JP7723905B2 - Electricity storage device and pressure absorbing member - Google Patents

Description

The present invention relates to an energy storage device having a plurality of energy storage elements arranged in a first direction and an extension member arranged along the plurality of energy storage elements, and a pressure absorbing member provided between the energy storage elements.

A battery system is known that includes a plurality of storage elements aligned in a first direction and a connecting bar (extension member) arranged along the plurality of storage elements (see, for example, Patent Document 1). Specifically, as shown in FIG. 10, this battery system includes a plurality of stacked battery cells 102, a pair of end plates 140 arranged on both ends of the plurality of battery cells 102, and connecting bars 143 arranged on both side surfaces of the plurality of battery cells 102. The connecting bar 143 is strip-shaped, and both ends of the connecting bar 143 in a predetermined direction are bent inward to form bent pieces that are fixed to the end plates 140. This secures the plurality of battery cells 102 in a stacked state.

However, when an energy storage device is used for a long period of time, the energy storage element may expand. Furthermore, as energy storage elements have become higher in capacity in recent years, the amount of expansion of energy storage elements with use tends to increase. Therefore, when such an energy storage device is used for a long period of time, there is a risk that the extension member will be deformed by the expansion of the energy storage element.

JP 2009-170258 A

Therefore, the objective of this embodiment is to provide an energy storage device and a pressure absorption member that can suppress deformation of the extension member caused by expansion of the energy storage element.

The power storage device of this embodiment is
A plurality of storage elements arranged in a first direction;
a pair of extension members extending in the first direction and sandwiching the plurality of energy storage elements from both sides in a second direction perpendicular to the first direction;
a pressure absorbing member at least a portion of which is elastically deformable in the first direction;
an adjacent member adjacent to the pressure absorbing member in the first direction,
The pressure absorbing member and the adjacent member are disposed between adjacent energy storage elements.

With this configuration, the pressure absorption member elastically deforms when a force is applied from the outside in the first direction, so when the energy storage element expands, the pressure absorption member can absorb the force caused by the expansion, thereby suppressing deformation of the extension member caused by the expansion of the energy storage element.

In the power storage device,
The adjacent member may form a flow path between the adjacent member and the pressure absorbing member, through which a fluid can flow.

In the power storage device,
The pressure absorbing member may have the same outer dimensions as the energy storage element.

With this configuration, the pressure absorbing member can be placed in a location in the energy storage device where the energy storage element can be placed, i.e., it can be placed in place of the energy storage element.

In the power storage device,
The pressure absorbing member may have an elastic portion that is elastically deformable in the first direction, and a pair of clamping portions that sandwich the elastic portion from both sides in the first direction and are capable of transmitting external forces in the first direction to the elastic portion.

With this configuration, when a force is applied to the pair of clamping portions from outside in the first direction, the elastic portion of the pressure absorbing member elastically deforms. Therefore, when the energy storage element expands, the pressure absorbing member can absorb the force caused by the expansion, thereby suppressing deformation of the extension member caused by the expansion of the energy storage element.

In the power storage device,
The energy storage element has a rectangular shape,
the elastic portion has a first portion and a second portion disposed on an outer side of the first portion in a direction perpendicular to the first direction,
The first portion may be more elastically deformable than the second portion.

With this configuration, when the energy storage element expands during use, the amount of expansion is greater at the center of the energy storage element. By varying the ease of elastic deformation between the first portion of the pressure absorbing member that overlaps with the center of the energy storage element and the second portion on the outside, when the energy storage element expands, the force can be absorbed by the entire pressure absorbing member.

In the power storage device,
each of the pair of clamping portions is a plate-shaped member extending in a direction perpendicular to the first direction,
The rigidity of each of the pair of clamping portions may be greater than the rigidity of the elastic portion.

With this configuration, even if a force caused by the expansion of the energy storage element or the like is applied to only one part of the clamping portion (plate-shaped member), the clamping portion has sufficient rigidity so that this force is transmitted to the elastic portion in a spread state across the entire clamping portion, allowing the pressure absorbing member to effectively mitigate this force.

In the power storage device,
One of the pair of clamping portions and the other clamping portion may be members having the same shape.

With this configuration, the pair of clamping parts are made of the same shape, which reduces the number of different parts.

In the power storage device,
one of the pair of clamping portions has an abutment portion extending toward the other of the pair of clamping portions,
A gap may be formed between the contact portion and the other clamping portion when the elastic portion is not elastically deformed.

With this configuration, when a force in the first direction is applied to each clamping portion, the contact portion comes into contact with the other clamping portion, preventing the clamping portions from coming closer together and preventing the elastic portion from being crushed too much.

The pressure absorbing member of this embodiment is
A pressure absorbing member that can be placed between adjacent energy storage elements in an energy storage device including a plurality of energy storage elements arranged in a predetermined direction,
A pair of clamping portions arranged at an interval from each other;
an elastic portion disposed between the pair of clamping portions,
the pair of clamping portions are capable of transmitting an external force to the elastic portion in an arrangement direction of the pair of clamping portions,
The elastic portion is characterized in that it is elastically deformable in the arrangement direction.

With this configuration, when the pressure absorbing member is arranged between the energy storage elements so that the arrangement direction of the clamping portions and the stacking direction of the energy storage elements are aligned, the elastic portions of the pressure absorbing member elastically deform when a force is applied to the pair of clamping portions from outside in the first direction. As a result, when the energy storage elements expand, the pressure absorbing member can absorb the force caused by the expansion. As a result, for example, in an energy storage device in which multiple energy storage elements are fixed in a stacked state by extension members, when the pressure absorbing member is arranged with the arrangement direction of the energy storage elements and the arrangement direction of the clamping portions aligned, deformation of the extension member caused by the expansion of the energy storage elements is suppressed.

The energy storage device of this embodiment can provide an energy storage device and a pressure absorbing member that can suppress deformation of the extension member caused by expansion of the energy storage element.

FIG. 1 is a perspective view of an electricity storage device according to one embodiment of the present invention. FIG. 2 is a perspective view of an energy storage element in the energy storage device according to the embodiment. FIG. 3 is a front view of the energy storage element of the energy storage device according to the embodiment. FIG. 4 is an exploded perspective view of the electricity storage device according to the embodiment. FIG. 5 is a perspective view of an inner spacer, an outer spacer, and an energy storage element of the energy storage device according to the embodiment. FIG. 6 is an exploded perspective view of the pressure absorbing member in the electricity storage device according to the embodiment. FIG. 7A is a cross-sectional view and an enlarged view of a main part of the pressure absorbing member in a state in which the elastic portion is not elastically deformed in the power storage device according to the same embodiment. FIG. 7B is a cross-sectional view and an enlarged view of a main part of the pressure absorbing member in a state in which the elastic portion in the power storage device according to the same embodiment is elastically deformed. FIG. 8A is a perspective view of an elastic member in a power storage device according to a modified example. FIG. 8B is a front view of the elastic member of FIG. 8A. 8C is a front view of the elastic member of FIG. 8A with a portion cut away. FIG. 9A is a perspective view of an elastic member in a power storage device according to a modified example. FIG. 9B is a perspective view of an elastic member in a power storage device according to a modified example. FIG. 10 is a perspective view for explaining a conventional electricity storage device.

One embodiment of the present invention will be described below with reference to Figures 1 to 7. 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 FIG. 1, the energy storage device comprises a plurality of energy storage elements 1 arranged in a first direction, a pair of extension members 31 extending in the first direction and sandwiching the plurality of energy storage elements from both sides in a second direction perpendicular to the first direction, a pressure absorbing member 5 at least a portion of which is elastically deformable in the first direction, and at least one spacer (adjacent member) 2 adjacent to the pressure absorbing member 5 in the first direction. In the energy storage device, the pressure absorbing member 5 and the spacer 2 are disposed between adjacent energy storage elements 1. Furthermore, in this energy storage device, the spacer 2 is also adjacent to the energy storage element 1.

The energy storage device further includes a holding member 3 that holds the energy storage element 1, spacer 2, and pressure absorbing member 5 together, and the extension member 31 is part of this holding member 3. The holding member 3 is made of a conductive material. Accordingly, the energy storage device includes an insulator 4 that is disposed between the energy storage element 1 and the holding member 3.

In this embodiment, multiple spacers 2 are provided. Furthermore, in this energy storage device, multiple spacers 2 are aligned in the first direction, and energy storage elements 1 or pressure absorbing members 5 are disposed between the spacers 2.

For convenience, in the following description, each direction will be described using a Cartesian coordinate system including the X-axis, Y-axis, and Z-axis directions. The direction in which the energy storage elements 1 are aligned (first direction) will be referred to as the X-axis direction. Furthermore, of the two axial directions perpendicular to the direction in which the energy storage elements 1 are aligned (X-axis direction), one direction (second direction) will be referred to as the Y-axis direction, and the remaining direction (third direction) will be referred to as the Z-axis direction. Accordingly, each drawing additionally illustrates three orthogonal axes (coordinate axes) corresponding to the X-axis, Y-axis, and Z-axis directions.

As shown in Figures 2 and 3, the energy storage element 1 comprises an electrode assembly including a positive electrode and a negative electrode, a case 10 that houses the electrode assembly, and a pair of external terminals 11 arranged on the outer surface of the case 10. The energy storage element 1 has a rectangular shape.

The case 10 has a case body 100 with an opening, and a cover plate 101 that closes the opening of the case body 100 and has a pair of external terminals 11 arranged on its outer surface.

The case body 100 comprises a closing portion 100a (see Figure 3) and a cylindrical body portion 100b that surrounds the closing portion 100a and is connected to the periphery of the closing portion 100a. In this embodiment, the body portion 100b has a flattened rectangular cylindrical shape.

The body portion 100b has a pair of first walls 100c that face each other with a gap between them, and a pair of second walls 100d that face each other with the pair of first walls 100c in between.

The first wall 100c and the second wall 100d are each formed in a rectangular shape. The body 100b is formed in a rectangular cylindrical shape. One end of the body 100b is closed by the closing portion 100a. In contrast, the other end of the body 100b is open and closed by the cover plate 101.

Each of the multiple energy storage elements 1 is aligned in one direction (see Figure 1). In this embodiment, each of the multiple energy storage elements 1 is aligned with the first wall 100c of the case 10 facing in one direction. The energy storage device includes a bus bar that electrically connects the external terminals 11 of two adjacent energy storage elements 1.

The pressure absorption member 5 can be arranged in an energy storage device that includes multiple energy storage elements 1 aligned in the X-axis direction (a predetermined direction). The pressure absorption member 5 is plate-shaped and extends in a direction perpendicular to the X-axis direction (extending in the Y-axis and Z-axis directions, which are orthogonal to the X-axis direction). The pressure absorption member 5 is also made of an insulating material.

In the energy storage device of this embodiment, as shown in FIG. 6 , the pressure absorbing member 5 has an elastic portion 50 that is elastically deformable in the X-axis direction, and a pair of clamping portions 51 that sandwich the elastic portion 50 from both sides in the X-axis direction and are capable of transmitting an external force in the X-axis direction to the elastic portion 50. In other words, the pressure absorbing member 5 has a pair of clamping portions 51 that are spaced apart from each other, and an elastic portion 50 that is disposed between the pair of clamping portions 51, and the pair of clamping portions 51 are capable of transmitting an external force to the elastic portion 50 in the alignment direction of the pair of clamping portions 51, and the elastic portion 50 is elastically deformable in the X-axis direction (alignment direction).

In addition, in the energy storage device of this embodiment, one pressure absorbing member 5 is disposed (see Figure 1). Furthermore, the pressure absorbing member 5 is disposed in the center of the energy storage device in the X-axis direction. As a result, when an impact load is applied to the energy storage device, the load acting on the pressure absorbing member 5 can be halved compared to when the pressure absorbing member 5 is disposed at the end of the energy storage device in the X-axis direction.

Each of the pair of clamping portions 51 is a plate-shaped member (see Figure 6). Each of the pair of clamping portions 51 extends in the Y-axis direction and the Z-axis direction, which are perpendicular to the X-axis direction. The pair of clamping portions 51 are plate-shaped members spaced apart from each other with the elastic portion 50 sandwiched between them. One clamping portion 52 and the other clamping portion 53 of the pair of clamping portions 51 are members of the same shape. Specifically, the shape of the clamping portion 51 as viewed from the X-axis direction is the same as the shape as viewed from the X-axis direction of the energy storage device 1 (for example, the shape as viewed from the X-axis direction of the case 10), and is specifically rectangular. In this embodiment, one clamping portion 52 is positioned inverted relative to the other clamping portion 53 around the Z-axis direction.

Furthermore, the rigidity of each of the pair of clamping portions 51 is greater than the rigidity of the elastic portion 50. The clamping portions 51 are made of a material such as a resin, such as polypropylene.

The external dimensions of the pressure absorption member 5 are the same as those of the energy storage element 1. In this embodiment, the external diameter of the clamping portion 51 is the same as the external dimensions of the energy storage element 1. This external diameter refers to the external dimension of each component when viewed from the X-axis direction. In this embodiment, the shape of the pressure absorption member 5 is determined by the pair of clamping portions 51, which have high rigidity, so even if the elastic portion 50 elastically deforms in the X-axis direction, the external diameter of the pressure absorption member 5 does not change.

Each clamping portion 51 has a first surface 511 and a second surface 512 located opposite the first surface 511. One clamping portion 52 of the pair of clamping portions 51 has protrusions 514, 516 as abutment portions extending toward the other clamping portion 53 of the pair of clamping portions 51. When the elastic portion 50 is not elastically deformed, a gap (gap in the X-axis direction) is formed between the protrusions 514, 516 and the other clamping portion 53. In this embodiment, each clamping portion 51 has a fixing portion 513 provided on the first surface 511 and fixed to the elastic portion 50, and protrusions 514, 515, 516 that protrude from the first surface 511 toward the elastic portion 50 in the X-axis direction.

The pair of clamping portions 51 are arranged with their first surfaces 511 facing each other. Specifically, the pair of clamping portions 51 are fixed to the elastic portion 50 at fixing portions 513 on the first surfaces 511. In the energy storage device of this embodiment, the pair of clamping portions 51 are fixed to the elastic portion 50 with adhesive at multiple fixing portions 513 (for example, six fixing portions 513 provided in an area excluding the outer periphery of the first surface 511).

In this embodiment, the fixing portions 513 are protrusions that protrude toward the elastic portion 50 in the X-axis direction. Each fixing portion 513 has the same shape and size. Some of the multiple fixing portions 513 are arranged side by side in the Y-axis direction on one side in the Z-axis direction. The remaining fixing portions 513 are arranged side by side in the Y-axis direction on the other side in the Z-axis direction. The fixing portions 513 arranged on one side in the Z-axis direction are arranged at equal intervals in the Y-axis direction. Similarly, the fixing portions 513 arranged on the other side in the Z-axis direction are arranged at equal intervals in the Y-axis direction.

Protrusions 514, 515, and 516 are protrusions that protrude toward the elastic portion 50 in the X-axis direction, and are, for example, ribs. The protrusion amounts in the X-axis direction of protrusions 514 and 516 are all equal and greater than the protrusion amount in the X-axis direction of protrusion 515. In other words, the dimensions in the X-axis direction of protrusions 514 and 516 are equal and smaller than the dimension in the X-axis direction of protrusion 515.

The protrusion 516 extends from one end of the first surface 511 in the Y-axis direction to the other end of the periphery of the clamping portion 51 in the Z-axis direction. As a result, in this embodiment, the protrusions 514 and 516 extend continuously. The protrusion 516, together with the protrusion 515, functions as a positioning member for the elastic portion 50 in the Y-axis direction.

The protrusion 515 extends from the other end of the first surface 511 in the Y-axis direction to the center of the periphery of the clamping portion 51 in the Z-axis direction (the area excluding both ends of the periphery of the clamping portion 51 in the Z-axis direction). The protrusion 516 of one of the pair of clamping portions 51 is positioned so as not to overlap with the other protrusion 515 in the X-axis direction (e.g., farther from the elastic portion 50 in the Y-axis direction than the protrusion 515) when the pair of clamping portions 51 is placed in the power storage device.

The protrusions 514 are located at both ends of the first surface 511 in the Z-axis direction. They extend from one end of the clamping portion 51's periphery in the Y-axis direction to a midpoint in the Y-axis direction (e.g., the center in the Y-axis direction). The protrusions 514 of each clamping portion 51 are positioned so that, when the pressure absorption member 5 is placed in the power storage device, the protrusions 514 of one clamping portion 51 and the protrusions 514 of the other clamping portion 51 do not overlap in the X-axis direction (e.g., the protrusions 514 of one clamping portion 51 are positioned at a position on the periphery of the other clamping portion 51 where no protrusions 514 are provided). The dimensions of the protrusions 514 in the X-axis direction are the same at each position in the Y-axis direction. The protrusions 514 at each end in the Z-axis direction all have the same shape. These protrusions 514 function as positioning members for the elastic portion 50 in the Z-axis direction.

Furthermore, the protrusions 514 and 516 function as stoppers that regulate the distance between the pair of clamping portions 51. The specific configuration of this stopper is described below.

The clamping portion 51 has a first surface 511 that clamps the elastic portion, and a stopper surface 517 that is disposed at a predetermined distance from the first surface 511 on the opposite side of the elastic portion 50 in the X-axis direction. In this embodiment, the stopper surface 517 is the tip surface of the protrusions 514, 516 in the protruding direction (X-axis direction). The stopper surface 517 also extends along the Y-axis direction. Furthermore, when the elastic portion 50 is not elastically deformed, a gap is formed between the stopper surface 517 and the elastic portion 50 in the X-axis direction (see Figure 7A).

Furthermore, when the elastic portion 50 is not elastically deformed, the distance between the pair of clamping portions 51 (specifically, the distance between the first surfaces 511 of the pair of clamping portions 51) is a first distance, and when the elastic portion 50 is elastically deformed, the distance can be changed from the first distance to a second distance (see Figure 7B) that is smaller than the first distance. Specifically, the distance between the pair of clamping portions 51 can be changed until the stopper surface 517 (the tip surface of the protrusions 514, 516 in the X-axis direction) of one clamping portion 52 abuts against the first surface 511 of the other clamping portion 53. Note that the dimension of the protrusions 514, 516 in the X-axis direction is equal to the second distance.

Furthermore, when the pressure absorbing member 5 is incorporated into the electricity storage device, a predetermined pressure is applied to the pressure absorbing member 5 in the X-axis direction, so even in an unused (brand new) electricity storage device, the distance between the pair of clamping portions 51 is smaller than the first distance.

The elastic portion 50 is made of a flexible elastic material such as a coil spring, spring, or rubber. In this embodiment, the elastic portion 50 is, for example, a single rubber plate. The elastic portion 50 extends in the Y-axis direction and Z-axis direction, which are perpendicular to the X-axis direction. The elastic portion 50 is a rectangular plate.

The elastic portion 50 has a first portion 500 and a second portion 501 that is positioned outside the first portion 500 in the Y-axis direction, which is perpendicular to the X-axis direction, and the first portion 500 is more susceptible to elastic deformation than the second portion 501. In other words, the first portion 500, which is the region of the elastic portion 50 that overlaps with the center of the energy storage device 1 (the center in the Y-axis direction and the Z-axis direction) when viewed from the X-axis direction, is more susceptible to elastic deformation than the second portion 501, which is the region located outside the first portion 500.

In this embodiment, the elastic portion 50 is a combination of multiple elastic members made of different materials (see Figure 6). Specifically, the first portion 500 of the elastic portion 50 is made of soft rubber, and the second portion 501 is made of hard rubber. This configuration also makes the first portion 500 more easily deformable than the second portion 501. Note that the entire elastic portion 50 may be a single elastic member made of the same material, for example, a single rubber plate.

In the elastic part 50, the first part 500 is located in the center in the Y-axis direction and extends over the entire area in the Z-axis direction. The second parts 501 are located at both ends in the Y-axis direction and extend over the entire area in the Z-axis direction. This allows the elastic part 50 to accommodate two different stacking loads. That is, the center in the Y-axis direction can accommodate low loads, and both ends in the Y-axis direction can accommodate high loads.

In the elastic portion 50, the first portion 500 may be located at the center in the Z-axis direction and extend over the entire area in the Y-axis direction, and in this case, the second portion 501 may be located at both ends in the Z-axis direction and extend over the entire area in the Y-axis direction. In addition, in the elastic portion 50, the first portion 500 may be located at the center in the Y-axis direction and the center in the Z-axis direction, and the second portion 501 may be arranged in a ring shape surrounding the first portion 500.

The spacer 2 is insulating (see Figures 1 and 4). The spacer 2 has a base adjacent to the case 10 (first wall 100c of the body 100b) of the energy storage element 1, and a restricting portion that prevents the energy storage element 1 adjacent to the base from shifting position.

The spacers 2 will be described in more detail. The energy storage device is equipped with two types of spacers 2 (2A, 2B) (see Figure 4). That is, the energy storage device is equipped with spacers 2 (hereinafter referred to as internal spacers) 2A that are placed between two energy storage elements 1 or between an energy storage element 1 and a pressure absorbing member 5, and spacers (hereinafter referred to as external spacers) 2B that are adjacent to the outermost energy storage element 1 among the multiple energy storage elements 1.

As described above, the energy storage device according to this embodiment includes multiple energy storage elements 1, and therefore internal spacers 2A are disposed between adjacent energy storage elements 1. In other words, the energy storage device includes multiple internal spacers 2A.

First, we will explain the internal spacer 2A placed between two adjacent energy storage elements 1. Note that the internal spacer 2A placed between two adjacent energy storage elements 1 and the internal spacer 2A placed between an adjacent energy storage element 1 and the pressure absorbing member 5 are the same member (same configuration), and the internal spacer 2A placed between two adjacent energy storage elements 1 will be specifically explained below.

As shown in Figure 5, the internal spacer 2A has a base 20A adjacent to the energy storage element 1 (first wall 100c of the case body 100).

The base 20A of the internal spacer 2A is sandwiched between two storage elements 1. Therefore, the base 20A of the internal spacer 2A has a first surface facing one of the two adjacent storage elements 1, and a second surface opposite the first surface facing the other of the two storage elements 1.

The base 20A of the internal spacer 2A has a first end positioned at a position corresponding to the cover plate 101 of the energy storage element 1, and a second end opposite the first end positioned at a position corresponding to the closing portion 100a of the energy storage element 1. The base 20A of the internal spacer 2A also has a third end positioned at a position corresponding to one second wall 100d of the energy storage element 1, and a fourth end opposite the third end positioned at a position corresponding to the other second wall 100d of the energy storage element 1.

The first and second ends of the base 20A of the internal spacer 2A extend in the Y-axis direction. The third and fourth ends of the base 20A of the internal spacer 2A extend in the Z-axis direction. Therefore, the base 20A of the internal spacer 2A is formed in a substantially rectangular shape. The base 20A of the internal spacer 2A is also formed to have a size substantially equal to that of the first wall 100c of the energy storage element 1.

In the energy storage device of this embodiment, a ventilation passage (flow path) for passing a fluid (temperature-regulating fluid) is formed between the first surface of the base 20A of the internal spacer 2A and the energy storage element 1, or between the second surface of the base 20A of the internal spacer 2A and the energy storage element 1. The internal spacer 2A, which is disposed between the energy storage element 1 and the pressure absorbing member 5, forms a flow path through which a fluid can flow between the internal spacer 2A and the pressure absorbing member 5. In this embodiment, the internal spacer 2A disposed between the energy storage element 1 and the pressure absorbing member 5 can be the same component as the internal spacer 2A disposed between the energy storage elements 1, thereby minimizing the increase in the number of component types.

In the energy storage element 1 according to this embodiment, the base 20A of the internal spacer 2A is formed in a rectangular waveform. A more specific explanation follows. The base 20A of the internal spacer 2A has a plurality of first abutment portions 200A that abut only one of two adjacent energy storage elements 1, a plurality of second abutment portions 201A that abut only the other of the two adjacent energy storage elements 1, and a plurality of connecting portions 202A that connect the first abutment portions 200A and the second abutment portions 201A.

Each first abutment portion 200A and each second abutment portion 201A are arranged alternately in the Z-axis direction, and one end of the first abutment portion 200A in the Z-axis direction is connected to the other end of the second abutment portion 201A in the Z-axis direction by a connecting portion 202A. As a result, in the energy storage device, ventilation paths are formed between the first surface of the base 20A of the internal spacer 2A and the energy storage element 1, and between the second surface of the base 20A of the internal spacer 2A and the energy storage element 1.

Next, we will explain the external spacer 2B. The external spacer 2B has a base (hereinafter referred to as the base) 20B that has a first surface facing the energy storage element 1 (first wall 100c of the case body 100) and a second surface opposite the first surface.

Furthermore, in this embodiment, the external spacer 2B faces the base 20B and the terminal member 30 (described later) of the holding member 3. In other words, the external spacer 2B is positioned between the energy storage device 1 and the terminal member 30.

The base 20B of the outer spacer 2B extends in the Y-axis direction and Z-axis direction, which are perpendicular to the X-axis direction. In other words, the base 20B is formed in a plate shape.

A ventilation passage is formed on the first surface of the base 20B of the external spacer 2B to allow fluid to pass between the first surface of the base 20B and the energy storage element 1.

As described above, the external spacer 2B in this embodiment is arranged adjacent to the internal spacer via the energy storage element 1. That is, the energy storage device is provided with a pair of external spacers 2B. The external spacer 2B is adjacent to the energy storage element 1 located at the farthest end of the multiple energy storage elements 1. That is, a pair of external spacers 2B are provided to sandwich the aligned multiple energy storage elements 1.

In this embodiment, the retaining member 3 is made of metal. As shown in FIG. 4, the retaining member 3 includes a pair of end members 30 arranged adjacent to each outer spacer 2B, and a pair of extension members 31 connecting the pair of end members 30.

Each of the pair of end members 30 has a first surface facing the outer spacer 2B and a second surface opposite the first surface. Each of the pair of end members 30 has a pressure contact portion 300 that abuts against the outer spacer 2B.

The end member 30 is made of metal. When viewed from the X-axis direction, the end member 30 has a shape corresponding to that of the energy storage element 1.

Each extension member 31 has connecting portions 310, 311 extending between a pair of end members 30. Each extension member 31 also has a fixing portion 313 that connects to the end member 30.

The connection portions 310, 311 are arranged at varying intervals in the Z-axis direction. Each of the connection portions 310, 311 has a first end in the longitudinal direction and a second end opposite the first end.

Furthermore, each of the first connection portions 310, 311 is bent along the longitudinal direction. One of the portions of each of the first connection portions 310, 311, separated by the bent portion, is positioned in a position corresponding to the cover plate 101 of the energy storage element 1. The other of the first connection portions 310, 311, separated by the bent portion, is positioned in a position corresponding to the second wall 100d of the energy storage element 1.

The fixed portion 313 has connecting portions 313a and 313b that connect the ends of the connecting portions 310 and 311, which are spaced apart in the Z-axis direction. The connecting portions 313a and 313b are also connected to the end member 30.

The insulators 4 have a shape that corresponds to each extension member 31. The insulators 4 are also positioned between each extension member 31 and multiple energy storage elements 1 to insulate them from each other.

In the above-described energy storage device, the pressure absorption member disposed between adjacent energy storage elements 1 elastically deforms when a force is applied from the outside in the X-axis direction. Therefore, when the energy storage elements 1 expand, the pressure absorption member 5 can absorb the force caused by the expansion. This suppresses deformation of the extension member 31 caused by the expansion of the energy storage elements 1.

Specifically, in this energy storage device, a pressure absorbing member 5 composed of a pair of clamping portions 51 and an elastic portion 50 sandwiched between them is disposed between adjacent energy storage elements 1. When a force is applied to the pair of clamping portions 51 from outside in the X-axis direction, the elastic portions 50 of the pressure absorbing member 5 elastically deform. Therefore, when the energy storage element 1 expands, the pressure absorbing member 5 can absorb the force caused by the expansion. This suppresses deformation of the extension member 31 caused by the expansion of the energy storage element 1. In particular, deformation of the portion of the extension member 31 adjacent to the elastic portions 50 is suppressed.

Furthermore, with the above-described pressure absorbing member 5, when the pressure absorbing member 5 is arranged between the energy storage elements 1 so that the arrangement direction (X-axis direction) of the clamping portions 51 coincides with the stacking direction of the energy storage elements 1, the elastic portions 50 elastically deform when a force is applied to the pair of clamping portions 51 from the outside in the X-axis direction. Therefore, when the energy storage elements 1 expand, the pressure absorbing member 5 can absorb the force caused by the expansion. As a result, for example, in an energy storage device in which multiple energy storage elements 1 are fixed in a stacked state by extension members 31, when the pressure absorbing member 5 is arranged with the arrangement direction of the energy storage elements 1 coincident with the arrangement direction of the clamping portions 51, deformation of the extension members 31 caused by the expansion of the energy storage elements 1 is suppressed.

In addition, in the energy storage device of this embodiment, the external dimensions of the pressure absorption member 5 are the same as those of the energy storage element 1, so the pressure absorption member 5 can be placed in the energy storage device where the energy storage element 1 can be placed; that is, it can be placed in place of the energy storage element. Furthermore, because the pressure absorption member 5 has such a size, it can be replaced with any of the energy storage elements 1 currently held by the extension member 31, making it possible to achieve a configuration that can absorb the expansion of the energy storage element 1 without changing the design of the energy storage device. In other words, without providing a separate structure to absorb the expansion of the energy storage element 1, i.e., without changing the design of the energy storage device, simply by replacing the energy storage element 1 with the pressure absorption member 5, it is possible to absorb the increase in pressure in the X-axis direction caused by expansion of the energy storage element 1 due to aging or other factors.

Furthermore, in the energy storage device of this embodiment, when the energy storage element 1 expands during use, the amount of expansion is greater at the center of the energy storage element 1. Therefore, in the elastic portion 50, the thickness of the first portion 500 is made smaller than the thickness of the second portion 501, and by changing the ease of elastic deformation between the first portion of the pressure absorbing member 5 that overlaps with the center of the energy storage element 1 and the outer second portion, when the energy storage element 1 expands, the force can be absorbed by the entire pressure absorbing member 5.

In the energy storage device of this embodiment, even if a force due to expansion of the energy storage element 1 or the like is applied to part of the clamping portion 51 (plate-shaped member) of the pressure absorbing member 5, the plate-shaped clamping portion 51 has sufficient rigidity (the rigidity of the clamping portion 51 is greater than the rigidity of the elastic portion 50), so this force is transmitted to the elastic portion 50 in a state where it is spread across the entire clamping portion 51, and the pressure absorbing member 5 can effectively mitigate this force.

Furthermore, in the energy storage device of this embodiment, the pair of clamping portions 51 are members of the same shape, which reduces the number of different parts.

Furthermore, in the energy storage device of this embodiment, when a force in the X-axis direction is applied to each clamping portion 51, the contact portion of one clamping portion 52 comes into contact with the other clamping portion 53, preventing the clamping portions 51 from getting closer to each other, thereby preventing the elastic portion 50 from being crushed too much.

The energy storage device according to the present invention is not limited to the above embodiment, and various modifications can of course be made without departing from the spirit of the present invention.

For example, while the power storage device was previously equipped with one pressure absorbing member 5, it may instead be equipped with multiple pressure absorbing members 5. Also, while the pressure absorbing member 5 was previously positioned at the center of the power storage device in the X-axis direction, it may instead be positioned elsewhere.

Furthermore, although the external dimensions of the pressure absorption member 5 were the same as those of the energy storage element 1, it does not have to be the same as the external dimensions of the energy storage element 1 as long as it fits within the extension member 31.

In the above embodiment, the power storage device was equipped with a pressure absorbing member 5, but instead of the pressure absorbing member 5, it may be equipped with an elastic member 6 that is elastically deformable in the X-axis direction. Below, we will explain modified shapes of such elastic members 6.

For example, as shown in Figures 8A and 8B, the elastic member 6 may be formed so that a portion thereof can be cut off. Specifically, the elastic member 6 may have a cut line 60. In this case, as shown in Figure 8C, a portion of the elastic member 6 (for example, the center portion aligned with the central portion of the energy storage element 1 that is prone to bulge) may be cut off before being incorporated into the energy storage device. The cut lines 60 may be, for example, multiple, arranged in a roughly concentric pattern with the center of the elastic member 6 as the center point. The cut lines 60 may be, for example, a slit that is partially connected in the circumferential direction, but may also be, for example, a half-cut.

The external dimensions of the elastic member 6 may be the same as those of the energy storage element 1. In this case, the elastic member 6 can be placed in a location in the energy storage device where the energy storage element 1 can be placed, i.e., it can be placed in place of the energy storage element 1. Furthermore, the energy storage element 1 may have a rectangular shape.

Also, as shown in Figures 9A and 9B, the elastic member 6 has a first portion 61 and a second portion 62 arranged outside the first portion 61 in a direction perpendicular to the X-axis direction, and the first portion 61 may be more elastically deformable than the second portion 62. For example, the elastic member 6 may have, in a portion (e.g., the first portion 61), a through-hole 63 penetrating in the X-axis direction or a recess 64 recessed toward the outside of the power storage device in the X-axis direction.

In this configuration, the elastic member 6 is provided with through holes 63 and recesses 64, which adjusts the ease of elastic deformation in the X-axis direction between the portion where the through holes 63 and recesses 64 are provided (e.g., the first portion 61) and other portions (e.g., the second portion 62). Therefore, when the energy storage element 1 expands, the elastic member 6 can effectively absorb the force caused by the expansion, thereby suppressing deformation of the extension member 31 caused by the expansion of the energy storage element 1.

In the above embodiment, the base 20A of the internal spacer 2A is generally rectangular and is approximately the same size as the first wall 100c of the energy storage element 1. However, the base 20A of the internal spacer 2A is not limited to being generally rectangular, nor is it limited to being approximately the same size as the first wall 100c of the energy storage element 1, as long as it can accommodate the orientations of two adjacent energy storage elements 1.

In the above embodiment, the internal spacer 2A was placed between the pressure absorption member 5 and the energy storage element 1, but it does not need to be placed between the pressure absorption member 5 and the energy storage element 1 if the surface of the pressure absorption member 5 is made of an insulating material such as resin or rubber.

1... Energy storage element, 2... Spacer (adjacent member), 2A... Internal spacer, 2B... External spacer, 3... Holding member, 4... Insulator, 5... Pressure absorbing member, 6... Elastic member, 10... Case, 11... External terminal, 20A, 20B... Base, 21... Case, 30... End member, 31... Extension member, 50... Elastic portion, 51, 52, 53... Clamping portion, 60... Cut line, 61... First portion, 62... Second portion, 63... Through hole, 64... Recess, 100... Case body, 100a... Closure portion, 100 b...body portion, 100c...first wall, 100d...second wall, 101...cover plate, 101a...gas exhaust valve, 102...battery cell, 140...end plate, 143...connecting bar, 200A...first abutment portion, 201A...second abutment portion, 202A...connecting portion, 310, 311...connecting portion, 313...fixing portion, 313a, 313b...connecting portion, 500...first portion, 501...second portion, 511...first surface, 512...second surface, 513...fixing portion, 514, 515, 516...protruding portion, 517...stopper surface

Claims (6)

A plurality of storage elements arranged in a first direction;
a pair of extension members extending in the first direction and sandwiching the plurality of energy storage elements from both sides in a second direction perpendicular to the first direction;
a pressure absorbing member at least a portion of which is elastically deformable in the first direction;
an adjacent member adjacent to the pressure absorbing member in the first direction,
the pressure absorbing member and the adjacent member are disposed between adjacent energy storage elements,
The electricity storage device , wherein the adjacent member forms a flow path between the adjacent member and the pressure absorbing member, through which a fluid can flow . 2. The electricity storage device according to claim 1 , wherein the pressure absorbing member has the same outer dimensions as the electricity storage element. A plurality of storage elements arranged in a first direction;
a pair of extension members extending in the first direction and sandwiching the plurality of energy storage elements from both sides in a second direction perpendicular to the first direction;
a pressure absorbing member at least a portion of which is elastically deformable in the first direction;
an adjacent member adjacent to the pressure absorbing member in the first direction,
the pressure absorbing member and the adjacent member are disposed between adjacent energy storage elements,
the pressure absorbing member has an elastic portion that is elastically deformable in the first direction, and a pair of clamping portions that sandwich the elastic portion from both sides in the first direction and are capable of transmitting a force applied from the outside to the elastic portion in the first direction,
The energy storage element has a rectangular shape,
the elastic portion has a first portion and a second portion disposed on an outer side of the first portion in a direction perpendicular to the first direction,
The power storage device, wherein the first portion is more easily elastically deformable than the second portion. each of the pair of clamping portions is a plate-shaped member extending in a direction perpendicular to the first direction,
The power storage device according to claim 3 , wherein the rigidity of each of the pair of clamping portions is greater than the rigidity of the elastic portion. 5. The power storage device according to claim 3 , wherein one clamping portion and the other clamping portion of the pair of clamping portions are members having the same shape. one of the pair of clamping portions has an abutment portion extending toward the other of the pair of clamping portions,
The power storage device according to any one of claims 3 to 5 , wherein a gap is formed between the contact portion and the other clamping portion when the elastic portion is not elastically deformed.