Battery Cell

Abstract

To provide a laminated cell type battery in which a current collector tab and a current collector tab lead are sandwiched and accommodated from above and below by an exterior body, and that suppresses the influence of external force on the current collector tab lead and the current collector tab even when an external force is applied to a place where the current collector tab and the current collector tab lead are accommodated.SOLUTION: One film of an exterior body is in contact with and covers the top, bottom and two sides of the battery, which are orthogonal to the end surface on which the battery's current collector tab and current collector tab lead are extended, and covers the end surface on which the battery's current collector tab and current collector tab lead protrude, and further, forms a triangular pyramid-shaped space portion so as to be folded from the short side on both sides of the end surface, and arranges and joins a reinforcing material in the triangular pyramid-shaped space portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a battery cell, and more particularly to a battery cell sealed with an exterior body. [Background technology]

[0002] In recent years, the demand for high-capacity, high-output battery devices has been rapidly expanding due to the widespread use of various large and small electric and electronic devices such as automobiles, personal computers, and mobile phones. Examples of such battery devices include liquid battery cells that use an organic electrolyte between the positive and negative electrodes, and solid battery cells that use a flame-retardant solid electrolyte instead of an organic electrolyte.

[0003] Among such battery devices, a laminate cell type battery cell is known in which a battery is wrapped in a laminate film (exterior body) and sealed in a plate shape. For applications such as EVs and HEVs, a battery cell assembly is used in which a number of such laminate cell type battery cells are arranged and housed in a case. By wrapping the battery in an exterior body, it is possible to prevent the intrusion of air into the battery (for example, Patent Document 1). In this specification, the term "battery" refers to a member composed of a laminate of electronic elements consisting of positive and negative electrodes and an electrolyte, a current collecting tab, and a current collecting tab lead, and a battery wrapped in a laminate film (exterior body) and sealed is called a "battery cell".

[0004] Patent Document 2 discloses a battery cell having an exterior body in which a single film is folded to house a battery, with the aim of effectively improving the volumetric energy density of a battery module while maintaining the airtightness of the laminate film (exterior body). According to Patent Document 2, this battery cell can effectively improve the volumetric energy density of a battery module while maintaining the airtightness of the exterior body. Patent Document 2 also describes a configuration in which the current collecting tab lead is housed by being sandwiched between the exterior body from above and below in such a battery cell. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-169204 A [Patent Document 2] WO2019 / 188825 Summary of the Invention [Problem to be solved by the invention]

[0006] In laminated cell type battery cells in which the current collecting tab and current collecting tab lead are sandwiched from above and below by an exterior body, if an external force is applied to the area where the current collecting tab and current collecting tab lead are housed, stress will be applied to the current collecting tab and current collecting tab lead, which may cause the electrodes to crack. In this case, the strength of the exterior body film itself is weak, so the exterior body film alone cannot adequately protect the built-in battery from external forces.

[0007] The present invention aims to suppress the effect that an external force has on the current collecting tab and current collecting tab lead in a laminate cell type battery in which the current collecting tab and current collecting tab lead are housed by being sandwiched from above and below with an exterior body, even when the external force is applied to the location where the current collecting tab and current collecting tab lead are housed. [Means for solving the problem]

[0008] In order to solve the above problems, in the battery cell of the present invention, the single film of the exterior body comprises a portion that contacts and covers the top, bottom and two side surfaces perpendicular to the end face from which the current collecting tab and current collecting tab lead of the battery extend, a portion that covers the end face from which the current collecting tab and current collecting tab lead of the battery protrudes and is folded from the short sides of both sides of the end face to form triangular pyramid-shaped spaces on both sides and is folded from the long sides of both sides of the end face to encase the end face and form a triangular prism as a whole, and a portion that extends further in the axial direction from the portion encasing the end face to join both opposing upper and lower surfaces to sandwich the current collecting tab and current collecting tab lead, and is characterized in that a reinforcing material is placed and joined in the triangular pyramid-shaped space.

[0009] By placing and joining a reinforcing material in the triangular pyramid-shaped space on both sides formed by folding in the short sides of the end face at the location covering the end face from which the current collecting tab and current collecting tab lead of the battery protrude, even if an external force is applied to the location where the current collecting tab and current collecting tab lead are housed, the effect of the external force on the current collecting tab and current collecting tab lead can be suppressed, and the problem of the electrode cracking due to stress being applied to the current collecting tab and current collecting tab lead can be suppressed.

[0010] In this case, the present invention is characterized in that the exterior body is made of one film.

[0011] By making the exterior body out of a single film, the number of joints required during packaging can be minimized, improving airtightness.

[0012] In this case, the present invention is characterized in that the battery is an all-solid-state battery cell made of a laminate using a solid electrolyte.

[0013] All-solid-state battery cells are fragile and easily damaged, particularly at corners and end faces. Therefore, the structure of the present invention, in which reinforcing materials are disposed and joined to triangular pyramidal spaces on both sides of the portion covering the end face from which the current collecting tab and current collecting tab lead of the battery protrude, can suppress the effect of external force on the current collecting tab and current collecting tab lead even when the external force is applied to the portion housing the current collecting tab and current collecting tab lead, and is effectively applied to all-solid-state battery cells in which the current collecting tab and current collecting tab lead protrude from the end face.

[0014] In addition, in this case, the present invention is characterized in that the reinforcing material is a tetrahedron with one open side, having three sides consisting of a triangular side that joins to the end face of the triangular pyramid-shaped space portion from which the current collecting tab and the current collecting tab lead extend, and two sides that join to each of the two faces that form the triangular side without joining to the end face when folded.

[0015] This reinforcing material is a reinforcing material for the triangular pyramid-shaped space on both sides formed by folding in the short sides of the end face of the battery at the portion covering the end face from which the current collecting tab and current collecting tab lead protrude, and it can be said to be the most basic reinforcing material that aims to reinforce three sides of the space. It is relatively lightweight and can efficiently reinforce all three sides that define the triangular pyramid-shaped space.

[0016] In this case, the present invention is characterized in that the reinforcing material is a hollow tetrahedron having four faces that define the four faces of the triangular pyramid-shaped space portion.

[0017] A planar reinforcing part that closes the triangular pyramid-shaped space is added to the tetrahedral reinforcing material with one open face, which strengthens the function of the reinforcing material and prevents an external force from entering the triangular pyramid-shaped space and acting on the three faces that define the triangular pyramid-shaped space to expand the triangular pyramid-shaped space.

[0018] In this case, the present invention is characterized in that the reinforcing material is a solid tetrahedron having four faces that define the four faces of the triangular pyramidal space portion.

[0019] Needless to say, this reinforcement force is stronger than the hollow reinforcement material. However, since it is a solid member, it increases the weight and requires a lot of material (resources). It is effective when it is necessary to reinforce the end faces of the battery from which the current collector tabs and current collector tab leads protrude.

[0020] In this case, the present invention is characterized in that the reinforcing material is a frame body made up of six linear members along six sides of the triangular pyramid-shaped space portion.

[0021] This is the lightest reinforcing material and therefore does not require a large amount of material (resources) as a reinforcing material for the triangular pyramid-shaped space on both sides formed by folding in the short sides of the end face of the battery at the portion covering the end face from which the current collecting tab and current collecting tab lead protrude. It is effective when reinforcement is necessary but the increase in weight due to reinforcement needs to be kept to a minimum.

[0022] In this case, the present invention is characterized in that the reinforcing material is formed integrally by combining and joining a plurality of pieces, and is capable of fixing the position of each battery cell when stacking the battery cells.

[0023] When the reinforcing material of the present invention is connected and integrated, the integrated reinforcing material is inserted into and joined to the four triangular pyramid-shaped spaces at the top, bottom, left, and right (top right, top left, bottom right, bottom left) of the battery cells stacked horizontally from front to back in a modularization, thereby making it possible to fix and join the positions of the stacked battery cells 2. In other words, the reinforcing material of the battery cell of the present invention can also function as a position fixing member when stacking the battery cells. Effect of the Invention

[0024] In this way, the present invention has an advantage that, by arranging and joining reinforcing material in the end face of the battery from which the current collecting tab and current collecting tab lead protrude, and in the triangular pyramid-shaped spaces on both sides formed by folding in from the short sides on both sides of the end face, even if an external force is applied to the location where the current collecting tab and current collecting tab lead are housed, the external force will affect the end face, and ultimately the current collecting tab and current collecting tab lead, causing stress to be applied to the current collecting tab and current collecting tab lead, thereby suppressing the occurrence of problems such as the electrodes connected to the current collecting tab and current collecting tab lead cracking. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a perspective view of a battery within a battery cell of the present invention. [Diagram 2] FIG. 1 is a perspective view showing the appearance of a battery cell of the present invention. [Diagram 3] FIG. 2 is a development view of an exterior body of a battery cell according to the present invention. [Figure 4] FIG. 2 is a perspective view of a battery cell according to the present invention, showing locations of reinforcing members. [Diagram 5] FIG. 2 is a diagram showing a tetrahedral reinforcing member of the present invention with one side open. [Figure 6] FIG. 2 is a perspective view of a reinforcing material that is an advanced version of the tetrahedral reinforcing material of the present invention, one of whose faces is open. [Figure 7] 1A to 1C are top, left, front, right and bottom views of a reinforcing material that is an advanced version of the tetrahedral reinforcing material of the present invention with one open side. [Figure 8] FIG. 2 is a development view of a reinforcing material of an improved form than the tetrahedral reinforcing material of the present invention, one of whose faces is open. [Figure 9] FIG. 2 shows a hollow tetrahedral reinforcement member of the present invention. [Figure 10] FIG. 2 shows a solid tetrahedral reinforcement of the present invention. [Figure 11] 11A and 11B are diagrams showing a reinforcing member for a frame body according to the present invention; [Figure 12]FIG. 13 is a diagram showing a reinforcing material of the present invention in which a plurality of pieces are integrated to form a fixing member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0027] The battery 1 of the present invention is an all-solid-state battery in the examples, and has a rectangular parallelepiped shape as shown in Fig. 1, and has six faces, namely, a top face 11a, a bottom face 11b, side faces 12a, 12b, and end faces 13a, 13b. When a central axis 15 connecting the centers of the end faces 13a and 13b is imagined, current collecting tabs and current collecting tab leads 14a and 14b are extended from the end faces 13a and 13b in the direction of the central axis 15. All-solid-state batteries are brittle and easily damaged, especially at corners and surface portions (end faces), and therefore are more suitable for applying the configurations of the embodiments of the present invention.

[0028] Fig. 2 shows a battery cell 2 in which a battery 1 of the present invention is covered and packaged with an exterior body 3 (Fig. 3). The battery cell 2 also has a top surface 21a, a bottom surface 21b, and side surfaces 22a, 22b defined in correspondence with the battery 1. The portions corresponding to the end surfaces 13a, 13b of the battery 1 are end surface folded parts 23a-1, 23a-2, 23b-1, 23b-2 in which the exterior body 3 is folded, and the outer surface has a triangular prism shape. In addition, the end surface folded parts 23a-1, 23a-2 and 23b-1, 23b-2 are folded in from the side surfaces 22a, 22b, respectively, to form triangular pyramid-shaped spaces 25a-1, 25a-2 and 25b-1, 25b-2, two on each side, for a total of four. Then, extending in the direction of central axis 15 from the end face folding portions 23a-1, 23a-2 and 23b-1, 23b-2 are current collecting tab and current collecting tab lead accommodating portions 24a-1, 24a-2 and 24b-1, 24b-2 which accommodate the current collecting tab and current collecting tab lead 14a, 14b by sandwiching them from above and below.

[0029] 3 shows an exploded view of the exterior body 3. The exterior body 3 has a top cover portion 31a and a bottom cover portion 31b as portions covering the top surface 11a and the bottom surface 11b of the battery 1, a side cover portion 32a as a portion covering the side surface 12a, and side cover portions 32b-1 and 32b-2 as portions covering the side surface 12b. The side cover portions 32b-1 and 32b-2 are joint portions that overlap and are joined to each other when the exterior body 3 covers and encases the battery 1. Therefore, the side surface 22a of the battery 1 is doubly covered by the side cover portions 32b-1 and 32b-2 of the exterior body 3.

[0030] The locations covering the end faces 13a, 13b of the battery 1 are end face covering portions 33a-1, 33a-2, 33b-1, 33b-2 which form end face folding portions 23a-1, 23a-2, 23b-1, 23b-2 in the shape of a triangular prism formed by folding the exterior body 3 of the battery cell 2, and are provided in a manner corresponding to the up and down directions of each of the end faces on both sides. At the ends of the end face covering portions 33a-1, 33a-2, 33b-1, 33b-2 extended in the direction of the central axis 15, current collecting tab and current collecting tab lead clamping portions 34a-1, 34a-2, 34b-1, 34b-2 which clamp the current collecting tabs and current collecting tab leads on both sides from above and below are provided. In addition, triangular pyramidal space forming portions 35a-1, 35a-21, 35a-22 and 35b-1, 35b-21, 35a-22 are formed, which are portions forming triangular pyramidal space portions 25a-1, 25a-2 and 25b-1, 25b-2, respectively, formed by folding from the side surfaces 22a, 22b. The triangular pyramidal space forming portions 35a-21 and 35a-22, and 35b-21 and 35b-22 overlap with each other, forming triangular pyramidal spaces with the double film of the exterior body 3.

[0031] Incidentally, by making the exterior body 3 out of a single film as described above, it is possible to minimize the number of joints when covering and packaging the battery 1, thereby improving the airtightness. Furthermore, the exterior body 3 having the development view of Fig. 3 is suitable for covering and packaging the battery 1 in which the current collecting tab and current collecting tab lead protrude from the end face in Fig. 1, particularly an all-solid-state battery which is brittle and easily damaged at the end face and corners, and by using the exterior body 3 having the development view of Fig. 3 made of a single film, the manufacturing efficiency of the battery cell 2 is improved.

[0032] In one embodiment of the present invention, as shown in Fig. 4, a reinforcing material 4 is arranged and joined to the triangular pyramid-shaped space shown by solid color in the front part. The reinforcing material 4 includes a material applied to at least a part of the faces or sides constituting the triangular pyramid-shaped spaces 25a-1, 25a-2, 25b-1, and 25b-2. By arranging and joining the reinforcing material 4 to the triangular pyramid-shaped spaces 25a-1, 25a-2, 25b-1, and 25b-2, even if an external force is applied to the portion where the current collecting tab and the current collecting tab lead are housed, the influence of the external force on the current collecting tab and the current collecting tab lead can be suppressed, and the problem of the electrode cracking due to the application of stress to the current collecting tab and the current collecting tab lead can be suppressed.

[0033] One example of the reinforcing material 4 in one embodiment of the present invention is a tetrahedral reinforcing material 41 with one open side, which has three sides consisting of a triangular surface that joins with the end surfaces 13a, 13b of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, 25b-2 from which the current collecting tabs and current collecting tab leads of the batteries 1 protrude, and two surfaces that do not join with the end surfaces 13a, 13b when folded but join with each of the two surfaces that form the triangular surface, as shown in Fig. 5. This tetrahedral reinforcing material 41 with one open side has the most basic configuration among the reinforcing materials 4 that are intended to reinforce the three surfaces of each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, 25b-2, is relatively lightweight, and can efficiently reinforce all three surfaces that define each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, 25b-2.

[0034] The tetrahedral reinforcing member 41 with one open face can be further developed to form a reinforcing member 41' as shown in Figures 6 to 8. Figure 6 shows a perspective view of the reinforcing member 41' in the developed form, and Figure 7 shows a top view, a left view, a front view, a right view, and a bottom view. Also, Figure 8 is a development view.

[0035] 6 to 8, in the reinforcing material 41' of the above-mentioned developed form, a slit 41a is formed in a part of the ridge line, and a hole 41b is provided at the tip of the slit 41a. A flat surface 41c is formed at the top, and a folded portion 41d is provided on the lower side so as to be folded outward.

[0036] The slits 41a create a leaf spring effect, which makes it possible to reduce not only external forces but also vibrations. To provide additional explanation on this point, a method of bending a plate in the direction of stress is generally used to create a leaf spring structure, but in the case of the tetrahedral reinforcing material 41 with one open face, bending the face to create a curved structure reduces the contact area with the exterior body 3, which would cause stress to concentrate in that area and lead to damage to the exterior body 3, and therefore the method of bending the face of the reinforcing material 41 to create a curved structure cannot be used.

[0037] Therefore, a method was adopted in which slits 41a are formed on a part of the ridge of reinforcing material 41 to form a leaf spring structure, as a method for eliminating stress concentration by having the entire surface of reinforcing material 41 in contact with each surface of triangular pyramidal space portions 25a-1, 25a-2, 25b-1, and 25b-2 of exterior body 3 bear stress, and for absorbing external forces and vibrations. Bending stress is mainly applied to each surface of triangular pyramidal space portions 25a-1, 25a-2, 25b-1, and 25b-2, but the leaf spring structure in which slits 41a are formed on a part of the ridge of reinforcing material 41 effectively relieves this bending stress.

[0038] The hole 41b provided at the tip of the slit 41a is for relieving stress generated at the tip of the slit 41a. That is, the hole 41b prevents stress from concentrating at the tip of the slit 41a and causing damage to the reinforcing material 41' from the tip of the slit 41a. In addition, when the reinforcing material 41' is made of metal, the presence of the hole 41b has the secondary effect of improving dimensional accuracy during sheet metal bending processing.

[0039] In addition, in the above-described developed form of reinforcing material 41', flat surface 41c is formed on the apex on the tip side in the insertion direction. When reinforcing material 41' is attached, stress that peels off the welded portion of exterior body 3 is generated in the attachment direction, but by forming flat surface 41c, this stress that peels off the welded portion can be reduced, contributing to maintaining airtightness.

[0040] Furthermore, a turned-out portion 41d that turns outward is provided at a location corresponding to an outer side of the triangular pyramid-shaped spaces 25a-1, 25a-2, 25b-1, and 25b-2 of the exterior body 3. This turned-out portion 41d improves the position retention of the reinforcing material 41'. In addition, this turned-out portion 41d allows the exterior body 3 to be sandwiched between the outer surface of the reinforcing material 41', eliminating the need for adhesive or double-sided tape and facilitating manufacturing.

[0041] Here, in the case where the reinforcing material 4 is used in the triangular pyramidal space portions 25a-1, 25a-2, 25b-1, and 25b-2 of the exterior body 3, as one embodiment, a reinforcing plate (not shown) can be disposed on the surface of the exterior body 3 in the triangular pyramidal space portions 25a-1, 25a-2, 25b-1, and 25b-2. In this case, the return portion 41d can sandwich the exterior body 3 and the reinforcing plate between the outer surface of the reinforcing material 41'. This can firmly reinforce the outer surface of the exterior body 3 in the triangular pyramidal space portions 25a-1, 25a-2, 25b-1, and 25b-2, which are the weakest strength portions. In addition, since the influence of an external force applied perpendicularly to the reinforcing plate can be reduced, the stress applied to the welded portion of the exterior body 3 can be reduced, and the airtightness can be improved. As a result, the effect of moisture on the battery 1 can be suppressed, and even if gas is generated inside the exterior body 3, the internal gas can be prevented from being discharged.

[0042] Another example of the reinforcing material 4 in one embodiment of the present invention is a reinforcing material 42 which is a hollow tetrahedron having four faces defining the four faces of each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2, as shown in Fig. 9. The reinforcing material 42 which is a hollow tetrahedron having four faces is stronger because planar reinforcing parts which close each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2 are added, and it is possible to prevent an external force from entering the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2 and acting on the three internal faces defining the triangular pyramidal spaces to deform each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2.

[0043] Another example of the reinforcing material 4 in one embodiment of the present invention is a reinforcing material 43, which is a solid tetrahedron having four faces that define the four faces of each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2, as shown in Fig. 10. The reinforcing material 43, which is a solid tetrahedron, is stronger because it is solid, but on the other hand, it increases the weight and requires a lot of material (resources). It is effective to adopt this reinforcing material 43 when there is a high degree of need to reinforce the end faces 13a and 13b of the battery and the four corners of the sides where the end faces 13a and 13b intersect with the side faces 12a and 12b.

[0044] Another example of the reinforcing material 4 in one embodiment of the present invention is a reinforcing material 44, which is a frame body made of six linear members along the six sides of each of the triangular pyramidal spaces 25a-1, 25a-2, 25b-1, and 25b-2, as shown in Fig. 11. This reinforcing material 44, which is a frame body, is the lightest among the examples given so far, and therefore does not require a large amount of material (resources). Although reinforcement is required for the end faces 13a and 13b of the battery 1 and the four corners of the sides where the end faces 13a and 13b intersect with the side faces 12a and 12b, this is effective when it is desired to minimize the increase in weight of the battery cell 2 due to the reinforcement.

[0045] In the case of the reinforcing member 44, which is a frame body, a flat surface can be formed at the top of the tip side in the insertion direction, similar to the above-mentioned developed form of the reinforcing member 41'. In this case, the tip portion in the insertion direction is cut out parallel to the bottom surface, and frames are arranged to connect the frames on each side cut out at the cut ends, forming a flat surface made up of triangular frames.

[0046] As the frame of the reinforcing material 44, which is the frame body, in addition to a linear (rod-shaped) frame, an L-shaped frame having an L-shaped cross section or a U-shaped frame having a U-shaped cross section can be used. In the L-shaped frame, the side where the two planes of the L shape intersect is disposed on the outside of the reinforcing material 44, and a slit and a hole at the tip of the slit can be provided on that side. In this way, by using an L-shaped frame as a frame for at least a part of the reinforcing material 44, which is the frame body, a slit and a hole at the tip of the slit can be formed on a part of the ridge line of the reinforcing material 44.

[0047] A U-shaped frame may also be used as at least a part of the frame of the reinforcing member 44, which is a frame body. If a U-shaped frame is used as the frame of the portion of the reinforcing member 44, which is a frame body, that corresponds to the side located outside the triangular pyramid-shaped space portions 25a-1, 25a-2, 25b-1, and 25b-2 of the exterior body 3, and one flat surface of the U-shape is positioned outside, a return portion that returns to the outside is provided. This return portion improves the position retention of the reinforcing member 44, and this return portion allows the exterior body 3 to be sandwiched between the reinforcing member 44 and the outer surface of the reinforcing member 44.

[0048] In another embodiment of the present invention, as shown in Fig. 12, a plurality of the reinforcing members 4 are combined and joined into an integral structure. When the reinforcing members 4 are connected and integrated into an integral structure, the integrated reinforcing members 4 are inserted into the four triangular pyramid-shaped spaces 25a-1, 25a-2, 25b-1, 25b-2 at the top, bottom, left, and right (top right, top left, bottom right, bottom left) of the battery cells 4 stacked horizontally from the front side to the rear side in a modularized structure, and joined to each other, thereby fixing and joining the positions of the stacked battery cells 2. In other words, the reinforcing members 4 of the battery cells 2 of the present invention can also function as position fixing members when stacking the battery cells 2 by being combined, joined, and integrated.

[0049] Resin or metal is used as the material for the reinforcing members 4, 41, 41', 42, 43, and 44 of the present invention. Resin is a preferred material because it can be molded as a single unit by injection molding, is low cost, is lightweight, and has sufficient strength to provide a reinforcing effect.

[0050] Although the above describes the manner in which the present invention can be implemented using examples, the present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various manners without departing from the spirit of the present invention. [Explanation of symbols]

[0051] 1 battery 11a Top 11b Bottom 12a,12b side 13a,13b end face 14a, 14b Current collecting tab and current collecting tab lead 15 Center axis 2 Battery Cells 21a Top 21b Bottom 22a,22b side 23a-1, 23a-2, 23b-1, 23b-2 End face folding part 24a-1, 24a-2, 24b-1, 24b-2 Current collecting tab and current collecting tab lead housing 25a-1, 25a-2, 25b-1, 25b-2 Triangular pyramid shaped space 3 Exterior body 31a Top cover 31b Bottom cover part 32a,32b-1,32b-2 Side cover 33a-1,33a-2,33b-1,33b-2 End cover part 34a-1, 34a-2, 34b-1, 34b-2 Current collecting tab and current collecting tab lead clamping portion 35a-1,35a-21,35a-22,35b-1,35b-21,35b-22 Triangular pyramidal space forming part 4 Reinforcement 41 Reinforcement of a tetrahedron with one side open 41' A reinforcement material with an advanced form of a tetrahedral reinforcement material with one side open 41a Slit 41b Hole at the tip of the slit 41c Top plane 41d Return part 42 Reinforcement material that is a hollow tetrahedron with four sides 43 Reinforcement material that is a solid tetrahedron 44 Reinforcement material consisting of a frame of six linear members

Claims

1. A battery cell including a battery and an exterior body that houses the battery, a current collecting tab and a current collecting tab lead extend from one end surface of the battery; The exterior body comprises a portion that contacts and covers the top, bottom and two side surfaces perpendicular to the end face from which the current collecting tab and current collecting tab lead of the battery extend, a portion that covers the end face from which the current collecting tab and current collecting tab lead of the battery protrude, and is folded from the short sides of both sides of the end face to form triangular pyramid-shaped spaces on both sides and is folded from the long sides of both sides of the end face to encase the end face and take on a triangular prism shape as a whole, and a portion that extends further in the axial direction from the portion encasing the end face to join both upper and lower opposing surfaces to sandwich the current collecting tab and current collecting tab lead, and the battery cell is joined by placing a reinforcing material in the triangular pyramid-shaped space.

2. The battery cell according to claim 1 , wherein the exterior body is made of a single film.

3. 3. The battery cell according to claim 1, wherein the battery is an all-solid-state battery cell made of a laminate using a solid electrolyte.

4. 4. The battery cell according to claim 1, wherein the reinforcing material is a tetrahedron with one open side, having three sides consisting of a triangular side that joins to an end face of the triangular pyramid-shaped space portion from which the current collecting tab and current collecting tab lead extend, and two sides that join to each of two other sides that form the triangular side but are not joined to the end face when folded.

5. 4. The battery cell according to claim 1, wherein the reinforcing member is a hollow tetrahedron having four faces that define the four faces of the triangular pyramid-shaped space portion.

6. The battery cell according to claim 4 or 5, wherein the reinforcing member has a slit formed in a portion of the ridge line.

7. The battery cell according to claim 6 , wherein a hole is formed at an end of the slit.

8. 4. The battery cell according to claim 1, wherein the reinforcing member is a solid tetrahedron having four faces that define the four faces of the triangular pyramid-shaped space portion.

9. A battery cell as described in any one of claims 4 to 8, wherein the reinforcing material has a folded portion that folds outward at a position corresponding to a side of the outer opening of the triangular pyramid-shaped space portion formed in the outer casing.

10. The battery cell according to claim 9 , wherein the return portion sandwiches the exterior body between itself and an outer surface of the reinforcing material.

11. A battery cell as described in claim 10, wherein a reinforcing plate is disposed between the triangular pyramidal space portion of the outer casing and the reinforcing material, and the return portion sandwiches the outer casing and the reinforcing plate between the outer casing and the outer surface of the reinforcing material.

12. 4. The battery cell according to claim 1, wherein the reinforcing member is a frame body made up of six frames arranged along six sides of the triangular pyramid-shaped space portion.

13. The battery cell according to claim 12 , wherein at least a portion of the frame of the reinforcing member made of a frame body is an L-shaped frame.

14. The battery cell according to claim 13 , wherein the L-shaped frame has a slit formed therein.

15. The battery cell according to claim 14 , wherein the reinforcing member made of the frame body is an L-shaped frame in which the slit is formed, so that the slit is formed in part of the edge line.

16. 16. The battery cell according to claim 14, wherein a hole is formed at an end of the slit.

17. The battery cell according to any one of claims 12 to 16, wherein at least a portion of the frame of the reinforcing member made of the frame body is a U-shaped frame.

18. The battery cell described in claim 17, wherein the reinforcing material consisting of the frame body has a folded portion that folds outward at a position corresponding to a side of the outer opening of the triangular pyramidal space portion formed in the outer body by using the U-shaped frame.

19. The battery cell according to claim 18 , wherein the return portion sandwiches the exterior body between itself and an outer surface of the reinforcing material.

20. A battery cell as described in claim 19, wherein a reinforcing plate is arranged between the triangular pyramidal space portion of the outer casing and the reinforcing material, and the return portion sandwiches the outer casing and the reinforcing plate between the outer surface of the reinforcing material.

21. The battery cell according to any one of claims 4 to 20, wherein the reinforcing member has a flat surface formed on a top portion thereof.

22. The battery cell according to any one of claims 1 to 21, wherein the reinforcing material is made of resin.

23. The battery cell according to any one of claims 1 to 22, wherein the reinforcing material is formed by combining and joining a plurality of pieces together to form an integral structure, and is capable of fixing the positions of the individual battery cells when the battery cells are stacked.

24. A battery cell module formed by stacking battery cells, A battery cell module formed by stacking battery cells and fixing the positions of the respective battery cells using the reinforcing material according to claim 23, the reinforcing material being formed by combining and joining a plurality of battery cells together to form an integrated structure.

25. A battery cell position fixing method for stacking battery cells to form a battery cell module, comprising the steps of: A battery cell position fixing method for fixing the position of each battery cell by using the reinforcing material according to claim 23, which is formed by combining and joining a plurality of battery cells together to form an integral structure when stacking the battery cells.

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