JP7551566B2 - Power storage device - Google Patents

Description

This disclosure relates to an electricity storage device.

There is known an energy storage device that includes a module stack having multiple energy storage modules, wiring connected to the module stack, and a guide member that guides the wiring along the side of the module stack (see, for example, Patent Document 1). In the battery pack described in Patent Document 1, the electric wires connected to the battery assembly are housed in a case provided on the side of the battery assembly.

JP 2015-207394 A

In the above-mentioned energy storage device, the module stack and the guide member expand and contract with different linear expansion coefficients, which may cause the guide member to be damaged.

The objective of this disclosure is to provide an electricity storage device that can prevent damage to the guide member.

The energy storage device according to one aspect of the present disclosure includes a module stack having a plurality of energy storage modules stacked in a first direction, a first constraining plate and a second constraining plate stacked on both sides of the module stack in the first direction and applying a constraining load to the module stack in the first direction, wiring connected to the module stack, and a guide member that guides the wiring along the side of the module stack, the side extending in the first direction and a second direction perpendicular to the first direction, and the guide member has an L-shaped main body including a first extension portion extending along the second direction and a second extension portion extending along the first direction, a first fixing portion provided at a first end of the main body and fixed to the first constraining plate, a second fixing portion provided at a second end of the main body and fixed to the second constraining plate, and a locking portion provided at a connection between the first extension portion and the second extension portion and engaged with the first constraining plate so as to be movable in the first direction and the second direction.

In the above-mentioned energy storage device, the L-shaped main body of the guide member is fixed to the first constraining plate by the first fixing portion, fixed to the second constraining plate by the second fixing portion, and engaged to the first constraining plate by the engaging portion. Therefore, the guide member can reliably guide the wiring along the side of the module stack without coming off the first constraining plate and the second constraining plate. The engaging portion is engaged to the first constraining plate so as to be movable in the first direction and the second direction. Therefore, when the module stack and the guide member expand and contract in the first direction and the second direction with different linear expansion coefficients, the engaging portion moves in the first direction and the second direction, thereby suppressing damage to the guide member. When the module stack and the guide member expand and contract in a third direction perpendicular to the first direction and the second direction with different linear expansion coefficients, the main body is deformed so as to bend starting from the first fixing portion, the second fixing portion, and the engaging portion, thereby suppressing damage to the guide member.

The wiring may be connected to the end of the module stack in the second direction, and the guide member may guide the wiring from the end to the second restraining plate. In this case, the distance over which the guide member guides the wiring in the second direction tends to be long, so a configuration in which the locking portion is movable in the second direction is particularly effective.

The wiring may include a first wiring and a second wiring, and the guide member may further have a third extension portion extending along the second direction and connected between the second end of the second extension portion and the connection portion, the third extension portion being disposed apart from the first extension portion in the first direction, the first wiring being guided by the first extension portion and the second extension portion, and the second wiring being guided by the third extension portion and the second extension portion. In this case, the first wiring and the second wiring can be guided separately by the first extension portion and the third extension portion, thereby reducing the effect of noise on the signals transmitted by the first wiring and the second wiring.

One of the first wiring and the second wiring may be connected to a voltage detection element, and the other may be connected to a temperature detection element. In this case, since the wiring connected to the voltage detection element generates electromagnetic noise (electromagnetic waves), a configuration that can reduce the effects of noise is particularly effective.

The guide member may further include a connecting portion that is spaced apart from the second extension portion in the second direction and extends along the first direction to connect the first extension portion and the third extension portion. In this case, the connecting portion makes it easier for the first extension portion and the third extension portion to be kept spaced apart from each other.

The first restraining plate has an edge portion adjacent to the module stack in a third direction perpendicular to the first and second directions when viewed from the first direction, and the edge portion has a recess that opens to the inside in the first direction and extends along the second direction, and the locking portion may be press-fitted into the recess. In this case, a configuration in which the locking portion is locked to the first restraining plate and can move in the first and second directions can be easily realized.

The first fixing portion may be inserted into a through hole that penetrates the first restraint plate in the first direction, or into a through hole that penetrates the first restraint plate in a third direction perpendicular to the first and second directions. In this case, the first fixing portion can be easily fixed to the first restraint plate.

The second fixing portion may be inserted into a through hole that penetrates the first restraint plate in the first direction, or into a through hole that penetrates the first restraint plate in a third direction perpendicular to the first and second directions. In this case, the second fixing portion can be easily fixed to the second restraint plate.

According to the present disclosure, an energy storage device is provided that can suppress damage to the guide member.

FIG. 1 is a perspective view of an electricity storage device according to an embodiment. FIG. 2 is a side view of the power storage device shown in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a schematic cross-sectional view showing the internal configuration of the electricity storage module. FIG. 7 is a plan view showing the inner surface of the restraint plate. FIG. 8 is a perspective view of the guide member. FIG. 9 is a perspective view of the guide member. FIG. 10 is a perspective view of the fixing portion. FIG. 11 is a cross-sectional view showing a state in which the fixing portion is fixed to the restraining plate. FIG. 12 is a cross-sectional view showing a state in which the fixing portion is fixed to the restraining plate. FIG. 13 is a perspective view of the second locking portion. FIG. 14 is a cross-sectional view showing a state in which the second locking portion is locked to the restraining plate. FIG. 15 is a perspective view showing a state in which the cover is closed. FIG. 16 is a perspective view showing a state in which the cover is open.

Embodiments of the present invention will now 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 duplicate descriptions will be omitted.

The energy storage device 1 according to this embodiment will be described with reference to Figures 1 to 16. The energy storage device 1 shown in Figure 1 is used, for example, as a battery for various vehicles such as a forklift, a hybrid vehicle, and an electric vehicle. The energy storage device 1 is, for example, a secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery. The energy storage device 1 may also be, for example, an electric double layer capacitor. In this embodiment, the case where the energy storage device 1 is a nickel-metal hydride battery is illustrated.

As shown in Figures 1 to 3, the energy storage device 1 includes a module stack 2, a restraining member 4, a pair of insulating plates 20, a duct 21, a pair of guide members 30, and a plurality of wirings L1 to L9 (nine in this embodiment). The module stack 2 includes a plurality of energy storage modules 3 (seven in this embodiment) stacked in the first direction D1, and a plurality of current collector plates 5 (eight in this embodiment).

The multiple storage modules 3 are stacked in the first direction D1 via the current collector plates 5. The multiple storage modules 3 are electrically connected in series in the first direction D1 via the current collector plates 5. The current collector plates 5 are plate-shaped members made of a conductive material such as a metal. Examples of materials for the current collector plates 5 include aluminum. A plating layer of nickel or the like may be formed on the surface of the current collector plates 5. In this embodiment, the area of the current collector plates 5 as viewed from the first direction D1 is smaller than the area of the storage modules 3.

3, the multiple current collectors 5 include a current collector 5A at one end in the first direction D1, a current collector 5B at the other end, and multiple (six in this embodiment) current collectors 5C interposed between the storage modules 3. The current collectors 5C are provided between the storage modules 3 adjacent to each other in the first direction D1 and are electrically connected to the multiple storage modules 3. Between the storage modules 3 adjacent to each other in the first direction D1, the current collectors 5C are arranged in contact with the exposed portion 60d of the other surface 60b of the metal plate 60B described later and the exposed portion 60d of the one surface 60a of the metal plate 60A.

The current collectors 5A and 5B are arranged to sandwich the multiple storage modules 3 and the multiple current collectors 5C from both sides in the first direction D1. The current collectors 5A and 5B are each stacked on the storage modules 3 located at the stacking ends in the first direction D1. The current collector 5A is stacked on the storage module 3 located at one stacking end in the first direction D1 and is electrically connected to at least the storage module 3. The current collector 5B is stacked on the storage module 3 located at the other stacking end in the first direction D1 and is electrically connected to at least the storage module 3.

A negative electrode terminal 7 (see FIG. 1) is connected to the current collector 5A. The negative electrode terminal 7 is pulled out from the edge of the current collector 5A in a second direction D2 perpendicular to the first direction D1. A positive electrode terminal 6 (see FIG. 1) is connected to the current collector 5B. The positive electrode terminal 6 is pulled out from the edge of the current collector 5B in the second direction D2. The positive electrode terminal 6 and the negative electrode terminal 7 are used to charge and discharge the storage device 1.

As shown in Figs. 4 and 5, the current collector plate 5C is provided with a plurality of flow paths 5a for circulating the cooling fluid. Here, the cooling fluid may be, for example, air or water. The flow paths 5a are through holes extending along a third direction D3 perpendicular to the first direction D1 and the second direction D2. The flow paths 5a have an inlet 5b through which the cooling fluid flows in and an outlet 5c through which the cooling fluid flows out. A plurality of flow paths 5a are arranged along the second direction D2. The plurality of current collector plates 5C function as heat sinks that radiate heat generated in the power storage module 3 by circulating the cooling fluid through the flow paths 5a. No flow paths are provided in the current collector plates 5A and 5B.

The module stack 2 has a plurality of detection elements 12 arranged on both sides of the current collector 5C in the second direction D2. The detection elements 12 are arranged at both ends 2b, 2c of the module stack 2 in the second direction D2. The detection elements 12 are provided between the adjacent storage modules 3 in the first direction D1 together with the current collector 5C. The detection elements 12 are sensors that monitor the state of the storage modules 3, including, for example, a temperature detection element (not shown) that detects the temperature of the storage module 3 and a voltage detection element (not shown) that detects the voltage output from the storage module 3. The detection elements 12 are formed with the same thickness as the current collector 5, for example, from an insulating resin having alkali resistance such as polypropylene (PP). The detection elements 12 are connected to both ends of the current collector 5C in the second direction D2.

The duct 21 is configured to allow the cooling fluid to flow into the inlet 5b of each flow path 5a. The duct 21 faces the side of the current collector 5C on which the inlet 5b is provided, and extends in the second direction D2. One end of the duct 21 in the second direction D2 (end 2b side) is open, and forms an inlet 21a that introduces the cooling fluid into the duct 21. The other end of the duct 21 in the second direction D2 (end 2c side) is closed. The cooling fluid that flows into the duct 21 from the inlet 21a flows through the duct 21 and is guided to the inlet 5b of the flow path 5a. The cooling fluid that flows into the flow path 5a from the inlet 5b flows through the flow path 5a and flows out from the outlet 5c.

As shown in FIG. 1, the duct 21 has an extension portion 21b. The extension portion 21b extends along the third direction D3 so as to face the outer surface 10a of the edge portion 10 described below. The extension portion 21b is formed in a shape and size that does not interfere with the engagement portion 14 described below. The extension portion 21b has a through hole through which a fixing screw 19 is inserted. The fixing screw 19 is inserted through the through hole and screwed into a hole (not shown) provided in the edge portion 10. In this way, the duct 21 is fixed to the restraining plate 8.

As shown in FIG. 6, each storage module 3 includes an electrode stack 51 and a resin sealing body 52 that seals the electrode stack 51. The storage module 3 is formed, for example, in a rectangular parallelepiped shape.

The electrode stack 51 includes a plurality of electrodes stacked in the first direction D1 via a separator 53, and metal plates 60A and 60B. The stack of the plurality of electrodes is provided between the metal plates 60A and 60B. The plurality of electrodes includes a stack of a plurality of bipolar electrodes 54, a negative terminal electrode 58, and a positive terminal electrode 59. The stack of the plurality of bipolar electrodes 54 is provided between the negative terminal electrode 58 and the positive terminal electrode 59.

The bipolar electrode 54 has a metal plate 55 including one side 55a and the other side 55b opposite to the one side 55a, a positive electrode 56 provided on the one side 55a, and a negative electrode 57 provided on the other side 55b. The positive electrode 56 is a positive electrode active material layer formed by applying a positive electrode active material to the metal plate 55. The negative electrode 57 is a negative electrode active material layer formed by applying a negative electrode active material to the metal plate 55. In the electrode laminate 51, the positive electrode 56 of one bipolar electrode 54 faces the negative electrode 57 of another bipolar electrode 54 adjacent to the other side of the first direction D1 across the separator 53. In the electrode laminate 51, the negative electrode 57 of one bipolar electrode 54 faces the positive electrode 56 of another bipolar electrode 54 adjacent to the other side of the first direction D1 across the separator 53.

The negative terminal electrode 58 has a metal plate 55 and a negative electrode 57 provided on the other surface 55b of the metal plate 55. The negative terminal electrode 58 is arranged on one end side of the first direction D1 so that the other surface 55b faces the center side of the first direction D1 in the electrode stack 51. A metal plate 60A is further laminated on one surface 55a of the metal plate 55 of the negative terminal electrode 58, and is electrically connected to one of the current collector plates 5 (see FIG. 3) adjacent to the storage module 3 via this metal plate 60A. The negative electrode 57 provided on the other surface 55b of the metal plate 55 of the negative terminal electrode 58 faces the positive electrode 56 of the bipolar electrode 54 at one end of the first direction D1 via the separator 53.

The positive terminal electrode 59 has a metal plate 55 and a positive electrode 56 provided on one side 55a of the metal plate 55. The positive terminal electrode 59 is arranged on the other end side of the first direction D1 so that the one side 55a faces the center side of the first direction D1 in the electrode stack 51. A metal plate 60B is further laminated on the other side 55b of the metal plate 55 of the positive terminal electrode 59, and is electrically connected to the other current collector plate 5 (see FIG. 3) adjacent to the storage module 3 via this metal plate 60B. The positive electrode 56 provided on one side 55a of the metal plate 55 of the positive terminal electrode 59 faces the negative electrode 57 of the bipolar electrode 54 at the other end of the first direction D1 via the separator 53.

The metal plate 55 is made of a metal such as nickel or a nickel-plated steel plate. As an example, the metal plate 55 is a rectangular metal foil made of nickel. Each metal plate 55 is one of the metal plates included in the electrode stack 51. The edge portion 55c of the metal plate 55 has a rectangular frame shape and is an uncoated area where the positive electrode active material and the negative electrode active material are not coated. For example, nickel hydroxide is used as the positive electrode active material constituting the positive electrode 56. For example, a hydrogen storage alloy is used as the negative electrode active material constituting the negative electrode 57. In this embodiment, the formation area of the negative electrode 57 on the other surface 55b of the metal plate 55 is one size larger than the formation area of the positive electrode 56 on one surface 55a of the metal plate 55. The electrode stack 51 has a plurality of stacked metal plates 55, 60A, 60B.

The separator 53 is a member for preventing short circuits between the metal plates 55, and is formed, for example, in a sheet shape. Examples of the separator 53 include a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP), and a woven or nonwoven fabric made of polypropylene, methylcellulose, or the like. The separator 53 may be reinforced with a vinylidene fluoride resin compound. The separator 53 is not limited to a sheet shape, and a bag-shaped one may also be used.

The metal plates 60A and 60B are substantially the same member as the metal plate 55, and are made of a metal such as nickel or nickel-plated steel. Both of the metal plates 60A and 60B are one of the metal plates included in the electrode stack 51. As an example, the metal plates 60A and 60B are rectangular metal foils made of nickel. The metal plates 60A and 60B are uncoated electrodes in which neither the positive electrode active material layer nor the negative electrode active material layer is coated on the one side 60a nor the other side 60b. In other words, the metal plates 60A and 60B are uncoated electrodes in which no active material layer is provided on both sides.

The metal plate 60A is located at one end of the electrode stack 51. The metal plate 60A causes the negative terminal electrode 58 to be disposed between the metal plate 60A and the bipolar electrode 54 along the first direction D1. The metal plate 60B is located at the other end of the electrode stack 51. The metal plate 60B causes the positive terminal electrode 59 to be disposed between the metal plate 60B and the bipolar electrode 54 along the first direction D1. In the electrode stack 51, the central region of the electrode stack 51 (the region in which the active material layers are disposed in the bipolar electrode 54, the negative terminal electrode 58, and the positive terminal electrode 59) bulges in the first direction D1 compared to the surrounding region. For this reason, the metal plates 60A and 60B are bent in a direction in which the central regions of the metal plates 60A and 60B are separated from each other. The central regions of one surface 60a of the metal plate 60A and the other surface 60b of the metal plate 60B are in contact with the current collector 5. That is, the current collector 5 is disposed in contact with the metal plates 60A and 60B at the stacking ends of the electrode stack 51.

The sealing body 52 is formed into a rectangular tubular shape as a whole by, for example, insulating resin. The sealing body 52 is provided so as to surround the side surface 51a along the first direction D1 of the electrode stack 51. The sealing body 52 holds the edge portion 55c at the side surface 51a. The sealing body 52 has a plurality of frame-shaped first sealing portions 61 provided on the edge portions of the metal plates included in the electrode stack 51 (i.e., the edge portion 55c of the metal plate 55 and the edge portion 60c of the metal plates 60A and 60B), and second sealing portions 62 surrounding the first sealing portions 61 from the outside along the side surface 51a and joined to each of the first sealing portions 61. The first sealing portion 61 and the second sealing portion 62 are, for example, insulating resin having alkali resistance. Examples of the constituent materials of the first sealing portion 61 and the second sealing portion 62 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), etc.

The first sealing portion 61 is provided continuously around the entire circumference of the edge portion 55c of the metal plate 55 or the edge portion 60c of the metal plates 60A and 60B, and forms a rectangular frame shape when viewed from the first direction D1. The first sealing portion 61 is welded to the edge portion 55c of the metal plate 55 or the edge portion 60c of the metal plates 60A and 60B by, for example, ultrasonic waves or heat, and is hermetically joined. The first sealing portion 61 extends outward beyond the edge portion 55c of the metal plate 55 or the edge portion 60c of the metal plates 60A and 60B when viewed from the first direction D1. The first sealing portion 61 includes an outer portion 61a that protrudes outward from the edge of the metal plate 55 or the metal plates 60A and 60B, and an inner portion 61b that is located inside the edge of the metal plate 55 or the metal plates 60A and 60B. The tip (outer edge) of the outer portion 61a of the first sealing portion 61 is joined to the second sealing portion 62 by a welding layer 63. The welding layer 63 is formed by bonding the tips of the first sealing portions 61 that are melted by, for example, hot plate welding. The outer portions 61a of the first sealing portions 61 adjacent to each other in the first direction D1 may be separated from each other or may be in contact with each other. In addition, the outer portions 61a of the first sealing portions 61 adjacent to each other in the first direction D1 may be bonded to each other by, for example, hot plate welding.

The first sealing portions 61 include a first sealing portion 61A provided on the bipolar electrode 54 and the positive terminal electrode 59, a first sealing portion 61B provided on the negative terminal electrode 58, a first sealing portion 61C provided on the metal plate 60A, and first sealing portions 61D and 61E provided on the metal plate 60B.

The first sealing portion 61A is joined to one surface 55a of the metal plate 55 of the bipolar electrode 54 and the positive terminal electrode 59. The inner portion 61b of the first sealing portion 61A is located between the edge portions 55c of the metal plates 55 adjacent to each other in the first direction D1. The area where the edge portions 55c on one surface 55a of the metal plate 55 overlap with the first sealing portion 61A is the bonding area between the metal plate 55 and the first sealing portion 61A.

In this embodiment, the first sealing portion 61A is formed with a two-layer structure by folding one film in two. The outer edge of the first sealing portion 61A embedded in the second sealing portion 62 is the folded portion (bent portion) of the film. The first layer of film constituting the first sealing portion 61A is bonded to one surface 55a. The inner edge of the second layer of film is located outside the inner edge of the first layer of film, forming a step portion on which the separator 53 is placed. The inner edge of the second layer of film is located inside the edge of the metal plate 55.

The first sealing portion 61B is joined to one surface 55a of the metal plate 55 of the negative terminal electrode 58. The inner portion 61b of the first sealing portion 61B is located between the edge portion 55c of the metal plate 55 of the negative terminal electrode 58 and the edge portion 60c of the metal plate 60A, which are adjacent to each other in the first direction D1. The area where the edge portion 55c on one surface 55a of the metal plate 55 and the inner portion 61b of the first sealing portion 61B overlap is the bonding area between the metal plate 55 and the first sealing portion 61B. The first sealing portion 61B is also joined to the other surface 60b of the metal plate 60A. The area where the edge portion 60c on the other surface 60b of the metal plate 60A and the first sealing portion 61B overlap is the bonding area between the metal plate 60A and the first sealing portion 61B. In this embodiment, the first sealing portion 61B is also joined to the edge portion 60c on the other surface 60b of the metal plate 60A. It can be said that the first sealing portion 61B is provided not only on the negative terminal electrode 58 but also on the metal plate 60A.

The first sealing portion 61C is joined to one surface 60a (outer surface) of the metal plate 60A. In this embodiment, the first sealing portion 61C is located at the end-most side in the first direction D1 among the multiple first sealing portions 61. The area where the edge portion 60c on one surface 60a of the metal plate 60A and the first sealing portion 61C overlap is the bonding area between the metal plate 60A and the first sealing portion 61C. The one surface 60a of the metal plate 60A has an exposed portion 60d exposed from the first sealing portion 61C. The current collecting plate 5 is arranged in contact with the exposed portion 60d.

In this embodiment, the outer edges of the first sealing parts 61B and 61C embedded in the second sealing part 62 are continuous. That is, the first sealing parts 61B and 61C are formed by folding one film in two, sandwiching the edge part 60c of the metal plate 60A. The outer edges of the first sealing parts 61B and 61C are the folded parts (bent parts) of the film. The film constituting the first sealing parts 61B and 61C is joined to the edge part 60c on both the one side 60a and the other side 60b of the metal plate 60A. In this way, by joining both sides of the metal plate 60A to the first sealing parts 61B and 61C, it is possible to suppress the seepage of the electrolyte due to the so-called alkaline creep phenomenon.

The first sealing portion 61D is joined to one surface 60a of the metal plate 60B. The inner portion 61b of the first sealing portion 61D is located between the edge portion 55c of the metal plate 55 of the positive terminal electrode 59 and the edge portion 60c of the metal plate 60B, which are adjacent to each other in the first direction D1. The area where the edge portion 60c on one surface 60a of the metal plate 60B and the first sealing portion 61D overlap is the bonding area between the metal plate 60B and the first sealing portion 61D.

The first sealing portion 61E is disposed at an edge portion 60c on the other surface 60b (outer surface) of the metal plate 60B. In this embodiment, the first sealing portion 61E is located at the other end side of the multiple first sealing portions 61 in the first direction D1. In this embodiment, the first sealing portion 61E is not joined to the metal plate 60B. The other surface 60b of the metal plate 60B has an exposed portion 60d exposed from the first sealing portion 61E. The current collecting plate 5 is disposed in contact with (in contact with) the exposed portion 60d.

In this embodiment, the outer edges of the first sealing portions 61D, 61E embedded in the second sealing portion 62 are continuous. That is, the first sealing portions 61D, 61E are formed by folding a single film in two, sandwiching the edge portion 60c of the metal plate 60B. The outer edges of the first sealing portions 61D, 61E are folded back portions (bent portions) of the film. The film constituting the first sealing portions 61D, 61E is joined to the edge portion 60c on one surface 60a of the metal plate 60B.

In the bonding region, the surfaces of the metal plates 55, 60A, and 60B are roughened. The roughened region may be only the bonding region, but in this embodiment, the entire one side 55a of the metal plate 55 is roughened. In addition, the entire one side 60a and the other side 60b of the metal plate 60A are roughened. In addition, the entire one side 60a of the metal plate 60B is roughened.

The roughening can be achieved, for example, by forming multiple protrusions by electrolytic plating. By forming multiple protrusions in the bonding region, the molten resin penetrates between the multiple protrusions formed by roughening at the bonding interface with the first sealing part 61 in the bonding region, and an anchor effect is exerted. This improves the bonding strength between the metal plates 55, 60A, 60B and the first sealing part 61. The protrusions formed during roughening have a shape that tapers from the base end side to the tip end side, for example. This makes the cross-sectional shape between adjacent protrusions an undercut shape, making it possible to enhance the anchor effect.

The second sealing portion 62 is provided on the outside of the electrode stack 51 and the first sealing portion 61 so as to surround the side surface 51a of the electrode stack 51, and constitutes the outer wall (housing) of the energy storage module 3. The second sealing portion 62 is formed, for example, by injection molding of resin, and extends over the entire length of the electrode stack 51 along the first direction D1. The second sealing portion 62 has a rectangular frame shape extending with the first direction D1 as its axial direction. The second sealing portion 62 is welded to the outer surface of the first sealing portion 61 by heat during injection molding, for example. The second sealing portion 62 has an outer peripheral surface 62a that follows the first direction D1.

The sealing body 52 forms an internal space V between adjacent electrodes in the first direction D1 and seals the internal space V. More specifically, the second sealing portion 62, together with the first sealing portion 61, seals between the bipolar electrodes 54 adjacent to each other in the first direction D1, between the negative electrode terminal electrode 58 and the bipolar electrode 54 adjacent to each other in the first direction D1, and between the positive electrode terminal electrode 59 and the bipolar electrode 54 adjacent to each other in the first direction D1. As a result, an airtightly partitioned internal space V is formed between the bipolar electrodes 54 adjacent to each other in the first direction D1, between the negative electrode terminal electrode 58 and the bipolar electrode 54, and between the positive electrode terminal electrode 59 and the bipolar electrode 54. The internal space V contains an electrolyte (not shown) containing an alkaline solution such as an aqueous potassium hydroxide solution. The electrolyte is impregnated into the separator 53, the positive electrode 56, and the negative electrode 57. The sealant 52 also seals between the metal plate 60A and the negative terminal electrode 58, and between the metal plate 60B and the positive terminal electrode 59.

As shown in Figures 1 to 3 and 7, the restraint member 4 includes a pair of restraint plates 8 and a plurality of connecting members 9 that connect the pair of restraint plates 8. The pair of restraint plates 8 includes a restraint plate 8A (second restraint plate) on the negative electrode terminal 7 side and a restraint plate 8B (first restraint plate) on the positive electrode terminal 6 side. Figure 7 shows the inner surface of the restraint plate 8B. The restraint plate 8A has the same shape as the restraint plate 8B, except for the position of the through hole 16d, which will be described later.

The pair of restraining plates 8 are stacked on both sides of the module stack 2 in the first direction D1, sandwiching the module stack 2. The pair of restraining plates 8 are connected by a plurality of connecting members 9, and apply a restraining load to the module stack 2 in the first direction D1. The plurality of energy storage modules 3 and the plurality of current collector plates 5 are sandwiched between the pair of restraining plates 8, and are unitized as the module stack 2. In this embodiment, the connecting members 9 are composed of a pair of bolts 9a and bolt collars 9b.

The pair of insulating plates 20 is made of an insulating material. The pair of insulating plates 20 is made of a resin such as polypropylene (PP). As shown in Figures 3 and 4, the pair of insulating plates 20 includes an insulating plate 20A on the negative terminal 7 side and an insulating plate 20B on the positive terminal 6 side.

An insulating plate 20A is provided between the current collector plate 5A and the restraining plate 8A. The insulating plate 20A is a member for ensuring insulation between the current collector plate 5A and the restraining plate 8A. The insulating plate 20A is in contact with the current collector plate 5A and the restraining plate 8A. The insulating plate 20A is stacked on the module stack 2 in the first direction D1. The insulating plate 20A is arranged so as to overlap the entire area of the current collector plate 5A when viewed from the first direction D1. The restraining plate 8A is stacked on the insulating plate 20A in the first direction D1, and applies a restraining load to at least the insulating plate 20A and the module stack 2.

An insulating plate 20B is provided between the current collecting plate 5B and the restraining plate 8B. The insulating plate 20B is a member for ensuring insulation between the current collecting plate 5B and the restraining plate 8B. The insulating plate 20B is in contact with the current collecting plate 5B and the restraining plate 8B. The insulating plate 20B is stacked on the module stack 2 in the first direction D1. The insulating plate 20B is arranged so as to overlap the entire area of the current collecting plate 5B when viewed from the first direction D1. The restraining plate 8B is stacked on the insulating plate 20B in the first direction D1, and applies a restraining load to at least the insulating plate 20B and the module stack 2.

As shown in Figures 1 to 3 and 7, the restraint plate 8 is a rectangular metal plate having an area slightly larger than the areas of the power storage module 3 and the current collector plate 5 when viewed from the first direction D1. The longitudinal direction of the restraint plate 8 coincides with the second direction D2. The lateral direction of the restraint plate 8 coincides with the third direction D3. The restraint plate 8 has a main body portion 11 and a pair of edge portions 10. The main body portion 11 overlaps with the module stack 2 when viewed from the first direction D1. The pair of edge portions 10 extend from the main body portion 11 in the third direction D3. The pair of edge portions 10 are adjacent to the module stack 2 when viewed from the first direction D1, and do not overlap with the module stack 2. In this embodiment, the pair of edge portions 10 are provided on both sides of the main body portion 11 in the third direction D3. That is, the main body portion 11 is sandwiched between the pair of edge portions 10 in the third direction D3.

The edge portion 10 has an outer surface 10a facing outward in the first direction D1 (the opposite side to the module stack 2 in the first direction D1) and an inner surface 10b facing inward in the first direction D1 (the side of the module stack 2 in the first direction D1). The main body portion 11 has an outer surface 11a facing outward in the first direction D1 and an inner surface 11b facing inward in the first direction D1. The inner surface 11b faces the insulating plate 20. The outer surface 10a is located more inward in the first direction D1 than the outer surface 11a. The inner surface 10b is located more inward in the first direction D1 than the inner surface 11b.

The pair of edges 10 are outer edge portions extending in the longitudinal direction (second direction D2) of the restraint plate 8. Each edge 10 has a plurality of (five in this embodiment) engaging portions 14. The engaging portions 14 are portions with which the bolts 9a engage. The engaging portions 14 are arranged at each edge 10 so as to be spaced apart from one another along the second direction D2. In this embodiment, the engaging portions 14 are arranged at equal intervals on the edge 10 in the second direction D2.

Each engagement portion 14 is provided with an insertion hole 14a through which the bolt 9a is inserted. The insertion hole 14a penetrates the engagement portion 14 along the first direction D1. The insertion hole 14a extends along the first direction D1 so as to connect the outer surface 10a and the inner surface 10b. The head of the bolt 9a is disposed on the outer surface 10a of the restraining plates 8A and 8B. The tip (screw tip) of the shaft of the bolt 9a protrudes from the inner surface 10b of the restraining plates 8A and 8B and is screwed into both ends of the bolt collar 9b. The bolt collar 9b is a columnar member that is disposed between the restraining plates 8A and 8B and extends in the first direction D1 so as to connect the restraining plates 8A and 8B. The bolt collar 9b is made of, for example, aluminum.

Each edge portion 10 has a plurality of (four in this embodiment) recesses 16 and a pair of recesses 17 that open inward in the first direction D1 (toward the module stack 2). The recesses 16 and the recesses 17 are grooves with a U-shaped cross section that extend along the second direction D2. The length of the recesses 16 in the second direction D2 is longer than the length of the recesses 17 in the second direction D2. The pair of restraining plates 8 are arranged such that the recesses 16 face each other in the first direction D1 and the recesses 17 face each other in the first direction D1.

The recess 16 has side walls 16a, 16b facing each other in the third direction D3, and a bottom wall 16c (see FIG. 11). The side wall 16a arranged on the inside of the third direction D3 (the module stack 2 side) faces the module stack 2 in the third direction D3. The multiple recesses 16 are arranged between adjacent engagement portions 14 in the second direction D2. The multiple recesses 16 are provided at positions corresponding to the current collector plate 5. In other words, the positional range of the multiple recesses 16 in the second direction D2 overlaps with the positional range of the current collector plate 5 in the second direction D2.

The recess 16A provided on one edge portion 10 is provided so as to be adjacent to the outlet 5c of the flow path 5a provided in the current collector plate 5C in the third direction D3 when viewed from the first direction D1. The recess 16A extends along the second direction D2 so as to be adjacent to the multiple outlets 5c in the third direction D3 when viewed from the first direction D1. The recess 16B provided on the other edge portion 10 is provided so as to be adjacent to the inlet 5b of the flow path 5a provided in the current collector plate 5C in the third direction D3 when viewed from the first direction D1. The recess 16B extends along the second direction D2 so as to be adjacent to the multiple inlets 5b in the third direction D3 when viewed from the first direction D1. The recess 16A corresponding to the first fixing portion 36 and the second fixing portion 37 described later is provided with a through hole 16d penetrating the bottom wall 16c in the first direction D1. Two through holes 16d are provided in each of the restraint plates 8A and 8B.

The recesses 17 have side walls and a bottom wall that face each other in the third direction D3. A pair of recesses 17 are arranged at a pair of ends in the second direction D2 of each edge portion 10. A plurality of engagement portions 14 and a plurality of recesses 16 are arranged between the pair of recesses 17. The pair of recesses 17 are provided at positions corresponding to the pair of detection elements 12 in the second direction D2. In other words, the positional range of each recess 17 in the second direction D2 overlaps with the positional range of the corresponding detection element 12 in the second direction D2.

As shown in FIG. 7, the main body 11 has a number of recesses 18 that open inward in the first direction D1. The recesses 18 have various shapes. The recesses 16, 17, and 18 function as reduced-material portions (thin-walled portions) of the restraining plate 8.

The wiring L1 to L9 shown in FIG. 2 is connected to the detection element 12 (see FIG. 4 and FIG. 5) of the module stack 2 and a signal output terminal of a control device (not shown), which is an external device. The control device is, for example, an ECU (Electronic Control Unit). The control device is disposed on the restraint plate 8A. The control device is provided at a position spaced apart from both ends of the restraint plate 8A in the second direction D2. The control device is, for example, provided at the center of the restraint plate 8A in the second direction D2. The detection signal of the detection element 12 is transmitted to the control device through the wiring L1 to L9. Since the detection element 12 is disposed at each end 2b, 2c of the module stack 2, it can be said that the wiring L1 to L9 is connected to each end 2b, 2c of the module stack 2.

Wirings L1 to L6 are connected to voltage detection elements included in detection element 12. Wirings L1 to L6 are each connected to detection elements 12 arranged at different stacking positions (positions in the first direction D1). Wirings L7 to L9 are connected to temperature detection elements (e.g., thermistors) included in detection element 12. Wirings L7 to L9 are each connected to detection elements 12 arranged at different stacking positions (positions in the first direction D1).

Wiring L1, L2, L7, and L8 are connected to the detection element 12 arranged at end 2b of the module stack 2. Wiring L3 to L6, and L9 are connected to the detection element 12 arranged at end 2c of the module stack 2. Wiring L1 to L9 are connected to the detection elements 12 so that the number of circuits connected to one detection element 12 is not two or more.

The pair of guide members 30 guide the wiring L1 to L9 along one side surface 2a of the module stack 2. The guide members 30 are attached to the side surface 2a. The side surface 2a is the opposite side of the duct 21, i.e., the side surface on the outlet 5c side, and extends in the first direction D1 and the second direction D2. The guide member 30A is disposed on the end portion 2b side, and guides the wiring L1, L2, L7, and L8 from the end portion 2b of the module stack 2 to the restraint plate 8A. The guide member 30B is disposed on the end portion 2c side, and guides the wiring L3 to L6, and L9 from the end portion 2c of the module stack 2 to the restraint plate 8A.

1, 2, 8 and 9, the guide member 30 has an L-shaped main body 31 including a first extension 32 and a second extension 33, a third extension 34, a connecting portion 35, a first fixing portion 36, a second fixing portion 37, a first locking portion 38, a second locking portion 39, a protruding portion 40, and a plurality of (six in this embodiment) cover portions 41. The guide member 30 is made of insulating resin such as polypropylene (PP). Each portion of the guide member 30 is integrally formed as a single member, for example, by injection molding of the resin. The linear expansion coefficient of the guide member 30 is greater than the linear expansion coefficient of the restraining plate 8 and the bolt collar 9b, for example.

The first extension portion 32 extends along the second direction D2. The second extension portion 33 extends along the first direction D1. The main body portion 31 may be generally L-shaped, and the angle between the first extension portion 32 and the second extension portion 33 is, for example, 45 degrees or more and 135 degrees or less. In the guide member 30A shown in Figures 8 and 9, the angle between the first extension portion 32 and the second extension portion 33 is 90 degrees. The guide member 30B differs from the guide member 30A in that the angle between the first extension portion 32 and the second extension portion 33 is greater than 90 degrees, but is otherwise identical to the guide member 30A.

The first extension portion 32 may extend along the second direction D2 when viewed from the first direction D1, and may be inclined with respect to the second direction D2 at a predetermined angle range (e.g., 45 degrees or less) when viewed from the third direction D3. The second extension portion 33 may extend along the first direction D1 when viewed from the second direction D2, and may be inclined with respect to the first direction D1 at a predetermined angle range (e.g., 45 degrees or less) when viewed from the third direction D3. The first extension portion 32 has a curved shape along the outer surface of the bolt collar 9b at the portion where it intersects with the bolt collar 9b. The first extension portion 32 extends through the outside of the bolt collar 9b.

The main body 31 includes a first end 31a, a second end 31b, a first connection portion 31c, and a second connection portion 31d. The first end 31a is one end of the first extension portion 32 in the second direction D2. The second end 31b is one end of the second extension portion 33 in the first direction D1. The first connection portion 31c is a portion where the other end of the first extension portion 32 in the second direction D2 and the other end of the second extension portion 33 in the first direction D1 are connected. The second connection portion 31d is a portion where the second extension portion 33 and the third extension portion 34 are connected, and is located between the second end 31b of the second extension portion 33 and the first connection portion 31c.

The third extension portion 34 extends along the first extension portion 32 in the second direction D2 and is connected to the second connection portion 31d. The third extension portion 34 is disposed away from the first extension portion 32 in the first direction D1. The third extension portion 34 is disposed side by side with the first extension portion 32 in the first direction D1. The length of the third extension portion 34 in the second direction D2 is equal to the length of the first extension portion 32 in the second direction D2. At the portion where the third extension portion 34 intersects with the bolt collar 9b, the third extension portion 34 has a curved shape that follows the outer surface of the bolt collar 9b. The third extension portion 34 extends through the outside of the bolt collar 9b.

The first extension portion 32, the second extension portion 33, and the third extension portion 34 are semi-cylindrical groove members with half of their circumference cut out, or groove members with a U-shaped cross section, and are configured to be able to accommodate the wirings L1 to L9 inside. The first extension portion 32, the second extension portion 33, and the third extension portion 34 are arranged on the side surface 2a so that the cut-out portion in the circumferential direction is located on the opposite side of the side surface 2a. The first extension portion 32, the second extension portion 33, and the third extension portion 34 are interposed between the wirings L1 to L9 and the side surface 2a, and protect the wirings L1 to L9 from contact with the side surface 2a.

In the guide member 30A, the wirings L1 and L2 are guided along the second direction D2 by the third extension portion 34 and along the first direction D1 by the second extension portion 33. In the guide member 30A, the wirings L7 and L8 are guided along the second direction D2 by the first extension portion 32 and along the first direction D1 by the second extension portion 33. In the guide member 30B, the wirings L3 to L6 are guided along the second direction D2 by the first extension portion 32 and along the first direction D1 by the second extension portion 33. In the guide member 30B, the wiring L9 is guided along the second direction D2 by the third extension portion 34 and along the first direction D1 by the second extension portion 33.

The connecting portion 35 extends along the first direction D1 and connects the first extension portion 32 and the third extension portion 34. The connecting portion 35 is disposed away from the second extension portion 33 in the second direction D2. The portion of the first extension portion 32 to which the connecting portion 35 is connected is located closer to one end (first end 31a) than the other end (first connection portion 31c) in the second direction D2. The portion of the third extension portion 34 to which the connecting portion 35 is connected is located closer to one end 34a than the other end (second connection portion 31d) in the second direction D2. The connecting portion 35 functions as a spacer that separates the first extension portion 32 and the third extension portion 34 in the first direction D1. The connecting portion 35 keeps the first extension portion 32 and the third extension portion 34 separated from each other in the first direction D1. The connecting portion 35 has multiple hollow portions (not shown) that penetrate the connecting portion 35 in the third direction D3.

As shown in Figures 1, 2 and 8 to 12, the first locking portion 38 is provided at the first end 31a. The first locking portion 38 is provided so as to protrude from the first end 31a toward the restraining plate 8B in the first direction D1. The first locking portion 38 is inserted into a recess 16A provided in the restraining plate 8B and is locked to the restraining plate 8B. The first locking portion 38 is locked to the restraining plate 8B so as to be movable in the first direction D1 and the second direction D2. The first locking portion 38 is press-fitted into the recess 16A. Since the recess 16A extends along the second direction D2, the first locking portion 38 can slide within the recess 16A along the second direction D2.

The first locking portion 38 has a pair of side surfaces 38a that face opposite each other in the third direction D3 and face the side walls 16a, 16b of the recess 16A. The first locking portion 38 has a plurality of hollowed-out portions 38b that penetrate the first locking portion 38 in the third direction D3. A protrusion 38c is provided at both ends of each side surface 38a in the third direction D3. The protrusion 38c protrudes in the third direction D3 and extends along the first direction D1. In the portion of the protrusion 38c on the first fixing portion 36 side, the height at which the protrusion 38c protrudes from the side surface 38a decreases as it approaches the first fixing portion 36.

When the first locking portion 38 is pressed into the recess 16A, the protrusion 38c receives stress from the side walls 16a and 16b in the third direction D3. As a result, as shown in FIG. 11, the tip of the protrusion 38c is plastically deformed so as to be crushed. As a result, the first locking portion 38 is locked into the recess 16A.

The first fixing portion 36 is provided at the first end 31a together with the first locking portion 38. The first fixing portion 36 is provided at the end of the first locking portion 38 on the side of the restraining plate 8B. The first fixing portion 36 is inserted into a through hole 16d that penetrates the restraining plate 8B in the first direction D1, and is fixed to the restraining plate 8B. The first fixing portion 36 has a shaft portion 42 and a pair of claw portions 43. The shaft portion 42 extends along the first direction D1. The pair of claw portions 43 are provided on both sides of the shaft portion 42 in the second direction D2 so as to sandwich the shaft portion 42 in the second direction D2. A stepped portion 43a is provided at the tip of the claw portion 43.

The pair of claws 43 are attached to the tip of the shaft 42 so that they can be opened and closed in the second direction D2 by elastic deformation. After the pair of claws 43 are inserted into the through hole 16d with the pair of claws 43 closed in the second direction D2 (the tips of the claws 43 approach the shaft 42 in the second direction D2), the pair of claws 43 open in the second direction D2 (the tips of the claws 43 move away from the shaft 42 in the second direction D2) and the stepped portion 43a comes into contact with and hooks onto the end of the outer surface 10a side of the through hole 16d (the corner formed by the inner surface of the through hole 16d and the outer surface 10a), thereby fixing the first fixing portion 36 to the restraining plate 8B.

The protruding portion 40 is provided at the second end 31b. The protruding portion 40 extends from the second end 31b in the third direction D3 and protrudes onto the outer surface 10a of the edge portion 10 of the restraining plate 8A. The protruding portion 40 has a plurality of recesses 40a that open to the outside in the first direction D1 (the opposite side to the outer surface 10a). The recesses 40a function as recesses (thin portions) of the protruding portion 40.

The second fixing portion 37 is provided at the second end 31b together with the overhanging portion 40. The second fixing portion 37 is provided on the surface facing the outer surface 10a of the overhanging portion 40. The second fixing portion 37 is inserted into the through hole 16d penetrating the restraining plate 8A in the first direction D1 and fixed to the restraining plate 8A. Although detailed illustration is omitted, the second fixing portion 37 has a shaft portion 42 and a pair of claw portions 43 like the first fixing portion 36, and is fixed to the restraining plate 8A by inserting the pair of claw portions 43 into the through hole 16d in a closed state and then opening the pair of claw portions 43. The first fixing portion 36 and the second fixing portion 37 are provided at positions that do not overlap each other when viewed from either the first direction D1 or the second direction D2.

1, 2, 8, 9, 13, and 14, the second locking portion 39 is provided on the first connection portion 31c. The second locking portion 39 is provided so as to protrude from the first connection portion 31c toward the restraining plate 8B in the first direction D1. The second locking portion 39 is inserted into a recess 16A provided in the restraining plate 8B and is locked to the restraining plate 8B. The second locking portion 39 is locked to the restraining plate 8B so as to be movable in the first direction D1 and the second direction D2. The second locking portion 39 is press-fitted into the recess 16A. Since the recess 16A extends along the second direction D2, the second locking portion 39 can slide in the recess 16A along the second direction D2. The first locking portion 38 and the second locking portion 39 are press-fitted into different recesses 16A.

The second locking portion 39 has a pair of side surfaces 39a that face opposite each other in the third direction D3 and face the side walls 16a, 16b of the recess 16A. The second locking portion 39 has a plurality of hollowed-out portions 39b that penetrate the second locking portion 39 in the third direction D3. A protrusion 39c is provided at both ends of each side surface 39a in the second direction D2. The protrusion 39c protrudes in the third direction D3 and extends along the first direction D1. In the portion of the protrusion 39c on the tip side of the second locking portion 39, the height at which the protrusion 39c protrudes from the side surface 39a decreases as it approaches the tip of the second locking portion 39.

When the second locking portion 39 is pressed into the recess 16A, the protrusion 39c receives stress in the third direction D3 from the side walls 16a and 16b (see FIG. 11). As a result, the tip of the protrusion 39c is plastically deformed so as to be crushed, similar to the protrusion 38c of the first locking portion 38. As a result, the second locking portion 39 is locked into the recess 16A.

As shown in Figs. 1, 2, 8 and 9, the multiple cover parts 41 cover the circumferentially cut-out portions of the first extension part 32, the second extension part 33 and the third extension part 34. The multiple cover parts 41 are arranged spaced apart from each other. In this embodiment, two cover parts 41 are provided on each of the first extension part 32, the second extension part 33 and the third extension part 34. The first end part 31a, the second end part 31b and one end part 34a of the third extension part 34 in the second direction D2 are all covered by the cover parts 41. The first connection part 31c and the second connection part 31d are not covered by the cover parts 41.

The multiple cover parts 41 are attached to the first extension part 32, the second extension part 33, and the third extension part 34 so as to be openable and closable. Figs. 15 and 16 show an example of a cover part 41 provided at one end 34a of the third extension part 34. The cover part 41 is connected to the third extension part 34 by a pair of hinge-shaped connecting parts 41a. The connecting parts 41a are thin-walled and configured to be elastically deformable. This allows the cover part 41 to be in a closed state (covering the cut-out part of the third extension part 34) as shown in Fig. 15, and an open state as shown in Fig. 16.

When the cover 41 is closed, it is fixed to the third extension 34 by a latch mechanism. The latch mechanism is composed of holes 41b, 41c provided in the cover 41, and protrusions 45, 46 provided in the first extension 32, the second extension 33, and the third extension 34 that engage with the holes 41b, 41c.

Next, we will explain the operation and effects of the energy storage device 1 according to this embodiment.

In the energy storage device 1, the L-shaped main body 31 of the guide member 30 is fixed to the restraint plate 8B by the first fixing portion 36, fixed to the restraint plate 8A by the second fixing portion 37, and engaged to the restraint plate 8B by the second engaging portion 39. Therefore, the guide member can reliably guide the wiring L1 to L9 along the side surface 2a of the module stack 2 without coming off the restraint plates 8A and 8B due to vibration or the like. The second engaging portion 39 is engaged to the restraint plate 8B so as to be movable in the first direction D1 and the second direction D2. Therefore, when the module stack 2 and the guide member 30 expand and contract in the first direction D1 and the second direction D2 with different linear expansion coefficients, the second engaging portion 39 moves in the first direction D1 and the second direction D2 in response to the deformation, thereby suppressing damage to the guide member 30. When the module stack 2 and the guide member 30 expand and contract in the third direction D3 with different linear expansion coefficients, the main body 31 deforms in a flexible manner starting from the first fixing portion 36, the second fixing portion 37, and the second locking portion 39, thereby preventing damage to the guide member 30.

The wiring L1 to L9 are connected to the detection elements 12 provided at the ends 2b and 2c of the module stack 2 in the second direction D2. The guide member 30 guides the wiring L1 to L9 from the detection elements 12 at the ends 2b and 2c to the restraining plate 8A. Because the wiring L1 to L9 are connected to the ends 2b and 2c of the module stack 2, the distance over which the guide member 30 guides the wiring L1 to L9 along the second direction D2 tends to be long. This tends to increase the difference in the amount of expansion and contraction along the second direction D2 between the guide member 30 and the module stack 2. Therefore, a configuration in which the second engaging portion 39 is movable in the second direction D2 is particularly effective.

The wiring L1 to L9 includes wiring L1 to L6 connected to the voltage detection element and wiring L7 to L9 connected to the temperature detection element. The wiring L1 to L6 connected to the voltage detection element generates electromagnetic noise (electromagnetic waves). Therefore, a configuration that can reduce the effect of electromagnetic noise on the temperature detection signal is particularly effective. The voltage level of the voltage detection signal is higher than the voltage level of the temperature detection signal.

The guide member 30 further has a third extension portion 34 extending along the second direction D2 and connected between the second end 31b and the first connection portion 31c of the second extension portion 33. The third extension portion 34 is arranged away from the first extension portion 32 in the first direction D1. The wiring L1, L2 is guided by the third extension portion 34 and the second extension portion 33 of the guide member 30A. The wiring L7, L8 is guided by the first extension portion 32 and the second extension portion 33 of the guide member 30A. In this way, according to the guide member 30A, the wiring L1, L2 connected to the voltage detection element and the wiring L7, L8 connected to the temperature detection element can be arranged by separating the paths by the first extension portion 32 and the third extension portion 34. Therefore, the influence of electromagnetic noise on the temperature detection signal can be reduced.

Wiring L3 to L6 are guided by the first extension portion 32 and the second extension portion 33 of the guide member 30B. Wiring L9 is guided by the third extension portion 34 and the second extension portion 33 of the guide member 30B. In this way, with the guide member 30B, the wiring L3 to L6 connected to the voltage detection element and the wiring L9 connected to the temperature detection element can be routed along separate paths by the first extension portion 32 and the third extension portion 34. This reduces the effect of electromagnetic noise on the temperature detection signal.

The guide member 30 includes a connecting portion 35 that connects the first extension portion 32 and the third extension portion 34. The connecting portion 35 is spaced apart from the second extension portion 33 in the second direction D2 and extends along the first direction D1. This makes it easier for the first extension portion 32 and the third extension portion 34 to be kept spaced apart from each other. This further reduces the effect of electromagnetic noise on the temperature detection signal.

When viewed from the first direction D1, the restraint plate 8B has an edge 10 adjacent to the module stack 2 in the third direction D3. The edge 10 has a recess 16 that opens to the inside of the first direction D1 and extends along the second direction D2. The second locking portion 39 is press-fitted into the recess 16A. This makes it easy to realize a configuration in which the second locking portion 39 is locked to the restraint plate 8B and can move in the first direction D1 and the second direction D2.

The first fixing portion 36 is inserted into the through hole 16d that penetrates the restraint plate 8B in the first direction D1. This makes it easy to fix the first fixing portion 36 to the restraint plate 8B.

The second fixing portion 37 is inserted into the through hole 16d that penetrates the restraint plate 8A in the first direction D1. This makes it easy to fix the second fixing portion 37 to the restraint plate 8A.

This disclosure is not limited to the above embodiments.

In the above embodiment, the through hole 16d penetrates the bottom wall 16c in the first direction D1, but for example, the through hole 16d may penetrate the side wall 16b arranged on the outside of the third direction D3 (the opposite side of the module stack 2) in the third direction D3. In this case, for example, the first fixing portion 36 and the second fixing portion 37 can be configured to protrude from the first end 31a and the second end 31b in the third direction D3 and be inserted into the corresponding through hole 16d.

In the above embodiment, the pair of restraining plates 8 have different shapes in terms of the positions of the through holes 16d, but they may have the same shape. In this case, for example, the shape of each restraining plate 8 can be a common shape in which the through holes 16d are provided at positions corresponding to the first fixing portion 36 and the second fixing portion 37.

In the above embodiment, the energy storage device 1 includes a pair of guide members 30, but it is sufficient to include at least one guide member 30. The wiring lines L1 to L9 are connected to a voltage detection element and a temperature detection element, but they may be connected to other elements. The guide member 30 does not need to include the third extension portion 34. It is sufficient for the guide member 30 to be configured to guide at least one wiring line.

In the above embodiment, the outer surface 10a is located inside the outer surface 11a in the first direction D1, but the outer surface 10a may be located on the same plane as the outer surface 11a or may be located outside the outer surface 11a in the first direction D1. The inner surface 10b is located inside the inner surface 11b in the first direction D1, but the inner surface 10b may be located on the same plane as the inner surface 11b or may be located outside the inner surface 11b in the first direction D1.

In the above embodiment, the area of the current collector 5 as viewed from the first direction D1 is smaller than the area of the storage module 3, but from the viewpoint of improving heat dissipation, it may be the same as the area of the storage module 3 or may be larger than the area of the storage module 3.

The insulating plate 20 may be box-shaped and connected to both ends of the bottom 20a in the second direction D2 and further having a pair of sides extending in the first direction D1.

1...energy storage device, 2...module stack, 2a...side surface, 2b, 2c...end portion, 3...energy storage module, 35...connecting portion, 8, 8A, 8B...restraint plate, 10...edge portion, 16, 16A, 16B...recess, 16d...through hole, 12...detecting element, 30, 30A, 30B...guide member, 31...main body portion, 31a...first end portion, 31b...second end portion, 31c...first connecting portion, 32...first extending portion, 33...second extending portion, 34...third extending portion, 36...first fixing portion, 37...second fixing portion, 38...first locking portion, L1 to L9...wiring.

Claims (8)

a module stack including a plurality of power storage modules stacked in a first direction;
a first constraining plate and a second constraining plate that are stacked on both sides of the module stack in the first direction and that apply a constraining load to the module stack in the first direction;
Wiring connected to the module stack;
a guide member that guides the wiring along a side surface of the module stack;
Equipped with
The side surface extends in the first direction and in a second direction perpendicular to the first direction,
The guide member is
an L-shaped main body including a first extension portion extending along the second direction and a second extension portion extending along the first direction;
a first fixing portion provided at a first end of the main body portion and fixed to the first restraint plate;
a second fixing portion provided at a second end of the main body portion and fixed to the second restraint plate;
a locking portion provided at a connection portion between the first extension portion and the second extension portion and locked to the first restraint plate so as to be movable in the first direction and the second direction;
having
Energy storage device. the wiring is connected to an end of the module stack in the second direction,
The guide member guides the wiring from the end portion to the second restraint plate.
The power storage device according to claim 1 . the wiring includes a first wiring and a second wiring,
the guide member further includes a third extending portion extending along the second direction and connected between the second end of the second extending portion and the connection portion,
The third extension portion is disposed apart from the first extension portion in the first direction,
the first wiring is guided by the first extension portion and the second extension portion,
the second wiring is guided by the third extension portion and the second extension portion;
The power storage device according to claim 1 or 2. One of the first wiring and the second wiring is connected to a voltage detection element, and the other is connected to a temperature detection element.
The power storage device according to claim 3 . The guide member further includes a connecting portion that is spaced apart from the second extending portion in the second direction, extends along the first direction, and connects the first extending portion and the third extending portion.
The power storage device according to claim 3 or 4. the first restraint plate has an edge portion adjacent to the module stack in a third direction perpendicular to the first direction and the second direction when viewed from the first direction,
The edge portion has a recess that opens to the inside in the first direction and extends along the second direction,
The locking portion is press-fitted into the recess.
The power storage device according to any one of claims 1 to 5. The first fixing portion is inserted into a through hole penetrating the first restraint plate in the first direction or a through hole penetrating the first restraint plate in a third direction perpendicular to the first direction and the second direction.
The power storage device according to any one of claims 1 to 6. The second fixing portion is inserted into a through hole penetrating the first restraint plate in the first direction or a through hole penetrating the first restraint plate in a third direction perpendicular to the first direction and the second direction.
The present invention relates to an electric storage device according to any one of claims 1 to 7.

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