Power storage device

Abstract

To improve the productivity of a power storage device.SOLUTION: A battery 100 comprises cell connections 10 and 20, each including a plurality of cells 11 to 14 and 21 to 24, and connection sections 2A and 2B that electrically connect adjacent cells, and a case 300 that houses the cell connections 10 and 20. The case 300 includes a case body 310 that holds the cell connections 10, 20 by sandwiching it. The cross-section of the case body 310 includes an opening formed in a predetermined direction (-Z direction).SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] JP 2023-502457 A (Patent Document 1) discloses a rectangular parallelepiped battery (electricity storage device) having a length L of 400 mm to 2500 mm and a ratio of length L to width H (L / H) of 4 to 21. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-502457 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described electricity storage device, there is a demand for further improvement in productivity in assembling the cells into the case and joining the case.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a power storage device with improved productivity. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage device including a cell assembly including a plurality of cells and connectors that electrically connect adjacent cells, and a case that houses the cell assembly. The case includes a first member that sandwiches and holds the cell assembly. A cross section of the first member is provided with an opening that opens in a predetermined direction.

[0007] In this way, the cell combined body can be assembled from the opening of the first member of the case. Therefore, compared to assembling the cell combined body by inserting it into the end of the cylindrical case, the cell combined body can be assembled more easily to the case. This improves the productivity of the energy storage device.

[0008] In one embodiment, the cross section of the first member has two wall surfaces arranged opposite each other, a connecting portion connecting one end of the two wall surfaces, and an opening portion. Each of the two wall surfaces has a recess that protrudes toward the opposing wall surface and has a bottom surface that abuts against the cell connector.

[0009] In this way, by assembling the cell connected body to the first member, the cells are sandwiched between the bottom surfaces of the recesses provided in the two opposing wall surfaces, and therefore the first member can hold the cell connected body.

[0010] Furthermore, in one embodiment, the case includes a second member that closes the opening of the first member to form a cylindrical body, a third member that closes one end of the cylindrical body, and a fourth member that closes the other end of the cylindrical body.

[0011] In this way, with the cell connected body assembled to the first member, the opening can be closed using the second member, third member, and fourth member, so that the entire periphery of the cell connected body can be covered with the case.

[0012] In one embodiment, the battery includes a cell assembly including a plurality of cells and connectors that electrically connect adjacent cells, and a case that houses the cell assembly. The case includes a cylindrical body that surrounds the periphery of the longitudinal faces of the cell assembly. The cylindrical body is formed by bending a plate-like member so that wall surfaces facing each longitudinal face of the cell assembly are formed, and one end of the plate-like member is joined to a member on the other end side of the plate-like member.

[0013] In this way, the cylindrical body can be constructed by joining one end to a member on the other end side, which prevents an increase in the number of joining points, and, for example, if the joining point between the one end and the other end side member is set at a position away from the cell assembly, joining can be performed without affecting the cell assembly, thereby improving the productivity of the energy storage device. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide a power storage device with improved productivity. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating an example of a configuration of a battery that is a power storage device according to an embodiment of the present invention. [Figure 2] 2 is an enlarged perspective view of the cell connected body shown in FIG. 1. FIG. [Figure 3] 2 is an exploded perspective view of a cell included in the cell connected body shown in FIG. 1. FIG. [Figure 4] 1 is a diagram showing an example of the configuration of a case of a battery that is an electricity storage device according to an embodiment of the present invention. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 10 is a diagram showing an example of the configuration of a battery that is a power storage device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and their description will not be repeated. In the drawings used below, the X-axis, Y-axis, and Z-axis are perpendicular to each other. The X-axis indicates a first in-plane direction of the battery (e.g., the length direction), the Y-axis indicates a second in-plane direction of the battery (e.g., the width direction), and the Z-axis indicates the height direction of the battery. Hereinafter, the directions indicated by the arrows of the X-axis, Y-axis, and Z-axis are indicated with a "+" and the opposite directions are indicated with a "-".

[0017] Fig. 1 is a diagram showing an example of the configuration of a battery 100, which is a power storage device according to this embodiment. "Case internal configuration diagram-Z" in Fig. 1 is a diagram showing the contents of the case as viewed from the +Z side. "Case internal configuration diagram-Y" in Fig. 1 is a diagram showing the contents of the case as viewed from the +Y side.

[0018] Battery 100 is a secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, or a sodium-ion battery. Examples of lithium-ion batteries include LFP batteries that use lithium iron phosphate as the positive electrode active material, and ternary batteries that use NMC (nickel-manganese-cobalt) as the positive electrode active material. The secondary battery may be a liquid secondary battery or an all-solid-state secondary battery. As will be described in detail later, battery 100 includes multiple cells that each function as a secondary battery. Battery 100 may include only cells of the same type (e.g., only LFP batteries) or cells of different types (e.g., LFP batteries and ternary batteries).

[0019] The battery 100 includes a case 300. The case 300 has a rectangular parallelepiped outer shape. The case 300 has a pair of faces F1 and F2 (first opposing faces) facing each other in the Z direction, a pair of faces F3 and F4 (second opposing faces) facing each other in the Y direction, and faces F5 and F6 (X-direction end faces) located at the ends in the X direction. The area of ​​each of the faces F1 and F2 is smaller than the area of ​​each of the faces F3 and F4. The length (dimension in the X direction) of the case 300 is longer than the width (dimension in the Y direction) of the case 300. The length of the case 300 may be 250 mm or more and 5000 mm or less, for example, approximately 1000 mm. The width of the case 300 may be 10 mm or more and 1250 mm or less, for example, approximately 50 mm. The ratio of the length of the case 300 to the width of the case 300 may be 4 or more and 25 or less. The height (dimension in the Z direction) of the case 300 may be 10 mm or more and 1250 mm or less, for example, about 100 mm, but the dimensions of the case 300 are not limited to the above.

[0020] Case 300 includes case body 310, first cover 320, second cover 330, and bottom 340. Case body 310 is a housing having openings at, for example, the +X-direction end, the -X-direction end, and the -Z-direction end. The opening at the -Z-direction end of case body 310 is closed by bottom 340 to form a cylindrical body, and cell assemblies 10 and 20 are housed inside the cylindrical body.

[0021] First lid 320 is a plate-like member (cover member) having an outer shape corresponding to the opening at the end of case body 310 in the +X direction, and closes the opening. Second lid 330 is a plate-like member (cover member) having an outer shape corresponding to the opening at the end of case body 310 in the -X direction, and closes the opening.

[0022] The case body 310, the first lid 320, the second lid 330, and the bottom 340 may be formed of the same material or different materials. The case body 310, the first lid 320, the second lid 330, and the bottom 340 may each be formed of a material such as metal. The case 300 may be made of aluminum. However, these materials can be changed as appropriate. For example, at least one of the first lid 320, the second lid 330, and the bottom 340 may be formed of an insulating material.

[0023] The cell assembly 10 includes four chargeable cells 11 to 14 and three connection parts 2A that electrically connect adjacent cells. The cells 11 to 14 are connected in a row along the X direction inside the case 300.

[0024] The cell assembly 20 includes four chargeable cells 21 to 24 and three connection parts 2B that electrically connect adjacent cells. The cells 21 to 24 are connected in a row along the X direction inside the case 300.

[0025] In this way, the cell connected bodies 10 and 20 are arranged parallel to each other along the X direction. Each of the faces F1 to F4 of the case 300 has a shape that extends along the connecting direction (X direction) of the cell connected bodies 10 and 20. Each of the faces F5 and F6 of the case 300 covers the ends of the cell connected bodies 10 and 20 in the X direction.

[0026] The cell assembly 10 and the cell assembly 20 are electrically connected within the case 300 of the battery 100. Specifically, as shown in FIG. 1, the −X-direction end (cell 14) of the cell assembly 10 and the −X-direction end (cell 24) of the cell assembly 20 are electrically connected within the case 300 via, for example, a U-shaped connection part 2C. The connection part 2C has a different shape from the connection parts 2A and 2B (the connection part 2C has a U-shaped cross section, while the connection parts 2A and 2B each have an I-shaped cross section). However, the connection part 2C basically has the same structure as the connection part 2A or 2B. The connection part 2C may be an integrally molded product or a composite of multiple separately molded parts. For example, the connection part 2C may be formed by connecting a protrusion 144B (FIG. 3) protruding from the cell 14 and a protrusion 144B (FIG. 3) protruding from the cell 24 via a conductive material (beam). The protrusion 144B will be described later.

[0027] The cell strings 10 and 20 are arranged so that the positions of the cells and the connecting portions are aligned. Cells 11, 12, 13, and 14 included in the cell string 10 are arranged in positions facing cells 21, 22, 23, and 24 included in the cell string 20, respectively.

[0028] The +X direction end (cell 11) of the cell connected body 10 is connected to the first cover body 320 via a connection terminal T1. The +X direction end (cell 21) of the cell connected body 20 is connected to the first cover body 320 via a connection terminal T2. Fig. 2 is an enlarged perspective view of the cell connected bodies 10 and 20 shown in Fig. 1.

[0029] The first cover 320 has an external terminal 322 and a connector 323. The external terminal 322 includes an electrode tab 322A joined (e.g., laser welded) to the connection terminal T1 (FIG. 1) of the cell assembly 10 and an electrode tab 322B joined (e.g., laser welded) to the connection terminal T2 (FIG. 1) of the cell assembly 20. The electrode tabs 322A and 322B are electrically connected to the cells 11 and 21, respectively. Each of the electrode tabs 322A and 322B may have an insulating seal structure made of ceramic around the electrode, for example. In this embodiment, the electrode tabs 322A and 322B function as a negative electrode tab and a positive electrode tab, respectively. However, this is not limiting, and the polarities may be reversed, with the electrode tab 322B serving as a negative electrode tab and the electrode tab 322A serving as a positive electrode tab.

[0030] Connector 323 includes, for example, an output terminal that outputs a detection signal indicating a state inside case 300 (for example, the temperature of each cell) detected by one or more sensors inside case 300 to the outside of the case, and an input terminal that inputs a control signal from the outside of the case to one or more devices inside case 300. For example, a temperature sensor may be provided for each cell inside case 300.

[0031] In this embodiment, the cell connected body 10 and the cell connected body 20 basically have the same configuration. Therefore, hereinafter, when there is no need to distinguish between the cells 11 to 14 and the cells 21 to 24, they will be referred to as "cell 1," and when there is no need to distinguish between the connection parts 2A and 2B, they will be referred to as "connection part 2."

[0032] Fig. 3 is an exploded perspective view of the cells included in the cell combination bodies 10, 20 shown in Fig. 1. The structures of the cell 1 and the connection part 2 will be described below with reference to Fig. 3. As shown in Fig. 3, the cell 1 includes two wound bodies 110A, 110B, spacers 120A, 120B, terminal members 130A, 130B, and covers 150A, 150B.

[0033] The wound bodies 110A and 110B have coated portions 111A and 111B, electrode tabs 112A and 112B, and electrode tabs 113A and 113B, respectively. Each of the coated portions 111A and 111B is a region of the electrode foil on the positive electrode sheet or the negative electrode sheet where an active material layer is provided. Each of the electrode tabs 112A, 112B, 113A, and 113B is a region of the positive electrode sheet or the negative electrode sheet where the electrode foil is exposed (an uncoated portion where no active material layer is provided). The electrode tabs 112A and 112B are located at the +X-direction ends of the wound bodies 110A and 110B, respectively. The electrode tabs 113A and 113B are located at the -X-direction ends of the wound bodies 110A and 110B, respectively.

[0034] The electrode tabs 112A and 112B are arranged to face each other in the Y direction, and a spacer 120A and a terminal member 130A are provided between the electrode tabs 112A and 112B. The electrode tabs 113A and 113B are arranged to face each other in the Y direction, and a spacer 120B and a terminal member 130B are provided between the electrode tabs 113A and 113B.

[0035] Each of the spacers 120A, 120B contains an insulating material (e.g., synthetic resin) and is insulating. Each of the spacers 120A, 120B has a shape in which the dimension in the Y direction increases with increasing distance from the coated portions 111A, 111B. The terminal member 130A is connected to an end face of the spacer 120A facing the +X direction. The terminal member 130B is connected to an end face of the spacer 120B facing the -X direction. Each of the terminal members 130A, 130B contains a conductive material (e.g., a metal such as aluminum) and is conductive. The wound body 110A and the wound body 110B are joined (e.g., laser welded) to each other via the terminal members 130A and 130B.

[0036] Each of the current collecting terminals 140A, 140B is a component that constitutes a part of the connection portion 2. The current collecting terminals 140A, 140B have support portions 142A, 142B and protrusions 144A, 144B, respectively. One of the current collecting terminals 140A and 140B functions as a positive electrode current collecting terminal, and the other functions as a negative electrode current collecting terminal. In one example, the positive electrode current collecting terminal is made of aluminum, and the negative electrode current collecting terminal is made of copper.

[0037] Each of the current collecting terminals 140A, 140B is formed in an L-shape. Each of the support portions 142A, 142B is formed in a plate shape on the YZ plane, and each of the protrusions 144A, 144B is formed in a plate shape on the XZ plane. The support portion 142A and the protrusion portion 144A may be formed separately and then joined together, or may be formed in an integrated state by bending. The support portion 142B and the protrusion portion 144B may also be formed separately and then joined together, or may be formed in an integrated state by bending. The support portion 142A is joined (e.g., laser welded) to the end face of the terminal member 130A in the +X direction. The support portion 142B is joined (e.g., laser welded) to the end face of the terminal member 130B in the -X direction.

[0038] The cover 150A covers the end of the cell 1 in the +X direction (including the electrode tabs 112A and 112B). However, the cover 150A has a through-hole h1 for the protrusion 144A. The protrusion 144A passes through the through-hole h1 and protrudes in the +X direction of the cell 1. The cover 150B covers the end of the cell 1 in the -X direction (including the electrode tabs 113A and 113B). However, the cover 150B has a through-hole h2 for the protrusion 144B. The protrusion 144B passes through the through-hole h2 and protrudes in the -X direction of the cell 1.

[0039] At the connection portion 2, of two adjacent cells 1, the protruding portion 144A of one cell 1 is joined (for example, by laser welding) to the protruding portion 144B of the other cell 1. The welded portion may be protected with tape or the like. In addition, a laminate film (not shown) is provided on the surfaces of the two wound bodies 110A and 110B.

[0040] The above-described configuration is merely one example of the configuration of the cell 1 and can be modified as appropriate. For example, the number of wound bodies included in the cell 1 is not limited to two, and may be one, three, or more. Furthermore, a laminate (for example, a laminate in which a positive electrode sheet and a negative electrode sheet are laminated with a separator interposed therebetween) may be used as the electrode body instead of the wound body.

[0041] In the battery 100 having the above configuration, there is a demand for further improvements in productivity for assembling the cell connected bodies 10, 20 to the case 300 and for joining the case 300. In particular, because the cell connected bodies 10, 20 have a rectangular parallelepiped shape, when the cell connected bodies 10, 20 are inserted into a state in which a cylindrical body is formed by the case main body 310 and the bottom 340, the cell connected bodies 10, 20 come into contact with the inside of the cylindrical body, and therefore, improvements in assembly are demanded.

[0042] Therefore, in this embodiment, the case 300 includes a case body 310 that sandwiches and holds the cell combinations 10 and 20, and the cross section of the case body 310 is provided with an opening that opens in a predetermined direction. More specifically, the cross section of the case body 310 is provided with two faces F3 and F4 that are arranged opposite each other, a connection portion that connects one end of the two faces F3 and F4, and an opening. Furthermore, each of the two faces F3 and F4 is provided with a recess that protrudes toward the opposing face and whose bottom surface abuts against the cell combinations 10 and 20.

[0043] In this way, the cell connected bodies 10, 20 can be assembled through the opening of the case body 310. Therefore, they can be housed in the case 300 without inserting them from the end of the cylindrical body. This makes it easy to assemble the cell connected bodies 10, 20 to the case 300. Furthermore, when the cell connected bodies 10, 20 are assembled to the case body 310, the cell connected bodies 10, 20 are sandwiched between the bottom surfaces of the recesses formed on the two opposing faces F3, F4, and the case body 310 can hold the cell connected bodies 10, 20.

[0044] FIG. 4 is a diagram showing an example of the configuration of a case 300 of a battery 100 which is an electricity storage device according to this embodiment.

[0045] As shown in Fig. 4, on each of the faces F3 and F4, which are two opposing wall surfaces of the case body 310, a plurality of recesses 350 (four in this embodiment, corresponding to the number of cells) are formed along the longitudinal direction of the faces F3 and F4 by recessing a predetermined region (for example, a rectangular region) inward (toward the cell connected bodies 10 and 20). More specifically, on the face F3, four recesses 350 are formed along the longitudinal direction of the case body 310 by recessing a rectangular region in the -Y direction. Furthermore, on the face F4, four recesses 350 are formed along the longitudinal direction of the case body 310 by recessing a rectangular region in the +Y direction.

[0046] On each of the faces F3 and F4, a plurality of rectangular slits 360 are provided between adjacent recesses 350. The slits 360 are formed to have a predetermined length with the Z direction as the longitudinal direction. Each of the plurality of slits 360 is provided at a position facing a connection portion 2B between cells in the cell connected bodies 10 and 20.

[0047] 5 is a cross-sectional view taken along line VV in FIG. 1. As shown in FIG. 5, the bottom surface of the recess 350 formed on the surface F3 faces the bottom surface of the recess 350 formed on the surface F4. The distance between the bottom surfaces (distance in the Y direction) is set to a length such that when the cell connected bodies 10 and 20 are assembled to the case body 310, the bottom surfaces of the recesses on the surfaces F3 and F4 come into contact with the cell connected bodies 10 and 20. Therefore, when the cell connected bodies 10 and 20 are assembled to the case body 310, the bottom surfaces of the recesses 350 on the surfaces F3 and F4 sandwich the cell connected bodies 10 and 20, thereby holding the cell connected bodies 10 and 20 within the case body 310.

[0048] The opening portion of the case body 310 in the -Z direction is blocked by the bottom 340, the opening portion of the case body 310 in the +X direction is blocked by the first lid body 320, and the opening portion of the case body 310 in the -X direction is blocked by the second lid body 330, thereby forming the case 300.

[0049] Although the surface F2, which is the connecting portion connecting the two wall surfaces F3 and F4, is described as being flat, it may be formed with an uneven portion so that the surface area is increased compared to when it is flat, or may be formed with a curved surface that is convex in the +Z direction or the -Z direction. In this way, the surface area of ​​surface F2 can be increased, thereby improving the heat dissipation performance of battery 100.

[0050] Furthermore, although the bottom 340 is described as being flat, the bottom 340 may also have a recess 342 recessed inward (toward the cell connected bodies 10 and 20) as shown by the dashed line in Figure 5. In this way, the positions of the cell connected bodies 10 and 20 in the -Z direction can be limited.

[0051] The operation of the battery 100 having the above structure will be described. Because the cross section of the case body 310 of the case 300 has an opening that opens in a predetermined direction (-Z direction), it is possible to assemble the cell assembled bodies 10, 20 to the case body 310 without inserting the cell assembled bodies 10, 20 through an opening in the +X or -X direction. When the cell assembled bodies 10, 20 are assembled to the case body 310, the bottom surfaces of the multiple recesses 350 provided on the faces F3, F4 of the case body 310 sandwich the Y-direction faces of the cell assembled bodies 10, 20, thereby restricting movement of the cell assembled bodies 10, 20 in the Y and Z directions within the case body 310.

[0052] As described above, in the battery 100 that is the energy storage device according to this embodiment, the cell connected bodies 10, 20 can be assembled from the opening of the case body 310 of the case 300. Therefore, the cell connected bodies 10, 20 can be housed in the case 300 without inserting them from the end of the case body 310 in the X direction. This allows the cell connected bodies 10, 20 to be easily assembled to the case 300. This improves the ease of assembly of the cell connected bodies 10, 20 to the case 300. Therefore, it is possible to provide an energy storage device with improved productivity.

[0053] Furthermore, by assembling the cell connected body 10 to the case body 310, the bottom surfaces of the recesses 350 provided on the two faces F3 and F4 come into contact with the cell connected bodies 10 and 20, thereby holding the cell connected bodies 10 and 20. This eliminates the need for additional parts to hold the cell connected bodies 10 and 20, thereby preventing an increase in the number of parts in the battery 100.

[0054] Furthermore, with the cell connected bodies 10 and 20 assembled to the case body 310, the opening of the case body 310 can be closed using the first lid body 320, the second lid body 330, and the bottom 340 to form the battery 100, which is an electricity storage device.

[0055] Furthermore, the provision of slits 360 allows air to flow into and out of battery 100, improving heat dissipation performance. Furthermore, if uneven portions are provided on face F1 or face F2, the increased surface area can improve heat dissipation performance.

[0056] Modifications will be described below.

[0057] In the above embodiment, the bottom portion 340 is described as closing the opening of the case main body 310 in the −Z direction, but the bottom portion 340 may be omitted.

[0058] Furthermore, in the above embodiment, the bottom 340 has been described as closing the opening of the case body 310 in the -Z direction, but when the case body 310 holds the cell connected bodies 10 and 20, the bottom 340 may be joined to the wall end (the end in the -Z direction) of at least one of the two faces F3 and F4 of the case body 310. Furthermore, the joining points are not limited to continuous welding using a laser, and may be joined by adhesive or spot welding.

[0059] Furthermore, in the above embodiment, the cell connected bodies 10 and 20 are sandwiched from the Y direction as an example, but may be sandwiched from the X direction, for example.

[0060] Furthermore, in the above-described embodiment, an example of a configuration in which an opening is formed in the -Z direction of the case body 310 to improve the assembly of the cell connected bodies 10, 20 and thereby improve the productivity of the battery 100 has been described. However, the configuration for improving the productivity of the battery 100 is not limited to forming an opening in the -Z direction. For example, the case body 310 may be configured to include a cylindrical body that surrounds the longitudinal surfaces of the cell connected bodies 10, 20. In this case, the cylindrical body is configured by bending a plate-like member to surround the cell connected bodies 10, 20 and joining one end of the plate-like member to a member on the other end side.

[0061] Fig. 6 is a diagram showing an example of the configuration of a battery 100, which is a power storage device according to a modified example. The battery 100 shown in Fig. 6 differs from the battery 100 shown in Fig. 1 in the configuration of the case 300. The configuration other than the case 300 is the same as that of the battery 100 shown in Fig. 1, and therefore detailed description thereof will not be repeated. Note that (A) and (B) in Fig. 6 are views of the contents of the case as viewed from the +X direction.

[0062] As shown in FIG. 6 , in this modification, the case 300 includes a case body 310, a first lid 320, and a second lid 330. The case body 310 is a housing having openings at its end in the +X direction and its end in the −X direction, for example. The case body 310 forms a cylindrical body, and the cell assemblies 10 and 20 are housed inside the cylindrical body. The first lid 320 and the second lid 330 shown in FIG. 6 have the same configuration as the first lid 320 and the second lid 330 shown in FIG. 1 , and therefore detailed description thereof will not be repeated. The case body 310, the first lid 320, and the second lid 330 may be formed of the same material or different materials. The case body 310, the first lid 320, and the second lid 330 may each be made of a metal, for example. The case 300 may be made of aluminum. However, these materials may be changed as appropriate. For example, at least one of the first lid 320 and the second lid 330 may be made of an insulating material.

[0063] The case body 310 includes a cylindrical body that surrounds the longitudinal surfaces (i.e., the Z-direction surfaces and the Y-direction surfaces) of the cell connected bodies 10 and 20. The cylindrical body is formed by bending a plate-like member so as to surround the periphery of the cell connected bodies 10 and 20 around the X-axis. One end of the bent plate-like member is then joined to the other end to form the cylindrical body.

[0064] 6A, the plate-like member is bent at right angles along the boundary between face F2 and face F4, the boundary between face F2 and face F3, the boundary between face F1 and face F3, and the boundary between face F1 and the excess portion to form a cylinder. One end of the plate-like member (i.e., one end of face F4 in the -Z direction) is then joined to the boundary between face F1 and the excess portion.

[0065] In this way, one end of the plate-like member (one end of the surface F4) can be joined to the member on the other end side (excess portion) to form a cylindrical body, which prevents an increase in the number of joining points and allows the joining points between the members on one end side and the other end side to be set at positions separated from the cell connected bodies 10, 20. Therefore, joining can be performed without affecting the cell connected bodies 10, 20. This improves the productivity of the battery 100, which is an energy storage device.

[0066] The joining location between one end of case body 310 and the other end of the component is not limited to the joining location shown in Fig. 6A. For example, as shown in Fig. 6B, the positional relationship between the excess portion and one end of face F4 may be reversed from the positional relationship shown in Fig. 6A, so that the excess portion is positioned outward (in the -Y direction) from one end of face F4, and one end of face F4 may be bent so that a step is formed at one end of face F4 so that the plane of the excess portion and face F4 (excluding the one end in the -Z direction) are flush with each other. In this case, one end of the excess portion is joined to the step of face F4.

[0067] In this way, one end of the plate-like member (one end of the excess portion) can be joined to the member on the other end side (the step portion of surface F4) to form a cylindrical body, which prevents an increase in the number of joining points and allows the joining points between the members on one end and the other end side to be set at positions separated from the cell connected bodies 10, 20. Therefore, joining can be performed without affecting the cell connected bodies 10, 20. This improves the productivity of the battery 100, which is an energy storage device.

[0068] The above-described modifications may be implemented in whole or in part in appropriate combination.

[0069] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 1, 11, 14, 21, 24 Cell, 2, 2A, 2B, 2C Connection part, 10, 20 Cell connected body, 100 Battery, 110A, 110B Wound body, 111A, 111B Coating part, 112A, 112B, 113A, 113B, 322A, 322B Electrode tab, 120A, 120B Spacer, 130A, 130B Terminal member, 140A, 140B Current collecting terminal, 142A, 142B Support part, 144A, 144B Protrusion part, 150A, 150B Cover, 300 Case, 310 Case body, 320 First cover body, 322 External terminal, 323 Connector, 330 Second cover body, 340 Bottom part, 342, 350 Recess, 360 Slit.

Claims

1. a cell assembly including a plurality of cells and a connection portion that electrically connects adjacent cells; a case for accommodating the cell assembly, the case includes a first member that sandwiches and holds the cell assembly, The electricity storage device, wherein the first member has an opening in a cross section that opens in a predetermined direction.

2. a cross section of the first member including two wall surfaces arranged opposite to each other, a connecting portion connecting one ends of the two wall surfaces, and the opening portion; The power storage device according to claim 1 , wherein each of the two wall surfaces is provided with a recess that protrudes toward the opposing wall surface and has a bottom surface that abuts against the cell connected body.

3. The case is a second member that closes the opening of the first member to form a cylindrical body; a third member provided to close one end of the cylindrical body; The power storage device according to claim 1 , further comprising: a fourth member provided to close the other end of the cylindrical body.

4. a cell assembly including a plurality of cells and a connection portion that electrically connects adjacent cells; a case for accommodating the cell assembly, the case includes a cylindrical body that surrounds the periphery of a surface of the cell connected body in the longitudinal direction, The cylindrical body is an energy storage device in which a plate-shaped member is bent so as to form wall surfaces facing each longitudinal surface of the cell connected body, and one end of the plate-shaped member is joined to a member on the other end side of the plate-shaped member.

Images