JP2023057462A - Power storage device - Google Patents

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

The present invention relates to an electricity storage device.

From the viewpoint of climate-related disasters, there is a growing interest in electric vehicles equipped with secondary batteries due to the need to reduce _CO2 emissions.

Patent Document 1 discloses a partition wall that separates a first space and a second space from each other and allows metal ions to pass between the first space and the second space; A secondary battery is described that includes a negative electrode that occludes and releases ions and a positive electrode that is disposed inside the second space and that occludes and releases metal ions. Here, the inside of the first space contains a first aqueous electrolyte containing metal ions, and the inside of the second space contains metal ions and has a pH lower than that of the first aqueous electrolyte. A second aqueous electrolyte having a pH is accommodated.

WO2020/218456

However, since the structure of accommodating the first aqueous electrolyte and the second aqueous electrolyte in the first space where the negative electrode is arranged and the second space where the positive electrode is arranged, respectively, is complicated, it takes longer. In addition, during the manufacturing process of the secondary battery, there is a high possibility that one of the first aqueous electrolyte and the second aqueous electrolyte will be mixed with the other electrolyte, resulting in a decrease in yield. Furthermore, due to heat cycles 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 mixed into the other space. decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electricity storage device capable of shortening the time required for manufacturing and improving yield and durability.

One aspect of the present invention is an electricity storage device comprising a positive electrode plate in which positive electrode mixture layers are formed on both sides of a positive electrode current collector, and a negative electrode plate in which negative electrode mixture layers are formed on both sides of a negative electrode current collector. , a solid electrolyte layer sandwiched between the positive electrode plate and the negative electrode plate, are provided in an exterior body, and a first space in contact with the positive electrode plate and the solid electrolyte layer; A joining member is further provided in the exterior body so as to separate the negative electrode plate and the second space in contact with the solid electrolyte layer, and the first electrolyte composition is placed in the first space. and a second electrolyte composition is disposed in the second space.

The first electrolyte composition may be different than the second electrolyte composition.

The power storage device includes at least one of the positive electrode plate and the negative electrode plate, and a plurality of the solid electrolyte layers, the positive electrode plate does not contact the second space, and the negative electrode plate The adjacent solid electrolyte layers may be joined via the joining member so as not to come into contact with the space.

In the above electricity storage device, the positive electrode mixture layer is formed on one surface of the positive electrode current collector, and an end member having a holding plate formed on the other surface is further provided in the exterior body, The solid electrolyte layer is sandwiched between an end member and the negative electrode plate adjacent to the end member, and the positive electrode current collector and the positive electrode mixture layer forming the end member are connected to the second electrode plate. The solid electrolyte layer sandwiched between the end member and the negative electrode plate adjacent to the end member and the holding plate are joined via the joining member so as not to contact the space. , and the holding plate and the exterior body may be joined via the joining member.

In the above electricity storage device, the negative electrode mixture layer is formed on one surface of the negative electrode current collector, and an end member having a holding plate formed on the other surface is further provided in the exterior body, The solid electrolyte layer is sandwiched between an end member and the positive electrode plate adjacent to the end member, and the negative electrode current collector and the negative electrode mixture layer that constitute the end member are connected to the first electrode plate. The solid electrolyte layer sandwiched between the end member and the positive electrode plate adjacent to the end member and the holding plate are joined via the joining member so as not to come into contact with the space. , and the holding plate and the exterior body may be joined via the joining member.

In the electric storage device, at least 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. good too.

In the above 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.

In the electricity storage device, the positive electrode plate, the negative electrode plate, and the solid electrolyte layer are substantially rectangular in plan view, and are in contact with the first space and the second space of the adjacent solid electrolyte layers. The regions provided with the joining members may overlap at least a part of two sides other than the side sides.

ADVANTAGE OF THE INVENTION According to this invention, the time required for manufacture can be shortened, and it can provide the electrical storage device which can improve a yield and durability.

It is a sectional view showing an example of an electricity storage device of this embodiment. FIG. 2 is a cross-sectional view of the electricity storage device of FIG. 1 along the ZZ′ direction; 1. It is a figure which shows an example of the manufacturing method of the electrical storage device of FIG. 1. It is a figure which shows the solid electrolyte layer used with the modification of the electrical storage device of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

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

The electricity storage device 10 includes a positive electrode plate 11 in which positive electrode mixture layers 11b are formed on both sides of a positive electrode current collector 11a, and a negative electrode plate 12 in which negative electrode mixture layers 12b are 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 the exterior body 14 . In addition, the power storage device 10 separates the first space 15A in contact with the positive electrode plate 11 and the solid electrolyte layer 13 and the second space 15B in contact with the negative electrode plate 12 and the solid electrolyte layer 13. As shown, a joint member 16 is further provided within the exterior body 14 . At this time, the positive electrode plate 11 has the 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 extends from the negative electrode current collector 12a to the second space. A negative electrode tab lead 12c extends on the side of 15B. Furthermore, in the electricity storage device 10, the first space 15A is filled with the first electrolyte solution as the first electrolyte composition, and the second electrolyte solution as the second electrolyte composition is filled in the second space 15A. is filled in the space 15B. Therefore, the time required to manufacture the electricity storage device 10 is shortened. Moreover, in the manufacturing process of the electric storage device 10, the possibility that either the first electrolytic solution or the second electrolytic solution is mixed with the other electrolytic solution is reduced, and the yield is improved. Furthermore, there is a possibility that the bonding member 16 will peel off due to thermal cycles or the like during charging and discharging of the electricity storage device 10, and components contained in either the first space 15A or the second space 15B will mix into the other space. is reduced and durability is improved.

Examples of the exterior body 14 include, but are not particularly limited to, a laminate film and the like.

Materials constituting the laminate film include, for example, aluminum and stainless steel.

Although the thickness of the exterior body 14 is not particularly limited, it is, for example, 50 μm or more and 500 μm or less.

The material constituting the joining member 16 is not particularly limited as long as it is possible to join the corresponding members so as to separate the first space 15A and the second space 15B. Examples include polyolefin resins, epoxy resins, polyurethane resins, acrylic resins, and silicone resins.

The power storage device 10 has a negative electrode mixture layer 17b formed on one surface of a negative electrode current collector 17a, and an end member 17 having a holding plate 17c formed on the other surface. A solid electrolyte layer 13 is sandwiched between the end member 17 and the positive electrode plate 11 adjacent to the end member 17 . At this time, the end member 17 has a negative electrode tab lead 17d extending from the negative electrode current collector 17a to the second space 15B side. In addition, the power storage device 10 is sandwiched between the end member 17 and the positive electrode plate 11 adjacent to the end member 17 so that the negative electrode current collector 17a and the negative electrode mixture layer 17b do not come into contact with the first space 15A. The solid electrolyte layer 13 and the holding plate 17 c are joined via the joining member 16 . Furthermore, in the electric storage device 10 , the holding plate 17 c and the exterior body 14 are joined via the joining member 16 .

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

As a material for the holding plate 17c, a material capable of holding the upper and lower surfaces of the electric storage device 10 and chemically stable with respect to the first electrolytic solution and the second electrolytic solution is used. If there is, it is not particularly limited, but examples thereof include stainless steel, copper, nickel, polyolefin resin, epoxy resin, polyurethane resin, acrylic resin, and silicone resin.

Although the thickness of the holding plate 17c is not particularly limited, it is, for example, 100 μm or more and 1000 μm or less.

Instead of the end member 17, an end member having a positive electrode mixture layer formed on one surface of the positive electrode current collector and a holding plate formed on the other surface may be used. In this case, the solid electrolyte layer 13 is sandwiched between the end member and the negative electrode plate 12 adjacent to the end member. The solid electrolyte layer 13 sandwiched between the end member and the negative electrode plate 12 adjacent to the end member and the holding plate are joined via the joining member 16 so as not to come into contact with the solid electrolyte layer 13 .

In the electricity storage device 10, the adjacent solid electrolyte layers 13 are joined via the joining member 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. ing. Therefore, the vibration resistance and volumetric energy density of the electricity storage device 10 are improved.

In the electric storage device 10, as shown in FIG. 2, 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. ing.

For example, as shown in FIG. 3 , the electricity storage device 10 has an outer circumference of an electrode group obtained by laminating a substantially rectangular solid electrolyte layer 13 , a positive electrode plate 11 , a solid electrolyte layer 13 , a negative electrode plate 12 , and the like, and an exterior. After welding and joining the body 14 via the joining member 16, the first space 15A and the second space 15B are filled with the first electrolytic solution and the second electrolytic solution, respectively. can do. At this time, a bonding member 16 is provided in a region 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 laminated has three sides of the positive electrode plate 11 other than the side on which the positive electrode tab lead 11c extends, that is, the side that contacts the first space 15A. is laminated, a joining member 16 is provided. In the solid electrolyte layer 13 on which the negative electrode plate 12 is laminated, the negative electrode plate 12 on three sides other than the side on which the negative electrode tab lead 12c extends, that is, the side that contacts the second space 15B is laminated. A joining member 16 is provided on the side of the connector. Therefore, in the electric storage device 10, the two sides other than the sides in contact with the first space 15A and the second space 15B of the adjacent solid electrolyte layers 13 have regions where the bonding members 16 are provided. Overlap.

The width of the bonding member 16 provided on the solid electrolyte layer 13 is not particularly limited, but is, for example, 1 mm or more and 10 mm or less.

The solid electrolyte layer 13 on which the positive electrode plate 11 is laminated may be provided with a joining member 16 on the side on which the positive electrode plate 11 is not laminated. A joining member 16 may be provided on the side where the plate 12 is not laminated.

Moreover, as shown in FIG. 4, the electric storage device 10 is joined at a part of two sides other than the sides in contact with the first space 15A and the second space 15B of the adjacent solid electrolyte layers 13. The regions in which the members 16 are provided may overlap.

The overlapping length L of the regions provided with the bonding members 16 of the adjacent solid electrolyte layers 13 is preferably 5 mm or more, 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.

Electricity storage device 10 has two positive electrode plates 11 , one negative electrode plate 12 and four solid electrolyte layers 13 . is not particularly limited.

Further, when the power 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. good too.

The electricity storage device 10 is not particularly limited as long as it is a device that can repeatedly store and release electrical energy. mentioned.

A case where the electricity storage device 10 is a lithium ion secondary battery will be described below.

Examples of the positive electrode current collector 11a include, but are not limited to, metal foil such as aluminum foil.

Although the thickness of the positive electrode current collector 11a is not particularly limited, it is, for example, 5 μm or more and 15 μm or less.

The positive electrode mixture layer 11b contains a positive electrode active material, and if necessary, may further contain a solid electrolyte, a conductive aid, a binder, and the like.

The positive electrode active material is _{not particularly} limited as long _as it _is capable of intercalating and deintercalating lithium ions _. Ni6 _/10Co2 / _{10Mn2 /10} )O2 _{, Li} (Ni8 _{/ 10Co1} / _{10Mn1 /10} )O2 _, Li( _{Ni0.8Co0.15Al0.05} )O _2, Li(Ni1 _/6Co4 / _{6Mn1/ 6} )O2 _, Li(Ni1/ _{3Co1 / 3Mn1/3} )O2 _{, LiCoO4} , _{LiMn2O4 , LiNiO2} , LiFePO ₄ , lithium sulfide, sulfur, and the like. These positive electrode active materials may be used alone or in combination.

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

Although the thickness of the positive electrode mixture layer 11b is not particularly limited, it is, for example, 20 μm or more and 1000 μm or less.

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

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

The negative electrode mixture layer 12b contains a negative electrode active material, and may further contain a solid electrolyte, a conductive aid, a binder, and the like, if necessary.

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

The negative electrode active material is not particularly limited as long as it is capable of intercalating and deintercalating lithium ions. materials and the like. These negative electrode active materials may be used alone or in combination.

Examples of carbon materials include artificial graphite, natural graphite, hard carbon, and soft carbon.

Although the thickness of the negative electrode mixture layer 12b is not particularly limited, it is, for example, 10 μm or more and 500 μm or less.

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

Although the thickness of the solid electrolyte layer 13 is not particularly limited, it is, for example, 20 μm or more and 150 μm or less.

The first electrolytic solution and the second electrolytic solution may be the same or different.

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.

Aqueous electrolytes contain an electrolyte and water.

Examples of the electrolyte contained in the aqueous electrolytic solution include lithium chloride, lithium sulfate, lithium acetate, lithium perchlorate, and the like. These electrolytes may be used alone or in combination.

A non-aqueous electrolytic solution contains an electrolyte and an organic solvent.

Examples of the electrolyte contained in the non-aqueous electrolytic solution include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bisfluorosulfonylimide, lithium bistrifluoromethanesulfonylimide, and the like. These electrolytes may be used alone or in combination.

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

A polymer gelling agent may be added to at least one of the first electrolytic solution and the second electrolytic solution to form a polymer gel electrolyte. That is, 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.

Further, instead of filling the first space 15A with the first electrolytic solution, a solid electrolyte having the same function as the first electrolytic solution may be placed, or the second space 15B may be filled with the second electrolytic solution. A solid electrolyte having the same function as the second electrolytic solution may be arranged instead of filling the liquid. These solid electrolytes may be arranged in the first space 15A or the second space 15B, or may be arranged in the first space 15A and the second space 15B.

Examples of the solid electrolyte include, but are not limited to, lithium ion conductive oxides, lithium ion conductive sulfides, and the like.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and the above embodiments may be changed as appropriate within the scope of the present invention.

REFERENCE SIGNS LIST 10 power storage device 11 positive electrode plate 11a positive current collector 11b positive electrode mixture layer 11c positive electrode tab lead 12 negative electrode plate 12a negative electrode current collector 12b negative electrode mixture layer 12c negative electrode tab lead 13 solid electrolyte layer 14 exterior body 15A first space 15B second space 16 joining member 17 end member 17a negative electrode current collector 17b negative electrode mixture layer 17c holding plate 17d negative electrode tab lead

Claims (8)

Between a positive electrode plate in which positive electrode mixture layers are formed on both sides of a positive electrode current collector, a negative electrode plate in which negative electrode mixture layers are formed on both sides of a negative electrode current collector, and the positive electrode plate and the negative electrode plate A solid electrolyte layer sandwiched between and is provided in the exterior body,
A joining member is provided in the exterior 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. is further provided in
A first electrolyte composition is disposed in the first space,
An electricity storage device, wherein a second electrolyte composition is disposed in the second space. 2. The electricity storage device of claim 1, wherein the first electrolyte composition is different from the second electrolyte composition. At least one of the positive electrode plate and the negative electrode plate, and a plurality of the solid electrolyte layers,
3. The adjacent solid electrolyte layers are joined via the joining member so that the positive electrode plate does not contact the second space and the negative electrode plate does not contact the first space. 3. The electricity storage device according to 1 or 2. An end member having a positive electrode mixture layer formed on one surface of the positive electrode current collector and a holding plate formed on the other surface is further provided in the exterior body,
The solid electrolyte layer is sandwiched between the end member and the negative electrode plate adjacent to the end member,
sandwiched between the end member and the negative electrode plate adjacent to the end member so that the positive electrode current collector and the positive electrode mixture layer constituting the end member do not contact the second space; The solid electrolyte layer and the holding plate are joined via the joining member,
The electricity storage device according to claim 3, wherein said holding plate and said exterior body are joined via said joining member. An end member having a negative electrode mixture layer formed on one surface of the negative electrode current collector and a holding plate formed on the other surface is further provided in the exterior body,
The solid electrolyte layer is sandwiched between the end member and the positive electrode plate adjacent to the end member,
sandwiched between the end member and the positive electrode plate adjacent to the end member so that the negative electrode current collector and the negative electrode mixture layer constituting the end member do not contact the first space; The solid electrolyte layer and the holding plate are joined via the joining member,
The electricity storage device according to claim 3, wherein said holding plate and said exterior body are joined via said joining member. 6. At least part of a region of said solid electrolyte layer that is not in contact with said first space and said second space and said exterior body are bonded via said bonding member. The electricity storage device according to any one of . The electricity storage device according to any one of claims 3 to 6, wherein the joining member is provided in a region of the solid electrolyte layer that is not sandwiched between the positive electrode plate and the negative electrode plate. The positive electrode plate, the negative electrode plate and the solid electrolyte layer are substantially rectangular in plan view,
2. The region where the bonding member is provided overlaps at least a part of two sides of the adjacent solid electrolyte layers other than the sides in contact with the first space and the second space. 8. The electricity storage device according to 7.

Images