ENERGY STORAGE DEVICE

Abstract

An energy storage device comprises a first energy storage cell, a second energy storage cell, and an adhesive material. A first recessed section is formed on a side face of a cell housing of the first energy storage cell, recessed from a main surface toward a gap between first arc-shaped sections. A second recessed section is formed on a side face of a cell housing of the second energy storage cell, recessed from a main surface toward a gap between second arc-shaped sections. The adhesive material fills both the first and second recessed sections.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention The present disclosure relates to an energy storage device. 2. Description of the state of the art JP 2021 - 089 812 A discloses a battery module in which several secondary batteries are arranged side by side. SUMMARY OF THE INVENTION In the battery module described in JP 2021 - 089 812 A, it is conceivable that a misalignment will occur between the secondary batteries (energy storage devices) when they expand (contract) due to charging and discharging. The present disclosure was made to solve the aforementioned problem, and one of its objectives is to provide an energy storage device that can suppress misalignment between adjacent energy storage cells. An energy storage device according to one aspect of the present disclosure comprises a first energy storage cell comprising a plurality of first wound electrode assemblies arranged side by side in a first direction, and a first housing that receives the first wound electrode assemblies; a second energy storage cell comprising a plurality of second wound electrode assemblies arranged side by side in the first direction, and a second housing that receives the second wound electrode assemblies; and an adhesive material arranged between the first housing and the second housing. Each of the first wound electrode assemblies is wound such that it surrounds a circumference of a first winding axis extending in an axial direction that intersects the first direction.Each of the second wound electrode assemblies is wound to surround a circumference along a second winding axis extending in the axial direction. The second energy storage cell is positioned adjacent to the first energy storage cell in a second direction that intersects both the first direction and the axial direction. The first housing comprises a first side surface located on the side of the second housing in the second direction. The second housing comprises a second side surface located on the first housing side in the second direction. Each of the first wound electrode assemblies is positioned opposite the first side surface and, viewed from a position away from the first energy storage cell in the axial direction, comprises a first arcuate section with an arcuate shape.Each of the second wound electrode assemblies is positioned opposite the second side surface and, viewed from a position axially removed from the second energy storage cell, comprises a second arc-shaped section. The first side surface comprises a first main surface and a first recessed section extending from the first main surface to a first gap formed in the first side surface between the first arc-shaped sections oriented in the first direction. The second side surface comprises a second main surface and a second recessed section extending from the second main surface to a second gap formed in the second side surface between the second arc-shaped sections oriented in the first direction.The adhesive material fills both the first recessed section and the second recessed section. According to the present disclosure, misalignment between adjacent energy storage cells can be suppressed. BRIEF DESCRIPTION OF THE FIGURES Features, advantages, and the technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying figures, in which the same reference numerals denote the same elements, and in which: Fig. 1 is a perspective exploded view illustrating the structure of an energy storage device according to a first embodiment; Fig. 2 is a top view illustrating the structure of the energy storage device according to the first embodiment; Fig. 3 is a perspective exploded view illustrating the structure of an energy storage cell according to the first embodiment; Fig. 4 is a sectional view illustrating the structure of the energy storage cell according to the first embodiment; Fig. 5 is a top view illustrating the structure of an energy storage device according to a second embodiment; Fig.6 is a sectional view illustrating the structure of the energy storage cell according to the second embodiment; and Fig. 7 is a sectional view along line VII-VII in Fig. 5. DETAILED DESCRIPTION OF THE EXECUTION FORMS Embodiments of the present disclosure are described with reference to the figures. It should be noted that identical or equivalent elements are designated by the same reference numerals in the figures mentioned below. First embodiment Fig. 1 is a perspective exploded view illustrating the structure of an energy storage device 1 according to a first embodiment of the present disclosure. The energy storage device 1 is, for example, installed in a vehicle (not shown). Examples of the vehicle are a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a battery electric vehicle. Note that the energy storage device 1 can also be provided in electrical equipment other than the vehicle (e.g., in a stationary energy storage device). Note that in the present description, the X-direction, the Y-direction, and the Z-direction are mutually perpendicular directions. For example, the X-direction and the Y-direction can each correspond to a forward-backward direction or longitudinal direction and a right-left direction or transverse direction, respectively, when the energy storage device 1 is installed in the vehicle. Furthermore, the Z-direction can be an up-down direction or vertical direction. In particular, a Z1-direction and a Z2-direction can each point upwards and downwards, respectively. Note that the X-direction and the Y-direction in the present disclosure are examples of the "second direction" and the "first direction," respectively. Furthermore, the Z-direction in the present disclosure is an example of an "axial direction." The energy storage device 1 comprises several energy storage stacks 10, a housing 20, an insulating plate 30, a plate element 40, a wiring plate 50, an accessory 60, and a cooling device 70. Each of the energy storage stacks 10 is in the form of a rectangular cuboid long in the Y direction. The energy storage stacks 10 are arranged in the X direction. Each of the energy storage stacks 10 comprises several energy storage cells 100 arranged in the Y direction. The housing 20 accommodates the energy storage stacks 10, the wiring plate 50, the accessories 60, and the cooling device 70. The housing 20 comprises a lower housing part 210 and an upper cover 220. The upper cover 220 is located above (Z1 side) the lower housing part 210. The lower housing part 210 is open at the top. The lower housing part 210 is made of a metal, for example aluminum or the like. The lower housing part 210 comprises a base plate 211, a perimeter wall 212, a partition wall 213 and a partition wall 214. The base plate 211 has the shape of a plate. The base plate 211 has a plurality of through holes 211h, which are spaced apart in the X and Y directions. The perimeter wall 212 extends vertically upwards from an outer perimeter edge area of ​​the base plate 211. The perimeter wall 212 has a shape that surrounds the energy storage stacks 10. An end plate 212c and an end plate 212d are arranged separately from each other in the Y-direction. The end plate 212c and the end plate 212d extend in the X-direction. The end plate 212c connects one end of a side wall 212a to one end of a side wall 212b. The end plate 212d connects the other end of the side wall 212a to the other end of the side wall 212b. The partition walls 213 and 214 are arranged within an area enclosed by the base plate 211 and the perimeter wall 212. Partition wall 213 is adjacent to the end plate 212c. Partition wall 214 is spaced from the end plate 212d in the Y direction. Partition walls 213 and 214 each extend in the X direction. The function of partition walls 213 and 214 is to delimit the energy storage stacks 10 on both sides in the Y direction. A space formed by the lower housing part 210 and the upper cover 220 accommodates the energy storage stacks 10, the wiring plate 50, the accessories 60 and the cooling device 70. The insulating plate 30 consists of an electrically insulating material (e.g., a plastic or resin composition). The insulating plate 30 is, for example, in the form of a plate. The insulating plate 30 has a plurality of through holes 30h spaced apart in the X and Y directions. The insulating plate 30 is arranged between the plate element 40 and the base plate 211 of the lower housing 210. The insulating plate 30 is attached to an underside of the base plate 211. The plate element 40 serves to protect the base plate 211 of the lower housing 210. The plate element 40 is designed to cover the insulating plate 30 and the underside of the base plate 211. The plate element 40 is, for example, in the form of a plate. The wiring plate 50 is arranged below the energy storage stacks 10. The wiring plate 50 comprises an insulating plate 51, several busbar modules 500, and several insulating protectors 52. The insulating plate 51 is made of an electrically insulating material (e.g., a resin composition). For example, the insulating plate 51 is made of a flexible plastic. The insulating plate 51 is, for example, in the form of a plate. The insulating plate 51 is arranged on a section of a top surface 211a of the bottom surface 211 of the lower housing 210, which is located between the partition 213 and the partition 214. The insulating plate 51 has several through holes 51h, which are formed at intervals in the X-direction and Y-direction. The busbar modules 500 are provided on a top surface 51a of the insulating plate 51. Each busbar module 500 comprises one or more busbars 510. Each busbar module 500 comprises several busbars 510 arranged in the Y-direction. Note that the number of busbar rows contained in the busbar module 500 can be one. Furthermore, the number of busbars 510 contained in the busbar row can be one. Each of the busbars 510 is made of a conductive material, such as a metal or the like. The busbar 510 electrically connects a pair of energy storage cells 100, which are arranged adjacent to each other in the Y direction. The energy storage stacks 10 are arranged on the top surfaces of the busbar modules 500. The external terminals of the energy storage cells 10 contained in each of the energy storage stacks 10 are connected to the busbar module 500, thus electrically connecting the energy storage cells 100 in series. The insulating protectors 52 are made of a heat-resistant material (e.g., mica). The insulating protectors 52 are provided on the upper surface 51a of the insulating plate 51. The insulating protectors 52 are designed to close the through-holes 51h arranged in the Y-direction. Each insulating protector 52 comprises a strip section 52a extending in the Y-direction and several blocking sections 52b formed on the underside of the strip section 52a. Each of the blocking sections 52b is arranged in a through-hole 51h. The cooling device 70 comprises several cooling plates 71, an accessory cooler 72, an upstream pipe 73, and a downstream pipe 74. Note that the cooling plate 71 is an example of a “cooling pipe” of the present disclosure. Each of the cooling plates 71 is arranged between a pair of energy storage stacks 10 that are adjacent to each other in the X direction. Each cooling plate 71 is designed in a plate shape that is long in the Y direction. Each cooling plate 71 has a channel through which coolant flows along the Y direction. In the first embodiment, the number of cooling plates 71 is five, but the number of cooling plates 71 is not limited to five. The number of cooling plates 71 is determined to match the number of energy storage stacks 10. The accessory cooler 72 cools the accessory 60. The accessory cooler 72 is positioned between the base plate 211 and the accessory 60. Fig. 2 is a top view schematically showing the energy storage device shown in Fig. 1 in a state in which its upper cover 220 is removed. Both the upstream pipe 73 and the downstream pipe 74 are pipes through which a coolant (water, oil, or the like) flows. An inlet opening 75 and an outlet opening 76 are provided at the end plate 212c of the circumferential wall 212. The upstream end section of the upstream pipe 73 is connected to the inlet opening 75. The upstream pipe 73 has six downstream end sections. One downstream end section of the upstream pipe 73 is connected to the accessory cooler 72. The remaining downstream end sections of the upstream pipe 73 are each connected to the cooling plate 71. The downstream pipe 74 has six upstream end sections. One upstream end section of the downstream pipe 74 is connected to the accessory cooler 72. The remaining upstream end sections of the downstream pipe 74 are each connected to the cooling plate 71. One end section of the downstream pipe 74 is connected to the outlet opening 76. The coolant supplied from the inlet opening 75 flows through the upstream pipe 73 into each of the cooling plates 71 and the accessory cooler 72, cools each of the energy storage cells 100 and the accessory 60, and then flows out of the outlet opening 76 through the downstream pipe 74. The cooling plates 71 are arranged between pairs of energy storage cells 100 that are adjacent in the X direction. Each cooling plate 71 is formed in a plate shape that is long in the Y direction. The side wall 212a, the side wall 212b, the end plate 212c and the end plate 212d are each provided with a fastening section 90, a fastening section 91, a fastening section 92 and a fastening section 93. Each of the fastening sections 90 to 93 is attached to a vehicle body (not shown in the figure). Fig. 3 is a perspective view showing the energy storage cells 100 adjacent to each other in the X direction. Note that in the following description of the energy storage cells 100, the energy storage cell 100 on the X1 side is referred to as energy storage cell 100A and the energy storage cell 100 on the X2 side is referred to as energy storage cell 100B. Note that energy storage cell 100A and energy storage cell 100B have the same structure. The energy storage cell 100A comprises a wound electrode assembly 300A, a wound electrode assembly 400A, a cell housing 500A, a cathode current collector 110A, and an anode current collector 120A. The energy storage cell 100B comprises a wound electrode assembly 300B, a wound electrode assembly 400B, a cell housing 500B, a cathode current collector 110B, and an anode current collector 120B. The energy storage cell 100A and the energy storage cell 100B are, respectively, examples of the "first energy storage cell" and the "second energy storage cell" of the present disclosure. Furthermore, the wound electrode assembly 300A is an example of the "first wound electrode assembly" and the "second electrode assembly" according to the present disclosure. The wound electrode assembly 400A is an example of a “first wound electrode assembly” and a “first electrode assembly” according to the present disclosure.The wound electrode assembly 300B is an example of a “second wound electrode assembly” and a “fourth electrode assembly” according to the present disclosure. The wound electrode assembly 400B is an example of a “second wound electrode assembly” and a “third electrode assembly” according to the present disclosure. Furthermore, the cell housing 500A and the cell housing 500B are examples of a “first housing” or receiving housing and a “second housing” according to the present disclosure. The 100A and 100B energy storage cells have the same basic structure. The 300B wound electrode assembly, the 400B wound electrode assembly, the 500B cell housing, the 110B cathode current collector, and the 120B anode current collector correspond to the 300A wound electrode assembly, the 400A wound electrode assembly, the 500A cell housing, the 110A cathode current collector, and the 120A anode current collector. Therefore, the following descriptions of components of the 100B energy storage cell that are identical to those of the 100A energy storage cell can be omitted or simplified. The wound electrode assembly 300A and the wound electrode assembly 400A are arranged side by side in the Y direction. The wound electrode assembly 300A and the wound electrode assembly 400A have the same construction. The wound electrode assembly 300A is wound such that it surrounds a circumference of a winding axis α1 extending in the Z-direction. The wound electrode assembly 400A is wound such that it surrounds a circumference of a winding axis α2 extending in the Z-direction. The position of the winding axis α1 in the X-direction is the same as the position of the winding axis α2 in the X-direction. Note that both the winding axis α1 and the winding axis α2 are examples of a "first winding axis" of the present disclosure. Similar to the wound electrode assembly 300A and the wound electrode assembly 400A, the wound electrode assembly 300B is wound such that it surrounds a circumference of a winding axis β1 extending in the Z direction, and the wound electrode assembly 400B is wound such that it surrounds a circumference of a winding axis β2 extending in the Z direction. Note that both the winding axis β1 and the winding axis β2 are examples of a “second winding axis” of the present disclosure. The wound electrode assembly 300A comprises a wound section 310A, a cathode terminal or cathode connection 320A and an anode terminal or anode connection 330A. The wound section 310A consists of an electrode plate group in which a cathode foil (not shown in the figure) and an anode foil (not shown in the figure) are wound with one or more separators (not shown in the figure) in between. The cathode terminal 320A protrudes from the wound section 310A towards the Z1 side. The cathode terminal 320A electrically connects the wound section 310A (cathode foil) and the cathode current collector plate 110A. Note that the cathode current collector plate 110A is electrically connected to an external cathode terminal of the energy storage cell 100A (not shown in the figure). The anode terminal 330A protrudes from the wound section 310A towards the Z1 side. The anode terminal 330A electrically connects the wound section 310A (anode foil) and the anode current collector plate 120A. Note that the anode current collector plate 120A is electrically connected to an external anode terminal of the energy storage cell 100A (not shown in the figure). The wound electrode assembly 400A comprises a wound section 410A, a cathode terminal 420A, and an anode terminal 430A. The wound section 410A, the cathode terminal 420A, and the anode terminal 430A have the same structures as the wound section 310A, the cathode terminal 320A, and the anode terminal 330A. The wound electrode assembly 300B comprises a wound section 310B, a cathode terminal 320B, and an anode terminal 330B. The wound electrode assembly 400B comprises a wound section 410B, a cathode terminal 420B, and an anode terminal 430B. The cell housing 500A accommodates the wound electrode assembly 300A and the wound electrode assembly 400A. The cell housing 500A comprises a base surface 510A and a circumferential wall 520A. The wound electrode assembly 300A and the wound electrode assembly 400A are surrounded by the circumferential wall 520A as viewed from position P1, which is located on the Z1 side of the cell housing 500A. The circumferential wall 520A has a side surface 521A, a side surface 522A, a side surface 523A and a side surface 524A. Note that side surface 521A is an example of a “first side surface” of the present disclosure. Side surface 521A is provided on an end section of cell housing 500A on the X2 side (cell housing 500B side). Side surface 522A is provided on an end section of cell housing 500A on the X1 side. Side surface 523A is provided on an end section of cell housing 500A on the Y2 side. Side surface 524A is provided on an end section of cell housing 500A on the Y1 side. An outlet valve 511A is provided on the bottom surface 510A. The outlet valve 511A is a pressure relief valve that releases gas to the outside from the cell housing 500A when the internal pressure of the gas in the cell housing 500A reaches or exceeds a certain value. The cell housing 500B contains the wound electrode assembly 300B and the wound electrode assembly 400B. The cell housing 500B comprises a base surface 510B and a circumferential wall 520B. The wound electrode assembly 300B and the wound electrode assembly 400B are surrounded by the circumferential wall 520B, as viewed from position P2, which is located on the Z1 side of the cell housing 500B. The perimeter wall 520B has a side surface 521B, a side surface 522B, a side surface 523B and a side surface 524B. Note that side surface 521B is an example of a “second side surface” of the present disclosure. Side surface 521B is provided on an end section of cell housing 500B on the X1 side (side facing cell housing 500A0). Side surface 522B is provided on an end section of cell housing 500B on the X2 side. Side surface 523B is provided on an end section of cell housing 500B on the Y2 side. Side surface 524B is provided on an end section of cell housing 500B on the Y1 side. An outlet valve 511B is provided on the underside 510B. The outlet valve 511B is a pressure relief valve, similar to the outlet valve 511A. The energy storage device 1 (Fig. 2) further comprises an adhesive material 600. The adhesive material 600 is arranged between the cell housing 500A and the cell housing 500B. The adhesive material 600 can consist of a resin (e.g., epoxy resin). Note that the material of the adhesive material 600 is not limited to this example. The cooling plate 71 passes through the adhesive material 600. Thus, the coolant flowing through the cooling plate 71 can effectively cool both the energy storage cell 100A and the energy storage cell 100B. Furthermore, the adhesive material 600 can cool both the energy storage cell 100A and the energy storage cell 100B. The adhesive material 600 comprises an adhesive layer 610 and an adhesive layer 620. The adhesive layer 610 is positioned (filled) between the cell housing 500A and the cooling plate 71. The adhesive layer 620 is positioned (filled) between the cell housing 500B and the cooling plate 71. The side surface 521A of the cell housing 500A comprises a main surface 525A. Furthermore, a recessed section 526A is formed in the side surface 521A, extending from the main surface 525A towards the X1 side. The recessed section 526A extends from an end section of the cell housing 500A on the Z1 side to an end section of the cell housing 500A on the Z2 side. Note that the main surface 525A and the recessed section 526A are, respectively, examples of the "first main surface" and the "first recessed section" of the present disclosure. A recessed section 527A with the same shape as the recessed section 526A is also formed in the side surface 522A of the cell housing 500A. The side surface 521B of the cell housing 500B comprises a main surface 525B. Furthermore, a recessed section 526B is formed in the side surface 521B, extending from the main surface 525B towards the X2 side. The recessed section 526B extends from an end section of the cell housing 500B on the Z1 side to an end section of the cell housing 500B on the Z2 side. Note that the main surface 525B and the recessed section 526B are, respectively, examples of the “second main surface” and the “second recessed section” of the present disclosure. A recessed section 527B similar to the recessed section 526B is also formed on the side surface 522B of the cell housing 500B. The wound electrode assembly 300A (the winding section 310A) comprises an arc-shaped section 340A and an arc-shaped section 350A. The arc-shaped section 340A is provided at an end section of the wound electrode assembly 300A on the X2 side. The arc-shaped section 350A is provided at an end section of the wound electrode assembly 300A on the X1 side. Viewed from position P1, the arc-shaped section 340A and the arc-shaped section 350A each have an arc-shaped form that is located in the Z direction away from the energy storage cell 100A. The arc-shaped section 340A is an example of a “first arc-shaped section” of the present disclosure. The wound electrode assembly 400A (the winding section 410A) comprises an arc-shaped section 440A and an arc-shaped section 450A. The arc-shaped section 440A is provided at an end section of the wound electrode assembly 400A on the X2 side. The arc-shaped section 450A is provided at an end section of the wound electrode assembly 400A on the X1 side. Viewed from position P1, both the arc-shaped section 440A and the arc-shaped section 450A have an arc-shaped form. Note that the arc-shaped section 440A is an example of a “first arc-shaped section” according to the present disclosure. The wound electrode assembly 300B (the wound section 310B) comprises an arc-shaped section 340B and an arc-shaped section 350B. The arc-shaped section 340B is provided at an end section of the wound electrode assembly 300B on the X1 side. The arc-shaped section 350B is provided at an end section of the wound electrode assembly 300B on the X2 side. Both the arc-shaped section 340B and the arc-shaped section 350B have an arc-shaped form when viewed from position P2, located in the Z direction away from the energy storage cell 100B. Note that the arc-shaped section 340B is an example of a “second arc-shaped section” according to the present disclosure. The wound electrode assembly 400B (winding section 410B) comprises an arc-shaped section 440B and an arc-shaped section 450B. The arc-shaped section 440B is provided at an end section of the wound electrode assembly 400B on the X1 side. The arc-shaped section 450B is provided at an end section of the wound electrode assembly 400B on the X2 side. Viewed from position P2, both the arc-shaped section 440B and the arc-shaped section 450B have an arc-shaped form. Note that the arc-shaped section 440B is an example of a “second arc-shaped section” according to the present disclosure. Fig. 4 is a partially enlarged view of the environment of the adhesive material 600 in a cross-section of the energy storage cell 100A and the energy storage cell 100B. As shown in Fig. 4, each of the arc-shaped sections 340A and the arc-shaped sections 440A is arranged in a position facing the side surface 521A. Each of the arc-shaped sections 340B and the arc-shaped sections 440B is arranged in a position opposite the side surface 521B. Arc-shaped section 340A and arc-shaped section 440A are arranged side by side in the Y-direction. A gap Ga1 is formed between arc-shaped section 340A and arc-shaped section 440A. Arc-shaped section 340B and arc-shaped section 440B are arranged side by side in the Y-direction. A gap Ga2 is formed between arc-shaped section 340B and arc-shaped section 440B. Note that gap Ga1 and gap Ga2 are examples of the "first gap" and the "second gap" respectively according to the present disclosure. The recessed section 526A is designed such that it extends from the main surface 525A of the cell housing 500A towards the gap Ga1. The recessed section 526B is designed such that it extends from the main surface 525B of the cell housing 500B towards the gap Ga2. In a conventional module, misalignment can occur between the energy storage cells when they expand (contract) due to charging and discharging. In the first embodiment, the adhesive material 600 (the adhesive layer 610) fills the recessed section 526A. The adhesive material 600 (the adhesive layer 620) fills the recessed section 526B. The side surface 521A includes a defining surface 528A, which defines the recessed section 526A. The side surface 521B includes a defining surface 528B, which defines the recessed section 526B. The defining surface 528B is located adjacent to the defining surface 528A in the X-direction. That is, the defining surface 528B is located in the same position as the defining surface 528A in the Y-direction. Note that an arrangement may be provided in which only a portion of the defining surface 528B is located within a region in the Y-direction in which the defining surface 528A is located. Furthermore, the defining surface 528A and the defining surface 528B are examples of the "first defining surface" and the "second defining surface," respectively, according to the present disclosure. The defining surface 528A extends from the main surface 525A into the gap Ga1. The defining surface 528B extends from the main surface 525B into the gap Ga2. The defining surface 528A has an inclined surface 5280A and an inclined surface 5281A. The inclined surface 5280A is located on the Y1 side relative to the inclined surface 5281A. The inclined surface 5280A is inclined such that the closer it is to the inclined surface 5281A (Y2 side), the further it is from the energy storage cell 100B (X1 side). The inclined surface 5281A is inclined such that the closer it is to the inclined surface 5280A (Y1 side), the further it is from the energy storage cell 100B. The X1 end sections of the inclined surface 5280A and the inclined surface 5281A are connected. It should be noted that inclined surface 5280A and inclined surface 5281A are examples of the “first inclined surface” and the “second inclined surface” respectively according to the present disclosure. The defining surface 528B has an inclined surface 5280B and an inclined surface 5281B. The inclined surface 5280B is located on the Y1 side relative to the inclined surface 5281B. The inclined surface 5280B is inclined such that it is farther from the energy storage cell 100A (X2 side) the closer it is to the inclined surface 5281B (Y2 side). The inclined surface 5281B is inclined such that it is farther from the energy storage cell 100A the closer it is to the side of the inclined surface 5280B (Y1 side). The X2 side end sections of the inclined surface 5280B and the inclined surface 5281B are connected to each other. It should be noted that inclined surface 5280B and inclined surface 5281B are examples of the “third inclined surface” and the “fourth inclined surface” respectively of the present disclosure. The inclined surface 5280A is in contact with the arcuate section 440A of the wound electrode assembly 400A. The inclined surface 5281A is in contact with the arcuate section 340A of the wound electrode assembly 300A. The inclined surface 5280B is in contact with the arcuate section 440B of the wound electrode assembly 400B. The inclined surface 5281B is in contact with the arcuate section 340B of the wound electrode assembly 300B. This allows the space of both the recessed section 526A and the recessed section 526B to be easily enlarged, and consequently, the amount of adhesive material 600 that fills both the recessed section 526A and the recessed section 526B can be increased. Note that in the first embodiment, the inclined surface 5280A, the inclined surface 5281A, the inclined surface 5280B and the inclined surface 5281B are each designed as a flat surface, while the defining surfaces that define the recessed sections may, for example, be curved. Furthermore, each of the recessed sections 526A and 526B has a triangular shape when viewed from the Z1 side, but may instead, for example, have a rectangular shape when viewed from the Z1 side. The adhesive layer 610 comprises an adhesive section 611 and an adhesive section 612. The adhesive layer 620 comprises an adhesive section 621 and an adhesive section 622. Adhesive section 611 and adhesive section 621 are each arranged between the main surface 525A of the cell housing 500A and the main surface 525B of the cell housing 500B. Specifically, adhesive section 611 is clamped between the main surface 525A and the cooling plate 71 in the X-direction. Adhesive section 621 is clamped between, or located between, the main surface 525B and the cooling plate 71 in the X-direction. Adhesive section 612 and adhesive section 622 are each arranged between the defining surface 528A of the cell housing 500A and the defining surface 528B of the cell housing 500B. Specifically, adhesive section 612 is clamped between the defining surface 528A and the cooling plate 71 in the X-direction. Adhesive section 622 is clamped between the defining surface 528B and the cooling plate 71 in the X-direction. Thus, the energy storage cell 100A can be attached more stably to the cooling plate 71 than in the case where the adhesive layer 610 only covers the adhesive section 612. Similarly, the energy storage cell 100B can be attached more stably to the cooling plate 71. The adhesive section 611 comprises a section between the wound electrode assembly 300A and the cooling plate 71 (hereinafter referred to as the first section) and a section between the wound electrode assembly 400A and the cooling plate 71 (hereinafter referred to as the second section). The adhesive section 612 is arranged between the first section of the adhesive section 611 and the second section of the adhesive section 611 and is integrally formed with the first section of the adhesive section 611 and the second section of the adhesive section 611. The adhesive section 621 comprises a section (hereinafter referred to as the first section) between the wound electrode assembly 300B and the cooling plate 71 and a section (hereinafter referred to as the second section) between the wound electrode assembly 400B and the cooling plate 71. The adhesive section 622 is arranged between the first section of the adhesive section 621 and the second section of the adhesive section 621 and is integrally formed with the first section of the adhesive section 621 and the second section of the adhesive section 621. Within the cooling plate 71, a channel 71a is formed through which the coolant flows. The channel 71a extends in the Y direction. Note that several channels 71a can be arranged in the Z direction. The cooling plate 71 is designed such that its thickness in the X-direction is constant. Accordingly, the thickness of the adhesive section 612 in the X-direction is greater than the thickness of the adhesive section 611 in the X-direction. The thickness of the adhesive section 612 in the X-direction gradually increases in the direction of the junction between the inclined surface 5280A and the inclined surface 5281A. The same applies to the adhesive sections 621 and 622. As described above, in the first embodiment, the adhesive material 600 fills both the recessed section 526A and the recessed section 526B. This allows the adhesive material 600 filling the recessed section 526A to bond the cell housing 500A to the cooling plate 71, and the adhesive material 600 filling the recessed section 526B to bond the cell housing 500B to the cooling plate 71. This prevents misalignment between the energy storage cell 100A and the energy storage cell 100B. Furthermore, the adhesive material 600 fills the recessed section 526A (recessed section 526B); even if a force (friction force) is exerted on the adhesive material 600 in the Y direction, it can be prevented from detaching from the side surface 521A (side surface 521B) due to the tensile force exerted in the Y direction. Second embodiment Next, a second embodiment of the present disclosure is described with reference to Figures 5, 6 to 7. An energy storage device 11 according to the second embodiment comprises a cooling device 170 instead of the cooling device 70 according to the first embodiment. Note that components identical to those of the first embodiment are designated with the same reference numerals as in the first embodiment and their description is not repeated. As shown in Fig. 5, the energy storage device 11 comprises the cooling device 170. The cooling device 170 comprises a plurality of coolant tubes 171, a plurality of cooling plates 172, a plurality of inlet or feed pipes 173, a plurality of outlet pipes 174, a plurality of connecting pipes 175 (Fig. 6), a plurality of coolant tubes 176 (Fig. 7), the accessory cooler 72, the upstream tube 73, and the downstream tube 74. Note that the connecting pipes 175 are an example of a “cooling tube” according to the present disclosure. Each of the cooling plates 172 is arranged between the energy storage cells 100, which are adjacent to each other in the Y direction. The cooling plates 172 each extend in the X direction and connect the inlet pipes 173 and the outlet pipes 174. Each of the inlet pipes 173 extends in the Y direction along the upstream pipe 73 and carries the coolant from the upstream pipe 73 to each of the cooling plates 172. The inlet pipes 173 are arranged in a row in the Y direction. Each of the drain pipes 174 extends in a Y-direction along the downstream pipe 74 and discharges the coolant from each of the cooling plates 172 into the downstream pipe 74. The drain pipes 174 are arranged in a Y-direction. The coolant flowing through the upstream pipe 73 flows into each of the coolant pipes 171. Viewed from a position on the Z1 side away from the energy storage device 11, each of the coolant pipes 171 is located between the energy storage cells 100 that are adjacent to each other in the X direction. Each of the coolant pipes 171 extends in the Y direction along the energy storage stack 10. The coolant flowing through each of the coolant pipes 171 is discharged from the outlet opening 76. The cooling plate 172 arranged on the Y1 side of the energy storage cell 100A and the energy storage cell 100B is referred to as cooling plate 172a, and the cooling plate 172 arranged on the Y2 side of the energy storage cell 100A and the energy storage cell 100B is referred to in the following description as cooling plate 172b, as shown in Fig. 6. Cooling plate 172a and cooling plate 172b are examples of a “first cooler” and a “second cooler” respectively of the present disclosure. The cooling plate 172a is arranged such that it extends over the side surface 524A of the cell housing 500A and the side surface 524B of the cell housing 500B. The cooling plate 172a can be in contact with the side surface 524A and the side surface 524B. Note that the side surface 524A and the side surface 524B are examples of the “first side surface of the housing” and the “third side surface of the housing” respectively of the present disclosure. The cooling plate 172b is arranged such that it extends over side surface 523A of cell housing 500A and side surface 523B of cell housing 500B. The cooling plate 172b can be in contact with side surface 523A and side surface 523B. Note that side surface 523A and side surface 523B are examples of the “second side surface of the housing” and the “fourth side surface of the housing” respectively of the present disclosure. The energy storage device 11 (Fig. 5) further comprises an adhesive material 1600. The adhesive material 1600 is arranged (filled) in the space between the energy storage cell 100A and the energy storage cell 100B, which are arranged next to each other in the X direction. In the second embodiment, the adhesive material 1600 extends in the Y direction and is also connected to the cooling plate 172a and the cooling plate 172b. That is, the adhesive material 1600 is connected to the cooling plate 172a and the cooling plate 172b. Thus, the cooling plate 172a and the cooling plate 172b are connected by the adhesive material 1600, which prevents misalignment between the cooling plate 172a and the cooling plate 172b. The connecting tubes 175 extend through the adhesive material 1600. Each connecting tube 175 has an annular cross-section, as shown in Fig. 6. The connecting tube 175 is positioned between the defining surface 528A, which defines the recessed section 526A, and the defining surface 528B, which defines the recessed section 526B. A portion of the connecting tube 175 can extend into both the recessed section 526A and the recessed section 526B. The connecting pipe 175 extends in the Z-direction within the adhesive material 1600. Thus, the coolant flowing through the connecting pipe 175 passes through the space between the energy storage cell 100A and the energy storage cell 100B, enabling it to effectively cool both cells. Furthermore, the connecting pipe 175 extends in the Z-direction so that it does not collide with the cooling plate 172. Fig. 7 is a sectional view along line VII-VII in Fig. 5. The connecting tube 175 runs in the Z-direction through the adhesive material 1600. Each of the connecting tubes 175 is connected to each of the coolant tubes 171 and the coolant tubes 176. Note that the coolant tubes 176 extend downwards (Z2-side) in the Y-direction from each of the coolant tubes 171. The connecting tubes 175 can be formed integrally with each of the coolant tubes 171 and the coolant tubes 176. Part of the coolant flowing through the coolant pipes 171 flows through the connecting pipes 175 and then into the coolant pipes 176. The coolant flowing into the coolant pipes 176 flows towards the Y1 side and is then discharged from the outlet opening 76 (Fig. 5) connected to the coolant pipes 176. Note that the dashed lines in Fig. 7 indicate the flow of the coolant. Both cooling plate 172a and cooling plate 172b have several channels 172c formed within them. The channels 172c are arranged in the Z-direction in each of the cooling plates 172a and 172b. Note that other configurations are identical to those of the first embodiment and are therefore not repeated. Modifications In the first and second embodiments described above, examples were provided in which the adhesive material is arranged between the main surface 525A and the main surface 525B, as well as between the defining surface 528A and the defining surface 528B, but the present disclosure is not limited thereto. The adhesive material can also be arranged only between the defining surface 528A and the defining surface 528B. In the first and second embodiments described above, an example was presented in which the cooling tubes (71, 175), through which the coolant flows, extend through the adhesive material, but the present disclosure is not limited to this. The cooling tubes need not extend through the adhesive material. The structures of the aforementioned embodiments and modifications can be combined with each other. It should be noted that the embodiment disclosed here is to be regarded in every respect as exemplary and not as limiting. The scope of this disclosure is defined in the claims and not in the description of the embodiment explained above, and furthermore, all modifications corresponding to the sense and scope of the claims are included therein. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature JP 2021 - 089 812 A [0002, 0003]

Claims

Energy storage device comprising: a first energy storage cell comprising a plurality of first wound electrode assemblies arranged side by side in a first direction, and a first housing accommodating the first wound electrode assemblies; a second energy storage cell comprising a plurality of second wound electrode assemblies arranged side by side in the first direction, and a second housing accommodating the second wound electrode assemblies; and an adhesive material arranged between the first housing and the second housing, wherein each of the first wound electrode assemblies is wound such that it surrounds a circumference of a first winding axis extending in an axial direction intersecting the first direction; each of the second wound electrode assemblies is wound such that it surrounds a circumference of a second winding axis extending in the axial direction;the second energy storage cell is arranged at a position adjacent to the first energy storage cell in a second direction that intersects both the first direction and the axial direction; the first housing comprises a first side surface arranged on the side of the second housing in the second direction; the second housing comprises a second side surface arranged on the side of the first housing in the second direction; each of the first wound electrode assemblies is arranged at a position opposite the first side surface and, viewed from a position away from the first energy storage cell in the axial direction, comprises a first arcuate section with an arcuate shape;Each of the second wound electrode arrangements is located at a position opposite the second side surface and, viewed from a position away from the second energy storage cell in the axial direction, comprises a second arc-shaped section with an arc-shaped form; the first side surface comprises a first main surface and also a first recessed section, which extends from the first main surface to a first gap formed in the first side surface between the first arc-shaped sections oriented in the first direction; the second side surface comprises a second main surface and also a second recessed section, which extends from the second main surface to a second gap formed in the second side surface between the second arc-shaped sections oriented in the first direction;and the adhesive material fills both the first recessed section and the second recessed section. Energy storage device according to claim 1, further comprising a cooling tube passing through the adhesive material. Energy storage device according to claim 1 or 2, further comprising a first cooler and a second cooler extending in the second direction, wherein the first housing comprises: a first housing side surface on one side in the first direction; and a second housing side surface on another side in the first direction; the second housing comprises: a third housing side surface on one side in the first direction; and a fourth housing side surface on the other side in the first direction; the first cooler is arranged to extend over the first housing side surface and the third housing side surface; the second cooler is arranged to extend over the second housing side surface and the fourth housing side surface; and the adhesive material extends in the first direction and is also connected to both the first cooler and the second cooler. Energy storage device according to claim 3, further comprising a cooling tube extending through the adhesive material, wherein the cooling tube extends in the axial direction within the adhesive material. Energy storage device according to claim 1 or 2, wherein: the first side surface comprises a first defining surface that defines the first recessed section; the second side surface comprises a second defining surface that defines the second recessed section; the first defining surface comprises a first inclined surface and a second inclined surface that is connected to the first inclined surface and is also arranged on one side of the first inclined surface in the first direction; the second defining surface comprises a third inclined surface and a fourth inclined surface that is connected to the third inclined surface and is also arranged on one side of the third inclined surface in the first direction; the first inclined surface is inclined in one direction such that it is further away from the second energy storage cell and closer to the second inclined surface;the second inclined surface is inclined in a direction such that it is farther from the second energy storage cell and closer to the first inclined surface; the third inclined surface is inclined in a direction such that it is farther from the first energy storage cell and closer to the fourth inclined surface; the fourth inclined surface is inclined in a direction such that it is farther from the first energy storage cell and closer to the third inclined surface; the first wound electrode assemblies comprise a first electrode assembly and a second electrode assembly arranged relative to the first electrode assembly on one side in the first direction; the second wound electrode assemblies comprise a third electrode assembly and a fourth electrode assembly arranged relative to the third electrode assembly on one side in the first direction;the first inclined surface is in contact with the first arcuate section of the first electrode assembly; the second inclined surface is in contact with the first arcuate section of the second electrode assembly; the third inclined surface is in contact with the second arcuate section of the third electrode assembly; and the fourth inclined surface is in contact with the second arcuate section of the fourth electrode assembly.

Images