Energy storage device

Abstract

Energy storage device (1), comprising: an energy storage module (3); a pair of current collector plates (5A; 5B) configured to be stacked in order to insert the energy storage module (3) between them in a first direction which is vertical; a pair of insulating plates (20A; 20B) configured to be stacked to insert the energy storage module (3) and the pair of current collector plates (5A; 5b) in the first direction between them; and a pair of locking plates (8A; 8B) configured to be stacked to insert the energy storage module (3), the pair of current collector plates (5A; 5B) and the pair of insulating plates (20A; 20B) in the first direction between them, wherein the energy storage module (3) comprises a receiving space which receives an electrolytic solution together with an energy generation element (13), a pressure adjustment valve (18) connected to the receiving chamber is provided on a side surface of the energy storage module (3), the insulating plate, which is arranged on a lower side in the first direction with respect to the energy storage module (3), is configured to encompass a main body section (21) arranged between the current collector plate and the locking plate, and a liquid receiving section (22) provided on an outer edge section (21c) of the main body section (21), arranged at least at a position corresponding to the pressure adjustment valve (18) when viewed from the first direction, and storing the electrolyte solution dispensed by the energy storage module (3), and the main body section (21) and the fluid intake section (22) are formed in one piece.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an energy storage device. BACKGROUND

[0002] An energy storage device comprising a plurality of stacked energy storage modules is known in the prior art. Furthermore, a bipolar battery with a bipolar electrode is known in the prior art, wherein a positive electrode is formed on one surface of an electrode plate and a negative electrode on the other surface. An electrolyte solution is located inside the sealed energy storage module. The plurality of energy storage modules are stacked and held in the stacking direction by locking plates at both end sections (Japanese Unexamined Patent Publication JP 2007 213 990 A). SUMMARY

[0003] In this setup, the electrolyte solution is contained within the sealed energy storage modules, but there is a possibility of leakage. Therefore, in the energy storage device described above, it is necessary to prevent the fluid from leaking out of the device.

[0004] It is an objective of the present disclosure to solve the above problem and to provide an energy storage device that can prevent the leakage of liquid outside the device.

[0005] An energy storage device according to the present disclosure comprises an energy storage module, a pair of current collector plates configured to be stacked to insert the energy storage module between them in a first direction, which is vertical, a pair of insulating plates configured to be stacked to insert the energy storage module and the pair of current collector plates between them in a first direction, and a pair of locking plates configured to be stacked to insert the energy storage module, the pair of current collector plates, and the pair of insulating plates between them in a first direction. The energy storage module is configured to include a receiving chamber that accommodates an electrolytic solution together with a power generating element. A pressure-adjusting valve, connected to the receiving chamber, is provided on a side face of the energy storage module.The insulating plate, located on a lower side in the first direction with respect to the energy storage module, is configured to comprise a main body section situated between the current collector plate and the locking plate, and a fluid receiving section provided at an outer edge section of the main body section, positioned at least at a location corresponding to the pressure adjustment valve when viewed from the first direction, and which stores the electrolyte solution dispensed by the energy storage module. The main body section and the fluid receiving section are formed as a single piece.

[0006] In this energy storage device, an insulating plate is positioned between the current collector plate and the locking plate. This ensures insulation between the locking plate and the current collector plate. In this configuration, the insulating plate, located on the underside of the energy storage module in the first direction, includes a fluid receiving section. This section is positioned at least one way from the pressure adjustment valve, and it stores the electrolyte solution ejected from the energy storage module. Therefore, the fluid receiving section can retain the fluid from the pressure adjustment valve even when the electrolyte solution is being ejected from the pressure adjustment valve within the energy storage module. In this case, the main body and the fluid receiving section are formed as a single unit.Therefore, it is possible to prevent liquid leakage at the boundary between the main body section and the liquid intake section. Based on the above explanations, it is possible to prevent liquid leakage from the device.

[0007] The liquid intake section is configured to include a bottom wall section and a receiving side wall section, and is formed in a recess shape through these sections. A drain port is provided in the liquid intake section, and this drain port discharges the electrolyte solution stored within the liquid intake section into a drain storage section in the energy storage device. In this case, the liquid intake section, in the form of a recess, acts as a container that receives the electrolyte solution flowing out of the energy storage module. Therefore, the amount of electrolyte solution that the liquid intake section can hold can be increased.Furthermore, the drain nozzle can ensure that the electrolyte solution stored in the liquid intake section flows to the drainage storage section, preventing it from overflowing.

[0008] The bottom wall section is configured to have a sloping section inclined relative to one plane direction of the main body section. The drain port is configured to be located at the bottom of the bottom wall section in the first direction. In this configuration, the liquid intake section can collect the absorbed electrolyte solution through the inclined section. Furthermore, the liquid intake section can drain the electrolyte solution from the drain port, preventing overflow.

[0009] The insulating plate can be configured to have a sidewall section extending to at least one side in the first direction at a different position than the fluid absorption section in the outer edge section of the main body section. In this case, the insulating plate can also ensure the insulation distance through the sidewall sections at a different position than the fluid absorption section. Furthermore, the sidewall sections can also serve as an alignment element between the insulating plate and the locking plate.

[0010] The energy storage module is configured to have current extraction surfaces at both ends when viewed from the first direction. The current collector plate, which is in contact with the insulating plate containing the fluid absorption section, is configured to have a flat plate section that is in electrical contact with the current extraction surface of the energy storage module, and an extraction section connected to the flat plate section that extracts current from the energy storage module. The extraction section is located on the side opposite the fluid absorption section with respect to the energy storage module when viewed from the first direction. In this configuration, the current collector plate can extract current at a high power level.Since the extraction section is located on the side opposite the liquid intake section, it is also possible to prevent the current collector plate and the locking plate from being short-circuited via the extraction section and the electrolytic solution.

[0011] According to the present disclosure, it is possible to provide an energy storage device that can prevent the leakage of liquid outside the device. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of an energy storage device according to an exemplary embodiment. Fig. Figure 2 is an unfolded perspective view of a configuration of the energy storage device near an end section on a negative side in the Z-axis direction. Fig. Figure 3 is an unfolded perspective view showing an overall configuration of an insulator and a locking plate. Fig. Figure 4 is a perspective view showing a state in which a current collector plate, an insulating plate and a locking plate are assembled. Fig. 5 is a cross-section along line VV in Fig. 4. Fig. Figure 6 is a cross-sectional view along line VI-VI in Fig. 4. Fig. Figure 7 is a cross-sectional view along line VII-VII in Fig. 4. Fig. Figure 8 is a cross-sectional view along line VIII-VIII in Fig. 2. Fig. Figure 9 is a cross-sectional view of an energy storage device according to a comparative example. DETAILED DESCRIPTION

[0012] Exemplary embodiments of the present disclosure are described in detail below with reference to the attached drawings. The same reference numerals are used for identical or equivalent elements in the description of the drawings, and duplicate descriptions are omitted.

[0013] An energy storage device 1 according to the present embodiment is described with reference to Fig. 1 described. Fig. Figure 1 is a side view of energy storage device 1.

[0014] The energy storage device 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The energy storage device 1 comprises a module stacking body 2 and a retaining or locking element 4. The module stacking body 2 comprises a plurality of stacked energy storage modules 3. The locking element 4 exerts a retaining force on the module stacking body 2 from both sides in the stacking direction (first direction). The energy storage module 3 has, for example, a rectangular shape when viewed from the stacking direction. For the sake of simplicity, in this description, the stacking direction is defined as the Z-axis direction, the longitudinal direction of the energy storage module 3 as viewed from the stacking direction as the Y-axis direction, and the transverse direction of the energy storage module 3 as the X-axis direction.The stacking direction is the direction in which the energy storage module 3 and a pair of current collector plates 5A and 5B (described later) are stacked. Furthermore, in this description, the terms "top" and "bottom" are used with respect to the orientation when the energy storage device 1 is used. The positive side in the Z-axis direction corresponds to the top side and the negative side to the bottom side. However, the terms "top" and "bottom" are not limited to the orientation of the energy storage device 1 at the time of delivery. In addition, in the energy storage device 1 according to the present embodiment, the insulating plate 20A can be arranged on the bottom side, since an insulating plate 20A on the top side and an insulating plate 20B on the bottom side have the same structure.

[0015] The module stack body 2 comprises a plurality (7 in the present embodiment) of energy storage modules 3 and a plurality (8 in the present embodiment) of current collector plates 5. The energy storage module 3 is, for example, a bipolar battery. The energy storage module 3 is a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery. However, the energy storage device 1 is not limited to the secondary batteries described above, but can, for example, be an electrical double-layer capacitor. In the present embodiment, the energy storage device 1 is a nickel-hydrogen secondary battery.

[0016] The numerous energy storage modules 3 are stacked above the current collector plates 5. The energy storage modules 3, which are adjacent to each other in the Z-axis direction, are electrically connected to each other via the current collector plates 5. In the present embodiment, as shown in Fig. As shown in Figure 1, the plurality of (8) current collector plates 5 are configured with a current collector plate 5A at one end in the Z-axis direction, a current collector plate 5B at the other end, and a plurality of (6) current collector plates 5C arranged between the energy storage modules 3. The current collector plates 5C are provided between the energy storage modules 3 that are adjacent to each other in the Z-axis direction. Between the energy storage modules 3 that are adjacent to each other in the Z-axis direction, the current collector plates 5C are arranged between the exposed electrode sections of the facing electrode stack bodies.

[0017] The current collector plates 5A and 5B are positioned on the positive and negative sides, respectively, in the Z-axis direction of the energy storage module 3, which is located at the stack end of the multiple energy storage modules 3. In this way, the current collector plates 5A and 5B are stacked such that the energy storage modules 3 lie between them in the Z-axis direction, which is the stacking direction. The Z-axis direction is vertical. As shown in Fig. As shown in Figure 1, a negative electrode terminal 7 is connected to one of the current collector plates 5A. A positive electrode terminal 6 (extraction section) is connected to the other current collector plate 5B. The negative electrode terminal 7 and the positive electrode terminal 6 project from the edge sections of the current collector plates 5A and 5B in the Y-axis direction. The energy storage device 1 is charged and discharged via the negative electrode terminal 7 and the positive electrode terminal 6. The negative electrode terminal 7 and the positive electrode terminal 6 are provided at the end sections of the energy storage device 1 on the negative side in the Y-axis direction.Furthermore, in the present embodiment, the negative electrode connection 7 is provided at a position closer to the positive side in the X-axis direction, and the positive electrode connection 6 is provided at a position closer to the negative side in the X-axis direction.

[0018] The locking element 4 comprises a pair of locking plates 8 (one locking plate 8A on the negative electrode connection side 7 and one locking plate 8B on the positive electrode connection side 6) that vertically enclose the module stack body 2 from both sides in the Z-axis direction, and a plurality of connecting elements 9 that connect the pair of locking plates 8. The pair of locking plates 8 holds the energy storage module 3 and the current collector plates 5A and 5B securely in the Z-axis direction, which is the stacking direction. Furthermore, the two locking plates 8 are stacked such that they vertically enclose the energy storage module 3, the current collector plates 5A and 5B, and the insulating plates 20A and 20B in the Z-axis direction, which is the stacking direction. The connecting element 9 exerts the holding force on the module stack body 2 in the Z-axis direction via the pair of locking plates 8.In the present embodiment, the connecting element 9 is equipped with a screw 9a and a nut 9b for fastening a pair of locking plates 8.

[0019] The locking plate 8 is a rectangular metal plate with an area that, viewed in the Z-axis direction, is one size larger than the areas of the energy storage module 3 and the current collector plate 5. The locking plate 8 comprises a main body section 11 that overlaps the module stack body 2 in the Z-axis direction, and an edge section 10 that extends from the main body section 11 in the X-axis direction and does not overlap the module stack body 2 in the Z-axis direction. In the present embodiment, a pair of edge sections 10 is provided on both sides of the main body section 11 in the X-axis direction. That is, the main body section 11 is positioned between the pair of edge sections 10.Edge section 10 has an outer surface 10a facing outwards in the Z-axis direction (the side opposite energy storage module 3 in the Z-axis direction), and an inner surface 10b facing inwards in the Z-axis direction (the side of energy storage module 3 in the Z-axis direction). Main body section 11 has an outer surface 11a facing outwards in the Z-axis direction and an inner surface 11b facing inwards in the Z-axis direction. The outer surface 10a is located inside the outer surface 11a in the Z-axis direction. The inner surface 10b is located inside the inner surface 11b in the Z-axis direction.

[0020] The pair of edge sections 10 are outer edge sections extending longitudinally (in the Y-axis direction) of the locking plate 8. The two edge sections 10 are arranged such that they do not overlap the module stack body 2 when viewed in the Z-axis direction. Each edge section 10 is provided with a plurality of insertion holes 10c into which a screw 9a is inserted. In each edge section 10, the plurality of insertion holes 10c are arranged such that they are separated from one another along the longitudinal direction (Y-axis direction) of the locking plate 8. In the present embodiment, the plurality of insertion holes 10c are arranged at equal intervals from one end to the other of the edge section 10 in the longitudinal direction of the locking plate 8.

[0021] The head of screw 9a is positioned on the outer surface 10a of the locking plate 8A. A pointed section (screw tip) of the shaft section of screw 9a protrudes from the outer surface 10a of the locking plate 8B. A nut 9b is screwed into the pointed section of screw 9a. The nut 9b is positioned on the outer surface 10a of the locking plate 8B. In this way, the multiple energy storage modules 3 and the multiple current collector plates 5 are positioned between the locking plates 8A and 8B and form a unit with the module stack body 2. Furthermore, a holding force is applied to the module stack body 2 in the Z-axis direction.

[0022] An insulating plate 20A is provided between the current collector plate 5A and the locking plate 8A. Additionally, an insulating plate 20B is provided between the current collector plate 5B and the locking plate 8B. The insulating plates 20A and 20B ensure insulation between the current collector plates 5A and 5B and the locking plates 8A and 8B.

[0023] Next, a configuration of the energy storage device 1 near the end section in the Z-axis direction is described with reference to Fig. 2 described in more detail. Fig. Figure 2 is an unfolded perspective view of the configuration of the energy storage device 1 near the end section on a negative side in the Z-axis direction. Fig. 2 describes the configuration near the end section that corresponds to the negative side (positive electrode connection side 6) in the Z-axis direction, but also near the end section that corresponds to the positive side (negative electrode connection side 7) in the Z-axis direction, has a structure with the same effect.

[0024] As in Fig. As shown in Figure 2, the energy storage device 1 comprises the energy storage module 3 at the end section in the Z-axis direction, a current collector plate 5B, the insulating plate 20B, and the locking plate 8B near the end section on the negative side in the Z-axis direction. The energy storage module 3, the current collector plate 5B, the insulating plate 20B, and the locking plate 8B have a rectangular plate shape, with the Y-axis direction being the longitudinal direction. The current collector plate 5B comes into contact with the insulating plate 20B, which has a liquid-receiving section 22 described later.

[0025] The energy storage module 3 is configured with a bipolar electrode, in which a positive electrode is formed on one surface of the electrode plate and a negative electrode on the other surface, and a stacked body 13 (energy generation element) configured by stacking a plurality of separators. Furthermore, a frame-shaped sealing element 14 (frame body) is provided on a circumferential section of the stacked body 13, so that the stacked body 13 is sealed by the sealing element 14. An electrolytic solution is enclosed inside the stacked body 13. The energy storage module 3 has current extraction surfaces 13a at both ends in the Z-axis direction. The current extraction surface 13a is a surface for extracting the current from the energy storage module 3 and is formed by exposing the electrodes of the stacked body 13 by the sealing element 14.

[0026] The current collector plate 5B comprises a flat plate section 15, which is provided for the energy storage module 3 and the positive electrode terminal 6 described above. The flat plate section 15 is in contact with the current extraction surface 13a of the energy storage module 3. The entire area of ​​the flat plate section 15 is shaped and sized to overlap the current extraction surface 13a when viewed in the Z-axis direction. The positive electrode terminal 6 is located on the outer edge section 15a of the flat plate section 15 on the negative side in the Y-axis direction. The positive electrode terminal 6 is located on the side opposite the liquid absorption section 22 with respect to the energy storage module 3 when viewed from the Z-axis direction. The liquid absorption section 22 is located on the positive side in the Y-axis direction.In this way, a pair of current collector plates can handle 5A (see . Fig. 1) and the current collector plate 5B is positioned such that the current extraction surfaces 13a are located between the modules at both end faces in the stacking direction. In the present embodiment, several energy storage modules 3 are stacked. Therefore, the current collector plate 5A (see Fig. 1) in contact with the current extraction surface 13a on the positive side in the Z-axis direction of the energy storage module 3, and the current collector plate 5B is in contact with the current extraction surface 13a on the negative side of the energy storage module 3 in the Z-axis direction. However, the energy storage device 1 can also comprise only one energy storage module 3. In this case, the current collector plates 5A and 5B are positioned such that the current extraction surfaces 13a are located between them on both sides of a power storage module 3.

[0027] The insulating plate 20B is an element made of an insulating material, such as resin, and is arranged between the current collector plate 5B and the locking plate 8B. The insulating plate 20B ensures insulation between the current collector plate 5B and the locking plate 8B. The insulating plate 20B is located on the lower side (i.e., the negative side in the Z-axis direction) of the energy storage module 3 in the stacking direction. The insulating plate 20B is positioned so that it overlaps the entire area of ​​the flat plate section 15 of the current collector plate 5B in the Z-axis direction. Consequently, the insulating plate 20B is positioned where the current collector plate 5B and the locking plate 8B are opposite each other, thus ensuring insulation between them.A terminal block protection section 16, which covers the terminal block 17 described later, is formed on a cover section 24 of the insulating plate 20B on the negative side in the Y-axis direction. The more detailed structure of the insulating plate 20B will be described later.

[0028] As described above, the locking plate 8B comprises a flat main body section 11 and a pair of edge sections 10, in which an insertion hole 10c is formed for inserting a bolt. The terminal block 17 is attached to the outer edge section 8a of the locking plate 8B on the negative side in the Y-axis direction. The positive electrode terminal 6 and the wiring (not shown) are connected to the terminal block 17.

[0029] The following describes a configuration of the insulator 20 based on a positional relationship between the energy storage module 3, the current collector plate 5B, and the locking plate 8B, with reference to the Fig. 3 to 8 are described in detail. Fig. Figure 3 is an unfolded perspective view showing an overall configuration of the insulator 20 and the locking plate 8B. Fig. Figure 4 is a perspective view showing a state in which the current collector plate 5B, the insulating plate 20B and the locking plate 8B are assembled. Fig. Figure 5 is a cross-sectional view along line VV in Fig. 4. Fig. Figure 6 is a cross-sectional view along line VI-VI in Fig. 4. Fig. Figure 7 is a cross-sectional view along line VII-VII in Fig. 4. Fig. Figure 8 is a cross-sectional view along line VIII-VIII in Fig. 2.

[0030] As in Fig. As shown in Figure 3, the insulating plate 20B comprises a main body section 21, a fluid receiving section 22, side wall sections 23A and 23B, and a cover section 24. The following description explains the position of the insulating plate 20B on the lower side of the energy storage module 3 in a vertical direction, taking into account its relationship to the flow of the electrolyte solution discharged from the energy storage module 3. That is, the electrolyte solution flows from the positive side to the negative side in the Z-axis direction. In the following description, the positive side in the Z-axis direction may sometimes be referred to as "top" and the negative side in the Z-axis direction as "bottom".The insulating plate 20B is also provided between the locking plate 8A and the current collector plate 5A, which is arranged on the positive side in the Z-axis direction, and thus the insulating plate 20B also has a configuration of the same effect, such as vertically symmetrical with the insulating plate 20B on the negative side in the Z-axis direction, which is in . Fig. 3 and the like. Therefore, when the positive side is oriented towards the bottom in the Z-axis direction, since the electrolytic solution discharged from the energy storage module 3 flows from the negative side to the positive side in the Z-axis direction, the insulating plate 20B on the side of the locking plate 8A absorbs the electrolytic solution.

[0031] The main body section 21 is a planar section located between the flat plate section 15 of the current collector plate 5B and the main body section 11 of the locking plate 8. The main body section 21 has a rectangular shape with a longitudinal direction along the Y-axis. The main body section 21 includes outer edge sections 21a and 21b, which form a pair of short sides that are parallel to each other in the Y-axis direction at both end faces in the X-axis direction.

[0032] The outer edge section 21a is located on the negative side in the Y-axis direction, and the outer edge section 21b is located on the positive side in the Y-axis direction. The main body section 21 comprises outer edge sections 21c and 21d, which form a pair of longitudinal sides parallel to each other in the Y-axis direction at both end faces in the X-axis direction. The outer edge section 21c is located on the negative side in the X-axis direction, and the outer edge section 21d is located on the positive side in the X-axis direction. The main body section 21 has essentially the same shape and size as the main body section 11 of the locking plate 8B. The main body section 21 is slightly longer on both sides in the Y-axis direction than the locking plate 8B (see Fig. 6 and Fig. 8) The main body section 21 has a shape and size that overlaps the entire area of ​​the flat plate section 15 of the current collector plate 5B as seen in the Z-axis direction.

[0033] The fluid intake section 22 is a section provided on the outer edge section 21b of the positive side of the main body section 21 in the Y-axis direction and receives the electrolyte solution dispensed from the energy storage module 3. As shown in Fig. As shown in Figure 4, a pressure-adjusting valve 18, which is connected to a receiving chamber for the electrolytic solution together with the stacked body 13, is provided on a side surface 3a on the positive side of the energy storage module 3 in the direction of the Y-axis. The pressure-adjusting valve 18 is a valve that preferably discharges the internal electrolytic solution when the pressure reaches a predetermined level if an abnormality occurs in the internal pressure of the energy storage module 3. That is, among the side surfaces of the energy storage module 3, the side surface 3a on the positive side in the Y-axis direction, where the pressure-adjusting valve 18 is provided, corresponds to a position where the electrolytic solution is most easily discharged.On the other hand, the insulating plate 20B has a liquid receiving section 22 on the outer edge section 21b on the positive side in the Y-axis direction, which is a position corresponding to the pressure adjustment valve 18. As described above, the liquid receiving section 22 is located in a position that is at least equivalent to the pressure adjustment valve 18 when viewed from the Z-axis direction, which is the stacking direction, and stores the electrolyte solution discharged from the energy storage module 3. Consequently, the liquid receiving section 22 can rapidly receive the electrolyte solution discharged by the pressure adjustment valve 18. In the figure, the pressure adjustment valve 18 is formed in a plurality of areas (a total of four areas), although a multi-stage outlet opening may be provided in one area.

[0034] As in Fig. 4 to Fig. As shown in Figure 6, the liquid intake section 22 is recessed or hollowed out towards the bottom, i.e., the negative side in the Z-axis direction (the side opposite the energy storage module 3). Consequently, the liquid intake section 22 is recessed towards the bottom and forms an interior SP (see Figure 6). Fig. 5), which serves as a container for receiving the electrolyte solution. The interior SP is open on its upper surface and extends in the X-axis direction along the outer edge section 21b of the main body section 21. The interior SP is located below the pressure adjustment valve 18. The interior SP extends in the X-axis direction so that it is located below all pressure adjustment valves 18.

[0035] As in Fig. As shown in Figure 4, the liquid receiving section 22 comprises a pair of receiving sidewall sections 31 and 32, which point in the direction of the Y-axis, and a bottom wall section 33, which forms the bottom surface that receives the electrolyte solution. The liquid receiving section 22 is formed in the form of a recess by the bottom wall section 33 and the receiving sidewall sections 31 and 32. The receiving recess section 35 is formed by the structure of the recess shape. A drain nozzle 37 is provided in the liquid receiving section 22, and the drain nozzle 37 directs the electrolyte solution stored in the liquid receiving section 22 to a drain storage section 50 (see Figure 4). Fig. 1) in the energy storage device 1. As in Fig. As shown in Figure 1, the drain storage section 50 is connected to a connecting line 51, and the connecting line 51 is connected to the drain nozzle 37. The drain storage section 50 is configured with a drain tray, a drain tank, and the like for storing the discharged electrolyte solution.

[0036] As in Fig. As shown in Figure 4, the receiving side wall section 31 extends from the outer edge section 21b of the main body section 21 to the lower side. The receiving side wall section 32 faces the receiving side wall section 31 at a position separated from the receiving side wall section 31 in the positive direction along the Y-axis, such that it is parallel to the receiving side wall section 31. The receiving side wall sections 31 and 32 have the same shape when viewed from the Y-axis direction. The receiving side wall sections 31 and 32 have a shape corresponding to the outer edge section 8b (see Figure 4). Fig. 3) the positive side of the locking plate 8B in the Y-axis direction when viewed from the Y-axis direction, and also act as a cover section that covers the outer edge section 8b. Therefore, the receiving side wall section 31 faces the outer edge section 8b of the locking plate 8B in a state where they are close together in the Y-axis direction (see Fig. 6) The receiving sidewall sections 31 and 32 extend over the entire length of the outer edge section 21b of the main body section 21 in the X-axis direction and further extend such that they cover the edge sections 10 on both sides of the locking plate 8E in the X-axis direction. The distance of receiving sidewall section 32 from receiving sidewall section 31 in the Y-axis direction is not particularly limited and can be appropriately adjusted according to the amount of electrolyte solution that can be discharged or ejected from the energy storage module 3. At a minimum, receiving sidewall section 32 is provided in a position on the positive side in the Y-axis direction with respect to the pressure adjustment valve 18 (see Fig. 6).

[0037] The bottom wall section 33 extends in the Y-axis direction between the receiving side wall section 31 and the receiving side wall section 32 and extends in the X-axis direction such that it corresponds to the entire area of ​​the outer edge section 21a of the main body section 21. As in Fig. As shown in Figure 5, the base wall section 33 comprises inclined sections 34A and 34B and a base section 36. The base section 36 is located in the central position of the main body section 21 in the X-axis direction. The inclined section 34A is located on the positive side of the base section 36 in the X-axis direction. The inclined section 34B is located on the negative side of the base section 36 in the X-axis direction.

[0038] The inclined sections 34A and 34B are inclined with respect to the plane direction (XY plane direction) of the main body section 21. The inclined section 34A is connected to the bottom section 36 by inclined from the position of the outer edge section 21d on the positive side of the main body section 21 in the X-axis direction towards the bottom side on the negative side in the X-axis direction. The inclined section 34B is connected to the bottom section 36 by inclined from the position of the outer edge section 21c on the negative side of the main body section 21 in the X-axis direction towards the bottom side on the positive side in the X-axis direction.

[0039] The bottom section 36 extends parallel to the direction of the XY plane between the inclined section 34A and the inclined section 34B. Bottom section 36 corresponds to the position furthest from the energy storage module 3 in the Z-axis direction, i.e., the lowest position below the bottom wall section 33. Therefore, the electrolyte solution that has fallen into the interior SP is guided through the inclined surfaces of the inclined sections 34A and 34B and collected in bottom section 36. The drain nozzle 37 is formed in this bottom section 36. Thus, the drain nozzle 37 is located at the position of the bottom wall section 33 that is at its lowest point in the Z-axis direction. The drain nozzle 37 is a tubular element that extends vertically. The drain nozzle 37 is open at the position of bottom section 36 and extends downwards from bottom section 36.

[0040] A plurality of downward-pointing ribs 39 are provided on the lower side of the bottom wall section 33. The rib 39 extends in the Y-axis direction between the receiving side wall section 31 and the receiving side wall section 32. The plurality of ribs 39 are arranged such that they are separated from each other at a predetermined distance in the X-axis direction. The provision of such ribs 39 improves the strength of the liquid receiving section 22. In addition, the plurality of ribs 39 also have a beneficial effect in ensuring the isolation distance described later.

[0041] On both sides in the X-axis direction, the fluid receiving sections 22 have shapes that correspond to the edge sections 10 of the locking plate 8B. In particular, an upper wall section 41 is provided, extending outwards in the X-axis direction from the upper ends of the side wall sections 23A and 23B. Furthermore, a side wall section 42 is formed, extending downwards in the X-axis direction from the outer end section of the upper wall section 41. The receiving side wall sections 31 and 32 also extend to the positions corresponding to these upper wall sections 41 and the side wall section 42 (see also Fig. 4).

[0042] The main body section 21 and the fluid-receiving section 22 are formed as a single piece. Here, the condition in which the main body section 21 and the fluid-receiving section 22 are formed as a single piece means a condition in which the main body section 21 and the fluid-receiving section 22 are connected without any interruption, so that the configuration materials are continuously connected. In particular, as shown in Fig. Figure 6 shows the outer edge section 21b of the main body section 21 and the upper end section of the receiving side wall section 31 connected as the same element in a state in which the configuration materials are continuously connected without the presence of a discontinuity (the boundary section between the main body section 221 and the fluid receiving section 222), as in Fig. Figure 9 illustrates this. If the insulating plate 20B is made of resin material, the main body section 21 and the liquid absorption section 22 are formed in one piece by molding in the same mold. If the main body section 21 and the liquid absorption section 22 are formed in the same process using a 3D printer or similar device, both are formed in one piece or integrally. Or, if the base material is processed by cutting or similar methods to form the shapes of the main body section 21 and the liquid absorption section 22, both are formed in one piece.

[0043] As in the Fig. 3 and Fig. As shown in Figure 4, side wall sections 23A and 23B extend towards the top (side of the energy storage module 3 in the stacking direction) at the positions of the outer edge sections 21d and 21c that are not the liquid receiving section 22. Side wall sections 23A and 23B extend along the Y-axis over the entire length of the outer edge sections 21d and 21c. Furthermore, near the end section on the positive side, side wall sections 23A and 23B extend along the Y-axis to the receiving side wall section 32 of the liquid receiving section 22.

[0044] The side wall section 23B is described with reference to Fig. 7 is described in more detail. The side wall section 23A has a shape symmetrical to the side wall section 23B in the X-axis direction. The side wall section 23B rises essentially vertically upwards from the outer edge section 21c of the main body section 21. The side wall section 23B is positioned such that it faces a rising surface 10d on the inside of the edge section 10 of the locking plate 8B in the X-axis direction, in a state where it has a slight gap in the X-axis direction. As a result, the side wall section 23B is positioned between the edge section 10 of the locking plate 8B, the current collector plate 5B, and the energy storage module 3 in the X-axis direction. The side wall section 23B extends the insulation distance between the current collector plate 5B and the locking plate 8B to a position higher than the edge section 10 of the locking plate 8B.In the present embodiment, the side wall section 23B extends to a position below the energy storage module 3, but the extent of the extension is not particularly limited.

[0045] As in Fig. 2 and Fig. As shown in Figure 3, the cover section 24 is provided on the outer edge section 21a of the main body section 21 on the negative side in the Y-axis direction. The cover section 24 extends downwards from the outer edge section 21a. The cover section 24 extends in the X-axis direction over the entire length of the outer edge section 21a. In addition, the cover section 24 rises upwards from the outer edge section 21a to cover the edge section 10 on both sides of the locking plate 8B and has a section that extends outwards from the outer edge section 21a in the X-axis direction. As shown in Fig. As shown in Figure 8, the cover section 24 faces the outer edge section 8a in the Y-axis direction on the negative side of the locking plate 8B in the Y-axis direction in a closed position. The cover section 24 extends downwards to essentially the same position as the lower side of the locking plate 8B.

[0046] The side wall sections 23A and 23B and the cover section 24 are formed integrally with the main body section 21. However, the side wall sections 23A and 23B and the cover section 24 need not necessarily be formed integrally with the main body section 21, and an element different from the main body section 21 can be attached to the main body section 21 from the rear.

[0047] The following describes the effects of the energy storage device 1 according to the present embodiment. The following description describes the effect of the insulating plate 20B between the current collector plate 5B on the negative side in the Z-axis direction and the locking plate 8B, but the same effect is realized for the insulating plate 20B between the current collector plate 5A on the positive side in the Z-axis direction and the locking plate 8A.

[0048] In the energy storage device 1, the insulating plate 20B is arranged between the current collector plate 5B and the locking plate 8B. The insulating plate 20B is positioned so that it overlaps the flat plate section 15 of the current collector plate 5B when viewed from the stacking direction. Consequently, the insulating plate 20B is always positioned where the locking plate 8B and the current collector plate 5B face each other in the stacking direction. Therefore, insulation between the locking plate 8B and the current collector plate 5B is ensured.In such a configuration, the insulating plate 20B, which is arranged on the lower side in the stacking direction with respect to the energy storage module 3, includes a liquid receiving section 22 located at a position that corresponds at least to the pressure adjustment valve 18 when viewed from the Z-axis direction, which is the stacking direction, and which stores the electrolyte solution discharged from the energy storage module 3. Therefore, the liquid receiving section 22 can receive the electrolyte solution from the pressure adjustment valve 18 even when the electrolyte solution is discharged from the pressure adjustment valve 18 in the energy storage module 3 (see the electrolyte solution L in ). Fig. 6) Furthermore, the insulating plate 20B, which absorbs the electrolytic solution discharged from the liquid receiving section 22, makes it possible to prevent the current collector plate 5B and the locking plate 8B from being short-circuited via the electrolytic solution.

[0049] On the other hand, in the present embodiment, the main body section 21 and the liquid receiving section 22 are formed integrally. Therefore, it is possible to prevent liquid leakage at the interface between the flat plate section 15 and the liquid receiving section 22. Based on the foregoing, it is possible to prevent liquid leakage to the outside of the device. Even if the electrolyte solution leaks from inside the energy storage module 3, as in the present embodiment, the condition in which the collected electrolyte solution, which is received by the liquid receiving section 22, is positioned so that it does not leak out at an unintended location, corresponds to a condition in which leakage to the outside of the device is suppressed.

[0050] Here, the insulating board 220 is used according to the comparative example with reference to Fig. 9 described. The insulating plate 220 includes a fluid absorption section 222 as an element separate from the main body section 221. The fluid absorption section 222 is connected to the main body section 221 by a fitting structure or the like. In this case, the insulation distance between the current collector plate 5B and the locking plate 8B is the distance along the path (the path of an arrow indicated by a dashed line). The path extends from the outer edge section of the current collector plate 5B to the positive side in the Y-axis direction along the upper surface of the main body section 221, and around the outer edge section 221b of the main body section 221 to extend to the negative side in the Y-axis direction along the lower surface of the main body section 221, and then reaches the locking plate 8B.As described above, since the isolation distance is limited to the distance between the upper surface and the lower surface near the outer edge section 221b on the negative side of the main body section 221 in the Y-axis direction, a long isolation distance cannot be guaranteed.

[0051] On the other hand, in the insulating plate 20B, the insulation distance between the current collector plate 5B and the locking plate 8B can be maintained for a longer period than in the case where the liquid intake section 222 and the main body section 221 are separate bodies, as in the comparative example. As in Fig. As shown in Figure 6, the path R1, which determines the insulation distance, traces a path with an H-shaped cross-section of the liquid receiving section 22 after the outer edge section 21b has been folded from the upper surface of the main body section 21, and then reaches the locking plate 8B from the lower surface of the main body section 21. In this way, the insulation distance is increased, as is the cross-sectional shape of the liquid receiving section 22. This ensures insulation between the locking plate 8B and the current collector plate 5B.

[0052] The liquid intake section 22 comprises the bottom wall section 33 and the intake side wall sections 31 and 32, and is configured as a recess by the bottom wall section 33 and the intake side wall sections 31 and 32. The drain nozzle 37 is provided in the liquid intake section 22, and the drain nozzle 37 discharges the electrolytic solution stored in the liquid intake section 22 to a drain storage section 50 in the energy storage device 1. In this case, a recessed intake section of the liquid intake section 22 acts as a reservoir that receives the electrolytic solution flowing out of the energy storage module 3. Therefore, the amount of electrolytic solution that can be received by the liquid intake section 22 can be increased.Furthermore, the drain nozzle 37 can allow the electrolytic solution stored in the liquid intake section 22 to flow into the drain storage section 50, so that it does not overflow.

[0053] The pressure-adjusting valve 18 is provided at the end section of the energy storage module 3, and the insulating plate 20B includes a fluid intake section 22 at a position at least equivalent to the pressure-adjusting valve 18. In this case, the fluid intake section 22 can be arranged in the insulating plate 20B near the pressure-adjusting valve 18, where the leakage is likely to occur. Therefore, the fluid intake section 22 can quickly absorb the electrolyte solution if the fluid leak from the pressure-adjusting valve 18 occurs.

[0054] The insulating plate 20B comprises the side wall sections 23A and 23B, which extend towards the top (one side) in the stacking direction at a position different from the liquid-receiving section 22 (outer edge sections 21c and 21d) of the outer edge section of the main body section 21. In this case, the insulating plate 20B can also ensure the insulating distance through the side wall sections 23A and 23B at a position different from the liquid-receiving section 22. In particular, as shown in Fig. As shown in Figure 7, the insulation distance, as specified in path R2, is extended by the amount by which side wall section 23B rises. Furthermore, side wall sections 23A and 23B can also serve as an alignment element between the insulating plate 20B and the locking plate 8B. Consequently, alignment between the insulating plate 20B and the locking plate 8B can be easily achieved by attaching the insulating plate 20B to the edge section 10 on both sides of the locking plate 8B along side wall sections 23A and 23B. Even at the end section of the negative side in the direction of the Y-axis, as shown in path R3 in Figure 7, the alignment can be achieved by attaching the insulating plate 20B to the edge section 10 on both sides of the locking plate 8B along side wall sections 23A and 23B. Fig. As specified in 8, the insulation distance is extended by the amount of the cover section 24.

[0055] The bottom wall section 33 comprises inclined sections 34A and 34B, which are inclined with respect to the XY plane direction, which is the plane direction of the main body section 21, and the drain nozzle 37 is provided at a position that is the lowest side of the bottom wall section 33 in the Z-axis direction. In this case, the liquid intake section 22 can collect the absorbed electrolyte solution through the inclined sections 34A and 34B. Furthermore, the liquid intake section 22 can drain the electrolyte solution from the drain nozzle 37, so that the collected electrolyte solution does not overflow.

[0056] The energy storage module 3 comprises the current extraction surfaces 13a at both ends in the Z-axis direction. The current collector plate 5B, which is in contact with the insulating plate 20B and has the liquid receiving section 22, comprises the flat plate section 15, which is in electrical contact with the current extraction surface 13a of the energy storage module 3, and the positive electrode terminal 6, which is connected to the flat plate section 15 and draws the current from the energy storage module 3. The positive electrode terminal 6 is provided on the side opposite the liquid receiving section 22 with respect to the energy storage module 3 when viewed from the Z-axis direction. In this case, the current collector plate 5B can draw the current at a high power.Since the positive electrode terminal 6 is located on the side opposite the liquid receiving section 22, it is also possible to prevent the current collector plate 5B and the locking plate 8B from being short-circuited via the positive electrode terminal 6 and the electrolytic solution.

[0057] The present disclosure is not limited to the embodiments described above.

[0058] The shape of the liquid receiving section is not limited to the embodiments described above; its shape is not particularly restricted as long as it is formed integrally with the main body section 21 and can receive the electrolyte solution released from the energy storage module 3. For example, the shape can be a curved groove, or the main body section 21 can simply be extended to the positive side in the Y-axis direction and bent so that it rises upwards at the tip end. Furthermore, the shape of the locking plate is not particularly restricted.

[0059] Furthermore, at least one of the side wall sections 23A and 23B and the cover section 24 of the insulating panel 20B can be omitted.

[0060] In the embodiment described above, the insulating plate 20B comprises the side wall sections 23A and 23B, which extend in the stacking direction at positions other than the liquid-receiving section 22 (the outer edge sections 21c and 21d) beneath the outer edge sections of the main body section 21 towards the top. However, depending on the shape of the locking plate, the insulating plate may have a side wall section that extends in the stacking direction towards the bottom. For example, by arranging the side wall section on the bottom so that it faces the side surface of the locking plate, alignment between the insulating plate and the locking plate is made possible, and thus the insulating distance can be increased. The insulating plate may have a side wall section that extends towards both the top and the bottom.

[0061] An energy storage device comprises an energy storage module, a pair of current collector plates configured to be stacked to insert the energy storage module vertically between them, a pair of insulating plates configured to be stacked to insert the energy storage module and the pair of current collector plates vertically between them, and a pair of locking plates configured to be stacked to insert the energy storage module, the pair of current collector plates, and the pair of insulating plates vertically between them. The energy storage module is configured to include a receiving chamber that accommodates an electrolytic solution along with a power generation element. A pressure-adjusting valve, commuting with the receiving chamber, is provided on a side face of the energy storage module.The insulating plate, located on a lower side in the first direction with respect to the energy storage module, is configured to comprise a main body section situated between the current collector plate and the locking plate, and a fluid receiving section provided at an outer edge section of the main body section, positioned at least at a location corresponding to the pressure adjustment valve when viewed from the first direction, and which stores the electrolyte solution dispensed by the energy storage module. The main body section and the fluid receiving section are formed as a single piece. REFERENCE MARK LIST: 1 Energy storage device 3 Energy storage module 5A; 5B Current collector plates 20A; 20B Insulation boards 8A; 8B Locking plates 13 Energy generation element 18 Pressure adjustment valve 21 Main body section 22 Fluid intake section 33 Floor wall section 31 Recording side wall section 37 drain spouts 50 Drainage storage section 34A; 34B inclined section 23A; 23B Side wall section 21c outer edge section 13a Current extraction areas 15 flat plate section 6 Extraction section

Claims

[1] Energy storage device (1), comprising: an energy storage module (3); a pair of current collector plates (5A; 5B) configured to be stacked in order to insert the energy storage module (3) between them in a first direction which is vertical; a pair of insulating plates (20A; 20B) configured to be stacked to insert the energy storage module (3) and the pair of current collector plates (5A; 5b) in the first direction between them; and a pair of locking plates (8A; 8B) configured to be stacked to insert the energy storage module (3), the pair of current collector plates (5A; 5B) and the pair of insulating plates (20A; 20B) in the first direction between them, wherein the energy storage module (3) comprises a receiving space which receives an electrolytic solution together with an energy generation element (13), a pressure adjustment valve (18) connected to the receiving chamber is provided on a side surface of the energy storage module (3), the insulating plate, which is arranged on a lower side in the first direction with respect to the energy storage module (3), is configured to encompass a main body section (21) arranged between the current collector plate and the locking plate, and a liquid receiving section (22) provided on an outer edge section (21c) of the main body section (21), arranged at least at a position corresponding to the pressure adjustment valve (18) when viewed from the first direction, and storing the electrolyte solution dispensed by the energy storage module (3), and the main body section (21) and the fluid intake section (22) are formed in one piece. [2] Energy storage device (1) according to claim 1, wherein the liquid receiving section (22) comprises a bottom wall section (33) and a receiving side wall section (31) and is formed in a recess shape through the bottom wall section (33) and the receiving side wall section (31), and a drain nozzle (37) is provided in the liquid receiving section (22), and the drain nozzle (37) discharges the electrolytic solution stored in the liquid receiving section (22) to a drain storage section (50) in the energy storage device (1). [3] Energy storage device (1) according to claim 2, wherein the bottom wall section (33) has an inclined section (5A; 34B) which is inclined with respect to a plane direction of the main body section (21), and the drain nozzle (37) is provided at a position which is a bottom side of the floor wall section (33) in the first direction. [4] Energy storage device (1) according to any one of claims 1 to 3, wherein the insulating plate has a side wall section (23A; 23B) which extends to at least one side in the first direction at a position other than the liquid receiving section (22) in the outer edge section (21c) of the main body section (21). [5] Energy storage device (1) according to any one of claims 1 to 4, wherein the energy storage module (3) has current extraction surfaces (13a) at both ends in the first direction, the current collector plate, which is in contact with the insulating plate with the liquid receiving section (22), comprises a flat plate section (15) which is in electrical contact with the current extraction surface (13a) of the energy storage module (3), and an extraction section (6) which is connected to the flat plate section (15) and extracts a current from the energy storage module (3), and the extraction section (6) is provided on a side opposite the liquid intake section (22) in relation to the energy storage module (3) when viewed from the first direction.

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