Power storage device

Abstract

The power storage device includes: a shell having a terminal configuration portion; a pair of output terminals, which are arranged in the terminal configuration portion; an electrode body, which is accommodated in the shell; a pair of collectors, which electrically connect the electrode body and the pair of output terminals; and an insulating electrode body holder, which abuts against a pair of first surfaces of the electrode body that are opposite to each other in a first direction X in which the pair of collectors are arranged, is fixed to the shell and clamps the electrode body in the first direction X.

Description

Technical Field

[0001] The present disclosure relates to a power storage device. Background Art

[0002] For example, as a power source for vehicles and the like requiring a relatively high output voltage, a power storage module having a plurality of power storage devices (e.g., batteries) connected in series is known. The power storage device used in such a power storage module generally includes: an outer can having an opening; an electrode body housed in the outer can; a sealing plate that seals the opening of the outer can; a pair of output terminals provided on the sealing plate; and a current collector that electrically connects the electrode body and the pair of output terminals (e.g., see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-49064 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the power storage device, considering the operability when the electrode body is stored in the outer can, an electrode body that is smaller than the internal space of the outer can is usually used. However, if a size difference occurs between the outer can and the electrode body, it is easy to generate space between the outer can and the electrode body. In addition, if a force is applied to the power storage device in a state where there is space between the outer can and the electrode body, the electrode body may be easily displaced relative to the outer can. When the electrode body is displaced relative to the outer can, the force generated by the displacement of the electrode body is applied to the collector sheet, the collector sheet is damaged, and the reliability of the power storage device may be reduced.

[0008] The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a technology for improving the reliability of a power storage device.

[0009] Solutions for solving problems

[0010] A technical solution disclosed herein is an electric storage device. The electric storage device includes: a housing having a terminal arrangement portion; a pair of output terminals disposed in the terminal arrangement portion; an electrode body housed in the housing; a pair of current collectors electrically connecting the electrode body and the pair of output terminals; and an insulating electrode body holder abutting against a pair of first surfaces of the electrode body that are opposite in a first direction in which the pair of current collectors are arranged, fixed to the housing and clamping the electrode body in the first direction.

[0011] Optional combinations of the above-described constituent elements and technical solutions obtained by converting the expression of the present disclosure into methods, apparatuses, systems, etc. may also be effective as technical solutions of the present disclosure.

[0012] Effects of the Invention

[0013] According to the present disclosure, the reliability of the power storage device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of the power storage device according to Embodiment 1.

[0015] Figure 2 It is a cross-sectional view of a region including a pair of output terminals of the power storage device.

[0016] Figure 3 (A) is a three-dimensional view of a retaining unit viewed from above. Figure 3 (B) is a stereoscopic view of one retaining unit viewed obliquely from below.

[0017] Figure 4 It is a cross-sectional view of a region including one holder unit of the power storage device.

[0018] Figure 5 (A) is a stereoscopic view of another retaining unit viewed from above. Figure 5 (B) is a stereoscopic view of another retaining unit viewed from obliquely below.

[0019] Figure 6 It is a perspective view of the power storage device according to the second embodiment.

[0020] Figure 7 It is a side view of the power storage device.

[0021] Figure 8 It is a perspective view showing an enlarged view of a region including a notch portion of the electrode body holder.

[0022] Fig. 9 (A) is a perspective view of a power storage device according to Modification 1. Fig. 9 (B) is a perspective view of the second electrode body holder. DETAILED DESCRIPTION

[0023] Hereinafter, the power storage device disclosed in the present invention will be described based on a preferred embodiment and with reference to the accompanying drawings. The embodiment does not limit the invention but is an example, and all the features and combinations thereof described in the embodiment are not limited to the features and combinations that are essential to the invention. The same or equivalent components, members, and processes shown in the various drawings are marked with the same figure numerals and repeated descriptions are appropriately omitted. In addition, the proportions and shapes of the various parts shown in the various figures are set for easy and convenient description, and are not to be interpreted in a limiting sense unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, the terms do not indicate any order or importance, but are used to distinguish a certain structure from other structures. In addition, in each of the drawings, a part of the components that are not important in describing the embodiment are omitted.

[0024] Figure 1 It is a perspective view of the power storage device 1 according to the first embodiment. Figure 2 FIG. 2 is a cross-sectional view of a region including a pair of output terminals of the power storage device 1. Figure 1 In FIG. 1 , the state of the inside of the power storage device 1 is shown in FIG. Figure 1 and Figure 2 In FIG. 1 , the electrode body 6 is schematically shown.

[0025] The power storage device 1 is a rechargeable secondary battery such as a lithium ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, or a capacitor. The power storage device 1 is a so-called square battery. The power storage device 1 includes a housing 2, a pair of output terminals 4, an electrode body 6, a pair of collectors 8, and an electrode body holder 10.

[0026] The housing 2 is a flat rectangular parallelepiped and has an outer can 12 and a sealing plate 14. The outer can 12 is, for example, a bottomed cylindrical shape and has a rectangular opening 12a. The electrode body 6, electrolyte, etc. are stored in the outer can 12 through the opening 12a. The sealing plate 14 is a rectangular plate that blocks the opening 12a and closes the outer can 12. The outer can 12 and the sealing plate 14 are conductive bodies, for example, made of metals such as aluminum, iron, and stainless steel. The opening 12a of the outer can 12 and the periphery of the sealing plate 14 are joined, for example, by laser welding or the like.

[0027] A pair of output terminals 4 is provided on the sealing plate 14. Thus, the sealing plate 14 constitutes a terminal configuration portion. Specifically, a positive output terminal 4 is provided near one end in the longitudinal direction of the sealing plate 14, and a negative output terminal 4 is provided near the other end. Hereinafter, the positive output terminal 4 is appropriately referred to as the positive terminal 4a, and the negative output terminal 4 is appropriately referred to as the negative terminal 4b. In addition, when there is no need to distinguish the polarity of the output terminal 4, the positive terminal 4a and the negative terminal 4b are collectively referred to as the output terminal 4. A pair of output terminals 4 are respectively inserted into the through holes 14a formed in the sealing plate 14. An insulating sealing member 16 is sandwiched between the pair of output terminals 4 and each through hole 14a.

[0028] In addition, a safety valve 18 is provided between a pair of output terminals 4 of the sealing plate 14. In addition, the safety valve 18 may not be provided. The safety valve 18 is configured to open the valve when the internal pressure of the housing 2 rises to a predetermined value or more, thereby releasing the gas inside the housing 2. The safety valve 18 is, for example, composed of a thin-walled portion that is thinner than other portions and a linear groove formed on the surface of the thin-walled portion, which is provided in a part of the sealing plate 14. In this structure, when the internal pressure of the housing 2 rises, the thin-walled portion ruptures starting from the groove, thereby opening the valve. The safety valve 18 is not limited to the above-mentioned irreversible valve, but may also be a self-recovering exhaust valve that closes again when the pressure in the housing 2 becomes below a certain value after the valve is opened.

[0029] In addition, an injection hole 20 is provided between a pair of output terminals 4 of the sealing plate 14. The injection hole 20 is used when injecting the electrolyte into the housing 2. In one example of the assembly process of the power storage device 1, after the electrode body 6 is housed in the outer can 12, the outer can 12 and the sealing plate 14 are laser welded. Then, the electrolyte is injected into the housing 2 through the injection hole 20. In addition, after the electrolyte is injected, the injection plug (not shown) is joined to the injection hole 20 by laser welding or the like. In addition, the injection hole 20 can be closed by riveting a rivet-type injection plug to the injection hole 20, or by pressing an injection plug formed of an elastic material into the injection hole 20.

[0030] In the description of the present embodiment, for the sake of convenience, the surface on one side where the sealing plate 14 (terminal configuration portion) is provided is used as the upper surface of the power storage device 1, and the surface on the opposite side is used as the bottom surface of the power storage device 1. In addition, the power storage device 1 has four side surfaces connecting the upper surface and the bottom surface. Two of the four side surfaces are a pair of long side surfaces connected to the long sides of the upper surface and the bottom surface. The long side surface is the main surface, which is the surface with the largest area among the six surfaces of the power storage device 1. The remaining two side surfaces other than the two long side surfaces are a pair of short side surfaces connected to the short sides of the upper surface and the bottom surface of the power storage device 1. These directions and positions are defined for convenience. Thus, for example, in the present disclosure, the portion defined as the upper surface does not necessarily mean that it is located above the portion defined as the bottom surface.

[0031] In addition, the direction in which a pair of collector sheets 24 described later are arranged (or the width direction of the main surface of the collector sheet 24) is set as the first direction X, the direction in which a pair of long side surfaces are arranged (or the stacking direction of the plurality of electrode plates constituting the electrode body 6) is set as the second direction Y, and the direction in which the upper surface and the bottom surface are arranged is set as the third direction Z. In addition, in the present disclosure, the direction in which the collector sheets 24 are arranged may also be the direction in which the collector sheets 24 are arranged when the electrode body 6 is observed from the second direction. That is, it does not necessarily represent the direction in which the imaginary straight line connecting the collector sheets 24 extends.

[0032] The housing 2 contains an electrode body 6, a pair of current collecting parts 8, and an electrode body holder 10. The electrode body 6 is an electrode group having a structure in which a plurality of electrode plates are stacked. Specifically, the electrode body 6 has a structure in which positive electrode plates as positive electrode plates and negative electrode plates as negative electrode plates are alternately stacked. An electrode plate separator is sandwiched between adjacent positive electrode plates and negative electrode plates. In the present embodiment, two electrode bodies 6 are arranged in the second direction Y and stored in the housing 2 (refer to Figure 4 ).

[0033] As an example, the positive electrode plate has a positive electrode collector formed of a metal foil and a positive electrode active material layer (positive electrode mixture layer) containing a positive electrode active material stacked on the surface of the positive electrode collector. The negative electrode plate has a negative electrode collector formed of a metal foil and a negative electrode active material layer (negative electrode mixture layer) containing a negative electrode active material stacked on the surface of the negative electrode collector. The positive electrode collector and the negative electrode collector each have an electrode portion on which the mixture layers of each electrode are stacked and a sheet portion extending from the edge of the electrode portion to form a collector sheet 24 described later.

[0034] Each electrode body 6 has a shape substantially similar to that of the case 2. Thus, each electrode body 6 has an upper surface opposite to the sealing plate 14 of the case 2, a bottom surface opposite to the bottom surface of the case 2, a pair of long side surfaces opposite to the pair of long side surfaces of the case 2, and a pair of short side surfaces opposite to the pair of short side surfaces of the case 2. A predetermined gap is provided between each surface of the case 2 and each surface of the electrode body 6.

[0035] The electrode body 6 and the pair of output terminals 4 are electrically connected by a pair of collectors 8. The collectors 8 include a positive collector 8a electrically connected to the positive terminal 4a and a negative collector 8b electrically connected to the negative terminal 4b. Hereinafter, when there is no need to distinguish the polarity of the collector 8, the positive collector 8a and the negative collector 8b are collectively referred to as the collector 8.

[0036] Each current collector 8 has a current collector plate 22 and a current collector sheet 24. The current collector plate 22 is fixed to the sealing plate 14 (terminal arrangement portion). Specifically, each current collector plate 22 is arranged on the surface of the sealing plate 14 facing the inside of the housing 2 via the second plate portion 28 described later of the electrode body holder 10, and is fixed to the sealing plate 14 via each output terminal 4. In this state, each current collector plate 22 is electrically connected to the end of each output terminal 4 located inside the housing 2.

[0037] The collector sheet 24 is a strip-shaped (tongue-shaped) portion connecting the electrode body 6 and the collector plate 22. The collector sheet 24 extends from each electrode plate of the electrode body 6 and is connected to the collector plate 22. The collector sheet 24 includes a positive electrode sheet 24a extending from the positive electrode plate and a negative electrode sheet 24b extending from the negative electrode plate. The positive electrode sheet 24a extending from the positive electrode plate is connected to the collector plate 22 fixed to the positive terminal 4a. The negative electrode sheet 24b extending from the negative electrode plate is connected to the collector plate 22 fixed to the negative terminal 4b. Hereinafter, when there is no need to distinguish the polarity of the collector sheet 24, the positive electrode sheet 24a and the negative electrode sheet 24b are collectively referred to as the collector sheet 24. The collector sheet 24 is formed by bundling the collector sheets 24 of the same polarity to each other to form a collector sheet stack. The stack is joined to the collector plate 22 by ultrasonic welding, laser welding, etc.

[0038] In addition, the current collector plate 22 on the positive electrode side and the current collector plate 22 on the negative electrode side may be respectively formed of one plate, or may be formed by combining a plurality of plates. In the case where the current collector plate 22 is formed of a plurality of plates, the plurality of plates can be divided into a plate to which the current collector sheet 24 is joined and a plate connected to the output terminal 4. Thus, the process of joining the current collector sheet 24 to the current collector plate 22 and the process of joining the output terminal 4 to the current collector plate 22 can be performed simultaneously. As an example, the plates are joined to each other after the two processes are completed.

[0039] Each collector sheet 24 is configured such that the main surface 24c faces the second direction Y intersecting with the first direction X in which the pair of collector portions 8 are arranged. That is, the end of each collector sheet 24 on the electrode body 6 side extends along the first direction X. In addition, the end on the collector plate 22 side also extends along the first direction X. Moreover, the collector sheet 24 extends toward the collector plate 22 while bending in the second direction Y and is connected to the collector plate 22. Therefore, the main surface 24c of the collector sheet 24 faces the second direction Y in a part of the region and faces the third direction Z in another part of the region and is opposite to the sealing plate 14. In addition, the collector sheet 24 may not be composed of the sheet portion possessed by the positive collector and the negative collector. For example, the collector sheet 24 may be composed of a conductive member independent of the positive collector and the negative collector, and the conductive member is respectively bonded to the positive collector and the negative collector.

[0040] The displacement of the electrode body 6 in the shell 2 is limited by the electrode body holder 10. The electrode body holder 10 abuts against a pair of first faces 6a of the electrode body 6 that are opposite to each other in the first direction X in which a pair of collectors 8 are arranged. The pair of first faces 6a of the electrode body 6 are a pair of short side faces extending in a direction intersecting with the terminal configuration portion. Furthermore, the electrode body holder 10 is fixed to the shell 2 and clamps the electrode body 6 in the first direction X. Thus, the displacement of the electrode body 6 in the first direction X is suppressed. In addition, the electrode body 6 is clamped in the first direction X by the electrode body holder 10, so that the displacement of the electrode body 6 in the second direction Y and the displacement in the third direction Z are also suppressed to a large extent.

[0041] The electrode body holder 10 has insulating properties. For example, the electrode body holder 10 is formed of an insulating thermoplastic resin such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), or NORYL (registered trademark) resin (modified PPE). In addition, it is preferred that the rigidity of the electrode body holder 10 is higher than that of the collector sheet 24.

[0042] The electrode body holder 10 of the present embodiment has a second plate portion 28 and a pair of first plate portions 26. The pair of first plate portions 26 extend along the third direction Z and abut against a pair of first surfaces 6a. Specifically, a predetermined gap is provided between a pair of first surfaces 6a of the electrode body 6 and a pair of short side surfaces of the shell 2. One first plate portion 26 is located between the first surface 6a on the positive terminal 4a side and the short side surface of the shell 2 opposite to the first surface 6a, and abuts against the first surface 6a. In addition, another first plate portion 26 is located between the first surface 6a on the negative terminal 4b side and the short side surface of the shell 2 opposite to the first surface 6a, and abuts against the first surface 6a. In addition, each first plate portion 26 of the present embodiment is separated from each short side surface of the shell 2. As a result, the contact between the electrode body 6 and the shell 2 can be more reliably suppressed.

[0043] The second plate portion 28 is formed integrally with each first plate portion 26. The first plate portion 26 and the second plate portion 28 of the present embodiment are integrally molded products of resin. In addition, the second plate portion 28 is interposed between the sealing plate 14 (terminal configuration portion) and the electrode body 6 and is fixed to the sealing plate 14. The second plate portion 28 has a through hole 28a at a position overlapping with each output terminal 4 when viewed from the third direction Z. The through hole 28a is provided for the end of each output terminal 4 located in the housing 2 to pass through. Therefore, the second plate portion 28 is fixed to the sealing plate 14 with the aid of each output terminal 4. In addition, the second plate portion 28 is interposed between the sealing plate 14 (terminal configuration portion) and the collector plate 22 to electrically insulate the two. That is, the second plate portion 28 also functions as an insulating member that electrically insulates the sealing plate 14 and the collector plate 22.

[0044] The second plate portion 28 is divided into a portion to which one first plate portion 26 is connected on the positive terminal 4a side and a portion to which another first plate portion 26 is connected on the negative terminal 4b side. That is, the electrode body holder 10 of the present embodiment is composed of a pair of holder units 10a and 10b arranged in the first direction X. The pair of holder units 10a and 10b respectively have a first plate portion 26 and a second plate portion 28. One holder unit 10a abuts against one first surface 6a of the electrode body 6 and is fixed to the housing 2. The other holder unit 10b abuts against the other first surface 6a of the electrode body 6 and is fixed to the housing 2.

[0045] More specifically, the first plate portion 26 of one retainer unit 10a abuts against a first surface 6a located on the positive terminal 4a side. The second plate portion 28 of one retainer unit 10a is fixed to the sealing plate 14 by means of the positive terminal 4a. That is, in a state where the second plate portion 28 is clamped by the sealing plate 14 and the collector plate 22, the positive terminal 4a penetrates the second plate portion 28 and the collector plate 22. Furthermore, by riveting the end portion of the positive terminal 4a on the electrode body side, the second plate portion 28 and the collector plate 22 are fixed to the sealing plate 14. The collector plate 22 and the sealing plate 14 are insulated by the second plate portion 28 interposed therebetween.

[0046] The first plate portion 26 of another retaining member unit 10b abuts against another first surface 6a located on the negative terminal 4b side. The second plate portion 28 of another retaining member unit 10b is fixed to the sealing plate 14 by means of the negative terminal 4b. That is, in a state where the second plate portion 28 is clamped by the sealing plate 14 and the collector plate 22, the negative terminal 4b passes through the second plate portion 28 and the collector plate 22. Furthermore, by riveting the end of the electrode body side of the negative terminal 4b, the second plate portion 28 and the collector plate 22 are fixed to the sealing plate 14. The collector plate 22 and the sealing plate 14 are insulated by the second plate portion 28 interposed therebetween. Thus, a pair of first surfaces 6a of the electrode body 6 are clamped in the first direction X by the retaining member unit 10a and the retaining member unit 10b.

[0047] Figure 3 (A) is a three-dimensional view of a retaining member unit 10a viewed from obliquely above. Figure 3 (B) is a perspective view of one holder unit 10a as viewed from obliquely below. In the holder unit 10a, the first plate portion 26 and the second plate portion 28 are connected at a right angle, and when viewed from the second direction Y, they are L-shaped.

[0048] The first plate portion 26 has a reinforcing rib 30 on the surface 26a facing the electrode body 6 side. The first plate portion 26 of the present embodiment has, for example, three reinforcing ribs 30. The three reinforcing ribs 30 are arranged at predetermined intervals in the second direction Y, and extend from the lower end to the upper end of the first plate portion 26 along the third direction Z. A protrusion 30a extending along the surface 28b of the second plate portion 28 facing the electrode body 6 side is provided at the upper end of each reinforcing rib 30. That is, the protrusion 30a of the reinforcing rib 30 constitutes a triangular rib fixed to the surface 26a of the first plate portion 26 facing the electrode body 6 side and the surface 28b of the second plate portion 28 facing the electrode body 6 side at the connection portion 32 between the first plate portion 26 and the second plate portion 28. By providing the reinforcing rib 30, the rigidity of the retaining member unit 10a can be improved. As a result, the displacement of the electrode body 6 in the first direction X can be more reliably suppressed. In addition, the reinforcing rib 30 may not be three, as long as there is one or more. In addition, the reinforcing rib 30 may extend from a region of the first wall portion 34 that faces the connecting portion 32. In addition, regarding the shape of the protruding portion 30a, the oblique side portion of the triangular rib may be a curved line.

[0049] The second plate portion 28 has a plurality of first wall portions 34 protruding toward the electrode body 6 side. The second plate portion 28 of the present embodiment has four first wall portions 34. Two first wall portions 34 are provided on both sides of the second plate portion 28 extending along the first direction X. One first wall portion 34 is provided on a side extending along the second direction Y at the end portion of the second plate portion 28 on the side opposite to the connecting portion 32. The remaining first wall portion 34 is provided in the area between the connecting portion 32 and the through hole 28a of the surface 28b facing the electrode body 6 side. Therefore, two first wall portions 34 extend along the first direction X, and two first wall portions 34 extend along the second direction Y. The ends of the four first wall portions 34 are continuous with each other, forming a rectangular frame when viewed from the third direction Z. The four first wall portions 34 surround the collector plate 22 when the retainer unit 10a and the collector plate 22 are fixed to the sealing plate 14. By providing the first wall portion 34, the contact between the collector plate 22 and the outer can 12 and the sealing plate 14 can be more reliably suppressed. In addition, the second plate portion 28 of the retainer unit 10a may also have a protrusion on its upper surface. In addition, the sealing plate 14 may also have a recessed portion at a position corresponding to the protrusion. By fitting the protrusion and the recessed portion, the rotation of the retainer unit 10a around the positive terminal 4a is suppressed. Therefore, the alignment of the retainer unit 10a with the sealing plate 14 and the retainer unit 10b becomes easy.

[0050] In addition, the second plate portion 28 has a recessed portion 36 that is bent toward the outside of the power storage device 1 in the first direction X at the end portion on the opposite side to the connection portion 32. The recessed portion 36 is arranged to overlap with the edge of the safety valve 18 when viewed from the third direction Z. That is, by providing the recessed portion 36, it is possible to avoid partial closure of the safety valve 18 by the retainer unit 10a.

[0051] In addition, the second plate portion 28 has a through hole 38 at a position overlapping with the injection hole 20 when viewed from the third direction Z. By providing the through hole 38, it is possible to avoid the injection hole 20 being blocked by the retainer unit 10a. In addition, the second plate portion 28 has a second wall portion 40 surrounding the outer periphery of the through hole 38 at the peripheral portion of the through hole 38 on the surface 28b facing the electrode body 6 side. The second wall portion 40 protrudes from the surface 28b facing the electrode body 6 side toward the electrode body 6 side.

[0052] Figure 4 1 is a cross-sectional view of a region of the power storage device 1 including one holder unit 10a. Figure 4, the electrode body 6 is schematically illustrated. The collector plate 22 has a through hole 42 at a position overlapping with the injection hole 20 when viewed from the third direction Z. By providing the through hole 42, it is possible to avoid the injection hole 20 being blocked by the collector plate 22. In addition, in a state where the retaining unit 10a and the collector plate 22 are fixed to the sealing plate 14, the second wall portion 40 is inserted into the through hole 42. The second wall portion 40 protrudes in the third direction Z to a position closer to the electrode body 6 side than the collector plate 22. The second wall portion 40 suppresses the displacement of the collector sheet 24 to the area overlapping with the injection hole 20 when viewed from the third direction Z. As a result, it is possible to avoid the injection hole 20 being blocked by the collector sheet 24.

[0053] Figure 5 (A) is a three-dimensional view of another retaining member unit 10b viewed from obliquely above, Figure 5 (B) is a stereoscopic view of another retaining member unit 10b observed from obliquely below. The first plate portion 26 and the second plate portion 28 of the retaining member unit 10b are connected at a right angle and are L-shaped when viewed from the second direction Y. Similar to the retaining member unit 10a, the first plate portion 26 has a reinforcing rib 30 on the surface 26a facing the electrode body 6. A protrusion 30a extending along the surface 28b of the second plate portion 28 facing the electrode body 6 is provided at the upper end of the reinforcing rib 30. By providing the reinforcing rib 30, the rigidity of the retaining member unit 10b can be improved. Thus, the displacement of the electrode body 6 in the first direction X can be more reliably suppressed. In addition, similar to the retaining member unit 10a, the reinforcing rib 30 may not be three, as long as there is one or more. In addition, the reinforcing rib 30 may also extend from the area of ​​the first wall portion 34 opposite to the connecting portion 32. In addition, with respect to the shape of the protrusion 30a, the hypotenuse portion of the above-mentioned triangular rib may also be a curve.

[0054] Similar to the holder unit 10a, the second plate portion 28 has a plurality of first wall portions 34 protruding toward the electrode body 6 side. Two first wall portions 34 are provided on both sides of the second plate portion 28 extending along the first direction X. One first wall portion 34 is provided on one side extending along the second direction Y at the end portion of the second plate portion 28 on the side opposite to the connecting portion 32. The remaining first wall portion 34 is provided in the area between the connecting portion 32 and the through hole 28a of the surface 28b facing the electrode body 6 side. The plurality of first wall portions 34 surround the collector plate 22 when the holder unit 10b and the collector plate 22 are fixed to the sealing plate 14. By providing the first wall portion 34, the contact between the collector plate 22 and the outer can 12 and the sealing plate 14 can be more reliably suppressed. In addition, similar to the holder unit 10a, the second plate portion 28 of the holder unit 10b may also have a protrusion on its upper surface. In addition, the sealing plate 14 may have a recessed portion at a position corresponding to the protrusion. The protrusion and the recessed portion are engaged with each other to prevent the holder unit 10b from rotating about the negative terminal 4b. Therefore, the holder unit 10b is easily aligned with the sealing plate 14 and the holder unit 10a.

[0055] As described above, the storage device 1 of the present embodiment includes: a shell 2, which has a terminal configuration portion; a pair of output terminals 4, which are arranged in the terminal configuration portion; an electrode body 6, which is accommodated in the shell 2; a pair of collectors 8, which electrically connect the electrode body 6 and the pair of output terminals 4; and an insulating electrode body retainer 10, which abuts against a pair of first surfaces 6a of the electrode body 6 that are opposite to each other in the first direction X where the pair of collectors 8 are arranged, is fixed to the shell 2 and clamps the electrode body 6 in the first direction X.

[0056] As a method of suppressing the expansion of the power storage device 1, in other words, the expansion of the shell 2, it is considered to provide a space between the shell 2 and the electrode body 6 that allows the expansion of the electrode body 6. By providing a space between the shell 2 and the electrode body 6, at least a part of the expansion of the electrode body 6 can be absorbed by the space, so the expansion of the power storage device 1 can be suppressed. As a result, the increase in the volume inside the power storage device can be suppressed, and the reduction in the capacitance of the power storage device 1 and the increase in the internal resistance can be suppressed. In addition, the breakage of the joint between the outer can 12 and the sealing plate 14 can also be suppressed. Therefore, the reliability of the power storage device 1 can be improved. In addition, by making the size of the electrode body 6 smaller than the size of the internal space of the shell 2 and forming a space between the two, the resistance such as friction that the electrode body 6 receives from the shell 2 when the electrode body 6 is stored in the shell 2 can be reduced. As a result, the workability when the electrode body 6 is stored in the shell 2 is improved.

[0057] However, if a space is provided between the housing 2 and the electrode body 6, the electrode body 6 is easily displaced relative to the housing 2 when the power storage device 1 vibrates. If the electrode body 6 is displaced relative to the housing 2, there is a risk that stress is concentrated on the collector sheet 24 that connects the electrode body 6 to the output terminal 4, and fatigue damage occurs in the collector sheet 24. In particular, the main surface 24c of the collector sheet 24 faces the second direction Y or the third direction Z that intersects the first direction X in which the pair of output terminals 4 are arranged. Therefore, the collector sheet 24 is difficult to displace in the first direction X compared to other directions. As a result, when the electrode body 6 is displaced in the first direction X, fatigue damage is more likely to occur in the collector sheet 24.

[0058] In contrast, in the power storage device 1 of the present embodiment, the electrode body 6 is sandwiched in the first direction X by the electrode body holder 10 fixed to the shell 2. As a result, when the power storage device 1 vibrates, etc., the displacement of the electrode body 6 relative to the shell 2 can be suppressed. In particular, the displacement of the electrode body 6 in the first direction X can be effectively suppressed. Therefore, the load applied to the collector sheet 24 connecting the output terminal 4 and the electrode body 6 can be reduced. Therefore, a space can be provided between the shell 2 and the electrode body 6 to suppress the expansion of the power storage device 1, and the electrical connection state between the electrode body 6 and the output terminal 4 can be stably maintained. In particular, the electrode body holder 10 and the collector sheet 24 are both fixed to the electrode body 6 and the terminal configuration portion, so the load applied to the collector sheet 24 by the electrode body holder 10 can be more reliably reduced.

[0059] That is, according to this embodiment, the reliability of the power storage device 1 can be improved from the two aspects of suppressing the expansion of the power storage device 1 and stably maintaining the connection state between the electrode body 6 and the output terminal 4. In addition, the capacity of the power storage device 1 can be increased while maintaining the reliability of the power storage device 1.

[0060] In addition, the electrode body holder 10 has a second plate portion 28 and a pair of first plate portions 26, the pair of first plate portions 26 abutting against a pair of first surfaces 6a of the electrode body 6, the second plate portion 28 being formed integrally with each first plate portion 26, interposed between the terminal arrangement portion and the electrode body 6 and fixed to the terminal arrangement portion. Thus, the displacement of the electrode body 6 in the first direction X can be more reliably suppressed.

[0061] In addition, the collector portion 8 has a collector plate 22 fixed to the terminal arrangement portion. And, the second plate portion 28 is interposed between the terminal arrangement portion and the collector plate 22 to electrically insulate the two. That is, the electrode body holder 10 of the present embodiment also functions as an insulating member that insulates the terminal arrangement portion and the collector plate 22. Thus, by providing the electrode body holder 10, an increase in the number of components of the power storage device 1 can be suppressed. In addition, the complication of the structure of the power storage device 1 can be suppressed. In addition, the complication of the assembly process of the power storage device 1 can be suppressed.

[0062] In addition, the electrode body holder 10 is composed of a pair of holder units 10a and 10b, one of which is in contact with one first surface 6a of the electrode body 6 and fixed to the housing 2, and the other holder unit 10b is in contact with the other first surface 6a of the electrode body 6 and fixed to the housing 2. That is, the pair of holder units 10a and 10b are arranged at intervals in the first direction X and are respectively fixed to the housing 2. As a result, the displacement of the electrode body 6 in the first direction X can be more reliably suppressed.

[0063] (Implementation Method 2)

[0064] Embodiment 2 has the same structure as Embodiment 1 except for the shape of the electrode body holder. Hereinafter, this embodiment will be described mainly focusing on the structure different from Embodiment 1, and the common structure will be briefly described or omitted. Figure 6 It is a perspective view of the power storage device according to the second embodiment. Figure 7 It is a side view of the power storage device. Figure 8 : is a perspective view showing an enlarged area of ​​the electrode body holder including the notch. Figure 6 and Figure 7 In FIG. 1 , the state of the inside of the power storage device is shown in FIG. Figure 6 to Figure 8 , the electrode body is schematically illustrated.

[0065] The power storage device 1 includes a housing 2, a pair of output terminals 4, an electrode body 6, a pair of collectors 8, and an electrode body holder 10. The displacement of the electrode body 6 in the housing 2 is limited by the electrode body holder 10. The electrode body holder 10 abuts against a pair of first surfaces 6a of the electrode body 6 that are opposite to each other in the first direction X in which the pair of collectors 8 are arranged. Furthermore, the electrode body holder 10 is fixed to the housing 2 and sandwiches the electrode body 6 in the first direction X. Thus, the displacement of the electrode body 6 can be suppressed. In particular, the displacement of the electrode body 6 in the first direction X can be suppressed.

[0066] The electrode body holder 10 has a second plate portion 28 and a pair of first plate portions 26. The first plate portion 26 and the second plate portion 28 of the present embodiment are integrally molded products of resin. A pair of first plate portions 26 extend along the third direction Z and abut against a pair of first surfaces 6a. Each first plate portion 26 is separated from the short side surface of the housing 2. The second plate portion 28 is formed integrally with each first plate portion 26, is interposed between the sealing plate 14 (terminal configuration portion) and the electrode body 6 and is fixed to the sealing plate 14.

[0067] The second plate portion 28 of the present embodiment has a snap-fitting protrusion 44 protruding toward the sealing plate 14. As an example, two snap-fitting protrusions 44 are respectively arranged at both ends of the sealing plate 14 in the first direction X so as to be arranged in the second direction Y. In addition, the sealing plate 14 has a through hole 46 at a position overlapping with each snap-fitting protrusion 44 when viewed from the third direction Z. Each snap-fitting protrusion 44 passes through the through hole 46. Thus, the second plate portion 28 is fixed to the sealing plate 14. For example, the second plate portion 28 is press-fitted and fixed to the sealing plate 14.

[0068] In addition, in the present embodiment, the thickness T2 of the second plate portion 28 is greater than the thickness T1 of the first plate portion 26. The thickness T2 of the second plate portion 28 is the size of the second plate portion 28 in the third direction Z. The thickness T1 of the first plate portion 26 is the size of the first plate portion 26 in the first direction X. In addition, the thickness T2 is greater than the distance from the lower surface of the sealing plate 14 to the lower end of the portion joined to the collector plate 22 in the collector sheet stack. Thus, the displacement of the electrode body 6 in the direction close to the sealing plate 14, in other words, the displacement in the third direction Z, can be easily suppressed by the electrode body holder 10. In addition, the second plate portion 28 of the present embodiment abuts against the sealing plate 14 (terminal configuration portion) and the electrode body 6. Thus, the displacement of the electrode body 6 in the third direction Z can be more reliably suppressed by the electrode body holder 10. As a result, the load applied to the collector sheet 24 can be further reduced.

[0069] In addition, the electrode body holder 10 is composed of a pair of holder units 10a and 10b arranged in the first direction X. The pair of holder units 10a and 10b respectively have a first plate portion 26 and a second plate portion 28. In addition, each second plate portion 28 has a snap-fitting protrusion 44. One holder unit 10a abuts against a first surface 6a of the electrode body 6 and is pressed and fixed to the sealing plate 14. The other holder unit 10b abuts against the other first surface 6a of the electrode body 6 and is pressed and fixed to the sealing plate 14. In addition, the method of fixing the electrode body holder 10 to the sealing plate 14 is not limited to press-fit fixing.

[0070] In addition, the electrode body holder 10 has a notch 48 in the area of ​​the connection portion 32 between the first plate portion 26 and the second plate portion 28 facing the electrode body 6. The notch 48 is a concave portion provided at the inner corner of the connection portion 32 between the first plate portion 26 and the second plate portion 28 and bent in a direction away from the electrode body 6. Therefore, the first plate portion 26 and the second plate portion 28 are smoothly connected at the connection portion 32. By providing the notch 48, when the first plate portion 26 is pressed toward the outer side of the power storage device 1 due to the displacement of the electrode body 6 in the first direction X, it is possible to suppress the stress from concentrating on the inner corner of the connection portion 32. Thus, it is possible to prevent the electrode body holder 10 from being damaged, and it is possible to more stably suppress the displacement of the electrode body 6. In addition, it is possible to suppress the stress from concentrating on the corner of the electrode body 6. Thus, it is possible to suppress the damage of the electrode body 6.

[0071] The power storage device 1 of the present embodiment includes a sealing plate 14 and a current collecting plate 22 (see Figure 2 ) A pair of insulating members 50 for insulation. That is, in the present embodiment, the second plate portion 28 and the insulating members 50 are separate members. Each insulating member 50 is fixed to the sealing plate 14 via each output terminal 4, and is interposed between the current collector plate 22 and the sealing plate 14 to electrically insulate the two.

[0072] The above describes in detail the implementation of the power storage device of the present disclosure. The above implementation merely shows a specific example of the implementation of the power storage device of the present disclosure. The content of the implementation does not limit the protection scope of the power storage device of the present disclosure, and various design changes such as changes, additions, and deletions of constituent elements can be made without departing from the scope of the idea of ​​the invention defined in the claims. The new implementation with added design changes has the effects of the combined implementation and the deformation. In the above implementation, the content that can make such design changes is emphasized with expressions such as "in this implementation", "in this implementation", etc., but even if there is no such expression, design changes are allowed. The shadow of the cross section marked in the accompanying drawings does not limit the material of the object marked with the shadow.

[0073] (Variant 1)

[0074] Fig. 9 (A) is a perspective view of the power storage device 1 according to the first modification. Fig. 9 (B) is a three-dimensional view of the second electrode body holder. Fig. 9In (A), the illustration of the outer can 12 is omitted. The power storage device 1 of the modification 1 has, in addition to the electrode body holder 10 that the power storage device 1 of the embodiment 1 or 2 has, an electrode body holder other than the electrode body holder 10. In the following description, for the sake of convenience, the electrode body holder 10 of the embodiment 1 or 2 is referred to as the first electrode body holder 10X, and the electrode body holder other than the first electrode body holder 10X is referred to as the second electrode body holder 10Y. In addition, in Fig. 9 In (A), the electrode body holder 10 according to the first embodiment is shown as a first electrode body holder 10X.

[0075] The electrode body 6 has a second surface 6b that connects the ends of a pair of first surfaces 6a on the side opposite to the terminal configuration portion to each other. The second surface 6b is the bottom surface of the electrode body 6. The second electrode body holder 10Y has a fourth plate portion 54 and a pair of third plate portions 52. The pair of third plate portions 52 extends along the third direction Z and abuts against the pair of first surfaces 6a. Specifically, one third plate portion 52 abuts against the first surface 6a on the positive terminal 4a side at a position lower than the first plate portion 26 of the first electrode body holder 10X. In addition, another third plate portion 52 abuts against the first surface 6a on the negative terminal 4b side at a position lower than the first plate portion 26 of the first electrode body holder 10X.

[0076] The fourth plate portion 54 extends along the first direction X and abuts against the second surface 6b of the electrode body 6, and both ends are connected to a pair of third plate portions 52. Therefore, the second electrode body holder 10Y is roughly U-shaped when viewed from the second direction Y. By attaching the second electrode body holder 10Y to the electrode body 6, the displacement of the electrode body 6 can be further suppressed. As a result, the reliability of the power storage device 1 can be further improved. In addition, in the power storage device disclosed in the present invention, the second electrode body holder 10Y is not necessary.

[0077] (other)

[0078] The electrode body 6 is not limited to a stacked electrode body in which a plurality of positive plates and a plurality of negative plates are alternately stacked with a plate separator. For example, the electrode body 6 may also be a flat wound electrode body in which a strip-shaped positive plate and a strip-shaped negative plate are stacked with a plate separator and compressed in a predetermined direction. In addition, the shape of the opening 12a of the outer can 12 may also be a quadrilateral such as a square, a polygonal shape other than a quadrilateral, etc. In addition, the terminal configuration portion may also be provided in the outer can 12. In addition, the output terminals 4 may not be arranged in the first direction X.

[0079] Description of Reference Numerals

[0080] 1. Power storage device; 2. Shell; 4. Output terminal; 6. Electrode body; 6a. First surface; 6b. Second surface; 8. Collecting part; 10. Electrode body holder; 10a, 10b. Holder unit; 10X. First electrode body holder; 10Y. Second electrode body holder; 22. Collector plate; 24. Collector sheet; 26. First plate portion; 28. Second plate portion; 32. Connecting portion; 48. Notch portion; 52. Third plate portion; 54. Fourth plate portion.

Claims

1. An electric storage device, It is characterized in that The power storage device comprises: a housing having a terminal arrangement portion; a pair of output terminals, which are arranged at the terminal configuration portion; an electrode body, which is accommodated in the shell; a pair of current collecting portions electrically connecting the electrode body and the pair of output terminals; and an insulating electrode body holder which abuts against a pair of first surfaces of the electrode body that are opposite to each other in a first direction in which the pair of current collecting portions are arranged, is fixed to the case and holds the electrode body in the first direction, The current collector portion includes a pair of current collector plates fixed to the terminal arrangement portion and a pair of belt-shaped current collector sheets respectively connecting the electrode body and the current collector plates. The collector sheet is bent in a second direction orthogonal to the first direction, The electrode body holder has a second plate portion and a pair of first plate portions, the pair of first plate portions abutting against the pair of first surfaces, the second plate portion being formed integrally with each of the first plate portions, interposed between the terminal arrangement portion and the electrode body and fixed to the terminal arrangement portion, The second plate portion is interposed between the terminal arrangement portion and the current collector plate to electrically insulate the two.

2. The power storage device according to claim 1, in, The thickness of the second plate portion is greater than the thickness of the first plate portion.

3. The power storage device according to claim 2, in, The second plate portion abuts against the terminal arrangement portion and the electrode body.

4. The power storage device according to any one of claims 1 to 3, in, The electrode body holder has a notch portion in a region of a connection portion between the first plate portion and the second plate portion that faces the electrode body.

5. The power storage device according to any one of claims 1 to 3, in, The electrode body holder is composed of a pair of holder units, One of the retaining members abuts against one of the first surfaces and is fixed to the housing. The other holder unit abuts against the other first surface and is fixed to the housing.

6. The power storage device according to any one of claims 1 to 3, in, The pair of first surfaces extend in a direction intersecting with the terminal arrangement portion, The electrode body has a second surface that connects the end portions of the pair of first surfaces on the side opposite to the terminal arrangement portion. The power storage device includes a second electrode body holder in addition to the electrode body holder, i.e., the first electrode body holder, the second electrode body holder having a fourth plate portion and a pair of third plate portions, the pair of third plate portions abutting against the pair of first surfaces, the fourth plate portion abutting against the second surface and connected to the pair of third plate portions.

Images