickness of solid electrolyte layer 13 is not particularly limited, but is, for example, not less than 20 μm and not more than 150 μm.

[0055] The first electrolyte and the second electrolyte may be the same or different.

[0056] When the first electrolytic solution and the second electrolytic solution are different, an aqueous electrolytic solution and a non-aqueous electrolytic solution (organic electrolytic solution) can be used as the first electrolytic solution and the second electrolytic solution, respectively.

[0057] The aqueous electrolyte contains an electrolyte and water.

[0058] Examples of the electrolyte contained in the aqueous electrolyte solution include lithium chloride, lithium sulfate, lithium acetate, lithium perchlorate, etc. These electrolytes may be used alone or in combination.

[0059] The non-aqueous electrolyte solution contains an electrolyte and an organic solvent.

[0060] Examples of the electrolyte contained in the non-aqueous electrolyte solution include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bisfluorosulfonylimide, lithium bistrifluoromethanesulfonylimide, etc. These electrolytes may be used alone or in combination.

[0061] Examples of the organic solvent contained in the non-aqueous electrolyte solution include propylene carbonate, ethylene carbonate, diethyl carbonate, ethyl methyl carbonate, diethylene glycol dimethyl ether, etc. These organic solvents may be used alone or in combination.

[0062] A polymer gel electrolyte may be prepared by adding a polymer gelling agent to at least one of the first electrolytic solution and the second electrolytic solution, i.e., at least one of the first electrolytic solution and the second electrolytic solution may be a polymer gel electrolyte having a polymer gelling agent as a matrix.

[0063] Also, instead of filling the first space 15A with the first electrolytic solution, a solid electrolyte having a similar function to the first electrolytic solution may be disposed, and instead of filling the second space 15B with the second electrolytic solution, a solid electrolyte having a similar function to the second electrolytic solution may be disposed. These solid electrolytes may be disposed in the first space 15A or the second space 15B, or may be disposed in the first space 15A and the second space 15B.

[0064] The solid electrolyte is not particularly limited, but examples thereof include lithium ion conductive oxides and lithium ion conductive sulfides.

[0065] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the above embodiment may be modified as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0066] 10. Energy storage devices 11 Positive electrode plate 11a Positive electrode current collector 11b Positive electrode composite layer 11c Positive electrode tab lead 12 Negative plate 12a Negative electrode current collector 12b Negative electrode composite layer 12c Negative electrode tab lead 13 Solid electrolyte layer 14 Exterior body 15A First Space 15B Second Space 16 Joining materials 17 End member 17a Negative electrode current collector 17b Negative electrode composite layer 17c retaining plate 17d Negative electrode tab lead

Claims

1. a positive electrode plate having a positive electrode mixture layer formed on both sides of a positive electrode current collector, a negative electrode plate having a negative electrode mixture layer formed on both sides of a negative electrode current collector, and a solid electrolyte layer sandwiched between the positive electrode plate and the negative electrode plate, a bonding member is further provided in the exterior body so as to separate a first space in contact with the positive electrode plate and the solid electrolyte layer from a second space in contact with the negative electrode plate and the solid electrolyte layer; a first electrolyte composition is disposed in the first space; A second electrolyte composition is disposed in the second space.

2. The power storage device of claim 1 , wherein the first electrolyte composition is different from the second electrolyte composition.

3. The battery includes a plurality of positive and negative electrode plates and a plurality of solid electrolyte layers, 3. The electricity storage device according to claim 1, wherein adjacent solid electrolyte layers are joined via the joining member such that the positive electrode plate does not contact the second space and the negative electrode plate does not contact the first space.

4. an end member having a positive electrode mixture layer formed on one surface of a positive electrode current collector and a holding plate formed on the other surface of the end member is further provided within the exterior body; the solid electrolyte layer is sandwiched between the end member and the negative electrode plate adjacent to the end member, a solid electrolyte layer sandwiched between the end member and the negative electrode plate adjacent to the end member and the retaining plate are joined via the joining member so that the positive electrode current collector and the positive electrode mixture layer constituting the end member do not come into contact with the second space, The power storage device according to claim 3 , wherein the holding plate and the exterior body are joined via the joining member.

5. an end member having a negative electrode mixture layer formed on one surface of a negative electrode current collector and a holding plate formed on the other surface of the end member is further provided within the exterior body; the solid electrolyte layer is sandwiched between the end member and the positive electrode plate adjacent to the end member, a solid electrolyte layer sandwiched between the end member and the positive electrode plate adjacent to the end member and the retaining plate are joined via the joining member so that the negative electrode current collector and the negative electrode mixture layer constituting the end member do not come into contact with the first space, The power storage device according to claim 3 , wherein the holding plate and the exterior body are joined via the joining member.

6. 6. The electricity storage device according to claim 3, wherein at least a part of a region of the solid electrolyte layer that is not in contact with the first space and the second space is joined to the exterior body via the joining member.

7. The power storage device according to claim 3 , wherein the joining member is provided in an area of ​​the solid electrolyte layer that is not sandwiched between the positive electrode plate and the negative electrode plate.

8. the positive electrode plate, the negative electrode plate, and the solid electrolyte layer are generally rectangular in plan view, 8. The power storage device according to claim 7, wherein adjacent two sides of the solid electrolyte layer other than the sides in contact with the first space and the second space have overlapping regions in which the joining members are provided.

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