JP2022086298A - Power storage cell and power storage device - Google Patents

Abstract

To provide a power storage cell and a power storage device which facilitate discharge of gas from a through part, and can prevent gas from accumulated at a boundary between a first wall part and a second wall part.SOLUTION: A resin frame 50 has a first wall part 51 provided with a through part 60, a second wall part 52 extending in a direction perpendicular to the first wall part 51, and a connection part 54 for connecting the first wall part 51 and the second wall part 52. The first wall part 51 has a first inner surface 51a facing a space S of the power storage cell 10. The second wall part 52 has a second inner surface 52a facing the space S of the power storage cell 10. The connection part 54 has an inclined surface 55 that faces the space S of the power storage cell 10, and connects the first inner surface 51a and the second inner surface 52a. An angle θ1 formed by the first inner surface 51a and the inclined surface 55 and an angle θ2 formed by the second inner surface 52a and the inclined surface 55 become obtuse.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power storage cell and a power storage device.

Conventionally, a power storage module as a power storage device described in Patent Document 1 is known.
The above-mentioned power storage module is configured by stacking a plurality of electrode units. The electrode unit includes a bipolar electrode and a resin frame that partitions a space together with adjacent bipolar electrodes. An electrolytic solution is housed in the space. When the resin frame is viewed in a plan view in the first direction in which the pair of electrodes are laminated, the resin frame has a rectangular annular shape. An injection port for injecting an electrolytic solution into a space is formed on one side of the resin frame. Of the four sides constituting the resin frame, the sides adjacent to each other are orthogonal to each other. The inlet also has a function of discharging the gas to the outside of the storage cell when gas is generated in the space.

Japanese Unexamined Patent Publication No. 2019-192584

When the gas generated in the space of the storage cell is discharged from the injection port, the gas flows toward one side of the resin frame provided with the injection port. At this time, there is a possibility that gas tends to accumulate at the boundary between each side portion continuous with the side portion provided with the injection port and the side portion provided with the injection port.

The storage cell that solves the above problems has active material layers facing each other, is interposed between the pair of electrodes overlapping each other and the pair of electrodes, and has a rectangular frame shape surrounding the active material layer. A storage cell including a resin frame that seals a space partitioned together with the pair of electrodes, and the penetration portion provided in the resin frame and extending to the outside of the space and the storage cell, and the penetration portion. The resin frame includes a closed portion to be closed, and the resin frame includes a first wall portion provided with the penetrating portion, a second wall portion extending in a direction orthogonal to the first wall portion, and the first wall portion and the first wall portion. The first wall portion has a first end surface facing the space, and the second wall portion has a second end surface facing the space. The connecting portion faces the space and has a changing surface connecting the first end surface and the second end surface, and the changing surface has an angle formed with each of the first end surface and the second end surface. It extends between the first end face and the second end face so as to have an blunt angle.

According to this, when the gas generated in the space of the storage cell is discharged to the outside of the storage cell in a state where the penetration portion is not blocked by the closed portion, the gas flows toward the penetration portion. At this time, there is a gas flowing along the second end face, the changing surface, and the first end face. Since the first end surface and the second end surface are connected by the changing surface, the gas can easily flow smoothly from the second end surface to the first end surface due to the changing surface. Therefore, the gas can be easily discharged from the penetrating portion, and the accumulation of gas at the boundary between the first wall portion and the second wall portion can be suppressed.

In the storage cell, the second wall portion is closer to the first end portion of the first wall portion in the first extension direction in which the first wall portion extends, and the second wall portion is said in the first extension direction. The first end surface provided near the second end portion of the first wall portion and the second end surface of the second wall portion provided near the first end portion are connected by the changing surface. It is preferable that the first end surface and the second end surface of the second wall portion provided near the second end portion are connected by the change surface.

According to this, in a state where the penetrating portion is not blocked by the blocked portion, the gas generated in the space of the storage cell is the first end surface due to the two changing surfaces provided corresponding to the two second wall portions. It becomes easy to flow smoothly. Therefore, the gas can be easily discharged from the penetrating portion, and the accumulation of gas at the boundary between the first wall portion and the second wall portion can be further suppressed.

In the storage cell, the resin frame is continuous on the side opposite to the first wall portion of the second wall portion, and the first wall portion is viewed in a plan view in a stacking direction in which the pair of electrodes overlap. The thickness of the first wall portion in the first thickness direction orthogonal to the first extension direction and the stacking direction is the thickness of the first wall portion having a third wall portion extending in the first extension direction in which the wall portion extends. It is equal to or greater than the thickness of the second wall portion in the second extending direction in which the two wall portions extend and the second thickness direction orthogonal to the stacking direction, and the thickness of the third wall portion in the first thickness direction. It is good.

According to this, the thickness of the first wall portion in the first thickness direction is equal to or greater than the thickness of the second wall portion in the second thickness direction and the thickness of the third wall portion in the third thickness direction. , The rigidity of the storage cell against the internal pressure is secured. Therefore, when the gas is discharged from the penetrating portion, the gas flows toward the first end surface due to the changing surface, and even if the gas concentrates on the penetrating portion, the sealing property at the position of the first wall portion is maintained on the second wall. It can be held in the same manner as the portion and the third wall portion.

In the storage cell, the thickness of the first wall portion changes in the first thickness direction orthogonal to the first extension direction in which the first wall portion extends and the stacking direction in which the pair of electrodes overlap. It is preferable that the connecting portion and the penetrating portion are arranged at a distance equal to or larger than the width of the penetrating portion in the first extending direction in the first extending direction.

According to this, it becomes easy to shift the position where the penetrating portion is provided in the first extension direction. Therefore, the degree of freedom in arranging the penetrating portion is improved.
In the storage cell, the changing surface may be an inclined surface extending between the first end surface and the second end surface in a plan view in a stacking direction in which the pair of electrodes overlap.

According to this, it is easier to manufacture the resin frame when the changing surface is an inclined surface as compared with the case where the changing surface is a curved surface. Therefore, the productivity of the storage cell can be improved. Therefore, the productivity of the storage cell is improved while facilitating the guidance of the gas to the penetrating portion.

In the storage cell, the inclined surface may extend to the penetration portion.
According to this, the gas can be directly guided to the penetrating portion along the inclined surface, so that the efficiency of degassing can be improved.

The power storage device for solving the above problems includes a plurality of power storage cells, and the plurality of power storage cells include at least one of the above power storage cells.
According to this, even in the power storage device, the gas can be easily discharged from the penetrating portion, and the accumulation of gas at the boundary between the first wall portion and the second wall portion can be suppressed.

According to the present invention, the gas can be easily discharged from the penetrating portion, and the accumulation of gas at the boundary between the first wall portion and the second wall portion can be suppressed.

Sectional drawing which shows the power storage device. Sectional drawing of the storage cell. Perspective view of the storage cell. FIG. 2 is a cross-sectional view taken along the line 4-4 of FIG. FIG. 2 is a cross-sectional view taken along the line 4-4 of FIG. FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. Sectional drawing of the resin frame in the modified example. The end view of the first wall part seen by the arrow E of FIG. Sectional drawing of the resin frame in the modified example. The perspective view of the storage cell in the modified example.

Hereinafter, an embodiment in which the power storage cell and the power storage device are embodied will be described with reference to FIGS. 1 to 6.
As shown in FIG. 1, the power storage device 1 includes a cell stack 2 composed of a plurality of stacked power storage cells 10. The direction in which the plurality of storage cells 10 are stacked is defined as the stacking direction C.

As shown in FIG. 2, the storage cell 10 includes a positive electrode 20, a negative electrode 30, a separator 40, and a resin frame 50. Looking at the storage cell 10 from the outside in the stacking direction C is called a plan view.

The positive electrode 20 is, for example, a rectangular electrode. The positive electrode 20 has a positive electrode current collector 21 having a rectangular shape in a plan view and a positive electrode active material layer 22 as an active material layer. The positive electrode current collector 21 has a first surface 21a and a second surface 21b located on the opposite side of the first surface 21a. The positive electrode active material layer 22 is provided on the first surface 21a of the positive electrode current collector 21. The positive electrode active material layer 22 is not provided on the second surface 21b of the positive electrode current collector 21. The positive electrode current collector 21 is located near the outer peripheral edge 21c of the positive electrode current collector 21 on the first surface 21a, and has an outer peripheral edge portion 21d in which the positive electrode active material layer 22 is not provided.

The negative electrode 30 is, for example, a rectangular electrode. The negative electrode 30 has a rectangular negative electrode current collector 31 in a plan view and a negative electrode active material layer 32 as an active material layer. The negative electrode current collector 31 has a first surface 31a and a second surface 31b located on the side opposite to the first surface 31a. The negative electrode active material layer 32 is provided on the first surface 31a of the negative electrode current collector 31. The negative electrode active material layer 32 is not provided on the second surface 31b of the negative electrode current collector 31. The negative electrode current collector 31 is located near the outer peripheral edge 31c of the negative electrode current collector 31 on the first surface 31a, and has an outer peripheral edge portion 31d without the negative electrode active material layer 32. The positive electrode 20 and the negative electrode 30 are examples of a pair of electrodes having an active material layer.

The first surface 21a of the positive electrode current collector 21 and the first surface 31a of the negative electrode current collector 31 face each other. That is, the positive electrode active material layer 22 and the negative electrode active material layer 32 face each other. The separator 40 is sandwiched between the positive electrode active material layer 22 and the negative electrode active material layer 32. That is, the positive electrode 20 and the negative electrode 30 overlap each other via the separator 40. The direction in which the positive electrode 20 and the negative electrode 30 overlap is defined as the stacking direction A, and the direction orthogonal to the stacking direction A toward the outer peripheral edge 21c (outer peripheral edge 31c) from the center of the positive electrode current collector 21 (negative electrode current collector 31) in a plan view. Is the radial direction B. The stacking direction C of the plurality of storage cells 10 coincides with the stacking direction A in which the positive electrode 20 and the negative electrode 30 overlap. Therefore, viewing the storage cell 10 in the stacking direction A is also described as a plan view.

The positive electrode active material layer 22 and the negative electrode active material layer 32 are each formed in a rectangular shape. The negative electrode active material layer 32 is formed to be one size larger than the positive electrode active material layer 22. In a plan view, the entire forming region of the positive electrode active material layer 22 is located inside the forming region of the negative electrode active material layer 32.

The separator 40 has a rectangular shape larger than the formation region of the negative electrode active material layer 32 in a plan view. The separator 40 has a rectangular shape smaller than that of the positive electrode current collector 21 and the negative electrode current collector 31 in a plan view. The separator 40 has a non-opposing portion 41 that does not face the positive electrode active material layer 22 and the negative electrode active material layer 32 in the stacking direction A.

As shown in FIGS. 2 and 3, the resin frame 50 is located between the positive electrode current collector 21 and the negative electrode current collector 31. The resin frame 50 contains an insulating material and insulates the positive electrode current collector 21 and the negative electrode current collector 31 to prevent a short circuit between the positive electrode current collector 21 and the negative electrode current collector 31. In the present embodiment, the material of the resin frame 50 is acid-modified polyethylene. The material of the resin frame 50 may be acid-modified polypropylene.

As shown in FIG. 2, the resin frame 50 is arranged between the outer peripheral edge portion 21d of the positive electrode current collector 21 and the outer peripheral edge portion 31d of the negative electrode current collector 31. The resin frame 50 is provided so as to be interposed between the positive electrode 20 and the negative electrode 30. The resin frame 50 has a rectangular frame shape surrounding the positive electrode active material layer 22 and the negative electrode active material layer 32. In a plan view, the resin frame 50 has a square frame shape. The resin frame 50 includes a portion sandwiched between the outer peripheral edge portion 21d of the positive electrode current collector 21 and the outer peripheral edge portion 31d of the negative electrode current collector 31, and the outer peripheral edge 21c and the negative electrode current collector of the positive electrode current collector 21. It has a portion located outside the outer peripheral edge 31c of the body 31.

The resin frame 50 has a square frame-shaped positive electrode side end face 50b on the end face near the positive electrode current collector 21 among both end faces in the stacking direction A, and a square frame-shaped negative electrode side on the end face near the negative electrode current collector 31. It has an end face 50c.

In the resin frame 50, a portion sandwiched between the outer peripheral edge portion 21d of the positive electrode current collector 21 and the outer peripheral edge portion 31d of the negative electrode current collector 31 is referred to as an intervening portion 50a. The resin frame 50 includes a portion that sandwiches the non-opposing portion 41 between the intervening portion 50a and the positive electrode current collector 21, and a first joint portion W1 in which the intervening portion 50a and the positive electrode current collector 21 are welded to each other. It is formed. The non-opposing portion 41 may be welded to the intervening portion 50a.

The first joint portion W1 is formed by welding a portion of the resin frame 50 on the positive electrode side end surface 50b where the outer peripheral edge portion 21d of the positive electrode current collector 21 overlaps and the outer peripheral edge portion 21d of the positive electrode current collector 21. .. In the first joint portion W1, the positive electrode side end surface 50b and the outer peripheral edge portion 21d of the positive electrode current collector 21 are welded over the entire circumference. Therefore, in a plan view, the first joint portion W1 has a square frame shape.

The resin frame 50 is formed with a second joint portion W2 in which the intervening portion 50a and the negative electrode current collector 31 are welded to each other. The second joint portion W2 is formed by welding a portion of the negative electrode side end surface 50c of the resin frame 50 where the outer peripheral edge portion 31d of the negative electrode current collector 31 overlaps and the outer peripheral edge portion 31d of the negative electrode current collector 31. .. In the second joint portion W2, the negative electrode side end surface 50c and the outer peripheral edge portion 31d of the negative electrode current collector 31 are welded over the entire circumference. Therefore, in a plan view, the second joint portion W2 has a square frame shape. When the non-opposing portion 41 is sandwiched between the intervening portion 50a and the positive electrode current collector 21, the second junction portion W2 may be formed to have a larger welding area than the first junction portion W1. The first joint portion W1 and the second joint portion W2 maintain the sealing property of the space S partitioned by the positive electrode 20, the negative electrode 30, and the resin frame 50 of the storage cell 10. That is, the resin frame 50 seals the space S that is partitioned together with the positive electrode 20 and the negative electrode 30. Specifically, the space S is partitioned and sealed by the positive electrode current collector 21, the negative electrode current collector 31, and the resin frame 50, and the positive electrode active material layer 22 and the negative electrode active material layer 32 are arranged in the space S. There is.

As shown in FIG. 1, in the cell stack 2, the plurality of storage cells 10 are the second surface 21b of the positive electrode current collector 21 of one of the storage cells 10 adjacent to each other in the stacking direction C and the second of the negative electrode current collectors 31. The surfaces 31b are stacked so as to be in contact with each other. The plurality of storage cells 10 are electrically connected in series. In the cell stack 2, a pseudo bipolar electrode 13 having a positive electrode current collector 21 and a negative electrode current collector 31 in contact with each other is formed by storage cells 10 adjacent to each other in the stacking direction C. One bipolar electrode 13 includes a positive electrode current collector 21, a negative electrode current collector 31, a positive electrode active material layer 22, and a negative electrode active material layer 32. In the resin frame 50 included in the plurality of storage cells 10, the portions located outside the outer peripheral edge 21c of the positive electrode current collector 21 and the outer peripheral edge 31c of the negative electrode current collector 31 are joined to each other and integrated. .. As a result, as the power storage device 1, the sealing property between the positive electrode current collector 21 and the negative electrode current collector 31 constituting the bipolar electrode 13 is ensured. A positive electrode current collector 21 and a positive electrode active material layer 22 are arranged as terminal electrodes at the first end 11 in the stacking direction C in the cell stack 2. A negative electrode current collector 31 and a negative electrode active material layer 32 are arranged as terminal electrodes at the second end 12 of the stacking direction C in the power storage device 1.

The power storage device 1 includes a pair of energizing bodies composed of a positive electrode energizing plate 71 and a negative electrode energizing plate 81 arranged so as to sandwich the cell stack 2 in the stacking direction C. The positive electrode current-carrying plate 71 and the negative electrode current-carrying plate 81 are each made of a good conductive material. The positive electrode current-carrying plate 71 is electrically connected to the positive electrode current collector 21 arranged on the outermost side of the first end portion 11. The negative electrode current-carrying plate 81 is electrically connected to the negative electrode current collector 31 arranged on the outermost side of the second end portion 12. The power storage device 1 is charged and discharged through terminals (not shown) provided on the positive electrode energizing plate 71 and the negative electrode energizing plate 81. As the material constituting the positive electrode current collecting plate 71 and the negative electrode current collecting plate 81, the same materials as those constituting the positive electrode current collector 21 and the negative electrode current collector 31 can be used. The positive electrode energizing plate 71 and the negative electrode energizing plate 81 may be made of a metal plate thicker than the positive electrode current collector 21 and the negative electrode current collector 31 used in the storage cell 10.

The positive electrode current collector 21 and the negative electrode current collector 31 are chemically inert electric conductors. As the material constituting the positive electrode current collector 21 and the negative electrode current collector 31, for example, a metal material, a conductive resin material, a conductive inorganic material, or the like can be used. Examples of the conductive resin material include a conductive polymer material and a resin obtained by adding a conductive filler to a non-conductive polymer material as needed. The positive electrode current collector 21 and the negative electrode current collector 31 may include a plurality of layers including one or more layers including the above-mentioned metal material or conductive resin material. A coating layer may be formed on the surfaces of the positive electrode current collector 21 and the negative electrode current collector 31 by a known method such as plating treatment or spray coating. The positive electrode current collector 21 and the negative electrode current collector 31 may be formed in, for example, a plate shape, a foil shape, a sheet shape, a film shape, a mesh shape, or the like. When the positive electrode current collector 21 and the negative electrode current collector 31 are metal foils, for example, aluminum foil, copper foil, nickel foil, titanium foil, stainless steel foil, or the like can be used. When stainless steel foil is used as the positive electrode current collector 21 and the negative electrode current collector 31, for example, when SUS304, SUS316, SUS301 or the like specified in JIS G 4305: 2015 is used, the positive electrode current collector 21 and the negative electrode current collector 21 and the negative electrode current collector are used. The mechanical strength of 31 can be secured. The positive electrode current collector 21 and the negative electrode current collector 31 may be the alloy foil or the clad foil of the above metal. In the present embodiment, the positive electrode current collector 21 is an aluminum foil and the negative electrode current collector 31 is a copper foil. When the positive electrode current collector 21 and the negative electrode current collector 31 are foil-shaped, the thickness may be, for example, 1 μm to 100 μm.

The positive electrode active material layer 22 contains a positive electrode active material capable of storing and releasing a charge carrier such as lithium ions, and the positive electrode active material includes a lithium ion composite metal oxide having a layered rock salt structure and a metal oxide having a spinel structure. A material that can be used as a positive electrode active material for a lithium ion secondary battery, such as a polyanionic compound, may be used. Further, two or more kinds of positive electrode active materials may be used in combination. In the present embodiment, the positive electrode active material layer 22 contains olivine-type lithium iron phosphate (LiFePO ₄ ) as a composite active material.

Examples of the negative electrode active material layer 32 include simple substances, alloys, carbon, metal compounds, elements that can be alloyed with lithium, or compounds thereof, which can store and release charge carriers such as lithium ions. Examples of carbon include natural graphite, artificial graphite, hard carbon (non-graphitizable carbon) or soft carbon (easy graphitizable carbon). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements that can be alloyed with lithium include silicon and tin. In the present embodiment, the negative electrode active material layer 32 contains graphite as a carbon-based material.

The positive electrode active material layer 22 and the negative electrode active material layer 32 each have a conductive auxiliary agent, a binder, an electrolyte (polymer matrix, ionic conductive polymer, electrolytic solution, etc.) and ionic conductivity for enhancing electrical conductivity as needed. It may further contain an electrolyte-supporting salt (lithium salt) or the like for enhancing the properties. The components contained in the active material layer or the compounding ratio of the components and the thickness of the active material layer are not particularly limited, and known knowledge about the lithium ion secondary battery can be appropriately referred to. The thickness of the active material layer is, for example, 2 μm to 150 μm. In order to form an active material layer on the surfaces of the positive electrode current collector 21 and the negative electrode current collector 31, a known method such as a roll coating method may be used. In order to improve the thermal stability of the positive electrode 20 or the negative electrode 30, a heat resistant layer is formed on the surface (one side or both sides) of the positive electrode current collector 21 and the negative electrode current collector 31 or on the surface of the positive electrode active material layer 22 and the negative electrode active material layer 32. May be provided. The heat-resistant layer may contain, for example, inorganic particles and a binder, and may also contain an additive such as a thickener.

The conductive auxiliary agent is, for example, acetylene black, carbon black, graphite or the like. Examples of the binder include fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene and rubber fluoride, and thermoplastic resins such as polypropylene and polyethylene. Examples of the binder include imide-based resins such as polyimide and polyamide, alkoxysilyl group-containing resins, acrylic resins containing monomer units such as acrylic acid and methacrylic acid, and styrene-butadiene rubber (SBR). Further, examples of the binder include alginates such as carboxymethyl cellulose, sodium alginate, and ammonium alginate, water-soluble cellulose ester cross-linking products, and starch-acrylic acid graft polymers. These binders can be used alone or in combination. As the solvent, for example, water, N-methyl-2-pyrodrin (NMP) and the like are used.

The separator 40 allows a charge carrier such as lithium ion to pass through while separating the positive electrode 20 and the negative electrode 30 to prevent a short circuit due to contact between the two electrodes. The separator 40 may be, for example, a porous sheet or a non-woven fabric containing a polymer that absorbs and retains an electrolyte. Examples of the material constituting the separator 40 include polypropylene, polyethylene, polyolefin, polyester and the like. The separator 40 may have a single-layer structure or a multi-layer structure. The multilayer structure may have, for example, an adhesive layer, a ceramic layer as a heat-resistant layer, and the like. The separator 40 itself may be composed of a polymer gel electrolyte or an electrolyte such as an electrolyte.

Examples of the electrolyte impregnated in the separator 40 include a liquid electrolyte (electrolyte solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent, a polymer gel electrolyte containing an electrolyte held in a polymer matrix, and the like. Can be mentioned.

When the separator 40 is impregnated with an electrolytic solution, the electrolyte salts thereof include LiClO ₄ , LiAsF _6, LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , etc. Known lithium salts can be used. Further, as the non-aqueous solvent, known solvents such as cyclic carbonates, cyclic esters, chain carbonates, chain esters, ethers and the like can be used. In addition, you may use two or more kinds of these known solvent materials in combination.

As shown in FIG. 3, the resin frame 50 has four wall portions and two connecting portions 54. The four wall portions included in the resin frame 50 are a first wall portion 51, two second wall portions 52, and a third wall portion 53. Two connecting portions 54 are continuous to the first wall portion 51. A second wall portion 52 is continuous with each of the two connecting portions 54. A third wall portion 53 is continuous on the opposite side of the two second wall portions 52 from the first wall portion 51. In a plan view, the first wall portion 51 and the third wall portion 53 extend in parallel. In plan view, the two second wall portions 52 extend in parallel.

In a plan view, the direction in which the first wall portion 51 extends between the two second wall portions 52 is referred to as the first extension direction D1, and the direction in which the third wall portion 53 extends is referred to as the third extension direction D3. In a plan view, the direction in which the two second wall portions 52 extend between the first wall portion 51 and the third wall portion 53 is referred to as the second extension direction D2. The first extension direction D1 and the second extension direction D2 are orthogonal to each other. That is, the two second wall portions 52 extend in a direction orthogonal to the first wall portion 51. The first extension direction D1 and the third extension direction D3 are parallel to each other. That is, the first extension direction D1 and the third extension direction D3 are in the same direction, and the third wall portion 53 extends in the first extension direction D1. The second extension direction D2 and the third extension direction D3 are orthogonal to each other. One of the two second wall portions 52 is provided near the first end portion of the first wall portion 51 in the first extension direction D1. The other of the two second wall portions 52 is provided near the second end of the first wall portion 51 in the first extension direction D1.

The thicknesses of the first wall portion 51, the two second wall portions 52, the third wall portion 53, and the two connecting portions 54 in the stacking direction A are all the same. Therefore, the positive electrode side end surface 50b is formed by one end surface of both end faces in the stacking direction A of the first wall portion 51, the two second wall portions 52, the third wall portion 53, and the two connection portions 54. The other end surface forms the negative electrode side end surface 50c.

As shown in FIGS. 3 and 4, the direction orthogonal to the first extension direction D1 and the stacking direction A is defined as the first thickness direction Dt1, and the dimension of the first wall portion 51 in the first thickness direction Dt1 is the thickness. Let's say T1. The first wall portion 51 has a plate shape in which the thickness T1 does not change. The first wall portion 51 has a first inner surface 51a facing the space S of the storage cell 10. The first inner surface 51a is a surface orthogonal to the first thickness direction Dt1 and extends in the first extension direction D1 in a plan view. The first wall portion 51 has a first outer surface 51b located on the opposite side of the first inner surface 51a in the first thickness direction Dt1. The first inner surface 51a and the first outer surface 51b are parallel. The first inner surface 51a is an example of the first end surface of the first wall portion 51.

The direction orthogonal to the second extension direction D2 and the stacking direction A is defined as the second thickness direction Dt2, and the dimension of the second wall portion 52 in the second thickness direction Dt2 is defined as the thickness T2. The second wall portion 52 has a plate shape in which the thickness T2 does not change. The second wall portion 52 has a second inner surface 52a facing the space S of the storage cell 10. The second inner surface 52a is a surface orthogonal to the second thickness direction Dt2, and is a surface extending in the second extension direction D2 in a plan view. The second wall portion 52 has a second outer surface 52b located on the side opposite to the second inner surface 52a in the second thickness direction Dt2. The second inner surface 52a and the second outer surface 52b are parallel. The second inner surface 52a is an example of the second end surface of the second wall portion 52.

The direction orthogonal to the third extension direction D3 and the stacking direction A is defined as the third thickness direction Dt3, and the dimension of the third wall portion 53 in the third thickness direction Dt3 is defined as the thickness T3. The first thickness direction Dt1 and the third thickness direction Dt3 are parallel to each other. That is, the first thickness direction Dt1 and the third thickness direction Dt3 are in the same direction, and the thickness T3 is the dimension of the third wall portion 53 in the first thickness direction Dt1. The third wall portion 53 has a plate shape in which the thickness T3 does not change. The third wall portion 53 has a third inner surface 53a facing the space S of the storage cell 10. The third inner surface 53a is a surface orthogonal to the third thickness direction Dt3, and is a surface extending in the third extension direction D3 in a plan view. The third wall portion 53 has a third outer surface 53b located on the side opposite to the third inner surface 53a in the third thickness direction Dt3. The third inner surface 53a and the third outer surface 53b are parallel. The third inner surface 53a is orthogonal to the second inner surface 52a of the two second wall portions 52. The third outer surface 53b is orthogonal to the second outer surface 52b of the two second wall portions 52.

Each of the two connecting portions 54 has an inclined surface 55 facing the space S of the storage cell 10 and connecting the first inner surface 51a and the second inner surface 52a. The first inner surface 51a and the second inner surface 52a provided near the first end portion in the first extension direction D1 of the first wall portion 51 are connected by an inclined surface 55. The first inner surface 51a and the second inner surface 52a provided near the second end portion in the first extension direction D1 of the first wall portion 51 are connected by an inclined surface 55.

In a plan view, the inclined surface 55 extends linearly between the first inner surface 51a and the second inner surface 52a. The inclined surface 55 has an obtuse angle θ1 formed with the first inner surface 51a. The inclined surface 55 has an obtuse angle θ2 formed with the second inner surface 52a. The inclined surface 55 is an example of a changing surface in which the angle formed by the first inner surface 51a and the second inner surface 52a is an obtuse angle.

Each of the two connecting portions 54 has a first connecting surface 54a that extends in the first extending direction D1 and the stacking direction A and is smoothly continuous with the first outer surface 51b of the first wall portion 51. Each of the two connecting portions 54 has a second connecting surface 54b that extends in the second extending direction D2 and the stacking direction A and is smoothly continuous with the second outer surface 52b of the second wall portion 52. The first connection surface 54a and the second connection surface 54b are orthogonal to each other.

The resin frame 50 has a first side surface 51s composed of a first outer surface 51b of the first wall portion 51 and a first connection surface 54a of the two connecting portions 54. The first side surface 51s is a rectangular surface having a long side extending in the first extending direction D1 and a short side extending in the stacking direction A.

The resin frame 50 has two second side surfaces 52s composed of a second outer surface 52b of the second wall portion 52 and a second connection surface 54b of one connection portion 54. The second side surface 52s is a rectangular surface having a long side extending in the second extending direction D2 and a short side extending in the stacking direction A.

The third outer surface 53b is a rectangular surface having a long side extending in the third extending direction D3 and a short side extending in the stacking direction A.
The thickness T1 of the first wall portion 51 is the same as the thickness T2 of the second wall portion 52. The thickness T1 of the first wall portion 51 is the same as the thickness T3 of the third wall portion 53. The thickness T2 of the second wall portion 52 is the same as the thickness T3 of the third wall portion 53. The thickness T1 of the first wall portion 51 may be thicker than the thickness T2 of the second wall portion 52. The thickness T1 of the first wall portion 51 may be thicker than the thickness T3 of the third wall portion 53.

As shown in FIG. 4, in a plan view, the thickness of the two connecting portions 54 in the first thickness direction Dt1 is equal to or greater than the thickness T1 of the first wall portion 51. In a plan view, the thickness of the two connecting portions 54 in the first thickness direction Dt1 is the thickness of the first wall portion 51 so that the two connecting portions 54 are directed from the second wall portion 52 to the first wall portion 51 in the first extension direction D1. It becomes thinner to match T1.

In a plan view, the thickness of the two connecting portions 54 in the second thickness direction Dt2 is equal to or greater than the thickness T2 of the second wall portion 52. In a plan view, the thickness of the two connecting portions 54 in the second thickness direction Dt2 becomes thicker as the thickness of the two connecting portions 54 goes from the first wall portion 51 to the second wall portion 52 in the second extending direction D2. It becomes thinner to match T2.

That is, in each of the two inclined surfaces 55, the thickness of the connecting portion 54 in the first thickness direction Dt1 increases from the second wall portion 52 toward the first wall portion 51 in the first extension direction D1 in a plan view. It is provided to be thin. Further, in each of the two inclined surfaces 55, the thickness of the connecting portion 54 in the second thickness direction Dt2 increases from the first wall portion 51 toward the second wall portion 52 in the second extending direction D2 in a plan view. It is provided to be thin. When the storage cell 10 is viewed in the first thickness direction Dt1, the boundary between each of the two inclined surfaces 55 and the first inner surface 51a coincides with the both end edges of the negative electrode active material layer 32 in the first extending direction D1. do.

As shown in FIGS. 2 and 3, the resin frame 50 includes a penetrating portion 60 and a closing portion 70. The penetration portion 60 is provided in the first wall portion 51. The penetration portion 60 is a through hole that penetrates the first wall portion 51. The penetrating portion 60 penetrates the first wall portion 51 in the first thickness direction Dt1. In the present embodiment, the penetration direction Dp of the penetration portion 60 in the first wall portion 51 coincides with the first thickness direction Dt1. The first extension direction D1 is orthogonal to the penetration direction Dp. The second extension direction D2 coincides with the penetration direction Dp. Therefore, the pair of second wall portions 52 extend in the penetration direction Dp. The third extension direction D3 is orthogonal to the penetration direction Dp. The penetrating portion 60 is provided on the negative electrode 30 side of the separator 40 in the stacking direction A. Therefore, the penetrating portion 60 faces the negative electrode active material layer 32 in the penetrating direction Dp. The penetrating portion 60 may be provided on the positive electrode 20 side of the separator 40 in the stacking direction A.

The cross section of the penetrating portion 60 when cut by a virtual surface extending in the first extending direction D1 and the stacking direction A has a rectangular shape. The penetrating portion 60 extends in the radial direction B between the space S of the storage cell 10 and the outside of the storage cell 10 in the first thickness direction Dt1. The penetrating portion 60 has a function as a gas discharge port for injecting an electrolyte into the space S of the storage cell 10 and then discharging the gas generated inside the storage cell 10 to the outside of the storage cell 10. The penetrating portion 60 may also have a function as an injection port provided for injecting an electrolyte into the space S of the storage cell 10. As the gas generated inside the storage cell 10, the air remaining before the electrolyte is injected into the storage cell 10 and the gas generated during the initial charge / discharge of the power storage device 1 are shown. The cross section when the penetrating portion 60 is cut by the virtual surface extending in the first extending direction D1 and the stacking direction A is not limited to a rectangular shape, but may be a circular shape. The shape of the penetrating portion 60 may be changed as appropriate.

The closing portion 70 is a resin member. The closed portion 70 closes the penetrating portion 60. The closing portion 70 is a sealing member that prevents the electrolyte injected into the storage cell 10 from leaking to the outside of the storage cell 10. Therefore, the electrolyte is injected into the space S of the storage cell 10 in the state before the penetrating portion 60 is closed by the closing portion 70. Further, the gas generated inside the storage cell 10 is discharged to the outside of the storage cell 10 in a state before the penetrating portion 60 is closed by the closing portion 70.

As shown in FIGS. 3 and 4, in a plan view, the width of the penetration portion 60 in the first extending direction D1 is smaller than the length between the two connecting portions 54 in the first wall portion 51. In a plan view, each of the two connecting portions 54 and the penetrating portion 60 are arranged at a distance equal to or larger than the width in the first extending direction D1 of the penetrating portion 60 in the first extending direction D1. Specifically, in the first extension direction D1, the length of the first wall portion 51 from the penetration portion 60 to each of the two connecting portions 54 is equal to or greater than the width of the penetration portion 60 in the first extension direction D1. be. For convenience of explaining the operation of this embodiment, the closed portion 70 is not intentionally shown in FIGS. 3 and 4.

As shown in FIG. 4, in the present embodiment, three types of power storage cells 10 for constituting the power storage device 1 are adopted. The difference between the three types of storage cells 10 is the difference in the position of the penetrating portion 60 in the first extension direction D1 as shown by the broken line in FIG. Of the penetrating portions 60 shown by the broken lines in FIG. 4, the penetrating portion located near the first end portion of the first wall portion 51 is referred to as the penetrating portion 60a, and the penetrating portion located near the second end portion of the first wall portion 51. The portion is referred to as a penetrating portion 60b. In a plan view, the penetrating portions 60, 60a, 60b do not overlap each other. The power storage device 1 is configured by stacking three types of power storage cells 10 including a power storage cell 10 having a penetration portion 60, a power storage cell 10 having a penetration portion 60a, and a storage cell 10 having a penetration portion 60b. There is.

In the storage cell 10 having the penetrating portion 60a, in the first extending direction D1, the connecting portion 54 near the second end of the first wall portion 51 and the penetrating portion 60a are in the first extending direction of the penetrating portion 60. They are arranged at intervals equal to or greater than the width in D1. In the storage cell 10 having the penetrating portion 60b, in the first extending direction D1, the connecting portion 54 near the first end portion of the first wall portion 51 and the penetrating portion 60b are in the first extending direction of the penetrating portion 60. They are arranged at intervals equal to or greater than the width in D1. Specifically, in the storage cell 10 having the penetrating portion 60a, in the first extension direction D1, the first wall portion 51 from the penetrating portion 60a to the connecting portion 54 near the second end of the first wall portion 51. The length is equal to or greater than the sum of the width of the penetrating portion 60 in the first extending direction D1 and the width of the penetrating portion 60b in the first extending direction D1. In the storage cell 10 having the penetrating portion 60b, the length of the first wall portion 51 from the penetrating portion 60b to the connecting portion 54 near the first end portion of the first wall portion 51 penetrates in the first extension direction D1. It is equal to or greater than the sum of the width of the portion 60 in the first extension direction D1 and the width of the penetration portion 60a in the first extension direction D1.

In the first extension direction D1, the connection portion 54 near the first end of the first wall portion 51 and the penetration portion 60a are arranged at a distance equal to or larger than the width of the penetration portion 60 in the first extension direction D1. It does not have to be. In the storage cell 10 having the penetrating portion 60b, in the first extending direction D1, the connecting portion 54 near the second end of the first wall portion 51 and the penetrating portion 60b are in the first extending direction of the penetrating portion 60. It does not have to be arranged at a distance equal to or larger than the width in D1. The widths of the penetrating portions 60, 60a, 60b in the first extension direction D1 are the same.

As shown in FIG. 6, in the power storage device 1, the penetrating portions 60, 60a, 60b of the adjacent power storage cells 10 are arranged so as not to overlap in the stacking direction C.
The operation of this embodiment will be described.

As shown in FIG. 4, in a state where the penetrating portion 60 is not blocked by the closing portion 70, the electrolyte is injected into the space S of the storage cell 10 via the penetrating portion 60. As shown by the arrows in FIG. 4, the injected electrolyte flows through the space S toward the third wall portion 53, and a part of the electrolyte is the first inner surface 51a of the first wall portion 51 and two. It travels through the inclined surface 55 and the two second inner surfaces 52a. The electrolyte filled in the space S invades the negative electrode active material layer 32 and also invades the separator 40 shown in FIG. The electrolyte impregnated in the separator 40 is also impregnated in the positive electrode active material layer 22.

As shown in FIG. 5, when gas is generated inside the storage cell 10, the penetration portion 60 is moved from the penetration portion 60 to the outside of the storage cell 10 by using a degassing device in a state where the penetration portion 60 is not blocked by the closing portion 70. Inhale the gas. As shown by the arrow in FIG. 5, the gas inside the storage cell 10 flows toward the first wall portion 51, and a part of the gas flows through the two second inner surfaces 52a and the two inclined surfaces 55. Is sucked toward the first wall portion 51. The gas sucked toward the first wall portion 51 is discharged to the outside of the storage cell 10 via the penetrating portion 60. Since a connecting portion 54 having an inclined surface 55 is provided between the first wall portion 51 and the two second wall portions 52, gas can be supplied between the first wall portion 51 and the second wall portion 52. It is hard to collect at the boundary.

The effect of this embodiment will be described.
(1) When the gas generated in the space S of the storage cell 10 is discharged to the outside of the storage cell 10 in a state where the penetrating portion 60 is not blocked by the closing portion 70, the gas flows toward the penetrating portion 60. At this time, there is gas flowing along the second inner surface 52a, the inclined surface 55, and the first inner surface 51a. Since the first inner surface 51a and the second inner surface 52a are connected by the inclined surface 55, the gas can easily flow smoothly from the second inner surface 52a to the first inner surface 51a by the inclined surface 55. Therefore, the gas can be easily discharged from the penetrating portion 60, and the accumulation of gas at the boundary between the first wall portion 51 and the second wall portion 52 can be suppressed.

(2) The gas generated inside the storage cell 10 can easily flow smoothly toward the first inner surface 51a by the two inclined surfaces 55 provided corresponding to the two second wall portions 52, respectively. Therefore, the gas can be easily discharged from the penetrating portion 60, and the accumulation of gas at the boundary between the first wall portion 51 and the second wall portion 52 can be further suppressed.

(3) The thickness T1 of the first wall portion 51 is equal to or larger than the thickness T2 of the second wall portion 52 and the thickness T3 of the third wall portion 53, and the rigidity of the power storage cell 10 with respect to the internal pressure is ensured. Therefore, when the gas is discharged from the penetrating portion 60, the gas flows toward the first inner surface 51a by the inclined surface 55, and even if the gas concentrates on the penetrating portion 60, the sealing property at the position of the first wall portion 51 Can be held in the same manner as the second wall portion 52 and the third wall portion 53.

(4) In a plan view, the first wall portion 51 has a plate shape in which the thickness T1 does not change. Then, in a plan view, the two connecting portions 54 and the penetrating portion 60 are arranged at a distance equal to or larger than the width in the first extending direction D1 of the penetrating portion 60 in the first extending direction D1. Therefore, the position where the penetrating portion 60 is provided is easily shifted in the first extension direction D1. Therefore, the degree of freedom in arranging the penetrating portion 60 is improved.

(5) It is easier to manufacture the resin frame 50 when the changing surface is an inclined surface 55 as compared with the case where the changing surface is a curved surface. Therefore, the productivity of the storage cell can be improved. Therefore, the productivity of the storage cell is improved while facilitating the guidance of the gas to the penetrating portion.

(6) In the present embodiment, the accumulation of gas at the boundary between the first wall portion 51 and the second wall portion 52 is suppressed, so that the time required for gas discharge is reduced, for example, when the power storage device 1 is manufactured. It can be shortened and productivity can be improved. Further, if the gas remains inside the power storage cell 10, the battery reaction may be hindered and the battery performance may deteriorate, while the gas storage device 1 and the power storage cell 10 of the present embodiment collect the gas. It can be suppressed. Therefore, deterioration of battery performance can be suppressed. In particular, when gas is discharged while restraining the storage cell 10 in the stacking direction A except for the vicinity of the first wall portion 51 provided with the penetrating portion 60 for promoting gas discharge, the first wall portion 51 and the first wall portion 51 and the first wall portion 51 are discharged. It is possible to suppress the application of stress to the positive electrode current collector 21, the negative electrode current collector 31, and the resin frame 50 due to the accumulation of gas at the boundary with the wall portion 52 and the increase in internal pressure.

(7) In the power storage device 1, the penetrating portions 60 of the storage cells 10 adjacent to each other in the stacking direction C are arranged on the first wall portion 51, but do not overlap in the stacking direction C. Therefore, in the power storage device 1, when the gas is discharged through the penetrating portion 60 or when the electrolytic solution is injected, the nozzles and the like connected to the penetrating portions 60 are less likely to interfere with each other. Therefore, the productivity of the power storage device 1 can be improved.

In addition, this embodiment can be implemented by changing as follows. The present embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.
○ The resin frame 50 of the storage cell 10 may be changed as shown in FIGS. 7 and 8.

As shown in FIGS. 7 and 8, the inclined surface 55 may be extended to the penetration portion 60. In this case, the width of the first wall portion 51 in the first extension direction D1 is substantially equal to the width of the penetration portion 60 in the first extension direction D1. When the storage cell 10 is viewed in the first thickness direction Dt1, the boundary between each of the two inclined surfaces 55 and the first inner surface 51a in the first extension direction D1 is the first extension of the negative electrode active material layer 32. It is located inside the edges at both ends in direction D1.

By making such a change, gas can be directly guided to the penetrating portion 60 along the inclined surface 55, so that the efficiency of degassing can be improved.
○ In a plan view, the shape of the surface of the two connecting portions 54 facing the space S may be changed as shown in FIG.

As shown in FIG. 9, in a plan view, the surface of the two connecting portions 54 facing the space S includes a curved surface 56. In the curved surface 56, the thickness of the connecting portion 54 in the first thickness direction Dt1 is the thickness of the first wall portion 51 so that the curved surface 56 is directed from the second wall portion 52 to the first wall portion 51 in the first extending direction D1. It is provided so as to be thin so as to coincide with T1. Further, in the curved surface 56, in the plan view, the thickness of the connecting portion 54 in the second thickness direction Dt2 increases from the first wall portion 51 toward the second wall portion 52 in the second extending direction D2 to the second wall portion 52. It is provided so as to be thin so as to match the thickness T2 of.

The curved surface 56 is a virtual surface of the surface of the connecting portion 54 facing the space S, which is in contact with the curved surface 56 while passing through the first inner surface 51a of the first wall portion 51 and an arbitrary position P on the curved surface 56 in a plan view. The angle θ1 formed with L is an obtuse angle. Further, the curved surface 56 touches the curved surface 56 while passing through the second inner surface 52a of the second wall portion 52 and an arbitrary position P on the curved surface 56 in the plan view of the surface of the connecting portion 54 facing the space S. The angle θ2 formed with the virtual surface L is an obtuse angle.

○ The penetration portion 60 is a through hole that penetrates the first wall portion 51 in the first thickness direction Dt1, but is not limited to this. For example, it may be changed as shown in FIG.
As shown in FIG. 10, the penetrating portion 60 may be a concave groove recessed from the negative electrode side end surface 50c. The penetrating portion 60 extends from the space S of the storage cell 10 to the outside of the storage cell 10 in the radiation direction B. A part of the opening of the penetrating portion 60 in the stacking direction A is closed by the first surface 31a of the negative electrode current collector 31. That is, a through hole extending in the radial direction B is formed by the penetrating portion 60 and the first surface 31a of the negative electrode current collector 31. The penetrating portion 60 is provided with a tubular member 90. The first end of the cylinder member 90 is located in the space S of the storage cell 10, and the second end of the cylinder member 90 extends to the outside of the storage cell 10. The inside of the tubular member 90 is closed by the sealing resin 91. That is, the tubular member 90 and the sealing resin 91 are examples of the closed portion. In this modified example, when the electrolyte is injected into the space S of the storage cell 10, the injection nozzle is inserted into the cylinder member 90 while the sealing resin 91 does not block the cylinder member 90. Then, the electrolyte is injected into the space S of the storage cell 10 via the injection nozzle and the cylinder member 90. Further, when the gas generated inside the storage cell 10 is discharged to the outside of the storage cell 10, the gas is discharged to the outside of the storage cell 10 via the tubular member 90.

○ In the present embodiment, the thickness of the two connecting portions 54 may always be constant in a plan view. The surface of the two connecting portions 54 facing the space S may be an inclined surface 55 or a curved surface 56. In this case, the first connecting surface 54a and the second connecting surface 54b are formed as an inclined surface or a curved surface along the inclined surface 55 or the curved surface 56.

○ The resin frame 50 has two connecting portions 54, but one of them may be omitted.
○ The penetrating portion 60 penetrated the first wall portion 51 in the first thickness direction Dt1, but is not limited to this. For example, the first thickness direction Dt1 and the penetration direction Dp of the penetration portion 60 do not have to match. Further, the first extension direction D1 and the penetration direction Dp do not have to be orthogonal to each other. That is, the direction in which the penetrating portion 60 extends may extend in a direction intersecting the first thickness direction Dt1 as long as the penetrating portion 60 extends to the space S and the outside of the storage cell 10.

○ In the present embodiment, the power storage device 1 may be configured to include the power storage cell 10 described in the above modification.
○ In the present embodiment, the second surface 21b of the positive electrode current collector 21 and the second surface 31b of the negative electrode current collector 31 are overlapped with each other in configuring the bipolar electrode 13, but for example, the positive electrode current collector 21 and the negative electrode current collector 31 may be integrally configured.

○ The positive electrode current collector 21 and the negative electrode current collector 31 are made of different materials, but the present invention is not limited to this. The positive electrode current collector 21 and the negative electrode current collector 31 may be made of the same material.
O The above-mentioned embodiment explains one aspect of the present invention. Therefore, the present invention can be arbitrarily modified without being limited to the above aspects.

1 ... power storage device, 10 ... power storage cell, 20 ... positive electrode, 21 ... positive electrode current collector, 21a ... first surface, 21d ... outer peripheral edge, 22 ... positive electrode active material layer, 30 ... negative electrode, 31 ... negative electrode current collector , 31a ... 1st surface, 31d ... outer peripheral edge portion, 32 ... negative electrode active material layer, 40 ... separator, 41 ... non-opposing portion, 50 ... resin frame, 51 ... first wall portion, 51a ... 1st surface, 52 ... 2nd wall part, 52a ... 1st surface, 53 ... 3rd wall part, 54 ... connection part, 55 ... inclined surface, 56 ... curved surface, 60, 60a, 60b ... penetration part, 70 ... closed part, 90 ... film, 91 ... Sealing resin, θ1, θ2 ... Angle, S ... Space, T1 ... First wall thickness, T2 ... Second wall thickness, T3 ... Third wall thickness, A ... Laminating direction , B ... Radiation direction, D1 ... First extension direction, D2 ... Second extension direction, D3 ... Third extension direction, Dt1 ... First thickness direction, Dt2 ... Second thickness direction, Dt3 ... Third Thickness direction, Dp ... Penetration direction.

Claims (7)

A pair of electrodes that have active material layers facing each other and overlap each other,
A storage cell that is interposed between the pair of electrodes, has a rectangular frame shape that surrounds the active material layer, and has a resin frame that seals a space partitioned by the pair of electrodes.
A penetrating portion provided in the resin frame and extending to the space and the outside of the storage cell,
It is provided with a closing portion that closes the penetrating portion.
The resin frame is
The first wall portion where the penetration portion is provided and the
A second wall portion extending in a direction orthogonal to the first wall portion,
It has a connecting portion for connecting the first wall portion and the second wall portion.
The first wall portion has a first end surface facing the space and has a first end surface.
The second wall portion has a second end surface facing the space and has a second end surface.
The connecting portion has a changing surface that faces the space and connects the first end surface and the second end surface.
The storage cell is characterized in that the changing surface extends between the first end surface and the second end surface so that the angle formed by each of the first end surface and the second end surface is an obtuse angle. The second wall portion is closer to the first end portion of the first wall portion in the first extension direction, which is the direction in which the first wall portion extends, and the first wall portion in the first extension direction. It is provided near the two ends, respectively.
The first end surface and the second end surface of the second wall portion provided near the first end portion are connected by the changing surface.
The storage cell according to claim 1, wherein the first end surface and the second end surface of the second wall portion provided near the second end surface are connected by the changing surface. The resin frame is continuous on the side opposite to the first wall portion of the second wall portion, and the first wall portion extends in a plan view in a stacking direction in which the pair of electrodes overlap. It has a third wall that extends in the extension direction,
The thickness of the first wall portion in the first extension direction and the first thickness direction orthogonal to the stacking direction is the second extending direction in which the second wall portion extends and the second thickness orthogonal to the stacking direction. The storage cell according to claim 1 or 2, wherein the thickness is equal to or greater than the thickness of the second wall portion in the thickness direction and the thickness of the third wall portion in the first thickness direction. The first wall portion has a plate shape in which the thickness does not change in the first thickness direction orthogonal to the first extension direction in which the first wall portion extends and the stacking direction in which the pair of electrodes overlap.
Claims 1 to claim 1, wherein in the first extension direction, the connection portion and the penetration portion are arranged at a distance equal to or larger than the width of the penetration portion in the first extension direction. The storage cell according to any one of 3. Claims 1 to 1, wherein the changing surface is an inclined surface extending between the first end surface and the second end surface in a plan view in a stacking direction in which the pair of electrodes overlap. The storage cell according to any one of claims 4. The storage cell according to claim 5, wherein the inclined surface extends to the penetrating portion. Equipped with multiple storage cells
A power storage device, wherein the plurality of power storage cells include at least the power storage cell according to any one of claims 1 to 6.

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