power storage device

Abstract

The energy storage device includes: an energy storage element having a container; and a spacer disposed along the energy storage element, the spacer being disposed in a first direction of the energy storage element, the container having a joint portion, the spacer having a spacer body facing the energy storage element in the first direction, and a first protrusion and a second protrusion protruding toward the energy storage element, the second protrusion being formed by a plate-like portion bent toward the energy storage element and disposed at a position closer to the joint portion than the first protrusion, the first protrusion being shorter than the first protrusion being shorter than the second protrusion being shorter than the second protrusion being shorter than the second protrusion.

Description

Technical Field

[0001] This invention relates to energy storage devices. Background Technology

[0002] Patent Document 1 discloses a battery pack composed of multiple square cells. The multiple square cells are arranged opposite each other with their long sides separated by a plate-like spacer made of resin. On the surface of the spacer, multiple ribs are formed parallel to each other in a direction perpendicular to the arrangement direction of the square cells, and these ribs abut against the long sides of the square cells. Between adjacent square cells, multiple cooling medium passages, divided by the adjacent ribs, are formed along the long side of the ribs, and the cross-sectional area of ​​the multiple cooling medium passages gradually decreases from the central side to the end side of the long side of the square cell.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-32932 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the spacers of conventional battery packs, although the thickness of the spacers between the ribs varies, the multiple ribs have the same structure, and the front ends of the multiple ribs in the thickness direction of the spacers are at the same position. Therefore, for example, a rib located close to the joint between the main body and the cover of the battery casing may press against the battery casing, thereby placing a relatively large load on that joint. This can lead to deterioration and other defects in the joint.

[0008] This invention was made by the inventors of this application with a new focus on the above-mentioned problems, and its purpose is to provide an energy storage device with improved reliability.

[0009] Methods for solving problems

[0010] One aspect of the present invention relates to an energy storage device comprising: an energy storage element having a container; and a spacer disposed along the energy storage element, the spacer being disposed in a first direction of the energy storage element, the container having a joint portion, the spacer having a spacer body opposing the energy storage element in the first direction, and a first protrusion and a second protrusion protruding toward the energy storage element, the second protrusion being formed of a plate-like portion bent toward the energy storage element and disposed at a position closer to the joint portion than the first protrusion, the first protrusion being shorter than the first protrusion by a first protrusion length protruding beyond the spacer body by a second protrusion length by a second protrusion length protruding beyond the spacer body by the first protrusion.

[0011] Invention Effects

[0012] According to the present invention, an energy storage device with improved reliability can be provided. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the structure of the energy storage device involved in the embodiment.

[0014] Figure 2 This is an exploded perspective view of the energy storage unit involved in the implementation method.

[0015] Figure 3 This is a perspective view showing the structure of the energy storage element involved in the implementation method.

[0016] Figure 4 This is a perspective view showing the structure of the spacer involved in the embodiment.

[0017] Figure 5 It is a cross-sectional view showing the positional relationship between the spacer and the energy storage element in the Z-axis direction according to the embodiment.

[0018] Figure 6 This is a cross-sectional view showing the arrangement of the spacers along the energy storage element in the embodiment.

[0019] Figure 7 This is a diagram showing a cross-section of the spacer involved in the embodiment, and a cross-section including the longitudinal extension of the first protrusion. Detailed Implementation

[0020] (1) An energy storage device according to one aspect of the present invention includes: an energy storage element having a container; and a spacer disposed along the energy storage element, the spacer being disposed in a first direction of the energy storage element, the container having a joint portion, the spacer having a spacer body opposite to the energy storage element in the first direction, and a first protrusion and a second protrusion protruding toward the energy storage element, the second protrusion being formed by a plate-like portion bent toward the energy storage element and disposed at a position closer to the joint portion than the first protrusion, the first protrusion being shorter than the first protrusion being shorter than the second protrusion being shorter than the second protrusion being shorter than the second protrusion being shorter than the second protrusion.

[0021] According to one aspect of the energy storage device of the present invention, the second protrusion is formed of a plate-like portion that bends toward the energy storage element. Therefore, the spacer can press the joint or a position near the joint with a relatively weak force using the second protrusion, and further, the first protrusion located away from the joint can be used to press the container. Thus, while improving the positional stability of the energy storage element in the energy storage device, deterioration or damage to the joint of the energy storage element is suppressed. In this way, the energy storage device of this embodiment is an energy storage device with improved reliability.

[0022] (2) Based on the energy storage device described in (1) above, the spacer may also have a third protrusion protruding toward the energy storage element. In a second direction orthogonal to the first direction, at least a portion of the first protrusion is disposed between the second protrusion and the third protrusion. The length of the third protrusion protruding beyond the main body of the spacer, i.e., the third protrusion length, is longer than the first protrusion length.

[0023] According to the energy storage device described in (2) above, the energy storage element can be compressed by a third protrusion that is longer than the first protrusion and located further away from the joint than the first protrusion. Therefore, the spacer can compress the energy storage element more reliably in a form that is less likely to cause deterioration or damage to the joint.

[0024] (3) Based on the energy storage device described in (2) above, the first protrusion may also include: a transverse extension that extends along a third direction orthogonal to the first direction and the second direction and is disposed between the second protrusion and the third protrusion; and a longitudinal extension that extends along the second direction and is arranged with the third protrusion in the third direction, wherein the first protrusion length is the length of the transverse extension that protrudes beyond the spacer body, and the length of the longitudinal extension that protrudes beyond the spacer body is longer than the first protrusion length.

[0025] According to the energy storage device described in (3) above, the longitudinal extension portion, which is part of the first protrusion, functions as a portion that compresses the energy storage element at a position relatively far from the joint, similar to the third protrusion. As a result, the positional stability of the energy storage element in the energy storage device is further improved.

[0026] (4) Based on the energy storage device described in (2) or (3) above, it is also possible that a plurality of the third protrusions are arranged along the second direction on the spacer body.

[0027] According to the energy storage device described in (4) above, multiple gas flow paths are formed by multiple third protrusions arranged along the second direction. As a result, the heat of the energy storage element is released efficiently.

[0028] (5) Based on any one of the above (1) to (4) energy storage devices, the first protrusion may be formed by the thick-walled portion of the spacer body.

[0029] According to the energy storage device described in (5) above, the protrusion length of the first protrusion is relatively short and the rigidity is relatively high. Therefore, the container can be supported more reliably while suppressing the load on the joint at a position relatively far from the joint in the container of the energy storage element.

[0030] Hereinafter, an energy storage device according to embodiments of the present invention (including variations thereof) will be described with reference to the accompanying drawings. The embodiments described below are general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement and connection methods of constituent elements, manufacturing processes, and order of manufacturing processes shown in the following embodiments are examples and are not intended to limit the present invention. Dimensions in the figures are not strictly illustrated. The same reference numerals are used for the same or identical constituent elements in the figures.

[0031] In the following description and accompanying drawings, the X-axis direction is defined as the orientation of a pair of terminals of a storage element or the orientation of opposing short sides of a storage element's container. The Y-axis direction is defined as the orientation of opposing long sides of a storage element's container, the thickness direction (flat direction) of the storage element's container, or the orientation of multiple storage elements in a storage unit. The Z-axis direction is defined as the protruding direction of the storage element's terminals, the orientation of the storage element's container body and cover, or the vertical direction. The X-axis, Y-axis, and Z-axis directions described above are intersecting (orthogonal in this embodiment). While it is possible that the Z-axis direction may not be vertical depending on the intended use, it will be described as vertical for ease of explanation below.

[0032] In the following explanation, the positive X-axis direction refers to the direction of the arrow on the X-axis, and the negative X-axis direction refers to the opposite direction of the positive X-axis direction. When referred to simply as the X-axis direction, it indicates either the positive or negative X-axis direction. When referred to as one side and the other side of the X-axis direction, it indicates one or the other of the positive and negative X-axis directions. The same applies to the Y-axis and Z-axis directions. The expressions "parallel" and "orthogonal," indicating relative directions or orientations, also include cases where the direction or orientation is not strictly defined. For example, two parallel directions do not necessarily mean that the two directions are completely parallel, but rather that they are roughly parallel, i.e., including, for example, a difference of a few percent.

[0033] In the following description, unless otherwise specified, ordinal numbers such as "first" and "second" do not refer to the quantity or order of the elements (components, parts, or phenomena, etc.) assigned ordinal numbers, but are used to avoid confusion among multiple elements and to distinguish multiple elements from other elements. In the following description, when it is expressed as "insulation," it means "electrical insulation." Materials with insulating properties are preferably those with a volume resistivity of 1 × 10⁻⁶. 6 Formed from materials with an Ωm or greater, more preferably from 1×10 7 The material is formed of Ωm or more, and is further preferably formed of 1×10 10 Materials with an Ωm or greater are formed.

[0034] (Implementation Method)

[0035] [1. Overall description of energy storage device 1]

[0036] Figure 1 This is a perspective view showing the structure of the energy storage device 1 according to the embodiment. Figure 1 The image shows the state in which the energy storage unit 10 has been removed from the housing body 610. Figure 2 This is an exploded perspective view of the energy storage unit 10 according to the embodiment. Figure 2 The diagram illustrates three energy storage elements 100 and four spacers 200 arranged consecutively in the Y-axis direction among the multiple energy storage elements 100 and multiple spacers 200 included in the energy storage unit 10. The Y-axis direction is an example of a first direction. Figure 3 This is a perspective view showing the structure of the energy storage element 100 according to the embodiment.

[0037] The energy storage device 1 is a device capable of being charged and discharged from an external source. For example, the energy storage device 1 is a battery module (battery pack) used for power storage or power supply purposes. Specifically, the energy storage device 1 is used as a battery for driving or starting the engine of moving vehicles such as motor vehicles, motorized two-wheelers, boats, ships, motorized snowmobiles, agricultural machinery, construction machinery, automated guided vehicles (AGVs), or railway vehicles for electric railways. Examples of motor vehicles include electric electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) motor vehicles. Examples of railway vehicles for electric railways include trams, monorail trains, linear motor trains, and hybrid trams equipped with both diesel engines and electric motors. Furthermore, the energy storage device 1 can also be used as a battery for stationary installations in homes or industrial and commercial applications.

[0038] like Figure 1As shown, the energy storage device 1 includes an energy storage unit 10 and a housing 600 that houses the energy storage unit 10. In addition to the above-described components, the energy storage device 1 may also include a bus unit having multiple busbars that are respectively connected to multiple energy storage elements 100, and electrical equipment such as a circuit board and relays for monitoring or controlling the charging and discharging states of the energy storage units 10.

[0039] In this embodiment, the energy storage unit 10 is a battery module having one or more energy storage elements 100. Specifically, the energy storage unit 10 includes a plurality of (34 in this embodiment) energy storage elements 100, a spacer 200 disposed in the Y-axis direction between two adjacent energy storage elements 100, and a spacer 250 disposed on the outer side of each of the energy storage elements 100 at both ends in the Y-axis direction.

[0040] The energy storage unit 10 is arranged along the Y-axis by a plurality of energy storage elements 100, a plurality of spacers 200, and a pair of spacers 250, thereby having a generally rectangular shape that is longer in the Y-axis direction. The terminals 140 of the plurality of energy storage elements 100 included in the energy storage unit 10 are respectively connected to conductive components such as busbars (not shown). The rectangular prism referred to here is a hexahedron whose faces are all composed of rectangles or squares.

[0041] In this embodiment, the energy storage unit 10 is a non-constraint type module that does not have constraint members (end plates and side plates, etc.) that constrain the plurality of energy storage elements 100 in the Y-axis direction. However, the energy storage unit 10 may also have constraint members that constrain the plurality of energy storage elements 100 and the plurality of spacers 200 and 250 in the Y-axis direction.

[0042] The energy storage element 100 is a secondary battery (single cell), more specifically a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 100 is as follows: Figure 2 and Figure 3The container 101 has a flat rectangular (square) shape as shown. Inside the container 101 are electrodes (not shown), current collectors, and an electrolyte. The electrodes are, for example, wound electrodes formed by winding plates and a separator. Each plate has a current collector foil as a strip of metal and an active material layer formed on the surface of the current collector foil. Alternatively, the electrodes can be stacked (multiple flat plates) or have a structure where strip-shaped plates are repeatedly folded and corrugated to create a wrinkled appearance. The electrolyte contained in the container 101 is not particularly limited in type and can be of various kinds without impairing the performance of the energy storage element 100. The energy storage element 100 can be a secondary battery other than a non-aqueous electrolyte secondary battery, or it can be a capacitor. The energy storage element 100 can also be a primary battery. The energy storage element 100 can also be a battery using a solid electrolyte. The shape of the energy storage element 100 is not limited to the square shape mentioned above, but can also be a polygonal prism shape, cylindrical shape, elliptical cylinder shape, oblong cylinder shape, etc.

[0043] Container 101 is as follows Figure 3 The container 101 is a cuboid-shaped housing consisting of a pair of long side surfaces 111, a pair of short side surfaces 112, a bottom surface 113 formed by a container body 102, and a terminal mounting surface 115 formed by a cover plate 103. After accommodating electrodes and the like inside the container body 102, the container body 102 and the cover plate 103 are welded together, thereby sealing the interior of the container 101. In other words, the energy storage element 100 according to this embodiment includes a joint portion 130, which serves as the joint between the container body 102 and the cover plate 103. The joint portion 130 is formed to extend along the X-axis and Y-axis directions, which intersect the Z-axis direction, which is the arrangement direction of the container body 102 and the cover plate 103. In this embodiment, the joint portion 130 is the part where the container body 102 and the cover plate 103 are fused together by welding. The material of the container 101 is not particularly limited; for example, stainless steel, aluminum, aluminum alloy, iron, electroplated steel sheet, or other weldable metals are preferred. The joining method used to form the joint 130 is not limited to welding; the joint 130 can also be formed by riveting, fitting, or bonding. However, from the viewpoint of sealing performance and durability, the joint 130 is preferably formed by welding.

[0044] The energy storage element 100 includes a terminal 140 disposed in the Z-axis direction. The Z-axis direction is an example of a second direction. The terminal 140 is electrically connected to an electrode body housed in a container 101. More specifically, a pair of terminals 140 protrude from a terminal mounting surface 115 of the container 101 in the positive Z-axis direction. A gas discharge valve 131 is also provided on the terminal mounting surface 115. One of the pairs of terminals 140 is electrically connected to the positive electrode of the electrode body, and the other is electrically connected to the negative electrode of the electrode body. The terminal 140 is formed of a metal such as aluminum, aluminum alloy, copper, or copper alloy.

[0045] Spacers 200 and 250 are insulating or heat-insulating plates disposed along the positive or negative Y-axis of the energy storage element 100 to insulate and / or heat-insulate the energy storage element 100 from each other or from other components. In this embodiment, spacers 200 and 250 are formed of insulating materials such as resin. Spacer 200 is also referred to as a "cell spacer" for example. Spacer 250 is also referred to as an "end spacer" for example. In this embodiment, spacers 200 and 250 also function as cell holders for holding one or more energy storage elements 100 disposed along the spacer 200 or 250.

[0046] The spacer 200 includes: a spacer body 201, which faces the energy storage element 100 in the Y-axis direction; and a side wall portion 202, which faces the energy storage element 100 in the X-axis direction. In this embodiment, the side wall portion 202 extends from the end of the spacer body 201 in the X-axis direction in both the positive and negative Y-axis directions, thereby facing the two energy storage elements 100 held by the spacer 200 in the X-axis direction. The spacer 200 also includes a bottom wall portion 203 facing the bottom surface 113 of the energy storage element 100. The bottom wall portion 203 extends from the end of the spacer body 201 in the negative Z-axis direction in both the positive and negative Y-axis directions, thereby facing the two energy storage elements 100 held by the spacer 200 in the Z-axis direction.

[0047] In this embodiment, the sidewall portion 202 is composed of multiple portions separated in the Z-axis direction, but the sidewall portion 202 may also be composed of a single continuous wall portion in the Z-axis direction. The sidewall portion 202 should have a size and shape that does not interfere with the sidewall portions 202 of adjacent spacers 200 of the spacer 200 having the sidewall portion 202. Specifically, when two spacers 200 arranged in the Y-axis direction are combined, the sidewall portions 202 of the two spacers 200 should have a size and shape that do not obstruct the combination of the two spacers 200.

[0048] The spacer 200 according to this embodiment has a plurality of protrusions that contact the energy storage element 100 disposed in the positive Y-axis direction. These protrusions are provided in the spacer 200 in a manner that provides balanced pressure to the energy storage element 100. For details regarding the plurality of protrusions provided in the spacer 200, please refer to... Figures 4-7 To be described later.

[0049] The spacer 250 is arranged along the end of the energy storage element 100 in the Y-axis direction of the energy storage unit 10. The spacer 250 is basically the same as the spacer 200 except that the number of energy storage elements 100 opposite to it in the Y-axis direction is 1, so the description of the structure of the spacer 250 is omitted.

[0050] The housing 600 is a generally rectangular (box-shaped) container that houses the energy storage unit 10. The housing 600 is disposed on the outside of the energy storage unit 10 to protect it from impacts and other effects. The housing 600 is formed from a metal component such as aluminum, aluminum alloy, stainless steel, iron, or electroplated steel sheet. In this embodiment, the housing 600 is formed by die casting of aluminum. Alternatively, a housing formed from an insulating component such as resin material may be used instead of the housing 600 to house the energy storage unit 10.

[0051] like Figure 1 As shown, the housing 600 has a housing body 610. The housing body 610 is an outer shell (box) with an opening 610a of a size that allows the energy storage unit 10 to be inserted in the positive Z-axis direction. The housing body 610 includes: a housing side wall portion 611, which is opposite to the energy storage unit 10 in the X-axis direction; a housing side wall portion 612, which is opposite to the energy storage unit 10 in the Y-axis direction; and a housing bottom wall portion 615, which supports the energy storage unit 10 from the negative Z-axis direction. The X-axis direction is an example of a third direction. The housing 600 may also include a cover (not shown) that seals the opening 610a of the housing body 610.

[0052] [2. Regarding the structure of spacer 200 and its surrounding area]

[0053] Next, regarding the spacer 200 and its surrounding structure, in addition to the above... Figures 1-3 In addition to using Figures 4-7 To illustrate. Figure 4 This is a perspective view showing the structure of the spacer 200 involved in the embodiment. Figure 5 This is a cross-sectional view showing the positional relationship between the spacer 200 and the energy storage element 100 in the Z-axis direction according to the embodiment. Figure 5 In the middle, it is schematically shown that through Figure 4 The cross-sections of a portion of the spacer 200 and the energy storage element 100 on the YZ plane of the VV line are shown. Figure 5In the diagram, the side wall portion 202, etc., located in the negative X-axis direction of the cross-section of the spacer 200, is omitted. Figure 5 The illustration omits internal elements (electrodes, etc.) of the container 101 of the energy storage element 100, as well as insulating members that insulate the terminals 140 from the container 101. These are related to... Figure 5 The relevant supplementary matters also apply appropriately to the following: Figure 6 and Figure 7 .

[0054] Figure 6 This is a cross-sectional view showing the state in which the spacer 200 is arranged along the energy storage element 100 according to the embodiment. Figure 7 This is a diagram showing a cross-section of the spacer 200 according to the embodiment, specifically a cross-section including the longitudinal extension 215 of the first protrusion 210. Figure 7 In the middle, it is schematically shown that through Figure 4 A section of spacer 200 in the YZ plane of line VII-VII shown.

[0055] like Figures 4-6 As shown, the spacer 200 according to this embodiment has a plurality of protrusions protruding toward the energy storage element 100. The plurality of protrusions includes a first protrusion 210, a second protrusion 220, and a third protrusion 230. The first protrusion 210, the second protrusion 220, and the third protrusion 230 are as follows... Figure 6 It functions as a part that presses against the long side 111 of the energy storage element 100, as shown.

[0056] More specifically, the energy storage unit 10, which includes multiple spacers 200 and multiple energy storage elements 100, is housed in the housing body 610 (see reference). Figure 1 In the case of [missing information], the energy storage unit 10 is housed in the housing body 610 in a compressed state in the Y-axis direction. The energy storage unit 10 housed in the housing body 610 is constrained in the Y-axis direction by a pair of housing sidewall portions 612 facing each other. As a result, the first protrusion 210, the second protrusion 220, and the third protrusion 230 provided by the spacer 200 [missing information]. Figure 6 As shown, the long side 111 of the energy storage element 100 is compressed. The constraint of the energy storage unit 10 in the Y-axis direction does not need to be performed by the housing body 610, and the energy storage device 1 can also have a constraint member to constrain the energy storage unit 10 in the Y-axis direction as described above.

[0057] In this embodiment, the contact positions of the first protrusion 210, the second protrusion 220, and the third protrusion 230 with the energy storage element 100 in the Z-axis direction are different, and the protrusion length of the first protrusion 210 is different from that of the second protrusion 220. Moreover, the protrusion length of the first protrusion 210 is also different from that of the third protrusion 230.

[0058] Specifically, such as Figure 5 and Figure 6 As shown, in the spacer 200, the second protrusion 220, the first protrusion 210, and the third protrusion 230 are arranged in the Z-axis direction in order of proximity to the Z-axis position P of the joint 130 provided by the container 101 of the energy storage element 100. In this embodiment, the position of the lower end (the end in the negative Z-axis direction) of the joint 130 is defined as the position P of the joint 130.

[0059] Thus, a second protrusion 220 is positioned in the Z-axis direction, close to position P of the joint 130. That is, the second protrusion 220 is located at a position where, if pressure is applied to the container 101 of the energy storage element 100, it is likely to exert a mechanical influence on the joint 130 as well. The second protrusion 220, positioned in this manner, is configured to prevent excessive force from pressing the container 101 in the positive Y-axis direction. A first protrusion 210, positioned in the Z-axis direction further away from the joint 130 than the second protrusion 220, is configured to press the container 101 with a greater force than the second protrusion 220. Furthermore, a third protrusion 230, positioned in the Z-axis direction further away from the joint 130 than the first protrusion 210, is configured to efficiently suppress the expansion of the container 101 of the energy storage element 100. More specifically, the structure of the energy storage device 1 according to this embodiment is described as follows.

[0060] The energy storage device 1 according to this embodiment includes: an energy storage element 100, which includes a container 101; and a spacer 200 disposed along the energy storage element 100. The spacer 200 is disposed in the Y-axis direction of the energy storage element 100. The container 101 includes a joint portion 130. The spacer 200 includes a spacer body 201 facing the energy storage element 100 in the Y-axis direction, and a first protrusion 210 and a second protrusion 220 protruding toward the energy storage element 100. The second protrusion 220 is formed by a plate-like portion bent toward the energy storage element 100, and is disposed at a position closer to the joint portion 130 than the first protrusion 210. The length by which the first protrusion 210 protrudes beyond the spacer body 201, i.e., the first protrusion length L1, is shorter than the length by which the second protrusion 220 protrudes beyond the spacer body 201, i.e., the second protrusion length L2.

[0061] Thus, in this embodiment, the second protrusion 220 is formed of a plate-like portion that bends toward the energy storage element 100. Therefore, the spacer 200 can press the joint 130 or a position close to the joint 130 with a relatively weak force using the second protrusion 220, and can press the container 101 using the first protrusion 210 located away from the joint 130.

[0062] More specifically, the second protrusion 220, formed by the plate-like portion bending towards the energy storage element 100, is easily deformed by a reaction force in the negative Y-axis direction from the energy storage element 100. Furthermore, the second protrusion length L2 is longer than the first protrusion length L1, therefore the contact between the second protrusion 220 and the container 101 is less likely to be obstructed by the first protrusion 210. In other words, as... Figure 6 As shown, when the spacer 200 is positioned at the point where the first protrusion 210 contacts the container 101 in the Y-axis direction, the second protrusion 220 will inevitably contact. Furthermore, due to the varying deformation energy (low rigidity) of the second protrusion 220, the force exerted by the second protrusion 220 on the container 101 is less likely to become excessive. Here, when the same force is applied, the component with a large deformation is designated as "low rigidity," and the component with a small deformation is designated as "high rigidity." That is, according to the spacer 200 of this embodiment, at least two points of balanced pressure can be applied to the container 101 of the energy storage element 100, both near the joint 130 and further away from the joint 130. Thus, while improving the positional stability of the energy storage element 100, deterioration or damage to the joint 130 of the energy storage element 100 is suppressed. Therefore, the energy storage device 1 according to this embodiment is an energy storage device with improved reliability.

[0063] In particular, when no protrusions other than the first protrusion 210 and the second protrusion 220 are disposed between the first protrusion 210 and the second protrusion 220, the distance between the first protrusion 210 and the second protrusion 220 can be brought closer. That is, the degree of freedom in positioning the first protrusion 210 relative to the second protrusion 220 in the long side 111 of the energy storage element 100 is increased. In addition, when the first protrusion 210 protrudes from the spacer body 201 toward the energy storage element 100 and is integrally formed with the spacer body 201, the rigidity of the first protrusion 210 becomes relatively high. That is, the container 101 can be further compressed using the first protrusion 210 located away from the joint 130.

[0064] In this embodiment, the spacer body 201 is a plate-shaped portion with a substantially uniform thickness (width in the Y-axis direction) T, and arranged in an orientation orthogonal to the Y-axis direction, which is the arrangement direction of the energy storage elements 100. The protrusion lengths (L1, L2) of the first protrusion 210 and the second protrusion 220 protruding from the spacer body 201 are as follows: Figure 5 As shown, this is the protruding length of the spacer 200 protruding from the protruding direction of these protrusions of the spacer body 201 when the spacer 200 is not positioned along the energy storage element 100.

[0065] That is, the reference for the protrusion lengths (L1, L2) in this embodiment is the plane of the spacer body 201 in the positive Y-axis direction. Therefore, the second protrusion length L2 being longer than the first protrusion length L1 can also be interpreted as the front end position of the second protrusion 220 being located in the positive Y-axis direction than the front end position of the first protrusion 210. The same applies to the protrusion length L3 of the third protrusion 230 protruding from the spacer body 201, which will be described later.

[0066] In this embodiment, the first protrusion 210 also functions as a portion of the flow path for the gas (e.g., air, hereinafter the same) forming the cooling energy storage element 100. Specifically, for example... Figure 4 As shown, the first protrusion 210 extends along the spacer body 201, allowing gas to flow along the spacer body 201 and the first protrusion 210 while exchanging heat with the energy storage element 100. For example, both the first protrusion 210 and the second protrusion 220 have portions extending along the X-axis direction. Thus, a gas flow path is formed between the first protrusion 210 and the second protrusion 220. The second protrusion 220 is located above this gas flow path (in the positive Z-axis direction), and therefore also functions as a seal to prevent gas leakage upwards (in the positive Z-axis direction).

[0067] In this embodiment, the first protrusion 210 is positioned opposite the main body of the electrode body (not shown) of the energy storage element 100 in the Y-axis direction. The main body of the electrode body is a portion on which an active material layer is formed, which is the portion of the electrode plate on which the active material layer is formed. That is, the first protrusion 210 is positioned opposite the active material layer forming portion of the electrode body in the Y-axis direction. As a result, the first protrusion 210 can efficiently suppress the bulging of the energy storage element 100 in the Y-axis direction, that is, the bulging of the electrode body in the Y-axis direction.

[0068] In this embodiment, the second protrusion 220 is formed at a position further outward in the X-axis direction than the active material layer forming portion of the electrode body (not shown) of the energy storage element 100, and its length in the X-axis direction is longer than that of the first protrusion 210. Specifically, for example... Figure 4As shown, the second protrusion 220 extends from the spacer body 201 of the spacer 200 to the sidewall portion 202. This shape allows the second protrusion 220 to closely contact the long side 111 and short side 112 of the energy storage element 100. As a result, the second protrusion 220 can more reliably function as a sealing portion, i.e., suppressing leakage of gas used for cooling the energy storage element 100.

[0069] More specifically, the first protrusion 210 in this embodiment is formed from the thick-walled portion of the spacer body 201. That is, in this embodiment, it can also be described as the second protrusion 220 being a hollow portion and the first protrusion 210 being a solid portion.

[0070] That is, the first protrusion length L1 of the first protrusion 210 involved in this embodiment is relatively short and the rigidity is relatively high. Therefore, the first protrusion 210 can suppress the burden on the joint 130 at a position relatively far from the joint 130 in the container 101 of the energy storage element 100, while supporting the container 101 more reliably.

[0071] The spacer 200 in this embodiment also includes a third protrusion 230 protruding toward the energy storage element 100. In the Z-axis direction, at least a portion of the first protrusion 210 is disposed between the second protrusion 220 and the third protrusion 230 (see reference). Figures 4-6 In the spacer 200 constructed in this way, such as... Figure 5 As shown, the length of the third protrusion 230 protruding from the spacer body 201, i.e., the third protrusion length L3, is longer than the first protrusion length L1.

[0072] Thus, in this embodiment, the energy storage element 100 can be compressed using the third protrusion 230, which is longer than the first protrusion 210 and located further away from the joint 130 than the first protrusion 210. Therefore, the spacer 200 can more reliably compress the energy storage element 100 in a manner that is less likely to cause deterioration or damage to the joint 130. Moreover, since the third protrusion length L3 is longer than the first protrusion length L1, the third protrusion 230 can more reliably press the central portion of the long side 111 in the Z-axis direction, which is the easily expandable part of the container 101 of the energy storage element 100. That is, the spacer 200 according to this embodiment can efficiently suppress the expansion of the energy storage element 100 using the third protrusion 230.

[0073] More specifically, preferably, when the spacer 200 is not arranged along the energy storage element 100 (see reference 100) Figure 5 The third protruding length L3 is longer than the first protruding length L1 and shorter than the second protruding length L2. Therefore, when the spacer 200 is arranged along the energy storage element 100 (see reference...), the third protruding length L3 is longer than the first protruding length L1 and shorter than the second protruding length L2. Figure 6This allows the second protrusion 220, which has lower rigidity, to more reliably contact the joint 130 of the container 101 or a position close to the joint 130, and allows the third protrusion 230 to press against a position of the container 101 away from the joint 130. In this embodiment, the third protrusion 230, like the first protrusion 210, is formed from a thick-walled portion in the spacer body 201. That is, the third protrusion 230 is a solid portion.

[0074] In particular, when no protrusions other than the first protrusion 210 and the third protrusion 230 are disposed between the first protrusion 210 and the third protrusion 230, the distance between the first protrusion 210 and the third protrusion 230 can be brought closer. That is, the degree of freedom in arranging the third protrusion 230 relative to the first protrusion 210 on the long side 111 of the energy storage element 100 is increased.

[0075] In this embodiment, the first protrusion 210 is as follows: Figure 4 As shown, it has a portion extending along the X-axis and a portion extending along the Y-axis. Specifically, the first protrusion 210 includes: a transverse extension 211 extending along the X-axis and disposed between the second protrusion 220 and the third protrusion 230; and a longitudinal extension 215 extending along the Z-axis and arranged with the third protrusion 230 in the X-axis direction. The first protrusion length L1 is the length by which the transverse extension 211 protrudes beyond the spacer body 201 in the Y-axis direction. The length by which the longitudinal extension 215 protrudes beyond the spacer body 201 in the Y-axis direction is longer than the first protrusion length L1. More specifically, as... Figure 4 and Figure 7 As shown, the first protrusion 210 includes a transverse extension 211 extending along the X-axis, a longitudinal extension 215 extending along the Z-axis, and a connecting portion 213 connecting the transverse extension 211 and the longitudinal extension 215. When the length of the longitudinal extension 215 protruding from the spacer body 201 is set to a fourth protrusion length L4, L1 < L4. The connecting portion 213 is as follows... Figure 7 As shown, it has an inclined surface in such a way that the transverse extension 211 and the longitudinal extension 215, which are of different lengths protruding from the spacer body 201, are connected.

[0076] According to this structure, the longitudinal extension 215, which is part of the first protrusion 210, functions similarly to the third protrusion 230 as a portion that compresses the energy storage element 100 at a position relatively far from the joint 130. This further improves the positional stability of the energy storage element 100 in the energy storage device 1. More specifically, the fourth protrusion length L4 of the longitudinal extension 215 is approximately the same as the third protrusion length L3 of the third protrusion 230. Therefore, the contact between one of the longitudinal extension 215 and the third protrusion 230 and the container 101 is less likely to obstruct the contact between the other of the longitudinal extension 215 and the container 101. That is, the longitudinal extension 215 and the third protrusion 230 can each properly contact the container 101. The longitudinal extension 215 can also further function, like the third protrusion 230, as a portion that effectively suppresses the expansion of the energy storage element 100.

[0077] In this embodiment, such as Figures 4-6 As shown, a plurality of third protrusions 230 are arranged in the Z-axis direction on the spacer body 201.

[0078] Thus, a plurality of third protrusions 230, including portions extending along the X-axis, are arranged in the Z-axis direction, thereby forming a plurality of gas flow paths arranged in the Z-axis direction. As a result, the heat of the energy storage element 100 is efficiently released. That is, the plurality of third protrusions 230 function as portions that improve the positional stability of the energy storage element 100, and also function as portions for efficiently releasing the heat of the energy storage element 100, in other words, for efficiently cooling the energy storage element 100.

[0079] More specifically, in this embodiment, such as Figures 4-6 As shown, a gas flow path is also formed between the first protrusion 210 and the third protrusion 230. As a result, heat exchange occurs with the gas over a relatively wide area of ​​the long side surface 111 of the energy storage element 100.

[0080] In this embodiment, two of the plurality of third protrusions 230, like the first protrusion 210, have a third transverse extension 231 extending along the X-axis direction and a third longitudinal extension 235 (see reference). Figure 4 Thus, the multiple third protrusions 230, together with the first protrusion 210, can form multiple gas flow paths extending along the Z-axis direction. This is advantageous from the viewpoint of efficiently releasing the heat of the energy storage element 100.

[0081] In this embodiment, the first protrusion 210 and the plurality of third protrusions 230 are solid portions as described above, for example... Figures 4-6As shown, a so-called comb-shaped portion is formed in the spacer 200. However, this is not necessary. The first protrusion 210 and the third protrusion 230 can each be formed from a plate-like portion that bends toward the energy storage element 100, just as the second protrusion 220, as long as their required mechanical strength can be ensured. In other words, the first protrusion 210 and the third protrusion 230 can each be a hollow portion. That is, the first protrusion 210 and the plurality of third protrusions 230 can also form a so-called corrugated portion in the spacer 200. In this case, the first protrusion 210 and the plurality of third protrusions 230 can also be located on both sides of the spacer 200 in the Y-axis direction. Thus, the spacer 200 can properly compress the two energy storage elements 100 disposed on both sides in the Y-axis direction, sandwiched between the spacer 200. The two energy storage elements 100 can be efficiently cooled by the gas flowing in the plurality of flow paths formed by the first protrusion 210 and the plurality of third protrusions 230 of the spacer 200.

[0082] [3. Explanation of variations]

[0083] The above describes the energy storage device 1 according to the embodiments of the present invention, but the present invention is not limited to the above embodiments. All points of the embodiments disclosed herein are illustrative, and the scope of the present invention includes all changes within the scope and equivalent meaning of the technical solution.

[0084] In the above embodiment, a plurality of protrusions, such as the first protrusion 210, that contact the energy storage element 100 are provided only on one of the two surfaces in the Y-axis direction of the spacer 200 (see reference). Figures 4-7 However, multiple protrusions, such as the first protrusion 210, may also be provided on both sides of the spacer 200 in the Y-axis direction. However, for example, from the viewpoint of suppressing the increase in the length of the energy storage unit 10 containing multiple spacers 200 in the Y-axis direction, it is preferable to provide multiple protrusions, such as the first protrusion 210, that contact the energy storage element 100 only on one of the two sides of the spacer 200 in the Y-axis direction.

[0085] The spacer 200 does not need to hold two energy storage elements 100. The spacer 200 may also hold only one energy storage element 100. That is, the side wall portion 202 of the spacer 200 may extend from the end of the spacer body 201 in the X-axis direction only towards the Y-axis direction. In this case, the bottom wall portion 203 of the spacer 200 may also extend from the end of the spacer body 201 in the negative Z-axis direction only towards that side in the Y-axis direction. In this case, the spacer 200 may also have multiple protrusions, such as the first protrusion 210, that contact the energy storage element 100.

[0086] The spacer 200 may not have the function of holding the energy storage element 100. For example, the spacer body 201 having multiple protrusions such as the first protrusion 210 may be treated as the spacer 200. In this case, the spacer 200 and the energy storage element 100 adjacent to the spacer 200 may be connected, for example, by double-sided adhesive tape or adhesive.

[0087] The spacer 200 may also omit the third protrusion 230. The spacer 200 may at least have a first protrusion 210 and a second protrusion 220. This allows for a relatively weak pressure on the joint 130 or a position close to the joint 130 using the second protrusion 220, while the container 101 can be pressed using the first protrusion 210 located away from the joint 130. In the absence of a third protrusion 230, for example, a third protrusion 230 may be provided on the long side 111 of the spacer body 201 and the container 101 (see reference). Figure 3 Between the central portion of the Z-axis and X-axis directions, a plate-shaped member is disposed for pressing the central portion.

[0088] The joint 130 of the container 101 does not need to be the part where the container body 102 and the cover plate 103 are joined. For example, if there is a part at the end of the long side 111 in the positive Z-axis direction where the filling plug sealing the filling port is joined to the container body 102, this joining part can also be treated as the joint 130 of the container 101. In this case, the second protrusion 220 presses the joint 130 or a position close to the joint 130 with a relatively weak force. Therefore, the positional stability of the energy storage element 100 is improved while suppressing the deterioration or damage of the joint 130. The position of the joint 130 is not particularly limited, and it can be disposed at any position on the long side 111 opposite to the spacer 200. That is, the joint 130 of the container 101 can be any part where two components or parts of the container 101 are joined.

[0089] In the above embodiments, the Z-axis direction is an example of the second direction, and the X-axis direction is an example of the third direction. However, it is also possible that the X-axis direction is the second direction and the Z-axis direction is the third direction. That is, in the X-axis direction, at least a portion of the first protrusion 210 may be disposed between the second protrusion 220 and the third protrusion 230. In this case, the first protrusion 210 may include a transverse extension 211 extending along the Z-axis direction and disposed between the second protrusion 220 and the third protrusion 230, and a longitudinal extension 215 extending along the X-axis direction and arranged with the third protrusion 230 in the Z-axis direction. That is, for example, a joint 130 may be disposed at the end of the long side 111 of the container 101 in the X-axis direction, and on the spacer 200, the second protrusion 220, the first protrusion 210, and the third protrusion 230 may be arranged in the X-axis direction in order from near to far from the joint 130.

[0090] In the above embodiment, the position where the second protrusion 220 contacts the container 101 is lower (in the negative Z-axis direction) than the position P of the joint 130, but the second protrusion 220 may also contact the joint 130. In this case, the second protrusion 220 is formed of a plate-like portion that bends towards the energy storage element 100, and therefore is easily deformed under the reaction force received from the joint 130. Thus, deterioration or damage to the joint 130 caused by the second protrusion 220 pressing against the joint 130 is suppressed.

[0091] The first protrusion 210 does not need to have both a transverse extension 211 and a longitudinal extension 215. The first protrusion 210 only needs to have at least a transverse extension 211. That is, the first protrusion 210 only needs to have a first protrusion length L1 shorter than a second protrusion length L2, and be able to contact the container 101 of the energy storage element 100 in the Z-axis direction at a position farther away from the joint 130 than the second protrusion 220.

[0092] The lengths of the first protrusion 210 and the second protrusion 220 in the X-axis direction need not be the lengths that contact approximately the entire area of ​​the long side surface 111 of the container 101 in the X-axis direction. For example, the lengths of the first protrusion 210 and the second protrusion 220 in the X-axis direction may only contact a predetermined range of the long side surface 111, including its center in the X-axis direction. This predetermined range may also be about one-third of the length of the long side surface 111 in the X-axis direction. However, from the viewpoint of more reliably improving the positional stability of the energy storage element 100, this predetermined range is preferably longer than one-third of the length of the long side surface 111 in the X-axis direction, more preferably longer than one-half of that length. Even more preferably, this predetermined range is the same as the length of the long side surface 111 in the X-axis direction.

[0093] The energy storage device 1 may also be without a housing 600. For example, an energy storage unit 10 having multiple energy storage elements 100 and multiple spacers 200 may also be housed as an energy storage device 1 in a device or bracket.

[0094] Schemes constructed by arbitrarily combining the constituent elements of the above-described embodiments and their variations are also included within the scope of this invention.

[0095] Industrial availability

[0096] This invention is applicable to energy storage devices and the like that have energy storage components such as lithium-ion secondary batteries.

[0097] Explanation of reference numerals in the attached figures

[0098] 1. Energy storage device

[0099] 100 energy storage components

[0100] 101 Container

[0101] 102 Container Body

[0102] 103 Cover Plate

[0103] 130 Joint

[0104] 200, 250 spacers

[0105] 201 Spacer Body

[0106] 210 First convex part

[0107] 211 Extension

[0108] 213 Connecting part

[0109] 215 Longitudinal Extension

[0110] 220 Second convex part

[0111] 230 The third convex part

[0112] 231 Third extension

[0113] 235 Third longitudinal extension

[0114] 600 housing

[0115] 610 Shell Body

[0116] L1 First protrusion length

[0117] L2 Second protrusion length

[0118] L3 Third protrusion length

[0119] L4 is the fourth protruding length.

Claims

1. An energy storage device, wherein, The energy storage device includes: an energy storage element having a container; and a spacer disposed along the energy storage element. The spacer is disposed in a first direction of the energy storage element. The container has a joint. The spacer includes a spacer body facing the energy storage element in the first direction, and a first protrusion and a second protrusion protruding toward the energy storage element. The second protrusion is formed of a plate-like portion that bends toward the energy storage element and is positioned closer to the joint than the first protrusion. The length by which the first protrusion protrudes beyond the main body of the spacer, i.e., the first protrusion length, is shorter than the length by which the second protrusion protrudes beyond the main body of the spacer, i.e., the second protrusion length.

2. The energy storage device according to claim 1, wherein, The spacer also has a third protrusion that protrudes toward the energy storage element. In a second direction orthogonal to the first direction, at least a portion of the first protrusion is disposed between the second protrusion and the third protrusion. The length by which the third protrusion protrudes beyond the main body of the spacer, i.e., the third protrusion length, is longer than the first protrusion length.

3. The energy storage device according to claim 2, wherein, The first protrusion includes: A transverse extension extending along a third direction orthogonal to the first and second directions, and disposed between the second protrusion and the third protrusion; and The longitudinal extension extends along the second direction and is arranged in the third direction with the third protrusion. The first protruding length is the length by which the extension portion protrudes beyond the spacer body. The length of the longitudinal extension that protrudes beyond the main body of the spacer is longer than the first protrusion length.

4. The energy storage device according to claim 2 or 3, wherein, The plurality of the third protrusions are arranged along the second direction on the spacer body.

5. The energy storage device according to any one of claims 1 to 3, wherein, The first protrusion is formed by the thick-walled portion in the spacer body.

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