JP2024068439A - Power storage device - Google Patents

Abstract

[Problem] To provide an energy storage device that can improve vibration resistance or impact resistance. [Solution] The energy storage device 1 includes energy storage elements 100 and spacers 200a aligned in a first direction, and a case 300 that houses the energy storage elements 100 and spacers 200a, the case 300 having a case wall portion 311 that faces the spacers 200a in a second direction perpendicular to the first direction, the spacer 200a having a spacer body 210 that faces the energy storage elements 100 in the first direction, and a protruding portion 230 that protrudes from the spacer body 210 toward the case wall portion 311, the protruding portion 230 having a first portion 231 that is an end portion on one side in the second direction that is connected to the spacer body 210, a second portion 232 that is an end portion on the other side in the second direction that faces the case wall portion 311, and a third portion 233 that is disposed between the first portion 231 and the second portion 232 and extends in a direction intersecting the second direction. [Selected Figure] FIG.

Description

The present invention relates to an energy storage device that includes an energy storage element, a spacer, and a case.

Conventionally, a storage battery device including a storage element, a spacer, and a case that houses the storage element and the spacer is widely known. For example, Patent Document 1 discloses a secondary battery device (storage battery device) in which secondary battery cells (storage elements) and a partition member (spacer) inserted between the secondary battery cells are housed in a case.

International Publication No. 2016/158395

In an energy storage device in which a storage element and a spacer are housed in a case, it is desirable to improve vibration resistance or impact resistance (resistance to external vibration or impact) in order to protect the storage element and spacer within the case. However, in an energy storage device with the above-mentioned conventional configuration, there is a risk that the vibration resistance or impact resistance cannot be sufficiently improved.

The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and aims to provide an electricity storage device that can improve vibration resistance or shock resistance.

The energy storage device according to one aspect of the present invention includes an energy storage element and a spacer arranged in a first direction, and a case that houses the energy storage element and the spacer. The case has a case wall that faces the spacer in a second direction perpendicular to the first direction. The spacer has a spacer body that faces the energy storage element in the first direction, and a protrusion that protrudes from the spacer body toward the case wall. The protrusion has a first part that is an end on one side of the second direction that is connected to the spacer body, a second part that is an end on the other side of the second direction that faces the case wall, and a third part that is disposed between the first part and the second part and extends in a direction that intersects with the second direction.

The energy storage device of the present invention can improve vibration resistance or impact resistance.

1 is a perspective view showing a configuration of an electricity storage device according to an embodiment; 2 is an exploded perspective view showing an energy storage element and a spacer included in an energy storage unit included in the energy storage device according to the embodiment; FIG. FIG. 2 is a perspective view showing a configuration of an energy storage element according to an embodiment. FIG. 2 is a perspective view showing a configuration of a case main body in the embodiment. 1A and 1B are a perspective view and a front view showing a configuration of a spacer according to an embodiment; 5 is a cross-sectional view showing the positional relationship between a spacer and a case main body according to the embodiment. FIG. 13 is a front view showing a configuration of a protrusion according to a first modified example of the embodiment. FIG. 13 is a top view showing a configuration of a protrusion according to a second modified example of the embodiment. FIG. 13 is a front view showing a configuration of a protrusion according to a third modified example of the embodiment. FIG.

(1) An energy storage device according to one aspect of the present invention includes an energy storage element and a spacer arranged in a first direction, and a case that houses the energy storage element and the spacer. The case has a case wall that faces the spacer in a second direction perpendicular to the first direction. The spacer has a spacer body that faces the energy storage element in the first direction, and a protrusion that protrudes from the spacer body toward the case wall. The protrusion has a first part that is an end on one side of the second direction that is connected to the spacer body, a second part that is an end on the other side of the second direction that faces the case wall, and a third part that is disposed between the first part and the second part and extends in a direction that intersects with the second direction.

According to this, in the energy storage device, the protruding portion of the spacer has a first portion on one side in the second direction that is connected to the spacer body, a second portion on the other side in the second direction that faces the case wall portion, and a third portion that is disposed between the first and second portions and extends in a direction intersecting the second direction. In this way, by having the protruding portion of the spacer have a third portion that extends in a direction intersecting the second direction, when the energy storage device is subjected to vibration or impact in the second direction, the protruding portion can absorb the vibration or impact. This can improve the vibration resistance or impact resistance of the energy storage device.

(2) In the energy storage device described in (1) above, the second portion may be in contact with the case wall, and the third portion may be spaced apart from the case wall.

With this, the second part of the protruding portion of the spacer comes into contact with the case wall and the third part is spaced apart from the case wall, making it easier for the protruding portion to absorb vibrations or shocks.

(3) In the energy storage device described in (1) or (2) above, a gap may be formed between the spacer body and the third portion.

In this way, a gap is formed between the spacer body and the third part of the protrusion in the spacer, allowing the third part to move relative to the spacer body, and therefore allowing the protrusion to absorb vibrations or shocks.

(4) In the energy storage device described in any one of (1) to (3) above, the protrusion may have a bent portion that is bent or curved from the third portion between at least one of the first portion and the second portion and the third portion.

With this, the protruding portion of the spacer has a bent portion between at least one of the first and second portions and the third portion, making it easier for the protruding portion to absorb vibrations or shocks.

(5) In the energy storage device described in any one of (1) to (4) above, the third portion may extend from the first portion in a third direction perpendicular to the first direction and the second direction when viewed from the second direction.

When the third portion of the spacer protrusion extends from the first portion in the first direction when viewed from the second direction, there is a risk that the spacer will tilt in the first direction when the protrusion absorbs vibration or impact. Since the first direction is the direction in which the energy storage element and the spacer are arranged, if the spacer tilts in the first direction, it will tilt toward the energy storage element, which may affect the energy storage element. Therefore, by having the third portion extend from the first portion in the third direction when viewed from the second direction, it is possible to prevent the spacer from tilting in the first direction and affecting the energy storage element.

(6) In the energy storage device described in any one of (1) to (5) above, the case wall portion may be a side wall of the case, and the protrusion portion may protrude from the spacer body toward the side wall.

With this, the protruding portion of the spacer protrudes toward the side wall of the case, so that when the spacer receives vibration or impact in the direction in which the side wall faces (horizontal direction), the protruding portion can absorb the vibration or impact.

(7) In the energy storage device described in any one of (1) to (6) above, the case wall portion may be a bottom wall of the case, and the protrusion portion may protrude from the spacer body toward the bottom wall.

With this, the protruding portion of the spacer protrudes toward the bottom wall of the case, so that when the spacer receives vibration or impact in the direction in which the bottom wall faces (vertical direction), the protruding portion can absorb the vibration or impact.

The following describes an energy storage device according to an embodiment of the present invention (including its variations) with reference to the drawings. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection forms, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. In each figure, dimensions are not strictly shown. In each figure, the same or similar components are given the same reference numerals.

In the following description and drawings, the X-axis direction is defined as the direction in which a pair of terminals of the storage element are arranged, the direction in which a pair of short sides of the storage element container face each other, or the direction in which the storage units are arranged. The Y-axis direction is defined as the direction in which a pair of long sides of the storage element container face each other, the thickness direction (flat direction) of the storage element or spacer, the direction in which the storage elements of the storage unit are arranged, or the direction in which the storage elements of the storage unit and the spacer are arranged. The Z-axis direction is defined as the direction in which the terminals of the storage element protrude, the direction in which the container body and the container lid of the storage element are arranged, the direction in which the case body and the lid of the case are arranged, the direction in which the opening and the bottom wall of the case body face each other, or the up-down direction. The X-axis direction, the Y-axis direction, and the Z-axis direction intersect with each other (orthogonal in this embodiment). Depending on the mode of use, the Z-axis direction may not be the up-down direction, but for convenience of explanation, the Z-axis direction will be described below as the up-down direction.

In the following description, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. When simply referring to the X-axis direction, it refers to both the positive X-axis direction and the negative X-axis direction, or either one of them. When referring to one side and the other side of the X-axis direction, it refers to one side and the other of the positive X-axis direction and the negative X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. In the following embodiments, the Y-axis direction is also called the first direction, the Z-axis direction is also called the second direction, and the X-axis direction is also called the third direction. Expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the directions or attitudes are not strictly the same. For example, two directions being parallel not only means that the two directions are completely parallel, but also means that the directions are substantially parallel, that is, that there is a difference of, for example, about a few percent. In the following description, when the term "insulation" is used, it means "electrical insulation".

(Embodiment)
[1. Description of the Power Storage Device 1]
First, a schematic configuration of the energy storage device 1 in this embodiment will be described. FIG. 1 is a perspective view showing the configuration of the energy storage device 1 according to this embodiment. FIG. 1 shows a state in which a cover 320 is removed from a case body 310 of a case 300 in the energy storage device 1. Thus, FIG. 1 shows two energy storage units 10 arranged inside the case 300. FIG. 2 is an exploded perspective view showing an energy storage element 100 and a spacer 200 included in the energy storage unit 10 included in the energy storage device 1 according to this embodiment. FIG. 2 shows the components of the energy storage unit 10 disassembled, and illustrates two energy storage elements 100 and three spacers 200 (spacers 200a) among them.

The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to the outside. The power storage device 1 is used for power storage or power supply. The power storage device 1 is used as a battery for driving or starting the engine of a moving object such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for an electric railway. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. Examples of the above-mentioned railway vehicles for an electric railway include electric trains, monorails, linear motor cars, and hybrid electric trains equipped with both a diesel engine and an electric motor. The power storage device 1 can also be used as a stationary battery for home or business use.

As shown in FIG. 1, the energy storage device 1 includes an energy storage unit 10 and a case 300 that houses the energy storage unit 10. The energy storage device 1 also includes external terminals (positive and negative external terminals) for electrically connecting to an external device, but these are not shown or described. In addition to the above components, the energy storage device 1 may also include electrical equipment such as a circuit board and a relay that monitors or controls the charging and discharging states of the energy storage unit 10.

The energy storage unit 10 is a battery module (battery assembly) having a plurality of energy storage elements 100. The energy storage unit 10 has a substantially rectangular parallelepiped shape that is long in the Y-axis direction (first direction) by arranging the plurality of energy storage elements 100 and the spacers 200 alternately in the Y-axis direction (first direction). In this embodiment, two energy storage units 10 arranged in the X-axis direction are housed inside the case 300. The energy storage unit 10 has a plurality of energy storage elements 100 and a plurality of spacers 200 (spacers 200a, 200b, and 200c). The energy storage unit 10 also includes a bus bar that connects the energy storage elements 100 in series or in parallel, a bus bar frame that holds the bus bar, and a bus bar that connects the energy storage elements 100 to external terminals, but these are not shown in the figures. The bus bar may connect all the energy storage elements 100 in series, or may connect some of the energy storage elements 100 in parallel and then connect them in series, or may connect all the energy storage elements 100 in parallel.

The energy storage element 100 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The energy storage element 100 has a flat rectangular parallelepiped shape (square, rectangular) in the Y-axis direction. In this embodiment, a plurality of energy storage elements 100 are arranged in the Y-axis direction, but the number of the arranged energy storage elements 100 is not particularly limited, and may be one, several tens of elements, or more. The size and shape of the energy storage element 100 are also not particularly limited, and may be an oblong cylinder shape, an elliptical cylinder shape, a cylindrical shape, a polygonal column shape other than a rectangular parallelepiped, or the like. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 100 may be a primary battery that can use the stored electricity without the user having to charge it, rather than a secondary battery. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element.

The spacer 200 is a flat member in the Y-axis direction (first direction) that is arranged alongside the energy storage element 100 and insulates and/or insulates the energy storage element 100 from other components. The spacer 200 is an insulating or heat-insulating plate that is arranged in the positive or negative Y-axis direction of the energy storage element 100 and insulates and/or insulates the energy storage elements 100 from each other or from the energy storage element 100 to the case 300. The spacer 200 is made of insulating materials such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), polyamide (PA), ABS resin, or composite materials thereof, or a material with thermal insulation properties such as mica.

The spacer 200 has walls on both sides of the energy storage element 100 in the X-axis direction and on both sides of the Z-axis direction, and thus holds the energy storage element 100 and also functions as a holder for positioning the energy storage element 100. The spacer 200 arranged at the center position of the energy storage unit 10 in the Y-axis direction (between the two energy storage elements 100 at the center position) is referred to as spacer 200b. The spacer 200 arranged at both ends of the energy storage unit 10 in the Y-axis direction (between the energy storage elements 100 at the ends and the case 300) is referred to as spacer 200c. The spacer 200 arranged between spacer 200b and spacer 200c (between the two energy storage elements 100 other than the center position) is referred to as spacer 200a. The spacers 200 (spacers 200a, 200b, and 200c) are arranged alternately with the energy storage elements 100. FIG. 2 shows a configuration in which the energy storage elements 100 and the spacers 200a are arranged alternately, and the spacers 200a, together with the spacers 200b and 200c, are arranged alternately with the energy storage elements 100.

2, the spacer 200a is an intermediate spacer (intermediate holder) that has walls on both sides in the X-axis direction and on both sides in the Z-axis direction of two storage elements 100 arranged on both sides of the spacer 200a in the Y-axis direction and holds the two storage elements 100. Similarly, the spacer 200b is a center plate (center spacer or center holder) that has walls on both sides in the X-axis direction and on both sides in the Z-axis direction of two storage elements 100 arranged on both sides of the spacer 200b in the Y-axis direction and holds the two storage elements 100. The spacer 200b has a function of increasing the rigidity of the storage unit 10 that is long in the Y-axis direction. The spacer 200c is an end spacer (end holder) that has walls on both sides in the X-axis direction and on both sides in the Z-axis direction of one storage element 100 arranged on one side of the spacer 200c in the Y-axis direction and holds the one storage element 100.

That is, the storage element 100 located at the center of the energy storage unit 10 in the Y-axis direction is held by the spacer 200a and the spacer 200b. The storage element 100 located at the end of the energy storage unit 10 in the Y-axis direction is held by the spacer 200a and the spacer 200c. The other storage elements 100 are held by the two spacers 200a. All the spacers 200 (spacers 200a, 200b, and 200c) may be made of the same material, or any of the spacers 200 may be made of a different material.

The case 300 is a container having a substantially rectangular parallelepiped (box-shaped) shape that constitutes the exterior body (outer shell) of the energy storage device 1. The case 300 is disposed outside the energy storage unit 10, fixes the energy storage unit 10 in a predetermined position, and protects it from impacts and the like. The case 300 is a metal case formed from metal members such as aluminum, aluminum alloy, stainless steel, iron, plated steel sheet, etc. In this embodiment, the case 300 is formed by die-casting aluminum (aluminum die-casting). The case 300 may be formed from an insulating member such as any resin material that can be used for the spacer 200 of the energy storage unit 10.

As shown in FIG. 1, the case 300 has a case body 310 constituting the body of the case 300, and a lid body 320 constituting the lid body of the case 300. The case body 310 is a housing (chassis) with an opening 310a formed in the positive direction of the Z axis, and accommodates the storage unit 10 (the storage element 100 and the spacer 200 (spacers 200a, 200b and 200c)). The lid body 320 is a flat rectangular member that closes the opening 310a of the case body 310. The case body 310 has two rectangular openings 310a aligned in the X axis direction, and after the storage unit 10 is inserted through each opening 310a, the case body 310 and the lid body 320 are joined by screwing with bolts or the like, welding, adhesives, or the like. As a result, the case 300 has a structure in which the inside is sealed (sealed). A terminal block for external terminals (positive and negative external terminals) may be attached to the case body 310 or the lid 320, and the external terminals may be arranged on the terminal block.

Next, the configurations of the energy storage element 100, the case 300 (particularly the case body 310), and the spacer 200 (particularly the spacer 200a) will be described in detail.

[1.1 Description of Energy Storage Element 100]
Fig. 3 is a perspective view showing a configuration of the energy storage element 100 according to the present embodiment. Fig. 3 shows an enlarged view of the energy storage element 100 shown in Fig. 2. Since the multiple energy storage elements 100 included in the energy storage unit 10 all have the same configuration, Fig. 3 shows one energy storage element 100, and the configuration of one energy storage element 100 will be described in detail below.

As shown in FIG. 3, the energy storage element 100 has a container 110 and a pair of terminals 140 (positive and negative electrodes). Inside the container 110, an electrode body, a pair of current collectors (positive and negative electrodes), and an electrolyte (non-aqueous electrolyte) are contained, and a gasket is disposed between the terminals 140 and the current collectors and the container 110, but these are not shown. There is no particular limit to the type of electrolyte as long as it does not impair the performance of the energy storage element 100, and various types can be selected. The gasket may be made of any material as long as it has insulating properties. In addition to the above components, the energy storage element 100 may have a spacer disposed on the side of the electrode body, an insulating film that wraps the electrode body, and an insulating film (shrink tube, etc.) that covers the outer surface of the container 110.

The container 110 is a rectangular parallelepiped (angular or box-shaped) case having a container body 120 with an opening and a container lid 130 that closes the opening of the container body 120. The container body 120 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 110, and an opening is formed on the Z-axis positive side. The container lid 130 is a rectangular plate-shaped member that is long in the X-axis direction and constitutes the lid of the container 110, and is arranged in the Z-axis positive direction of the container body 120. The container lid 130 is provided with a gas exhaust valve 131 that releases pressure when the pressure inside the container 110 increases excessively, and a liquid injection part (not shown) for injecting electrolyte into the container 110. The material of the container 110 (container body 120 and container lid 130) is not particularly limited, and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate, but resin can also be used.

After the electrode body and the like are accommodated inside the container body 120, the container body 120 and the container lid portion 130 are joined by welding or the like to close (seal) the inside of the container 110. The container 110 has a pair of long sides 111 on both sides in the Y-axis direction, a pair of short sides 112 on both sides in the X-axis direction, and a bottom surface 113 on the negative Z-axis side. The long sides 111 are rectangular flat surfaces that form the long sides of the container 110 and are arranged opposite the adjacent spacers 200 in the Y-axis direction. The long sides 111 are adjacent to the short sides 112 and the bottom surface 113, and have a larger area than the short sides 112. The short sides 112 are rectangular flat surfaces that form the short sides of the container 110 and are arranged opposite the wall portions of the spacers 200 and the case 300 in the X-axis direction. The short sides 112 are adjacent to the long sides 111 and the bottom surface 113, and have a smaller area than the long sides 111. The bottom surface 113 is a rectangular flat surface that forms the bottom surface of the container 110, and is disposed opposite the wall of the spacer 200 and the bottom wall of the case 300 in the Z-axis direction. The bottom surface 113 is disposed adjacent to the long side surface 111 and the short side surface 112.

The terminals 140 are electrode terminals (positive and negative terminals) of the energy storage element 100 that are arranged on the container lid 130. Specifically, the terminals 140 are arranged protruding from the upper surface (terminal arrangement surface) of the container lid 130 in the positive direction of the Z axis. The terminals 140 are electrically connected to the positive and negative plates of the electrode body via a current collector. In other words, the terminals 140 are metal members that conduct electricity stored in the electrode body to the external space of the energy storage element 100 and introduce electricity into the internal space of the energy storage element 100 to store electricity in the electrode body. The terminals 140 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

The electrode body is a storage element (power generating element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a positive electrode active material layer formed on a positive electrode substrate layer, which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is a negative electrode active material layer formed on a negative electrode substrate layer, which is a current collector foil made of a metal such as copper or a copper alloy. As the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it can absorb and release lithium ions. The separator can be a microporous sheet or nonwoven fabric made of resin. In this embodiment, the electrode body is formed by stacking the electrode plates (positive electrode plate and negative electrode plate) in the Y-axis direction. The electrode body may be any type of electrode body, such as a wound type electrode body formed by winding the electrode plates (positive electrode plate and negative electrode plate), a stack type (stack type) electrode body formed by stacking multiple flat electrode plates, or a bellows type electrode body in which the electrode plates are folded in a bellows shape.

The current collectors are conductive current collecting members (positive and negative current collectors) that are electrically and mechanically connected to the terminal 140 and the electrode body. The positive current collector is made of aluminum or an aluminum alloy, etc., like the positive electrode substrate layer of the positive electrode plate of the electrode body, and the negative current collector is made of copper or a copper alloy, etc., like the negative electrode substrate layer of the negative electrode plate of the electrode body.

[1.2 Description of case body 310]
Next, a detailed description will be given of the configuration of the case body 310 of the case 300. Fig. 4 is a perspective view showing the configuration of the case body 310 according to the present embodiment.

As shown in FIG. 4, the case body 310 has case walls 311 to 314. That is, the case body 310 has case wall 311 on the bottom surface in the negative Z-axis direction, a pair of case walls 312 on both side surfaces in the X-axis direction, case wall 313 in the center in the X-axis direction, and a pair of case walls 314 on both side surfaces in the Y-axis direction. The case body 310 is a single member in which the case wall 311, the two case walls 312, the case wall 313, and the two case walls 314 are integrated. That is, the case body 310 is integrally molded by aluminum die casting or the like, and is formed integrally as a single member (one part).

The case wall 311 is the bottom wall of the case body 310 (the bottom wall of the case 300). The case wall 311 is a flat, rectangular wall (bottom wall) that is parallel to the XY plane and long in the Y-axis direction, and is arranged with its main surface (the surface with the largest area) facing the Z-axis direction (the second direction perpendicular to the first direction) to form the bottom surface of the case body 310. The case wall 311 is arranged opposite the energy storage unit 10 (the energy storage element 100 and the spacer 200 (spacers 200a, 200b, and 200c)) in the Z-axis direction (second direction). Specifically, the case wall 311 is arranged in the negative Z-axis direction of the energy storage unit 10 so as to cover the entire surface of the energy storage unit 10 in the negative Z-axis direction, and supports the energy storage unit 10 from the negative Z-axis direction. The case wall 311 is arranged adjacent to the case walls 312, 313, and 314.

The case wall 312 is a side wall of the case body 310 (side wall of the case 300). The case wall 312 is arranged with its main surface (the surface with the largest area) facing the X-axis direction (third direction) to form the side surface (long side surface) of the case body 310 in the X-axis direction, and is a flat, rectangular wall (long side wall) that is parallel to the YZ plane and long in the Y-axis direction. The case wall 312 is a wall that rises in the Z-axis positive direction from the X-axis direction end of the case wall 311, and is arranged opposite the storage unit 10 (storage element 100 and spacer 200 (spacers 200a, 200b, and 200c)) in the X-axis direction (third direction). The case wall 312 is adjacent to the case walls 311 and 314. In this embodiment, two case walls 312 are arranged opposite each other at both ends of the case body 310 in the X-axis direction. The case wall 312 in the positive X-axis direction is arranged in the positive X-axis direction of the power storage unit 10 so as to cover the entire surface of the power storage unit 10 in the positive X-axis direction. The case wall 312 in the negative X-axis direction is arranged in the negative X-axis direction of the power storage unit 10 so as to cover the entire surface of the power storage unit 10 in the negative X-axis direction.

The case wall 313 is a partition wall of the case body 310 (partition wall of the case 300). The case wall 313 is arranged with its main surface (the surface with the largest area) facing the X-axis direction (third direction) and is a rectangular parallelepiped wall (partition wall) that is long in the Y-axis direction and divides the space inside the case body 310. The case wall 313 is a wall that rises in the positive direction of the Z-axis from the center of the case wall 311 in the X-axis direction and is arranged opposite the storage unit 10 (storage element 100 and spacer 200 (spacers 200a, 200b, and 200c)) in the X-axis direction (third direction). Specifically, the case wall 313 is arranged between two storage units 10 arranged in the X-axis direction. Since the case wall 313 is a wall located on the side of the storage unit 10, it can also be said to be a side wall of the case body 310 (side wall of the case 300). The case wall 313 is disposed in the negative X-axis direction of the power storage unit 10 so as to cover the entire surface of the negative X-axis direction of the power storage unit 10 in the positive X-axis direction. The case wall 313 is disposed in the positive X-axis direction of the power storage unit 10 so as to cover the entire surface of the positive X-axis direction of the power storage unit 10 in the negative X-axis direction. The case wall 313 is adjacent to the case walls 311 and 314.

The case wall 314 is a side wall of the case body 310 (side wall of the case 300). The case wall 314 is a flat, rectangular wall (short side wall) that is parallel to the XZ plane and long in the X-axis direction, and is arranged with its main surface (the surface with the largest area) facing the Y-axis direction (first direction) to form the side surface (short side surface) of the case body 310 in the Y-axis direction. The case wall 314 is a wall that rises in the Z-axis positive direction from the Y-axis end of the case wall 311, and is arranged opposite the storage unit 10 (spacer 200c of the spacer 200) in the Y-axis direction (first direction). The case wall 314 is adjacent to the case walls 311, 312, and 313. In this embodiment, two case walls 314 are arranged opposite each other at both ends of the case body 310 in the Y-axis direction. The case wall 314 in the positive Y-axis direction is disposed in the positive Y-axis direction of the energy storage unit 10 (spacer 200c in the positive Y-axis direction) so as to cover almost the entire surface of the energy storage unit 10 (spacer 200c in the positive Y-axis direction). The case wall 314 in the negative Y-axis direction is disposed in the negative Y-axis direction of the energy storage unit 10 (spacer 200c in the negative Y-axis direction) so as to cover almost the entire surface of the energy storage unit 10 (spacer 200c in the negative Y-axis direction).

With the above-mentioned configuration, the case body 310 has an opening 310a that opens toward the Z-axis positive direction (one side of the second direction). That is, the two case walls 312, the case wall 313, and the two case walls 314 form two openings 310a aligned in the X-axis direction. The opening 310a is a rectangular opening that is long in the Y-axis direction as viewed from the Z-axis direction and is positioned opposite the case wall 311 of the case body 310. The opening 310a is positioned opposite the power storage unit 10 in the Z-axis direction and is formed to a size that allows the power storage unit 10 to pass through in the Z-axis direction. That is, the opening 310a is an opening in which the surface of the case body 310 in the Z-axis positive direction is open.

[1.3 Description of spacer 200a]
Next, the configuration of the spacer 200a of the spacer 200 will be described in detail. Fig. 5 is a perspective view and a front view showing the configuration of the spacer 200a according to the present embodiment. Specifically, Fig. 5(a) is a perspective view showing an enlarged view of the spacer 200a shown in Fig. 2. Fig. 5(b) is a front view showing a further enlarged view of the configuration of the protruding portion 230 of the spacer 200a shown in Fig. 5(a) as viewed from the negative Y-axis direction. Since the multiple spacers 200a included in the energy storage unit 10 all have the same configuration, Fig. 5 shows one spacer 200a, and the configuration of one spacer 200a will be described in detail below.

6 is a cross-sectional view showing the positional relationship between the spacer 200a and the case body 310 according to this embodiment. Specifically, FIG. 6(a) is a cross-sectional view showing a cross section of the case body 310 cut along a plane parallel to the XZ plane in a state in which the spacer 200a is arranged in the case body 310. Since the half of the case body 310 in the positive X-axis direction and the half in the negative X-axis direction have the same configuration, FIG. 6(a) illustrates the half in the positive X-axis direction and omits the half in the negative X-axis direction. FIG. 6(b) is a cross-sectional view showing an enlarged view of the protrusion 230 in the positive X-axis direction of the spacer 200a shown in FIG. 6(a) and the configuration around it. Since the protrusion 230 in the positive X-axis direction of the spacer 200a and the configuration around it have the same configuration, FIG. 6(b) illustrates the configuration in the positive X-axis direction and omits the configuration in the negative X-axis direction.

As shown in FIG. 5, both ends of the spacer 200a in the X-axis direction have the same shape. In other words, the spacer 200a has a shape that is symmetrical with respect to a plane that passes through the center position and is parallel to the YZ plane. The spacer 200a has a spacer body 210, a spacer wall portion 220, and a protrusion portion 230.

The spacer body 210 is a flat, rectangular part constituting the main body of the spacer 200a, and is arranged parallel to the XZ plane. The spacer body 210 is arranged facing the energy storage element 100 in the Y-axis direction (first direction). In this embodiment, the spacer body 210 is arranged in the positive or negative Y-axis direction of the energy storage element 100, facing the long side surface 111 in the Y-axis direction so as to cover the entire surface of the long side surface 111 of the container 110 of the energy storage element 100, and in contact with the long side surface 111. The spacer body 210 has a plurality of L-shaped curved grooves formed therein through which a cooling gas (air, etc.) passes.

The spacer wall portions 220 are walls arranged on both sides of the energy storage element 100 in the Z-axis direction and on both sides of the energy storage element 100 in the X-axis direction. Specifically, the spacer wall portions 220 have a pair of first spacer wall portions 221 and 222 arranged on both sides of the energy storage element 100 in the Z-axis direction, and a pair of second spacer wall portions 223 and a pair of second spacer wall portions 224 arranged on both sides of the energy storage element 100 in the X-axis direction.

The first spacer wall 221 is a flat plate-shaped portion that protrudes in the Y-axis direction from the Z-axis positive end of the spacer body 210, and is arranged parallel to the XY plane. Specifically, a pair of first spacer walls 221 that protrude from both ends of the X-axis direction of the Z-axis positive end of the spacer body 210 in the Y-axis direction are arranged at both ends of the X-axis direction of the spacer 200a. The first spacer wall 221 is arranged along the container lid 130 of the container 110 of the storage element 100 in the Z-axis positive direction of the storage element 100. In detail, the first spacer wall 221 is arranged opposite the container lid 130 in the Z-axis direction at both ends of the X-axis direction of the storage element 100 so as to cover approximately half of the container lid 130 on the Y-axis positive side or the Y-axis negative side.

The first spacer wall 222 is a flat plate-shaped portion that protrudes in the Y-axis direction from the negative Z-axis end of the spacer body 210 and extends in the X-axis direction, and is arranged parallel to the XY plane. Specifically, the first spacer wall 222 is arranged to protrude on both sides in the Y-axis direction and extend in the X-axis direction from one end to the other end in the negative Z-axis direction of the spacer body 210. The first spacer wall 222 is arranged along the bottom surface 113 of the container 110 of the energy storage element 100 in the negative Z-axis direction of the energy storage element 100. In detail, the first spacer wall 222 is arranged opposite the bottom surface 113 in the Z-axis direction so as to cover approximately half of the bottom surface 113 on the positive Y-axis side or the negative Y-axis side, from one end to the other end in the X-axis direction of the bottom surface 113.

The second spacer wall 223 is a flat plate-like portion that protrudes in the Y-axis direction from the X-axis end and the Z-axis positive end of the spacer body 210, and is arranged parallel to the YZ plane. Specifically, a pair of second spacer walls 223 that protrude from the Z-axis positive end of both ends of the X-axis direction of the spacer body 210 on both sides in the Y-axis direction are arranged at both ends of the spacer 200a in the X-axis direction. The second spacer wall 223 is arranged along the short side surface 112 of the container 110 of the energy storage element 100. In detail, the second spacer wall 223 is arranged opposite the short side surface 112 in the X-axis direction at the Z-axis positive end on both sides of the energy storage element 100 in the X-axis direction so as to cover approximately half of the Y-axis positive side or Y-axis negative side of the short side surface 112.

The second spacer wall 224 is a flat plate-like portion that protrudes in the Y-axis direction from the X-axis direction end and the Z-axis negative direction end of the spacer body 210, and is arranged parallel to the YZ plane. Specifically, a pair of second spacer walls 224 that protrude from the Z-axis negative direction ends of both ends of the X-axis direction of the spacer body 210 on both sides in the Y-axis direction are arranged at both ends of the spacer 200a in the X-axis direction. The second spacer wall 224 is arranged along the short side surface 112 of the container 110 of the energy storage element 100. In detail, the second spacer wall 224 is arranged opposite the short side surface 112 in the X-axis direction at the Z-axis negative direction ends on both sides of the X-axis direction of the energy storage element 100 so as to cover approximately half of the Y-axis positive side or Y-axis negative side of the short side surface 112.

In this way, the spacer wall portion 220 is arranged to cover the four corners of the energy storage element 100 located at both ends in the Z-axis direction and both ends in the X-axis direction of the energy storage element 100. This allows the spacer 200a to hold the energy storage element 100.

The protrusion 230 is a portion that protrudes from the spacer body 210 in the negative Z direction. In this embodiment, the protrusion 230 protrudes in the negative Z direction from the end of the spacer body 210 in the X direction. Specifically, a pair of protrusions 230 are arranged protruding in the negative Z direction from the ends of both ends of the spacer body 210 in the X direction in the negative Z direction. The ends of the spacer body 210 in the X direction are portions located at the ends when the spacer body 210 is divided into thirds in the X direction, and both ends of the spacer body 210 in the X direction are portions located at the ends when the spacer body 210 is divided into thirds.

6, when the spacer 200a is disposed in the case body 310, the protrusion 230 protrudes from the spacer body 210 toward the case wall 311. That is, the protrusion 230 protrudes from the spacer body 210 toward the bottom wall of the case 300 (the bottom wall of the case body 310). Specifically, the tips of the pair of protrusions 230 in the negative Z-axis direction are disposed in contact with the surface of the case wall 311 in the positive Z-axis direction, and a space is formed between the first spacer wall 222 and the case wall 311. In this embodiment, the protrusion 230 is integrated (integrally formed) with the spacer body 210, but it may be configured separately from the spacer body 210 and connected (in contact or joined) to the spacer body 210.

As shown in Figures 5 and 6, the protruding portion 230 has a first portion 231, a second portion 232, a third portion 233, and a bent portion 234. In this embodiment, the first portion 231, the second portion 232, and the third portion 233 are continuously connected to each other and integrated (integrally formed), but may be formed by joining separate members.

The first part 231 is an end of the protrusion 230 in the positive Z-axis direction (one side in the second direction) that is connected to the spacer body 210. The first part 231 is a flat part that extends linearly from the spacer body 210 in the negative Z-axis direction and is parallel to the YZ plane that extends linearly in the Y-axis direction. The length of the first part 231 in the Y-axis direction is longer than the length of the Z-axis direction. The length of the first part 231 in the Y-axis direction is longer than the length of the spacer body 210 in the Y-axis direction and is equal to the length of the first spacer wall 222 and the second spacer wall 224 in the Y-axis direction. As described above, in this embodiment, the first part 231 is continuously connected to the spacer body 210 and is integrated (integrally formed) with the spacer body 210, but it may be configured separately from the spacer body 210 and connected to the spacer body 210 by contact or bonding.

The second part 232 is an end of the protruding part 230 in the negative Z-axis direction (the other side in the second direction) facing the case wall part 311. The second part 232 is a flat part that extends linearly from the third part 233 in the negative Z-axis direction and is parallel to the YZ plane that extends linearly in the Y-axis direction. In this embodiment, the second part 232 extends in the negative Z-axis direction from the outer end of the third part 233 in the X-axis direction. In other words, the second part 232 of the protruding part 230 in the positive X-axis direction of the pair of protruding parts 230 extends in the negative Z-axis direction from the end of the third part 233 in the positive X-axis direction. The second part 232 of the protruding part 230 in the negative X-axis direction extends in the negative Z-axis direction from the end of the third part 233 in the negative X-axis direction.

When the spacer 200a is placed in the case body 310, the second part 232 contacts the case wall 311. Specifically, the end face of the second part 232 in the negative Z-axis direction contacts the face of the case wall 311 in the positive Z-axis direction (see FIG. 6). The length of the second part 232 in the Y-axis direction is longer than the length in the Z-axis direction. In the Y-axis direction, the second part 232 has the same length as the first part 231. In other words, the length of the second part 232 in the Y-axis direction is longer than the length of the spacer body 210 in the Y-axis direction and is equal to the length of the first spacer wall 222 and the second spacer wall 224 in the Y-axis direction. In this embodiment, the second part 232 is longer than the first part 231 in the Z-axis direction, but may be the same length as the first part 231 or shorter than the first part 231.

The third portion 233 is disposed between the first portion 231 and the second portion 232, and is an intermediate portion (part of the middle portion from one end to the other end) of the protruding portion 230 extending in a direction intersecting the Z-axis direction (second direction). The third portion 233 extends from the first portion 231 toward the X-axis direction (third direction perpendicular to the first and second directions) when viewed from the Z-axis direction (second direction). Specifically, the third portion 233 is a flat portion that extends linearly in the X-axis direction from the first portion 231 toward the second portion 232, and is parallel to the XY plane that extends linearly in the Y-axis direction. In this embodiment, the third portion 233 extends from the first portion 231 in a direction facing outward in the X-axis direction. In other words, the third portion 233 of the protruding portion 230 in the X-axis positive direction of the pair of protruding portions 230 extends in the X-axis positive direction from the first portion 231 toward the second portion 232. The third portion 233 of the protrusion 230 in the negative X-axis direction extends in the negative X-axis direction from the first portion 231 to the second portion 232.

With this configuration, a gap is formed between the spacer body 210 (first spacer wall portion 222) and the third portion 233. In this embodiment, the third portion 233 is disposed away from the spacer body 210 (first spacer wall portion 222). Furthermore, the third portion 233 is disposed away from the case wall portion 311. The length of the third portion 233 in the Y-axis direction is longer than the length in the X-axis direction. In the Y-axis direction, the third portion 233 has the same length as the first portion 231 and the second portion 232. In other words, the length of the third portion 233 in the Y-axis direction is longer than the length of the spacer body 210 in the Y-axis direction and is equal to the length of the first spacer wall portion 222 and the second spacer wall portion 224 in the Y-axis direction.

The bent portion 234 is a portion bent or curved from the third portion 233 and disposed between at least one of the first portion 231 and the second portion 232 and the third portion 233. In this embodiment, the protruding portion 230 has two bent portions 234 bent from the third portion 233 between both the first portion 231 and the second portion 232 and the third portion 233. The bent portions 234 have the same length as the first portion 231, the second portion 232, and the third portion 233 in the Y-axis direction, and extend linearly in the Y-axis direction. As a result, the protruding portion 230 is a portion that is approximately S-shaped (crank-shaped) when viewed from the Y-axis direction. Specifically, the protruding portion 230 in the X-axis positive direction of the pair of protruding portions 230 has a bent portion 234 bent from the Z-axis negative direction to the X-axis positive direction between the first portion 231 and the third portion 233, and has a bent portion 234 bent from the X-axis positive direction to the Z-axis negative direction between the third portion 233 and the second portion 232. The protruding portion 230 in the negative X-axis direction has a bent portion 234 bent from the negative Z-axis direction to the negative X-axis direction between the first portion 231 and the third portion 233, and has a bent portion 234 bent from the negative X-axis direction to the negative Z-axis direction between the third portion 233 and the second portion 232. Any one of these bent portions 234 may be curved.

[2. Description of Effects]
As described above, according to the energy storage device 1 of this embodiment, the protruding portion 230 of the spacer 200a has a first part 231 in the Z-axis positive direction (one side in the second direction) connected to the spacer body 210, and a second part 232 in the Z-axis negative direction (the other side in the second direction) facing the case wall part 311. The protruding portion 230 further has a third part 233 disposed between the first part 231 and the second part 232 and extending in a direction intersecting the Z-axis direction (second direction). In this way, when the energy storage device 1 is subjected to vibration or impact in the Z-axis direction (second direction), the protruding portion 230 can absorb the vibration or impact. This can improve the vibration resistance or impact resistance of the energy storage device 1.

By having the third portion 233 on the protruding portion 230 of the spacer 200a, the position of the spacer 200a (and the energy storage element 100) in the Z-axis direction can be adjusted during manufacturing, such as joining a bus bar to the energy storage element 100. Even if the protruding portion 230 of the spacer 200a is bent in the Z-axis direction, the protruding portion 230 having the third portion 233 can absorb vibrations or shocks by using its restoring force. By having the protruding portion 230 on the spacer 200a, other members can be placed in the gap between the spacer 200a and the case wall portion 311. When cooling air is passed between the spacer 200a and the case wall portion 311, by having the protruding portion 230 on the spacer 200a, a passage for the cooling air can be secured.

By arranging a pair of protrusions 230 at both ends of the spacer body 210 of the spacer 200a in the X-axis direction, the pair of protrusions 230 can stably support the spacer 200a and stably absorb vibrations or impacts.

The second portion 232 of the protruding portion 230 of the spacer 200a contacts the case wall portion 311, and the third portion 233 is spaced apart from the case wall portion 311, so that the protruding portion 230 is easily structured to absorb vibrations or shocks.

In the spacer 200a, a gap is formed between the spacer body 210 and the third portion 233 of the protruding portion 230, so that the third portion 233 can move relative to the spacer body 210, allowing the protruding portion 230 to absorb vibrations or shocks.

The protrusion 230 of the spacer 200a has a bent portion 234 between at least one of the first portion 231 and the second portion 232 and the third portion 233, which makes it easier for the protrusion 230 to absorb vibrations or shocks.

When the third portion 233 of the protruding portion 230 of the spacer 200a is configured to extend from the first portion 231 in the Y-axis direction (first direction) when viewed from the Z-axis direction (second direction), the spacer 200a may tilt in the Y-axis direction (first direction) when the protruding portion 230 absorbs vibration or impact. Since the Y-axis direction (first direction) is the arrangement direction of the energy storage element 100 and the spacer 200a, if the spacer 200a tilts in the Y-axis direction (first direction), it will tilt toward the energy storage element 100, which may affect the energy storage element 100. Therefore, by having the third portion 233 extend from the first portion 231 in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction), it is possible to prevent the spacer 200a from tilting in the Y-axis direction (first direction) and affecting the energy storage element 100. In particular, because a pair of protrusions 230 are provided at both ends of the spacer 200a in the X-axis direction, tilting of the spacer 200a can be prevented even when the protrusions 230 absorb vibrations or shocks.

By extending the third portion 233 from the first portion 231 in a direction facing outward in the X-axis direction, the spacer 200a can be stably supported. By extending the third portion 233 from the first portion 231 in a direction facing outward in the X-axis direction, the gap between the spacer 200a and the case wall portion 311 can be made larger, making it easier to place other components in the gap, and when the gap is used as a passage for cooling air, the passage can be made larger.

The protrusion 230 of the spacer 200a protrudes toward the bottom wall (case wall portion 311) of the case 300, so that when the spacer 200a receives vibration or impact in the direction in which the bottom wall faces (vertical direction), the protrusion 230 can absorb the vibration or impact.

[3. Description of Modifications]
Although the energy storage device 1 according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. The embodiment disclosed herein is illustrative in all respects, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

(Variation 1)
In the above embodiment, the position of the protrusion 230 provided on the spacer 200a is not particularly limited. The protrusion 230 does not have to be arranged at both ends in the X-axis direction of the Z-axis negative direction end of the spacer body 210, and may be arranged at any position of the Z-axis negative direction end of the spacer body 210, such as the X-axis center of the Z-axis negative direction end of the spacer body 210. The protrusion 230 may be arranged at the Z-axis positive direction end of the spacer body 210. In this case, the protrusion 230 protrudes toward the upper wall (upper wall of the lid 320) of the case 300 as the case wall part. Alternatively, the protrusion 230 may be arranged at the X-axis direction end of the spacer body 210 as shown in FIG. 7. FIG. 7 is a front view showing the configuration of the protrusion 230a according to the first modification of this embodiment. FIG. 7 is a view corresponding to FIG. 5(b).

7, in this modified example, a protrusion 230a is arranged instead of the protrusion 230 in the above embodiment. The protrusion 230a protrudes in the X-axis positive direction from the second spacer wall 223 at the X-axis positive end and Z-axis positive end of the spacer body 210. The protrusion 230a may protrude in the X-axis positive direction from the second spacer wall 224 at the X-axis positive end and Z-axis negative end of the spacer body 210. The protrusion 230a may protrude in the X-axis positive direction from the X-axis positive end and Z-axis central portion of the spacer body 210. In other words, a pair of protrusions 230a may be arranged at both ends in the Z-axis direction of the X-axis positive end of the spacer body 210, or one or more protrusions 230a may be arranged at other positions of the X-axis positive end of the spacer body 210. Similarly, a pair of protrusions 230a may be arranged at both ends in the Z-axis direction of the negative X-axis end of the spacer body 210, or one or more protrusions 230a may be arranged at other positions on the negative X-axis end of the spacer body 210.

In this way, the protrusion 230a is arranged at any position of the X-axis end of the spacer body 210 and protrudes from the spacer body 210 toward the case wall 312 or 313, which is the side wall of the case 300. The protrusion 230a and the case wall 312 or 313 in this modification correspond to the protrusion 230 and the case wall 311 in the above embodiment. In other words, the protrusion 230a and the case wall 312 or 313 in this modification have a configuration in which the protrusion 230 and the case wall 311 in the above embodiment are rotated 90° around the Y axis. In other words, in this modification, the X-axis direction is an example of the second direction, and the Z-axis direction is an example of the third direction. The protrusion 230a shown in FIG. 7 has a first part 231, which is an end in the X-axis negative direction (one side of the second direction), and a second part 232, which is an end in the X-axis positive direction (the other side of the second direction). The protruding portion 230a further has a third portion 233 disposed between the first portion 231 and the second portion 232, extending in a direction intersecting the X-axis direction (second direction) (specifically, the Z-axis direction (third direction)), and a bent portion 234 bent from the third portion 233. The rest of the configuration of this modified example is the same as that of the above embodiment, so a detailed description will be omitted.

As described above, the energy storage device according to this modified example can achieve the same effects as the above embodiment. In particular, since the protrusion 230a protrudes toward the side wall of the case 300 (case wall portion 312 or 313), when the spacer 200a receives vibration or impact in the direction in which the side wall faces (horizontal direction, X-axis direction), the protrusion 230 can absorb the vibration or impact.

In this modified example, the protrusion 230a protrudes toward the side wall of the case body 310 (case wall 312 or 313), but it may also protrude toward the side wall of the lid 320. In other words, it is sufficient that the protrusion 230a protrudes toward the side wall of the case 300.

(Variation 2)
In the above embodiment, the shape of the protrusion 230 provided on the spacer 200a is not particularly limited. Fig. 8 is a top view showing the configuration of the protrusion 230b according to the second modification of the embodiment. Fig. 8 is a top view showing the configuration of the spacer body 210 and the protrusion 230b when viewed from the positive direction of the Z axis.

As shown in FIG. 8, in this modified example, protrusion 230b is arranged instead of protrusion 230 in the above embodiment. Protrusion 230b protrudes in the positive X-axis direction from the end of spacer body 210 in the positive X-axis direction. Protrusion 230b may protrude in the negative X-axis direction from the end of spacer body 210 in the negative X-axis direction. Protrusion 230b may be arranged from one end to the other end of spacer body 210 in the Z-axis direction, or may be arranged at the end or center of spacer body 210.

The protruding portion 230b protrudes from the spacer body 210 toward the case wall portion 312 or 313, which is the side wall of the case 300. The protruding portion 230b shown in FIG. 8 has a first portion 231, which is an end portion in the negative X-axis direction (one side of the second direction), and a second portion 232, which is an end portion in the positive X-axis direction (the other side of the second direction). The protruding portion 230b further has a third portion 233 disposed between the first portion 231 and the second portion 232, which extends in a direction intersecting the X-axis direction (second direction) (a direction inclined from the X-axis direction to the Y-axis direction), and a bent portion 234 curved from the third portion 233. The third portion 233 is a portion that curves in a curved shape (curved shape) in the positive Z-axis direction as it approaches the positive X-axis direction. When the protruding portion 230b contacts the case wall portion 312, the surface of the second portion 232 in the positive X-axis direction may come into surface contact with the case wall portion 312, or the end portion of the second portion 232 in the positive Y-axis direction may come into linear contact with the case wall portion 312. The rest of the configuration of this modified example is the same as in the above embodiment, so detailed description will be omitted.

As described above, the energy storage device according to this modified example can achieve the same effects as the above-described embodiment. In particular, the protrusion 230b has a curved third portion 233, which gives it a relatively large elastic force in the X-axis direction, making it easier to absorb vibrations or shocks.

In this modification, the protrusion 230b may be disposed in the same position or in the same orientation as in the above embodiment or modification 1. In addition to this modification, the protrusion provided on the spacer 200a may take various forms.

(Variation 3)
In the above embodiment, the protruding portion 230 does not have to have the bent portion 234. Fig. 9 is a front view showing a configuration of a protruding portion 230c according to the third modification of the present embodiment. Fig. 9 is a view corresponding to (b) of Fig. 5.

As shown in FIG. 9, in this modification, protrusion 230c is arranged instead of protrusion 230 in the above embodiment. Protrusion 230c does not have bent portion 234 in the above embodiment. In other words, protrusion 230c has first portion 231, second portion 232, and third portion 233 that extend in the same direction intersecting with the Z-axis direction (second direction). In this modification, first portion 231, second portion 232, and third portion 233 are flat portions that are linearly inclined in the positive X-axis direction as they approach the negative Z-axis direction. The rest of the configuration of this modification is the same as in the above embodiment, so detailed description will be omitted.

As described above, the energy storage device according to this modified example can achieve the same effects as the above embodiment. In particular, the protruding portion 230c does not have the bent portion 234 of the above embodiment, so the configuration can be simplified.

(Other Modifications)
In the above embodiment, the second portion 232 of the protruding portion 230 is in direct contact with the case wall portion 311, but it may be indirectly in contact with the case wall portion 311 via an insulating sheet, a spacer, or the like. In other words, the case wall portion 311 may have an insulating sheet, a spacer, or the like, and the second portion 232 may be in contact with the case wall portion 311 by contacting the insulating sheet, spacer, or the like. Alternatively, the second portion 232 may be disposed apart from the case wall portion 311, and may be in contact with the case wall portion 311 when it is subjected to vibration or impact.

In the above embodiment, the first part 231 of the protrusion 230 extends linearly from the spacer body 210 in the Z-axis direction, but it may extend in a direction inclined from the Z-axis direction, or may extend in a curved (bent) shape rather than in a linear shape. The same applies to the second part 232.

In the above embodiment, the third portion 233 of the protruding portion 230 extends linearly in the X-axis direction from the first portion 231 to the second portion 232, but may extend in a direction inclined from the X-axis direction to the Z-axis direction. In other words, the third portion 233 may extend from the first portion 231 toward the X-axis direction when viewed from the Z-axis direction. The third portion 233 may extend from the first portion 231 toward the second portion 232 in the Y-axis direction, or in a direction between the X-axis direction and the Y-axis direction. In other words, the third portion 233 may extend in a direction intersecting the Z-axis direction. The third portion 233 may extend in a curved (curved) shape instead of a linear shape. The third portion 233 extends from the first portion 231 in a direction facing outward in the X-axis direction, but may extend from the first portion 231 in a direction facing inward in the X-axis direction. In this case, the second portion 232 may extend in the negative Z-axis direction from the inner end of the third portion 233 in the X-axis direction.

In the above embodiment, two power storage units 10 arranged in the X-axis direction are accommodated inside the case 300, but three or more power storage units 10 arranged in the X-axis direction may be accommodated inside the case 300, or only one power storage unit 10 may be accommodated inside the case 300. When only one power storage unit 10 is accommodated inside the case 300, the case 300 does not have a case wall portion 313, but has a pair of case walls 312. A plurality of power storage units 10 arranged in the Y-axis direction may be accommodated inside the case 300. When a plurality of power storage units 10 are accommodated in the case 300, the above-mentioned configuration may be provided for each of the multiple power storage units 10, or the above-mentioned configuration may not be provided for any of the power storage units 10.

In the above embodiment, the case body 310 is configured to have sufficient height in the Z-axis direction to house the power storage unit 10 and to house the power storage unit 10 so that it is almost not exposed when viewed from the XY plane, but this is not essential. The case body 310 may have a height of about two-thirds or half of the power storage unit 10 in the Z-axis direction to house the part of the power storage unit 10 in the negative Z-axis direction and expose the part of the power storage unit 10 in the positive Z-axis direction without housing it. In this case, the lid 320 may have a height of about one-third or half of the power storage unit 10 in the Z-axis direction to house the part of the power storage unit 10 in the positive Z-axis direction.

In the above embodiment, all spacers 200 (all spacers 200a) have the above configuration, but any of the spacers 200a may not have the above configuration. In the spacer 200a, both sides in the X-axis direction have the above configuration, but one side in the X-axis direction may not have the above configuration.

In the above embodiment, the spacer 200a has a pair of first spacer wall portions 221 and 222, a pair of second spacer wall portions 223, and a pair of second spacer wall portions 224, but is not limited to having all of these walls. The spacer 200a may be a holder that holds the energy storage element 100 by having at least one of these walls, or it may be a plate-shaped spacer or the like that does not have all the walls (does not hold the energy storage element 100).

In the above embodiment, it is assumed that spacer 200a of spacers 200 has the above configuration, but spacer 200b or spacer 200c may have the above configuration. In other words, any one of the multiple spacers 200 may have the same configuration as spacer 200a.

In the above embodiment, the spacers 200 (spacers 200a, 200b, and 200c) are arranged alternately with the energy storage elements 100 in the Y-axis direction, but the configuration may be such that none of the spacers 200 is arranged. The configuration may be such that only one spacer 200 (spacer 200a, 200b, or 200c) is arranged.

In the above embodiment, the case 300 has a case body 310 and a lid 320, but it does not have to have a lid 320.

In the above embodiment, the energy storage unit 10 may include restraining members (end plates, side plates, etc.) that restrain the multiple energy storage elements 100 and the spacer 200.

The scope of the present invention also includes configurations constructed by arbitrarily combining the components of the above-described embodiment and its modified examples.

The present invention can be applied to energy storage devices equipped with energy storage elements such as lithium ion secondary batteries.

REFERENCE SIGNS LIST 1 Energy storage device 10 Energy storage unit 100 Energy storage element 110 Container 140 Terminal 200, 200a, 200b, 200c Spacer 210 Spacer body 220 Spacer wall 221, 222 First spacer wall 223, 224 Second spacer wall 230, 230a, 230b, 230c Projection 231 First part 232 Second part 233 Third part 234 Bent part 300 Case 310 Case body 310a Opening 311, 312, 313, 314 Case wall 320 Lid

Claims (7)

Energy storage elements and spacers arranged in a first direction;
a case that accommodates the storage element and the spacer,
the case has a case wall portion facing the spacer in a second direction perpendicular to the first direction,
The spacer is
a spacer body facing the energy storage element in the first direction;
a protrusion protruding from the spacer body toward the case wall,
The protrusion is
a first portion which is an end portion on one side in the second direction and which is connected to the spacer body;
a second portion which is an end portion on the other side in the second direction and faces the case wall portion;
a third portion disposed between the first portion and the second portion and extending in a direction intersecting the second direction. The power storage device according to claim 1 , wherein the second portion is in contact with the case wall, and the third portion is spaced apart from the case wall. The power storage device according to claim 1 , wherein a gap is formed between the spacer body and the third portion. The power storage device according to claim 1 , wherein the protruding portion has a bent portion that is bent or curved from the third portion between at least one of the first portion and the second portion and the third portion. The power storage device according to claim 1 , wherein the third portion extends from the first portion in a third direction perpendicular to the first direction and the second direction when viewed from the second direction. the case wall portion is a side wall of the case,
The power storage device according to claim 1 , wherein the protrusion protrudes from the spacer body toward the side wall. the case wall portion is a bottom wall of the case,
The power storage device according to claim 1 , wherein the protrusion protrudes from the spacer body toward the bottom wall.

Images