Power storage device

Abstract

To provide a power storage device that can suppress a decrease in insulation between a bipolar electrode and a restraint plate.SOLUTION: A power storage device includes a restraining plate that sandwiches and restrains a laminate, a pair of current collector plates, and a pair of insulating plates from a first direction, and a terminal block provided on the side surface of the restraining plate extending in the first direction and a third direction intersecting both the first direction and the second direction and to which a terminal bolt fixed, and the restraining plate has a pair of protruding portions that protrude in the second direction from the side surface to which the terminal block is fixed when viewed from the first direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Patent Document 1 discloses an electricity storage device that includes a plurality of stacked batteries, a restraining member that sandwiches the plurality of batteries, and an insulating spacer that electrically insulates the plurality of batteries from the restraining member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 026966 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a configuration in which stacked bipolar electrodes are constrained in the stacking direction by constraining plates, an insulating member may be disposed between the bipolar electrodes and the constraining plates to electrically insulate them. In such a configuration, if an external force is applied to the energy storage device in a direction intersecting the stacking direction of the bipolar electrodes, for example, and the insulating member is damaged, it is conceivable that the insulation between the bipolar electrodes and the constraining plates will be reduced.

[0005] The present disclosure provides an electricity storage device that can suppress damage to an insulating plate between a bipolar electrode and a restraint plate. [Means for solving the problem]

[0006] The energy storage device of the present disclosure includes a stack having an energy storage module in which electrodes including a plurality of bipolar electrodes are stacked along a first direction; a pair of current collector plates stacked on both ends of the stack in the first direction; a pair of insulating plates sandwiching the stack and the pair of current collector plates from the first direction; a restraining plate sandwiching and restraining the stack, the pair of current collector plates, and the pair of insulating plates from the first direction; and a terminal block provided on a first side surface of the restraining plate extending in the first direction and in a third direction intersecting both the first and second directions and to which a terminal bolt electrically connected to a terminal of at least one of the current collector plates is fixed, the terminal bolt protruding in a second direction intersecting the first direction; the restraining plate has a pair of protrusions that, when viewed from the first direction, protrude in the second direction beyond the first side surface to which the terminal block is fixed; the terminal block is disposed between the pair of protrusions when viewed from the first direction; the insulating plate includes a terminal block protective portion that covers at least a portion of the terminal block; and the pair of protrusions protrude beyond the terminal block protective portion in the second direction.

[0007] In the above-described energy storage device, a pair of insulating plates are sandwiched between restraining plates in a first direction. In the second direction, the protruding portions formed on the restraining plates protrude further than the terminal block protection portion in the second direction, and the terminal block protection portion covers the terminal block disposed between the pair of protruding portions. With this configuration, an external force applied to the energy storage device in the second or third direction is likely to act on the pair of protruding portions. For example, if the energy storage device moves relatively in the second direction and comes into contact with a wall surface or the like, only the protruding portion protruding in the second direction comes into contact with the wall surface or the like. In this case, damage to the terminal block protection portion of the insulating plate located between the pair of protruding portions is suppressed. In this way, damage to the insulating plate is suppressed in the above-described energy storage device.

[0008] In one example, the insulating plate may have a peripheral wall that stands along the first direction, and the peripheral wall may have a first wall portion that stands in a direction away from the adjacent restraint plate along the first direction in a range where the protruding portion is formed in the third direction, and a second wall portion that stands in a direction opposite to the first wall portion along the first direction in a range between the pair of protruding portions in the third direction. With this configuration, liquid is prevented from accumulating inside the peripheral wall formed on the insulating plate.

[0009] In one example, the first wall portion has a first side wall that is aligned with the third direction when viewed from the first direction, and the pair of protruding portions may protrude further in the second direction than the first side wall. In this configuration, for example, when the power storage device moves relatively in the second direction and comes into contact with a wall surface or the like, only the protruding portions that protrude in the second direction come into contact with the wall surface or the like. In this case, damage to the first side wall that is recessed in the second direction more than the protruding portions is suppressed.

[0010] In one example, the second wall portion has a second side wall that covers the first side surface along the third direction when viewed from the first direction, and the first side wall may protrude further than the second side wall in the second direction. In this configuration, the insulation distance between the current collecting plate and the restraint plate can be increased by the length of the peripheral wall.

[0011] In one example, the second wall portion has a third side wall that extends along the second direction when viewed from the first direction so as to cover the second side surface of the protruding portion that extends along the second direction, and the second side wall and the third side wall may be continuous with each other and cover the first side surface and second side surface of the restraint plate. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide an electricity storage device that can suppress deterioration of the insulation between the bipolar electrode and the restraint plate. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of an example of a power storage device. [Figure 2] FIG. 2 is an exploded perspective view showing the configuration of one end portion in the Y-axis direction of an example of a power storage device. [Figure 3] FIG. 2 is a perspective view showing an example of a power storage device with a terminal cover attached; [Figure 4] FIG. 2 is a perspective view showing the vicinity of a terminal block in an example of a power storage device. [Figure 5] 10 is a diagram illustrating a configuration of an end portion on the other side in the Y-axis direction in the example power storage device. FIG. [Figure 6] 10 is a diagram illustrating a configuration of an end portion on the other side in the Y-axis direction in the example power storage device. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. The drawings show an orthogonal coordinate system having an X-axis direction, a Y-axis direction, and a Z-axis direction. Hereinafter, the Z-axis direction may be referred to as the up-down direction. Furthermore, one side and the other side of the X-axis direction, the Y-axis direction, and the Z-axis direction may be referred to as the positive side and the negative side, depending on the orientation of each coordinate axis.

[0015] FIG. 1 is a schematic diagram of an example of a power storage device. FIG. 2 is an exploded perspective view showing the configuration of an end portion of the example of the power storage device in the Y-axis direction. The power storage device 1 is used as a battery for various vehicles, such as a forklift, a hybrid vehicle, or an electric vehicle. The example of the power storage device 1 includes a stack 2 including a plurality of stacked bipolar electrodes, current collecting plates 5A and 5B, insulating plates 20A and 20B, restraint plates 8A and 8B, and a terminal block 70. For convenience, the Z-axis direction is defined as the stacking direction of the electrodes including the bipolar electrodes, the Y-axis direction is defined as the longitudinal direction of the power storage module 3 as viewed from the stacking direction, and the X-axis direction is defined as the lateral direction of the power storage module 3, which is substantially perpendicular to the stacking direction. In this embodiment, the Z-axis direction coincides with the vertical direction, with the positive side of the Z-axis direction coinciding with the upper vertical direction and the negative side of the Z-axis direction coinciding with the lower vertical direction.

[0016] The stack 2 in one example includes a plurality of (seven in this embodiment) power storage modules 3 and a plurality of (six in this embodiment) conductive plates 5C. The power storage modules 3 are configured by stacking a plurality of electrodes including bipolar electrodes. The stack 2 is configured by alternately stacking power storage modules 3 and conductive plates 5C. Note that the stack 2 may have only one power storage module 3, in which case the conductive plate 5C is not included. The power storage module 3 is, for example, a secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery. However, the power storage device 1 is not limited to the above-mentioned secondary battery and may be, for example, an electric double layer capacitor. In this embodiment, the power storage device 1 is a nickel-metal hydride secondary battery.

[0017] The bipolar electrodes of the energy storage module 3 have a positive electrode (positive electrode active material layer) formed on a first surface (e.g., the lower surface) that is one surface of the electrode plate, and a negative electrode (negative electrode active material layer) formed on a second surface (e.g., the upper surface) that is the other surface. The energy storage module 3 includes an electrode stack 13 configured by alternately stacking a plurality of bipolar electrodes and separators (see FIG. 2). In addition, a frame-shaped sealing member 14 (sealing portion) made of insulating resin is provided on the side surface of the electrode stack 13. In other words, the side surface of the electrode stack 13 is sealed with the sealing member 14. Inside the electrode stack 13, an electrolytic solution (electrolyte) is sealed in a space defined by the sealing member 14 and electrodes adjacent in the Z-axis direction.

[0018] The energy storage module 3 includes a positive terminal electrode and a negative terminal electrode, each having a current extraction surface 13a on the positive side and the negative side at both ends in the Z-axis direction. The current extraction surface 13a is a surface from which current is extracted from the energy storage module 3, and is formed by exposing the electrodes of the electrode stack 13 from the sealing member 14. That is, the positive terminal electrode has an electrode plate and a positive electrode provided on a first surface of the electrode plate, and the current extraction surface 13a is formed by the second surface of the electrode plate being exposed from the sealing member 14. The negative terminal electrode has an electrode plate and a negative electrode provided on a second surface of the electrode plate, and the current extraction surface 13a is formed by the first surface of the electrode plate being exposed from the sealing member 14.

[0019] The multiple energy storage modules 3 are stacked in the Z-axis direction via conductive plates 5C. The energy storage modules 3 adjacent to each other in the Z-axis direction are electrically connected to each other via the conductive plates 5C. In other words, the stack 2 is formed by alternately stacking energy storage modules 3 and conductive plates 5C. Between the energy storage modules 3 adjacent to each other in the Z-axis direction, the conductive plates 5C are formed in the shape of rectangular plates and are arranged in contact with each other between the current extraction surfaces 13a of the electrode stacks 13 facing each other.

[0020] As shown in FIG. 1 , current collector plates 5A and 5B are stacked at one end and the other end of stack 2 in the Z-axis direction (first direction), which is also the stacking direction of stack 2. That is, the pair of current collector plates 5A and 5B are arranged at positions sandwiching stack 2 in the Z-axis direction, which is the stacking direction. One example of current collector plate 5A has a rectangular plate-shaped main body 15 that is in contact with a negative-side current extraction surface 13a of electrode stack 13 of power storage module 3 located at one end of stack 2, and a negative electrode terminal 7 (terminal) that protrudes in the Y-axis direction from an outer edge 15a of main body 15 as a base end. For example, negative electrode terminal 7 is plate-shaped and formed integrally with main body 15.

[0021] The current collector plate 5B has the same shape as the current collector plate 5A. That is, the current collector plate 5B has a rectangular plate-shaped main body 15 that is in contact with the positive-side current extraction surface 13a of the electrode stack 13 of the power storage module 3 located at the other end of the stack 2, and a positive terminal 6 (terminal) that protrudes in the Y-axis direction from the outer edge 15a of the main body 15 as a base end. Charging and discharging of the power storage device 1 is performed via the negative terminal 7 and the positive terminal 6. Note that, in one example, the negative terminal 7 is provided closer to the positive side in the X-axis direction, and the positive terminal 6 is provided closer to the negative side in the X-axis direction. In the following description, the current collector plates 5A and 5B may be referred to as current collector plates 5.

[0022] The restraint plate 8 restrains the stack 2 and the current collector plates 5A, 5B in the Z-axis direction. The restraint plate 8 is a substantially rectangular metal plate having an area slightly larger than the area of ​​the energy storage module 3 when viewed from the Z-axis direction. The restraint plate 8 has a main body portion 11 that overlaps the stack 2 when viewed from the Z-axis direction, and an edge portion 10 that extends from the main body portion 11 in the X-axis direction but does not overlap the stack 2 when viewed from the Z-axis direction. In this embodiment, the pair of edge portions 10 are provided on both sides of the main body portion 11 in the X-axis direction. In other words, the main body portion 11 is sandwiched between the pair of edge portions 10.

[0023] The edge portion 10 has an inner surface 10b facing inward in the Z-axis direction and an outer surface 10a facing outward in the Z-axis direction. The main body portion 11 has an inner surface 11b facing inward in the Z-axis direction (toward the energy storage module 3 in the Z-axis direction) and an outer surface 11a, which is the surface opposite the inner surface 11b, facing outward in the Z-axis direction (opposite the energy storage module 3 in the Z-axis direction). The outer surface 10a extends from the edge of the outer surface 11a toward the outside in the X-axis direction, slanting inward in the Z-axis direction. The inner surface 10b is located more inward in the Z-axis direction than the inner surface 11b.

[0024] The pair of edge portions 10 are outer edge portions extending in the longitudinal direction (Y-axis direction) of the restraint plate 8. The pair of edge portions 10 are arranged so as not to overlap with the stack 2 when viewed in the Z-axis direction. Each edge portion 10 is provided with a plurality of insertion holes 10c through which the bolts 9a are inserted. As shown in FIG. 2 , one example of the insertion holes 10c is provided in a notched portion in which the outer surface 10a is formed along the XY plane. In each edge portion 10, the plurality of insertion holes 10c are arranged so as to be spaced apart from one another along the longitudinal direction (Y-axis direction) of the restraint plate 8. In this embodiment, the plurality of insertion holes 10c are arranged at equal intervals from one end of the edge portion 10 to the other end in the longitudinal direction of the restraint plate 8. In the illustrated example, a protrusion 10d that protrudes inward in the Z-axis direction is formed at the outer edge of the edge portion 10 in the X-axis direction. The plurality of insertion holes 10c penetrate the protrusion 10d.

[0025] The head of the bolt 9a is disposed on the outer surface 10a of the restraint plate 8A. The tip (thread tip) of the shaft of the bolt 9a protrudes from the outer surface 10a of the restraint plate 8B. A nut 9b is threaded onto the tip of the bolt 9a. The nut 9b is disposed on the outer surface 10a of the restraint plate 8B. In this way, the multiple energy storage modules 3, the multiple conductive plates 5C, and the current collector plates 5A, 5B are sandwiched between the restraint plates 8A, 8B. In addition, a restraint load in the Z-axis direction is applied to the stack 2.

[0026] The constraining plate 8 also has a protruding portion 18. The protruding portion 18 is a portion that protrudes in the Y-axis direction beyond the side surface 8a (first side surface) of the main body portion 11. That is, the protruding portion 18 protrudes outward along the Y-axis direction when viewed from the Z-axis direction. The side surface 8a extends along the X-axis direction (third direction) and the Z-axis direction on the main body portion 11 of the constraining plate 8, and is a surface on which a terminal block 70 can be installed, as described below. In one example, the protruding portion 18 is formed at both ends of the side surface 8a of the main body portion 11 in the X-axis direction, at a position that includes the range in which the edge portion 10 is formed. In the illustrated example, the protruding portion 18 is formed from both end edges of the constraining plate 8 in the X-axis direction to a position beyond the edge portion 10. The pair of protruding portions 18 have side surfaces 8b (second side surfaces) that face each other in the X-axis direction. The pair of protruding portions 18 also have side surfaces 8c (third side surfaces) that are parallel to the side surface 8a. The side surfaces 8c are end surfaces in the Y-axis direction.

[0027] Insulating plates 20A and 20B provide electrical insulation between constraining plate 8 and current collecting plates 5A and 5B. Insulating plate 20A is provided between current collecting plate 5A and constraining plate 8A. Insulating plate 20A is a member for ensuring insulation between current collecting plate 5A and constraining plate 8A, and is formed, for example, from an insulating resin. Insulating plate 20B is provided between current collecting plate 5B and constraining plate 8B. Insulating plate 20B is a member for ensuring insulation between current collecting plate 5B and constraining plate 8B, and is formed, for example, from an insulating resin.

[0028] The terminal block 70 is provided on the side surface 8a, which is the terminal block installation surface, of the restraint plate 8. The terminal block 70 is disposed between the pair of protrusions 18 when viewed from the Z-axis direction. In the exemplary energy storage device 1, a terminal block 70 is similarly provided on each of the restraint plates 8A and 8B. The negative electrode terminal 7 of the current collector plate 5A is fixed to the terminal block 70 provided on the restraint plate 8A. The positive electrode terminal 6 of the current collector plate 5B is fixed to the terminal block 70 provided on the restraint plate 8B. The exemplary terminal block 70 has a substantially rectangular parallelepiped pedestal portion 71 whose longitudinal direction is in the X-axis direction. The pedestal portion 71 is formed, for example, from an insulating resin. In the illustrated exemplary embodiment, the size of the pedestal portion 71 along the Y-axis direction at both end portions in the X-axis direction is smaller than the size along the Y-axis direction at the central portion in the X-axis direction. That is, base portion 71 includes a central portion 72 that protrudes in the Y-axis direction from the center in the X-axis direction, and a pair of end portions 73, 75 that are recessed in the Y-axis direction at both ends in the X-axis direction relative to central portion 72. Central portion 72 of base portion 71 is provided with terminal bolt 32 that protrudes in the Z-axis direction.

[0029] Base portion 71 of terminal block 70 is fixed to side surface 8a of restraint plate 8 with fixing bolt 19. In one example, a pair of ends 73, 75 constituting base portion 71 are each formed with a through hole that passes through terminal block 70 in the Y-axis direction. Base portion 71 is fixed to side surface 8a by fastening fixing bolt 19 inserted into the through hole to side surface 8a of restraint plate 8A. Base portion 71 protrudes at least further toward the negative side in the Y-axis direction than energy storage module 3.

[0030] FIG. 3 is a perspective view showing an example of a power storage device with a terminal cover attached. While FIG. 3 shows the terminal cover 100 attached to the terminal block 70 on the negative terminal 7 side, a similar terminal cover 100 may be attached to the terminal block 70 on the positive terminal 6 side. As shown in FIG. 3, the terminal cover 100 that covers the negative terminal 7 and the terminal bolt 32 may be attached to the terminal block 70 of the power storage device 1. The wiring 36 connected to the terminal bolt 32 is held by the terminal cover 100 so as to be aligned along the Y-axis direction, which is the axial direction of the terminal bolt 32. In one example, the terminal cover 100 may have an opening 128 for guiding the wiring 36 connected to the terminal bolt 32 to the outside. Note that holding the wiring 36 along the Y-axis direction only requires that the wiring 36 be held in a state where it intersects the XZ plane, and the extension direction of the wiring 36 does not necessarily have to be completely aligned with the Y-axis direction.

[0031] An example of the terminal cover 100 is made of resin. For example, the resin constituting the terminal cover 100 may be resistant to the electrolyte of the power storage module 3. For example, when the power storage module 3 is a nickel-metal hydride secondary battery, examples of the resin material include polyethylene and polypropylene.

[0032] The terminal cover 100 is attached to the terminal block 70 disposed between the pair of protruding portions 18 when viewed from the Z-axis direction. Because the terminal cover 100 covers the terminal block 70, the terminal block 70 is not depicted in FIG. 3 . The terminal cover 100 may be disposed between the pair of protruding portions 18, biased toward one of the protruding portions 18. In one example, the negative terminal 7 is disposed closer to the positive side in the X-axis direction, and therefore the terminal cover 100 attached to the negative terminal 7 is disposed close to the protruding portion 18 disposed on the positive side in the X-axis direction. For example, the distance between the terminal cover 100 and the protruding portion 18 may be smaller than the diameter of the wiring 36. Furthermore, the terminal cover 100 and the protruding portion 18 may be in contact with each other.

[0033] Fig. 4 is a diagram for explaining the structure of the vicinity of the terminal block in an example of a power storage device. Fig. 4 shows the vicinity of the terminal block on the positive electrode side of the power storage device 1. Fig. 4 shows a state in which the terminal cover 100 is removed from the power storage device 1. Note that in the example of the power storage device 1, the vicinity of the negative electrode terminal also has a similar structure.

[0034] As shown in FIG. 4 , the positive electrode terminal 6 has a first piece 41, a second piece 42, and a bent portion 47, and is configured to be substantially L-shaped when viewed in the X-axis direction. The first piece 41 is a plate-like portion that extends in the Y-axis direction from an outer edge portion 15a, which is the edge of the main body 15, when viewed in the Z-axis direction. The second piece 42 is a plate-like portion that bends from the tip of the first piece 41 toward the terminal block 70 (the positive side in the Z-axis direction) along the stacking direction and is attached to the terminal block 70. A through-hole 43 that penetrates in the Y-axis direction is formed at approximately the center of the second piece 42. A terminal bolt 32 is inserted into the through-hole 43.

[0035] The terminal bolt 32 protrudes in the Y-axis direction from the end face of the central portion 72 of the base portion 71 (see FIG. 2). The tip of the terminal bolt 32 in the Y-axis direction may be located, for example, on the negative side of the Y-axis direction relative to the side surface 8c of the protruding portion 18. The terminal bolt 32 extends parallel to the Y-axis direction toward the negative side of the Y-axis direction. The second piece 42 of the positive terminal 6 and a connection terminal connected to the wiring 36 are attached to the terminal bolt 32 by being pressed by a nut (not shown) fastened to the terminal bolt 32.

[0036] The first piece 41 and the second piece 42 both extend parallel to the X-axis direction and have the same size in the X-axis direction. The bent portion 47 is a portion that connects the first piece 41 and the second piece 42, and is formed by bending the plate material that constitutes the positive electrode terminal 6.

[0037] The positive electrode terminal 6 is formed with a spring portion 50 that relieves stress acting on the positive electrode terminal 6. This spring portion 50 can relieve stress acting on the positive electrode terminal 6 attached to the terminal bolt 32. An example of the spring portion 50 includes a bent portion 51, an extending portion 53, and a bent portion 52. The bent portion 51 is formed at the end of the positive electrode terminal 6 on the positive side in the Y-axis direction, in a region where the outer edge portion 15a and the positive electrode terminal 6 are connected, and is a portion that bends the first piece 41 toward the terminal block 70 in the Z-axis direction. The extending portion 53 is a portion that extends from the bent portion 51 along the Y-axis direction. The bent portion 52 is a portion that bends the first piece 41 from the end of the extending portion 53 on the negative side in the Y-axis direction to the side opposite the bent portion 51.

[0038] The insulating plate 20 has a main body 21 and a wall portion 24 (peripheral wall). The main body 21 of the insulating plate 20 is a flat plate-like portion disposed between the main body 15 of the current collector plate 5 and the main body 11 of the restraint plate 8. The main body 21 has a substantially rectangular shape with its longitudinal direction aligned in the Y-axis direction.

[0039] The wall portion 24 rises from the periphery of the insulating plate 20 toward the positive or negative side in the Y-axis direction. For example, the wall portion 24 includes a first wall portion 24A and a second wall portion 24B. The first wall portion 24A is formed in the range in the X-axis direction where the protruding portion 18 is formed. The first wall portion 24A rises in a direction away from the adjacent restraint plate 8 along the Z-axis direction. That is, the first wall portion 24A rises toward the positive side in the Z-axis direction. The second wall portion 24B is formed in the range between the pair of protruding portions 18 in the X-axis direction. The second wall portion 24B rises in a direction along the side surface 8a of the adjacent restraint plate 8. That is, the second wall portion 24B rises toward the negative side in the Z-axis direction.

[0040] The first wall portion 24A includes a sidewall 25a (first sidewall) extending along the X-axis direction when viewed from the Z-axis direction, and a sidewall 25b extending along the Y-axis direction. The sidewall 25a and the sidewall 25b are connected to each other at a corner of the main body portion 21. The sidewall 25a and the sidewall 25b may have the same height in the Z-axis direction. In the illustrated example, the sidewall 25a and the sidewall 25b have approximately the same height as the protrusion 10d in the Z-axis direction. The sidewall 25a is located on the positive side of the side surface 8c of the protrusion 18 in the Y-axis direction. In other words, the protrusion 18 protrudes further in the Y-axis direction than the sidewall 25a. The sidewall 25b is formed along the protrusion 10d. A gap may be formed between the sidewall 25b and the protrusion 10d.

[0041] The second wall portion 24B includes a sidewall 25c (second sidewall) extending along the X-axis direction when viewed from the Z-axis direction, and a sidewall 25d (third sidewall) extending along the Y-axis direction. The sidewall 25c extends along the side surface 8a of the restraint plate 8 and covers the side surface 8a. The sidewall 25c is located on the positive side of the Y-axis direction relative to the sidewall 25a. The sidewall 25d is formed continuously with the sidewall 25c at both ends of the sidewall 25c in the X-axis direction. The sidewall 25d is formed along the side surface 8b of the overhanging portion 18 and covers a portion of the side surface 8b (the region on the positive side of the Y-axis direction in the illustrated example). The sidewall 25d is located on the positive side of the Y-axis direction relative to the side surface 8c of the overhanging portion 18. The position of the edge of the sidewall 25d on the negative side in the Y-axis direction coincides with the position of the sidewall 25a.

[0042] In one example, the side wall 25c is formed with a terminal block protector 16 that covers at least a portion of the terminal block 70 and the fixing bolt 19. The terminal block protector 16 is provided so as to protrude from the side wall 25c to the negative side in the Y-axis direction. The terminal block protector 16 has a box-like shape that accommodates the base portion 71 of the terminal block 70 inside.

[0043] The terminal block protector 16 has an upper wall portion 22 extending from the main body portion 21 toward the negative side in the Y-axis direction, a pair of side wall portions 23, 23 extending from the side wall 25c toward the negative side in the Y-axis direction, and an end wall portion 26 extending parallel to the side wall 25c at the negative end portions of the upper wall portion 22 and the side wall portions 23, 23 in the Y-axis direction. The upper wall portion 22 is disposed to cover the terminal block 70 from above. The upper wall portion 22 has a recessed portion 27 formed therein that is recessed downward more than other regions. When viewed from the Z-axis direction, the recessed portion 27 overlaps with the spring portion 50 of the positive terminal 6 and is configured to accommodate the spring portion 50.

[0044] The side walls 23, 23 are arranged to cover the terminal block 70 from both sides in the X-axis direction. The end wall 26 is arranged to cover the end (end face) of the terminal block 70 in the Y-axis direction. The end wall 26 is open at the position of the central portion 72 of the terminal block 70 so as to expose the central portion 72. Furthermore, a sleeve wall 26a facing the side wall 23 is formed at the position where the opening in the end wall 26 is formed (see FIG. 2). The fixing bolt 19 that fixes the terminal block 70 to the side surface 8a can be accommodated in the space formed by the side wall 23, the upper wall 22, the end wall 26, and the sleeve wall 26a.

[0045] The end wall portion 26 of the terminal block protector 16 is located on the positive side of the Y-axis direction relative to the side surface 8c of the protruding portion 18. In other words, the protruding portion 18 protrudes further in the negative Y-axis direction than the terminal block protector 16. That is, the protruding portion 18 protrudes further in the negative Y-axis direction than the terminal block 70. In one example, the position of the end wall portion 26 in the Y-axis direction may be the same as the position of the side wall 25a. Note that in the illustrated example, the insulating plate 20 is located on the positive side of the Y-axis direction relative to the side surface 8c of the protruding portion 18 at any position in the X-axis direction.

[0046] 5 and 6 are diagrams illustrating the configuration of the end portion on the positive side in the Y-axis direction in an example of a power storage device. FIG. 5 is an exploded view of FIG. 6. In FIGS. 5 and 6, only the restraint plate 8 and the insulating plate 20 are shown. On the positive side in the Y-axis direction, the restraint plate 8 has a pair of overhanging portions 18. The configuration of the pair of overhanging portions 18 is the same on the positive side and the negative side in the Y-axis direction. However, the restraint plate 8 does not have a terminal block on the positive side in the Y-axis direction. Between the pair of overhanging portions 18, the restraint plate 8 has a side surface 8a that is aligned with the XZ plane.

[0047] In the range in the X-axis direction where the protruding portions 18 are formed, the insulating plate 20 has a first wall portion 24A, similar to the negative side in the Y-axis direction. In the range between the pair of protruding portions 18 in the X-axis direction, the insulating plate 20 has a liquid receiving portion 24C. The liquid receiving portion 24C is a portion for receiving the electrolyte discharged from a pressure adjustment valve (not shown) provided in the electricity storage module 3.

[0048] The liquid receiving portion 24C has a bottom wall portion 28 and a storage side wall portion 29, which form a concave shape. The storage side wall portion 29 has a frame shape surrounding the liquid receiving portion 24C and protrudes further toward the negative side in the Z-axis direction than the main body portion 21 of the insulating plate 20. The bottom wall portion 28 forms the bottom surface of the rectangular space surrounded by the storage side wall portion 29. In the illustrated example, the bottom wall portion 28 is inclined toward the negative side in the Z-axis direction as it approaches the positive side in the X-axis direction. The bottom wall portion 28 is provided with a discharge port 28a for discharging the received electrolyte to the outside.

[0049] The liquid receiving portion 24C is located on the negative side in the Y-axis direction of the side surfaces 8c of the pair of overhanging portions 18. That is, the pair of overhanging portions 18 overhang further in the positive side in the Y-axis direction than the liquid receiving portion 24C. The liquid receiving portion 24C may also be located on the positive side in the Z-axis direction than the pair of overhanging portions 18. That is, the pair of overhanging portions 18 overhang further in the negative side in the Z-axis direction than the liquid receiving portion 24C.

[0050] As described above, the energy storage device 1 comprises a laminate 2 including a plurality of bipolar electrodes stacked in the Z-axis direction, a pair of current collector plates 5 stacked on both ends of the laminate 2 in the Z-axis direction, a pair of insulating plates 20 sandwiching the laminate 2 and the pair of current collector plates 5 from the Z-axis direction, a restraint plate 8 sandwiching and restraining the laminate 2, the pair of current collector plates 5, and the pair of insulating plates 20 from the Z-axis direction, and a terminal block 70 provided on a side surface 8a of the restraint plate 8 extending in the X-axis and Z-axis directions, to which a terminal bolt 32 electrically connected to a terminal of the current collector plate 5 and protruding in the Y-axis direction is fixed. When viewed from the Z-axis direction, the restraint plate 8 has a pair of protrusions 18 protruding in the Y-axis direction from the side surface 8a to which the terminal block 70 is fixed. When viewed from the Z-axis direction, the terminal block 70 is positioned between the pair of protrusions 18, and the pair of protrusions 18 protrude further in the Y-axis direction than the terminal block protective portion 16.

[0051] In the above-described energy storage device 1, a pair of insulating plates 20 are sandwiched between restraining plates 8 in the Z-axis direction. In the Y-axis direction (second direction), the overhanging portions 18 formed on the restraining plates 8 overhang further than the terminal block protection portion 16 in the Y-axis direction, and the terminal block protection portion 16 is disposed between the pair of overhanging portions 18. This configuration allows external forces acting on the energy storage device 1 in the Y-axis direction or the X-axis direction to act on the pair of overhanging portions 18, making it easier for the terminal block protection portion 16 to be protected from the external force. For example, if the energy storage device 1 moves relatively in the Y-axis direction and comes into contact with a wall surface or the like, only the overhanging portions 18 overhanging in the Y-axis direction come into contact with the wall surface or the like. In this case, damage to the terminal block protection portion 16 of the insulating plate 20 located between the pair of overhanging portions 18 is suppressed. Furthermore, if an object collides with the energy storage device 1 along the X-direction at the end portion in the Y-axis direction, damage to the terminal block protection portion 16 located between the pair of overhanging portions 18 is suppressed. In the power storage device 1, damage to the insulating plate 20 (terminal block protection portion 16) is suppressed, and therefore deterioration of the insulation between the bipolar electrodes and the restraint plate 8 can be suppressed.

[0052] In the above-described energy storage device 1, at the end on the positive side in the Y-axis direction, the liquid receiving portion 24C is disposed between the pair of protruding portions 18 when viewed from the Z-axis direction, and the pair of protruding portions 18 protrude further in the Y-axis direction than the liquid receiving portion 24C. Therefore, even on the positive side in the Y-axis direction, the pair of protruding portions function as protective members, thereby suppressing damage to the liquid receiving portion 24C (insulating plate).

[0053] In one example, insulating plate 20 has wall portions 24 that stand along the Z-axis direction, and wall portion 24 may have a first wall portion 24A that stands in a direction away from the adjacent restraint plate 8 along the Z-axis direction in the range in which overhanging portions 18 are formed in the X-axis direction, and a second wall portion 24B that stands in a direction opposite to that of first wall portion 24A along the Z-axis direction in the range between the pair of overhanging portions 18 in the X-axis direction. With this configuration, liquid is prevented from accumulating inside wall portions 24 formed on insulating plate 20.

[0054] As an example, the first wall portion 24A has a sidewall 25a that extends along the X-axis direction when viewed from the Z-axis direction, and the pair of overhanging portions 18 may overhang beyond the sidewall 25a in the Y-axis direction. In this configuration, for example, when the energy storage device 1 moves relatively in the Y-axis direction and comes into contact with a wall surface or the like, only the overhanging portions 18 that overhang in the Y-axis direction come into contact with the wall surface or the like. In this case, damage to the sidewall 25a that is recessed in the Y-axis direction beyond the overhanging portions 18 is suppressed.

[0055] As an example, second wall portion 24B has sidewall 25c that covers side surface 8a along the X-axis direction when viewed from the Z-axis direction, and sidewall 25a may protrude further than sidewall 25c in the Y-axis direction. In this configuration, the insulation distance between the current collecting plate and restraint plate 8 at the position of sidewall 25a can be increased by the protruding length of sidewall 25a.

[0056] In one example, second wall portion 24B has side wall 25d along the Y-axis direction when viewed from the Z-axis direction so as to cover side surface 8b of protruding portion 18 along the Y-axis direction, and side wall 25c and side wall 25d are continuous with each other and may cover side surface 8a and side surface 8b of restraint plate 8. In this configuration, liquid that has accumulated inside wall portion 24 formed on insulating plate 20 can be discharged along side wall 25c and side wall 25d.

[0057] Although the embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment.

[0058] Although an example has been shown in which the tip of the terminal bolt 32 in the Y-axis direction is located on the negative side of the side surface 8c of the protrusion 18 in the Y-axis direction, the tip of the terminal bolt 32 may also be located on the positive side of the side surface of the protrusion 18 in the Y-axis direction. [Explanation of symbols]

[0059] 1...electricity storage device, 2...laminated body, 5...current collecting plate, 6...positive terminal (terminal), 8...restraint plate, 8a...side surface (first side surface), 8b...side surface (second side surface), 16...terminal block protection portion, 18...extension portion, 20...insulating plate, 24...wall portion (peripheral wall), 25a...side wall (first side wall), 25c...side wall (second side wall), 25d...side wall (third side wall), 32...terminal bolt, 70...terminal block, 100...terminal cover.

Claims

1. a stacked body having an electricity storage module in which electrodes including a plurality of bipolar electrodes are stacked along a first direction; a pair of current collector plates stacked on both ends of the stack in the first direction; a pair of insulating plates sandwiching the laminate and the pair of current collecting plates from the first direction; a restraining plate that sandwiches and restrains the laminate, the pair of current collecting plates, and the pair of insulating plates from the first direction; a terminal block provided on a first side surface of the restraint plate, the first side surface extending in the first direction and a third direction intersecting both the first direction and the second direction, to which a terminal bolt electrically connected to at least one terminal of the current collecting plate and protruding in a second direction intersecting the first direction is fixed; the restraint plate has a pair of protruding portions that protrude in the second direction beyond the first side surface to which the terminal block is fixed, when viewed from the first direction; the terminal block is disposed between the pair of protruding portions when viewed from the first direction, the insulating plate includes a terminal block protection portion that covers at least a portion of the terminal block; The pair of protruding portions protrude further than the terminal block protection portion in the second direction.

2. the insulating plate has a peripheral wall that stands up along the first direction, The peripheral wall is a first wall portion standing in a direction away from the adjacent restraint plate along the first direction within a range in which the overhang portion is formed in the third direction; The power storage device according to claim 1 , further comprising: a second wall portion that stands in a direction opposite to the first wall portion along the first direction in a range between the pair of protruding portions in the third direction.

3. the first wall portion has a first side wall extending along the third direction when viewed from the first direction, The power storage device according to claim 2 , wherein the pair of protruding portions protrude further than the first side wall in the second direction.

4. the second wall portion has a second side wall that covers the first side surface along the third direction when viewed from the first direction, The power storage device according to claim 3 , wherein the first side wall protrudes further than the second side wall in the second direction.

5. the second wall portion has a third side wall extending along the second direction as viewed from the first direction so as to cover a second side surface of the protruding portion extending along the second direction, The power storage device according to claim 4 , wherein the second side wall and the third side wall are continuous with each other and cover the first side surface and the second side surface of the restraint plate.

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