JP7748619B2 - Power storage device - Google Patents

Description

The present invention relates to an energy storage device equipped with multiple energy storage elements.

Conventionally, energy storage modules have been known that include a battery group in which multiple batteries are stacked horizontally (see Patent Document 1).

In this energy storage module, as shown in Figure 10, storage batteries 501 are rectangular and arranged in an upright position, stacked alternately in the X-axis direction with insulating separators 502. Rectangular end plates 504 are arranged at both ends of the storage battery group in the stacking direction, with insulating end holders 503 interposed between them. The end plates 504 are connected to each other by a pair of restraining bands 505 arranged on either side in the Y-axis direction and extending in the X-axis direction, clamping and holding the storage battery group together in the X-axis direction.

One or more intermediate plates 506 are arranged inside the battery group in the stacking direction. The intermediate plates 506 have the same shape as the batteries 501. Specifically, the intermediate plates 506 are constructed by attaching insert nuts to a plate-shaped resin plate of uniform thickness. As a result, a screw hole 507a and a pair of screw holes 507b, one above the other and one below the screw hole 507a, are formed on each side of the intermediate plate 506.

The restraint band 505 has a flat surface 5051 that extends in the stacking direction parallel to the side surface of the battery group. Near the center of the flat surface 5051 in the stacking direction, there is a hole 5052 that is coaxial with the screw hole 507a formed on one side of the intermediate plate 506, and a pair of holes 5053 that are coaxial with the pair of screw holes 507b. Bolts are inserted into the holes 5052, 5053 of the restraint band 505, and each bolt is screwed into the screw holes 507a, 507b formed on both side surfaces of the intermediate plate 506. In this way, the intermediate plate 506 is fixed to the restraint band 505.

In recent years, there has been a demand for smaller and lighter energy storage modules, which has led to a demand for thinner components (reduced dimensions in the stacking direction) of the components that make up the energy storage module 500, such as the intermediate plate 506 that is placed between adjacent batteries 501 and fixed to the restraining band 505.

However, in the above-mentioned energy storage module 500, since the intermediate plate 506 is fixed to the restraint band 505, expansion of the storage battery 501, etc., can easily place a load on the fixed portion with the restraint band 505. As a result, the module was made thick overall (so that the dimensions in the stacking direction were large) to ensure sufficient strength.

Japanese Patent Application Laid-Open No. 2016-122572

The present embodiment aims to provide an energy storage device that includes an adjacent member that is thin-walled while maintaining the strength of the fixed portion with the extension member.

The power storage device of this embodiment is
A plurality of storage elements arranged in a first direction;
an extension member adjacent to the plurality of energy storage elements in a second direction perpendicular to the first direction and extending along the first direction;
an adjacent member disposed between two adjacent storage elements and fixed to the extension member;
The adjacent member is
a main body portion extending in a direction perpendicular to the first direction between the energy storage elements;
a fastening member disposed at an end of the main body portion in the second direction and used to fasten the adjacent member to the extension member;
The thickness dimension in the first direction of the base, which is a portion of the main body other than the arrangement portion where the fastening member is arranged in a third direction perpendicular to each of the first direction and the second direction, is approximately the same as or less than the thickness dimension of the arrangement portion, and the base has a thin-walled portion in at least a part of the third direction that is thinner than the arrangement portion.

As described above, this embodiment makes it possible to provide an energy storage device equipped with an adjacent member that is thin-walled while ensuring the strength of the fixed portion with the extension member.

FIG. 1 is a perspective view of the electricity storage device according to this embodiment. FIG. 2 is an exploded perspective view of the electricity storage device, with some of the components omitted. FIG. 3 is a perspective view of a second adjacent member included in the power storage device. FIG. 4 is a perspective view of the second adjacent member. FIG. 5 is a view of the second adjacent member as viewed from the Y-axis direction. FIG. 6 is a view of the second adjacent member as viewed from the X-axis direction. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a perspective view of a second adjacent member according to another embodiment. FIG. 10 is an exploded perspective view of a conventional electricity storage module.

The power storage device of this embodiment is
A plurality of storage elements arranged in a first direction;
an extension member adjacent to the plurality of energy storage elements in a second direction perpendicular to the first direction and extending along the first direction;
an adjacent member disposed between two adjacent storage elements and fixed to the extension member;
The adjacent member is
a main body portion extending in a direction perpendicular to the first direction between the energy storage elements;
a fastening member disposed at an end of the main body portion in the second direction and used to fasten the adjacent member to the extension member;
The thickness dimension in the first direction of the base, which is a portion of the main body other than the arrangement portion where the fastening member is arranged in a third direction perpendicular to each of the first direction and the second direction, is approximately the same as or less than the thickness dimension of the arrangement portion, and the base has a thin-walled portion in at least a part of the third direction that is thinner than the arrangement portion.

With this configuration, the thickness of the main body is set to the same or less than the placement location (the location where the fastening member is located) where loads are most likely to be applied, and the base, which is the other location in the third direction, has a thinner portion that is thinner (smaller in thickness) than the placement location. This allows the adjacent member to be made thinner while maintaining the strength of the fixed portion (placement location) with the extension member on the adjacent member.

In the power storage device,
The main body portion is
a plurality of the placement portions arranged at intervals in the third direction and each extending in the second direction;
the base portion having a plate shape that connects adjacent arrangement portions and extends in a direction perpendicular to the first direction,
Each of the arrangement portions abuts against the adjacent member and the adjacent energy storage element,
The thin portion may form a gap between the adjacent member and the adjacent energy storage element.

With this configuration, a flow path through which a temperature-regulating fluid can flow can be formed in the area surrounded by the thin-walled portion, the adjacent arrangement portion sandwiching the base, and the storage element. In other words, by utilizing the arrangement portion, which has a thickness dimension greater than that of the thin-walled portion to ensure strength, a flow path through which a temperature-regulating fluid can flow between the adjacent member and the adjacent storage element can be formed.

In addition, in the power storage device,
The base may have a protrusion that protrudes in the first direction and abuts against an energy storage element adjacent to the adjacent member.

With this configuration, the protrusions as well as the placement portion come into contact with the energy storage element, allowing sufficient pressing force (force in the first direction) to be applied to the energy storage element.

In the power storage device,
The main body portion is
the arrangement portion extending in the second direction and abutting against the energy storage element adjacent to the adjacent member;
the base portion having a plate shape extending in a direction perpendicular to the first direction at a position adjacent to the arrangement portion in the third direction,
the base portion has a protrusion at a position spaced apart from the arrangement portion in the third direction, the protrusion protruding in the first direction to abut against an energy storage element adjacent to the adjacent member and extending in the second direction,
The portion between the arrangement portion and the convex portion in the third direction of the base may constitute the thin-walled portion in which a gap is formed between the adjacent member and the adjacent storage element in the first direction.

With this configuration, a flow path through which a temperature-regulating fluid can flow can be formed in the area surrounded by the thin-walled portion, the arrangement portion, the protrusion, and the storage element. In other words, by utilizing the arrangement portion, which has a thickness greater than that of the thin-walled portion to ensure strength, and the protrusion that protrudes from the thin-walled portion, a flow path through which a temperature-regulating fluid can flow between an adjacent member and an adjacent storage element can be formed.

One embodiment of the present invention will be described below with reference to Figures 1 to 8. Note that the names of the components in this embodiment are those used in this embodiment and may differ from the names of the components in the background art.

As shown in Figures 1 and 2, the energy storage device includes a plurality of energy storage elements 10 arranged in a predetermined direction, a plurality of adjacent members 2 adjacent to the energy storage elements 10 in the predetermined direction, a holding member 4 that holds the plurality of energy storage elements 10 and the plurality of adjacent members 2, and a first fastening member 5 that secures at least one adjacent member 2 to the holding member 4. The energy storage device 1 also includes at least one insulator 6 arranged between the plurality of energy storage elements 10 and the holding member 4, and a plurality of bus bars 8 that electrically connect different energy storage elements 10 to each other.

Each of the multiple energy storage elements 10 is a primary battery, secondary battery, capacitor, etc. The energy storage element 10 of this embodiment is a chargeable and dischargeable non-aqueous electrolyte secondary battery. More specifically, the energy storage element 10 is a lithium ion secondary battery that utilizes electron transfer that occurs with the movement of lithium ions.

Specifically, each energy storage element 10 comprises an electrode body, a case 13 that houses the electrode body together with an electrolyte, an external terminal 14 that is at least partially exposed to the outside of the case 13, and a current collector that connects the electrode body and the external terminal 14.

In the electrode assembly, positive and negative electrodes are stacked alternately with separators between them. Lithium ions move between the positive and negative electrodes in this electrode assembly, causing the energy storage element 10 to charge and discharge.

The case 13 has a case body 131 with an opening and a plate-shaped cover plate 132 that closes (blocks) the opening of the case body 131. The case body 131 is a rectangular cylinder with a bottom, and the case 13 has a rectangular parallelepiped (six-sided) shape. Specifically, the case body 131 has a rectangular closing portion 131a, a pair of long wall portions 131b extending from each long side of the closing portion 131a in the normal direction to the closing portion 131a, and a pair of short wall portions 131c extending from each short side of the closing portion 131a in the normal direction to the closing portion 131a.

The case 13 configured as described above has a flat rectangular parallelepiped shape, and the multiple energy storage elements 10 are lined up in the specified direction with the wide faces (long wall portions 131b) of the case 13 facing each other.

In the following description, the direction in which multiple energy storage elements 10 are lined up (first direction) is the X-axis of the Cartesian coordinate system, the direction in which a pair of narrow surfaces (short wall portions 131c) of the case 13 face each other (second direction) is the Y-axis of the Cartesian coordinate system, and the normal direction of the blocking portion 131a (third direction) is the Z-axis of the Cartesian coordinate system.

The adjacent members 2 are insulating and are arranged between the energy storage elements 10 lined up in the X-axis direction, or between an energy storage element 10 and a member lined up in the X-axis direction relative to the energy storage element 10 (in this embodiment, part of the holding member 4). The adjacent members 2 form flow paths R between adjacent energy storage elements 10, allowing the flow of a temperature-regulating fluid (in this embodiment, a gas such as air). The energy storage device 1 of this embodiment includes multiple adjacent members 2, and these multiple adjacent members 2 include multiple types of adjacent members 2A, 2B, and 2C.

Specifically, the multiple adjacent members 2 include a first adjacent member 2A arranged between two adjacent energy storage elements 10, a second adjacent member (adjacent member) 2B arranged between the adjacent energy storage elements 10 and fixed to the holding member 4, and a third adjacent member 2C adjacent to the energy storage element 10 between the holding member 4 and the energy storage element 10 at the farthest end in the X-axis direction. That is, the energy storage device 1 includes the first adjacent member 2A, the second adjacent member 2B, and the third adjacent member 2C as adjacent members 2. The energy storage device 1 of this embodiment includes multiple first adjacent members 2A, one second adjacent member 2B, and two (a pair) third adjacent members 2C. Each of these multiple first adjacent members 2A is arranged between each energy storage element 10 except for between the energy storage elements 10 where the second adjacent member 2B is arranged.

Each of the multiple first adjacent members 2A has a first main body portion 21A that extends in a direction perpendicular to the X-axis direction between adjacent energy storage elements 10 in the X-axis direction, and at least one first restricting portion 25A that restricts movement of an adjacent energy storage element 10 relative to the first main body portion 21A. Furthermore, each of the multiple first adjacent members 2A forms at least one flow path R between adjacent energy storage elements 10, through which a temperature-regulating fluid can flow.

The first body portion 21A faces the long wall portion 131b of the case 13 of the energy storage element 10, with a portion of the body abutting against it. This first body portion 21A cooperates with an adjacent energy storage element 10 to form a flow path R between the energy storage element 10 and the first body portion 21A, through which a temperature-regulating fluid can flow. In this embodiment, the first body portion 21A is a rectangular plate of a size corresponding to the energy storage element 10 when viewed from the X-axis direction, and its cross-sectional shape along the X-Z plane (a plane including the X-axis and Z-axis directions) is a rectangular waveform.

The first restricting portions 25A extend in the X-axis direction from at least the corners of the rectangular first main body portion 21A and abut against the energy storage element 10 (more specifically, the case 13) adjacent to the first main body portion 21A from the outside in the Y-Z plane (a plane including the Y-axis direction and the Z-axis direction), thereby restricting relative movement of the energy storage element 10 with respect to the first main body portion 21A in the Y-Z plane direction. In this embodiment, the first restricting portions 25A extend from the first main body portion 21A in both directions in the X-axis direction.

As shown in Figures 3 to 8, the second adjacent member 2B has a second main body portion (main body portion) 21B that extends in a direction perpendicular to the X-axis direction (Y-Z plane direction) between two adjacent energy storage devices 10, and a second fastening member (fastening member) 22B that is arranged at the end of the second main body portion 21B in the Y-axis direction and is used to secure the second adjacent member 2B to the holding member 4. The second adjacent member 2B also has at least one second restricting portion 25B that restricts movement of the energy storage device 10 adjacent to the second main body portion 21B relative to the second main body portion 21B. The second adjacent member 2B also has an engaging portion 26B that engages with the holding member 4.

This second adjacent member 2B also forms at least one flow path R between adjacent energy storage elements 10, through which the temperature control fluid can flow. The second adjacent member 2B of this embodiment forms multiple flow paths R between adjacent energy storage elements 10. Furthermore, the second adjacent member 2B of this embodiment is made of resin, except for the second fastening member 22B, which is made of metal.

The second body portion 21B has a shape corresponding to the energy storage device 10 when viewed in the X-axis direction, and in this embodiment, the second body portion 21B is rectangular when viewed in the X-axis direction (see Figure 6). In the Z-axis direction, this second body portion 21B has an arrangement portion 211B where the fastening member is arranged, and a base portion 212B which is a portion other than the arrangement portion 211B. In this embodiment, the second body portion 21B has multiple arrangement portions 211B and multiple base portions 212B. In addition, the second body portion 21B in this embodiment has at least one hollow portion 216B therein (see Figure 8).

The multiple placement portions 211B are spaced apart along the Z axis and extend in the Y axis direction. Each of these multiple placement portions 211B abuts against the energy storage device 10 (more specifically, the long wall portion 131b) adjacent to the second adjacent member 2B. In this embodiment, the multiple placement portions 211B are spaced apart in the Z axis direction in the second main body portion 21B, and each placement portion 211B extends continuously from one end of the second main body portion 21B to the other end in the Y axis direction. Specifically, when viewed from the Y axis direction, each of the multiple placement portions 211B bulges out in an arc shape on both sides in the X axis direction relative to the portion adjacent in the Z axis direction (the thin-walled portion 213B described below; see Figure 7), and a second fastening member 22B is disposed at each end in the Y axis direction. In this embodiment, the second main body portion 21B has three placement portions 211B.

Each of the multiple base portions 212B is plate-shaped and extends in a direction perpendicular to the X-axis direction. The dimension (thickness) of each base portion 212B in the X-axis direction is approximately the same as or less than the thickness of the arrangement portion 211B, and each base portion 212B has a thin portion 213B in at least a portion in the Z-axis direction that is thinner than the arrangement portion 211B. This thin portion 213B forms a gap between the second adjacent member 2B and the adjacent energy storage element 10, and at least a portion of this gap forms a flow path R. In this embodiment, the thickness of the base portion 212B is less than the thickness of the arrangement portion 211B.

Specifically, the multiple bases 212B include at least one first base (base) 212B1 connecting adjacent placement portions 211B in the Z-axis direction, and at least one second base 212B2 that forms an end of the second main body portion 21B in the Z-axis direction and is adjacent to the placement portion 211B. In the second main body portion 21B of this embodiment, a first base 212B1 is disposed between each of the placement portions 211B. Furthermore, a second base 212B2 is disposed on the outside of each of the placement portions 211B disposed at one end and the other end of the multiple placement portions 211B disposed at intervals in the Z-axis direction in the second main body portion 21B. In other words, the second main body portion 21B of this embodiment has two first bases 212B1 and two second bases 212B2.

Each first base portion 212B1 has a thin portion 213B and a protrusion 214B that protrudes from the thin portion 213B in the X-axis direction and abuts against the energy storage element 10 adjacent to the second adjacent member 2B.

The thin-walled portion 213B is a plate-shaped portion extending in a plane direction perpendicular to the X-axis direction (Y-Z plane direction), and as described above, its thickness is smaller than that of the arrangement portion 211B. The thin-walled portion 213B of this first base portion 212B1 extends from one arrangement portion 211B to the other arrangement portion 211B between adjacent arrangement portions 211B spaced apart in the Z-axis direction, and also extends from one end of the second main body portion 21B to the other in the Y-axis direction.

The convex portion 214B protrudes in the X-axis direction from the thin portion 213B at a position spaced from the arrangement portion 211B in the Z-axis direction, abuts against the energy storage element 10 adjacent to the second adjacent member 2B, and extends in the Y-axis direction. In this embodiment, the convex portion 214B protrudes from one surface 2131B and the other surface 2132B of the thin portion 213B in the X-axis direction. That is, the first base portion 212B1 in this embodiment has two convex portions 214B. The convex portion 214B on one surface 2131B and the convex portion 214B on the other surface 2132B each extend in the Y-axis direction at the same position in the Z-axis direction. In this embodiment, each convex portion 214B is located at a central position between the arrangement portions 211B in the Z-axis direction. Furthermore, in this embodiment, each convex portion 214B extends continuously from a position spaced a distance d1 from one end of the thin portion 213B in the Y-axis direction to a position spaced a distance d2 from the other end (see FIG. 6). Furthermore, the height of the convex portion 214B (the amount of protrusion from the thin portion 213B) is the same at each position in the Y-axis direction, and the width (dimension in the Z-axis direction) is also the same at each position in the Y-axis direction. Furthermore, in this embodiment, the distance d1 and the distance d2 are the same in the first base portion 212B1.

Each second base portion 212B2 has a thin portion 213B and a seal portion 215B that protrudes from the thin portion 213B in the X-axis direction and extends in the Y-axis direction.

The thinned portion 213B of the second base portion 212B2 has a similar configuration to the thinned portion 213B of the first base portion 212B1, and the thickness dimension of the thinned portion 213B of the second base portion 212B2 is the same as the thickness dimension of the thinned portion 213B of the first base portion 212B1. Furthermore, one of the thinned portions 213B in the Z-axis direction (the upper portion in Figure 6) has multiple (two in the example shown in Figure 6) cutout portions 2135B spaced apart in the Y-axis direction. These cutout portions 2135B are recessed from one edge toward the other edge in the Z-axis direction.

The seal portion 215B extends continuously from one end of the second main body portion 21B to the other in the Y-axis direction and is in close contact with the energy storage device 10 adjacent to the second adjacent member 2B. In this embodiment, two seal portions 215B are arranged on each of the surfaces 2131B and 2132B of the thin-walled portion 213B in the X-axis direction. Each seal portion 215B on the surface 2131B is arranged in the same position in the Z-axis direction as the corresponding seal portion 215B on the surface 2132B. The width of each seal portion 215B at each position in the Y-axis direction (dimension in the Z-axis direction) is smaller than the width of the protruding portion 214B, and at least the tip (top) of each seal portion 215B in the protruding direction (X-axis direction) is in close contact with the energy storage device 10. In this embodiment, the seal portion 215B extends to the second restrictor 25B.

At least one hollow portion 216B is a hole extending from one end face of the second main body portion 21B to the other end face in the Z-axis direction, or a hole extending from the other end face to one end face. In this embodiment, the second main body portion 21B has multiple hollow portions 216B (see Figure 8). These multiple hollow portions 216B reduce the weight of the second adjacent member 2B and suppress shrinkage during molding.

A second fastening member 22B is disposed at each end of each placement portion 211B in the Y-axis direction. That is, the second adjacent member 2B has multiple second fastening members 22B. Each of these multiple second fastening members 22B fastens the second adjacent member 2B and the retaining member 4 by engaging with a first fastening member 5. In this embodiment, each second fastening member 22B is an insert nut and has a female thread on the inner surface of a hole extending in the Y-axis direction. Furthermore, in this embodiment, each first fastening member 5 is a bolt and fastens the second adjacent member 2B and the retaining member 4 by engaging (threading) with the second fastening member 22B.

In this embodiment, three second fastening members 22B are arranged at each end of the second adjacent member 2B in the Y-axis direction, spaced apart in the Z-axis direction. The second fastening member 22B at one end of these three second fastening members 22B and the second fastening member 22B at the other end engage with the first fastening member 5 inserted through the retaining member 4, thereby fastening the second adjacent member 2B to the retaining member 4. Furthermore, when other components such as ducts are attached to the energy storage device 1, the central second fastening member 22B of the three second fastening members 22B engages with the first fastening member 5 inserted through the retaining member 4 as well, thereby fastening the second adjacent member 2B to the retaining member 4 and the other component.

The second restricting portions 25B extend in the X-axis direction from at least the corners of the rectangular periphery of the second main body portion 21B when viewed in the X-axis direction, and restrict relative movement of the energy storage element 10 in the Y-Z plane direction with respect to the second adjacent member 2B by abutting the energy storage element 10 adjacent to the second adjacent member 2B from the outside in the Y-Z plane direction. The second restricting portions 25B extend from the second main body portion 21B to both sides in the X-axis direction.

The engaging portions 26B protrude in the Y-axis direction from the end (end surface) of the second main body portion 21B in the Y-axis direction. Specifically, multiple engaging portions 26B are arranged at intervals in the Z-axis direction on the end surface of the second main body portion 21B in the Y-axis direction. In the second adjacent member 2B of this embodiment, two engaging portions 26B are arranged at intervals in the Z-axis direction on each end of the second main body portion 21B in the Y-axis direction. Each of these two engaging portions 26B is cylindrical with a tapered tip, and is arranged at a position corresponding to each first base portion 212B1 in the Z-axis direction (i.e., between the arrangement portions 211B).

Returning to Figures 1 and 2, each of the two third adjacent members 2C has a third main body portion 21C that extends in a direction perpendicular to the X-axis direction between adjacent energy storage elements 10 in the X-axis direction and a portion of the holding member 4 (terminal member 41, described below), and at least one third restricting portion 25C that restricts movement of an adjacent energy storage element 10 relative to the third main body portion 21C. In addition, each of the two third adjacent members 2C forms at least one flow path R between adjacent energy storage elements 10, through which a temperature-regulating fluid can flow.

The third body portion 21C is a portion that faces the long wall portion 131b of the energy storage element 10, with a portion of the portion abutting the long wall portion 131b. Like the first body portion 21A of the first adjacent member 2A and the second body portion 21B of the second adjacent member 2B, this third body portion 21C also cooperates with the adjacent energy storage element 10 to form a flow path R between the energy storage element 10 and the third body portion 21C, through which a temperature-regulating fluid can flow. In this embodiment, the third body portion 21C forms multiple flow paths R between the adjacent energy storage elements 10.

Specifically, the third main body portion 21C is a rectangular plate of a size corresponding to that of the adjacent energy storage element 10 when viewed in the X-axis direction. More specifically, the third main body portion 21C extends in a direction perpendicular to the X-axis direction at each of one end and the other end of the energy storage device 1 in the X-axis direction, and has two opposing surfaces 210C that face adjacent energy storage elements 10 (long wall portions 131b of the case 13) or terminal members 41, and multiple ridges 214C that protrude from the opposing surfaces 210C that face the energy storage elements 10.

On the opposing surface 210C facing the energy storage element 10, each of the multiple ridges 214C extends in the Y-axis direction and is spaced apart in the Z-axis direction. The tip of each of these multiple ridges 214C in the protruding direction (X-axis direction) abuts against the energy storage element 10 adjacent to the third main body portion 21C. As a result, a flow path R is formed on the energy storage element 10 side of the third main body portion 21C by the opposing surface 210C on the energy storage element 10 side, the two adjacent ridges 214C spaced apart in the Z-axis direction on the opposing surface 210C, and the energy storage element 10 (case 13) facing the opposing surface 210C.

The third restricting portion 25C extends in the X-axis direction from at least the corners of the rectangular third main body portion 21C and restricts relative movement of the energy storage element 10 in the Y-Z plane direction with respect to the third main body portion 21C by abutting the energy storage element 10 (more specifically, the case 13) adjacent to the third main body portion 21C from the outside in the Y-Z plane direction. In this embodiment, the third restricting portion 25C extends from the third main body portion 21C toward one side in the X-axis direction (the energy storage element 10 side).

The holding member 4 surrounds the multiple energy storage elements 10 and the multiple adjacent members 2, thereby holding the multiple energy storage elements 10 and the multiple adjacent members 2 together. The holding member 4 is made of a conductive material such as metal.

Specifically, the holding member 4 has a pair of end members 41 arranged on both sides of the multiple energy storage elements 10 (a stack of energy storage elements 10) in the X-axis direction, and an extension member 42 adjacent to the multiple energy storage elements 10 in the Y-axis direction and extending along the X-axis direction. The holding member 4 of this embodiment has a pair of extension members 42, each of which connects the pair of end members 41 to each other. The holding member 4 also has at least one fastening member 43 that fastens the end member 41 and the extension member 42. The holding member 4 of this embodiment has multiple fastening members 43.

Each of the pair of end members 41 is positioned so as to sandwich the third adjacent member 2C between itself and the energy storage element 10 positioned at the end (outermost) in the X-axis direction. Each of the pair of end members 41 is a rectangular plate of a size corresponding to the energy storage element 10 when viewed in the X-axis direction. Specifically, each end member 41 is rectangular and elongated in the Y-axis direction, and has multiple through holes 411 spaced apart in the Z-axis direction at both ends in the Y-axis direction.

Each of the pair of extension members 42 has an extension member main body 420 facing the short wall portion 131c of each energy storage element 10; a first arm portion 421 extending from one end of the extension member main body 420 in the Z-axis direction (the upper end in Figure 2) along the Y-axis direction along the cover plate 132 of each energy storage element 10 and also extending in the X-axis direction; a second arm portion 422 extending from the other end of the extension member main body 420 in the Z-axis direction along the closing portion 131a of each energy storage element 10 and also extending in the Y-axis direction along the X-axis direction; and a pair of third arm portions 423 extending from each end of the extension member main body 420 in the X-axis direction along the terminal member 41 and also extending in the Y-axis direction along the Z-axis direction.

The extension member main body 420 is plate-shaped and extends along the short wall portion 131c of each energy storage element 10. It has multiple first through holes 4201 that penetrate in the Y-axis direction to allow the temperature control fluid to flow into and out of each flow path R, and multiple second through holes 4202 that penetrate in the Y-axis direction at positions corresponding to the second fastening members 22B of the second adjacent member 2B. The extension member main body 420 also has a third through hole 4203 that penetrates in the Y-axis direction at a position corresponding to the engaging portion 26B of the second adjacent member 2B. The first fastening member 5 is inserted into this second through hole 4202, and the engaging portion 26B of the second adjacent member 2B is inserted into the third through hole 4203.

The first arm 421 is strip-shaped and long in the X-axis direction, with a constant dimension (width) in the Y-axis direction at each position in the X-axis direction. The second arm 422 is strip-shaped and long in the X-axis direction, with a constant dimension (width) in the Y-axis direction at each position in the X-axis direction. The width of this second arm 422 is greater than the width of the first arm 421. Each of the pair of third arms 423 has a plurality of through holes 4231 spaced apart in the Z-axis direction. Each through hole 4231 is located at a position corresponding to a through hole 411 in the end member.

Each of the multiple fastening members 43 fastens the end member 41 and the extension member 42 together by passing through the through hole 411 of the end member 41 and the through hole 4231 of the extension member 42 (third piece 423). In this embodiment, each fastening member 43 is composed of a bolt 431 and a nut 432.

The insulator 6 has insulating properties. This insulator 6 is disposed between the extension member 42 and the multiple energy storage elements 10. Specifically, the energy storage device 1 includes a pair of insulators 6, each of which covers at least the area of the extension member 42 that faces the multiple energy storage elements 10. As a result, each insulator 6 provides insulation between the extension member 42 and the multiple energy storage elements 10. Each insulator 6 has through holes 61, 62, 63 of a size and shape corresponding to the through holes 4201, 4202, 4203 of the extension member main body 420 at positions corresponding to the through holes (first through hole 4201, second through hole 4202, third through hole 4203) of the extension member main body 420.

Each of the multiple bus bars 8 is a plate-shaped member having electrical conductivity, such as metal. Each bus bar 8 provides electrical continuity between the external terminals 14 of the energy storage elements 10. In this embodiment, the multiple bus bars 8 connect (provide electrical continuity) the multiple energy storage elements 10 included in the energy storage device 1 in series.

With the above-described energy storage device 1, the thickness dimension of the second main body portion 21B of the second adjacent member 2B is set based on the arrangement portion 211B (the portion where the second fastening member 22B is arranged) where load is likely to be applied, and the base portion 212B, which is another portion in the Z axis direction, is set to be smaller than the arrangement portion 211B. Furthermore, the first base portion 212B1 has a thin portion 213B that is thinner (smaller in thickness) than the arrangement portion 211B. This allows the second adjacent member 2B to be thinned while maintaining the strength of the fixed portion (arrangement portion 211B) with the extension member 42 in the second adjacent member 2B. This allows the energy storage device 1 to be downsized in the X axis direction, or, if the dimension of the energy storage device 1 in the X axis direction is not changed, the width of each flow path R formed between the energy storage elements 10 in the X axis direction can be increased, thereby improving cooling and heating efficiency.

Furthermore, in the second adjacent member 2B of the energy storage device 1 of this embodiment, the second main body portion 21B includes a plurality of arrangement portions 211B spaced apart in the Z-axis direction and each extending in the Y-axis direction, and a plate-shaped first base portion 212B1 connecting adjacent arrangement portions 211B and extending in a direction perpendicular to the X-axis direction (Y-Z plane direction). Each arrangement portion 211B abuts against the energy storage element 10 adjacent to the second adjacent member 2B, and the thin-walled portion 213B forms a gap between the second adjacent member 2B and the adjacent energy storage element 10. In other words, in the second adjacent member 2B, the main body portion includes arrangement portions 211B extending in the Y-axis direction and abutting against the energy storage element 10 adjacent to the second adjacent member 2B, and a plate-shaped first base portion 212B1 extending in a direction perpendicular to the X-axis direction at a position adjacent to the arrangement portion 211B in the Z-axis direction. The first base 212B1 has a convex portion 214B that protrudes in the X-axis direction and abuts against the energy storage element 10 adjacent to the second adjacent member 2B and extends in the Y-axis direction at a position spaced from the arrangement portion 211B in the Z-axis direction, and the portion of the first base 212B1 between the arrangement portion 211B and the convex portion 214B in the Z-axis direction forms a thin portion 213B where a gap is formed between the second adjacent member 2B and the adjacent energy storage element 10 in the X-axis direction. This makes it possible to form a flow path R in the energy storage device 1, through which a temperature-regulating fluid can flow, in a region surrounded by the thin portion 213B, the arrangement portion 211B adjacent to the first base 212B1 sandwiched between them, and the energy storage element 10. In other words, by utilizing the placement portion 211B, which has a thickness dimension greater than that of the thin portion 213B to ensure strength, a flow path R can be formed between the second adjacent member 2B and the adjacent energy storage element 10, allowing the flow of a fluid for regulating the temperature of the energy storage element 10.

Furthermore, in the second adjacent member 2B of the energy storage device 1 of this embodiment, the first base portion 212B1 has a convex portion 214B that protrudes in the X-axis direction and abuts against the energy storage element 10 adjacent to the second adjacent member 2B. In this way, by having the convex portion 214B abut against the energy storage element 10 in addition to the arrangement portion 211B, a sufficient pressing force (force in the X-axis direction) can be applied to the energy storage element 10.

The energy storage device of the present invention is not limited to the above-described embodiments, and various modifications can of course be made without departing from the spirit of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, or part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, part of the configuration of one embodiment can be deleted.

In the second adjacent member 2B of the energy storage device 1 in the above embodiment, the convex portions 214B extend continuously in the Y-axis direction between positions spaced apart by distances d1 and d2 from each edge of the second main body portion 21B in the Y-axis direction (see Figure 6), but this configuration is not limited thereto.

The convex portion 214B does not have to be a configuration (convex strip) extending in a predetermined direction as described above, but may instead be, for example, a columnar shape extending in the X-axis direction, a cone or truncated cone shape (see Figure 9), or a hemispherical shape.

Furthermore, the convex portion 214B may extend intermittently in the Y-axis direction, or may be configured to be curved or bent in whole or in part (i.e., it does not have to be a shape that extends straight in the Y-axis direction). Furthermore, the width of the convex portion 214B at each position in the Y-axis direction (dimension in the Z-axis direction) does not have to be the same.

In addition, in the second main body portion 21B in the above embodiment, the positions of the convex portion 214B on one surface in the X-axis direction and the convex portion 214B on the other surface in the Z-axis direction are the same, but they may be different.

In other words, the convex portion 214B is not limited to any particular shape, as long as it protrudes from the thin portion 213B in the X-axis direction and abuts against the energy storage element 10 adjacent to the second adjacent member 2B.

In addition, in the second adjacent member 2B of the above embodiment, the first base portion 212B1 has one convex portion 214B on each of the faces 2131B, 2132B in the X-axis direction, but this configuration is not limited to this. The first base portion 212B1 may have multiple convex portions 214B arranged at intervals in the Z-axis direction on each of the faces 2131B, 2132B in the X-axis direction. Furthermore, the first base portion 212B1 may be configured without any convex portions 214B (i.e., the entire first base portion 212B1 may be configured with thin-walled portions 213B).

Furthermore, in the second adjacent member 2B of the energy storage device 1 of the above embodiment, the thickness dimension (dimension in the X-axis direction) of the first base portion 212B1, more specifically the distance in the X-axis direction between the tips of the convex portions 214B on both sides of the first base portion 212B1, is less than the thickness dimension of the arrangement portion 211B, but this configuration is not limited. The first base portion 212B1 may have a portion whose thickness dimension is slightly greater than that of the arrangement portion 211B. In other words, the thickness dimension of the first base portion 212B1 only needs to be approximately the same as or less than the thickness dimension of the arrangement portion 211B.

Specifically, in the first base portion 212B1, the tip (top) of the convex portion 214B may protrude slightly (e.g., 0.005 mm) in the X-axis direction from the arrangement portion 211B. This protrusion amount is such that even when expansion (expansion of the case 13) occurs in the energy storage element 10 adjacent to the second adjacent member 2B due to aging or charge/discharge, each arrangement portion 211B and each convex portion 214B in the second adjacent member 2B maintains contact with the energy storage element 10 (case 13).

Furthermore, although the energy storage device 1 in the above embodiment includes one second adjacent member 2B, it may also include multiple second adjacent members 2B.

In addition, in the above embodiment, the energy storage element is described as being used as a chargeable and dischargeable non-aqueous electrolyte secondary battery (e.g., a lithium-ion secondary battery), but the type and size (capacity) of the energy storage element are arbitrary. In addition, in the above embodiment, a lithium-ion secondary battery is described as an example of an energy storage element, but this is not limited to this. For example, the present invention can also be applied to energy storage elements of various secondary batteries, as well as primary batteries and capacitors such as electric double layer capacitors.

1...electricity storage device, 2...adjacent member, 2A...first adjacent member, 2B...second adjacent member (adjacent member), 2C...third adjacent member, 21A...first main body portion, 21B...second main body portion (main body portion), 21C...third main body portion, 210C...opposing surface, 211B...arrangement portion, 212B...base portion, 212B1...first base portion (base portion), 212B2...second base portion, 213B...thin portion, 2131B...one one surface, 2132B...the other surface, 2135B...notch portion, 214B...projection portion, 214C...projection strip, 215B...seal portion, 216B...hollow portion, 22B...second fastening member, 25A...first restricting portion, 25B...second restricting portion, 25C...third restricting portion, 26B...engaging portion, 4...retaining member, 41...terminating member, 411...through hole, 42...extension member, 420...extension member main body, 4201...third First through hole, 4202...second through hole, 4203...third through hole, 421...first arm portion, 422...second arm portion, 423...third arm portion, 4231...through hole, 43...fastening member, 431...bolt, 432...nut, 5...first fastening member, 6...insulator, 61, 62, 63...through hole, 8...bus bar, 10...energy storage element, 13...case, 131...case main body, 131a...blocking portion , 131b...long wall portion, 131c...short wall portion, 132...cover plate, 14...external terminal, 500...storage module, 501...storage battery, 502...separator, 503...end holder, 504...end plate, 505...restraint band, 5051...flat surface, 5052, 5053...hole portion, 506...intermediate plate, 507a, 507b...screw hole, d1, d2...spacing, R...flow path

Claims (4)

A plurality of storage elements arranged in a first direction;
an extension member adjacent to the plurality of energy storage elements in a second direction perpendicular to the first direction and extending along the first direction;
an adjacent member disposed between two adjacent storage elements and fixed to the extension member;
The adjacent member is
a main body portion extending in a direction perpendicular to the first direction between the energy storage elements;
a fastening member disposed at an end of the main body portion in the second direction and used to fasten the adjacent member to the extension member;
a thickness dimension in the first direction of a base, which is a portion of the main body portion other than the arrangement portion where the fastening member is arranged in a third direction perpendicular to each of the first direction and the second direction, is approximately equal to or less than the thickness dimension of the arrangement portion, and the base has a thin-walled portion in at least a part of the third direction that is thinner than the arrangement portion. The main body portion is
a plurality of the placement portions arranged at intervals in the third direction and each extending in the second direction;
the base portion having a plate shape that connects adjacent arrangement portions and extends in a direction perpendicular to the first direction,
Each of the arrangement portions abuts against the adjacent member and the adjacent energy storage element,
The energy storage device according to claim 1 , wherein the thin portion forms a gap between the adjacent member and the adjacent energy storage element. The energy storage device described in claim 2, wherein the base has a protrusion that protrudes in the first direction and abuts against the energy storage element adjacent to the adjacent member. The main body portion is
the arrangement portion extending in the second direction and abutting against the energy storage element adjacent to the adjacent member;
the base portion having a plate shape extending in a direction perpendicular to the first direction at a position adjacent to the arrangement portion in the third direction,
the base portion has a protrusion at a position spaced apart from the arrangement portion in the third direction, the protrusion protruding in the first direction to abut against an energy storage element adjacent to the adjacent member and extending in the second direction,
2. The energy storage device of claim 1, wherein the portion of the base between the arrangement portion and the convex portion in the third direction constitutes the thin-walled portion in which a gap is formed between the adjacent member and the adjacent energy storage element in the first direction.