Power storage device

Abstract

A power storage device 1 is provided with: an outer casing 10 that has a main body 12, which houses a power storage element 20, and that has a lid 11, which is joined integrally with an opening 15 in the main body 12 and which covers the opening 15; and a restricting member 200. The restricting member 200 has: a contact part 201 that contacts an upper surface 11a, which is the surface of the lid 11 on the reverse side from the main body 12, and that restricts movement of the lid 11 in a direction away from the opening 15; and a fixed part 202 that is fixed to the main body 12.

Description

[Technical Field]

[0001] The present invention relates to an energy storage device including an energy storage element and an exterior body that houses the energy storage element. [Background technology]

[0002] Patent Document 1 discloses an energy storage device including an energy storage element and an exterior body that houses the energy storage element. In this energy storage device, a recess is formed in the outer peripheral wall of the exterior body, and a reinforcing member is disposed in the recess to improve the rigidity of the exterior body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-195378 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional energy storage device described above, the reinforcing member is endlessly provided to surround the four side walls of the main body of the exterior body. This prevents deformation of the side walls of the exterior body. However, when gas is released from the energy storage element inside the exterior body, the pressure inside the exterior body (internal pressure) rises suddenly, and the exterior body is subjected to a force (internal pressure) from the inside. This internal pressure acts not only on the main body of the exterior body but also on the lid that closes the opening of the main body. In other words, the lid is subjected to a force from the inside that tends to push it away from the main body. This makes it easy for stress to concentrate at the joint between the lid and the main body, which can result in damage such as cracking at the joint. Furthermore, the internal pressure that the lid experiences increases as the airtightness of the exterior body increases. Therefore, when the periphery of the opening and the lid are integrally joined by welding or the like to ensure airtightness at the opening of the main body, the internal pressure that the lid experiences tends to increase, which can result in large bending stress or tensile stress occurring at the joint between the lid and the main body. If such stress causes cracks or other damage to the joint, gas inside the exterior body may leak from unexpected locations in the exterior body, which may reduce the safety of the storage device.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and has an object to provide a power storage device with improved safety. [Means for solving the problem]

[0006] An energy storage device according to one embodiment of the present invention comprises a main body that houses an energy storage element, an exterior body having a lid that is integrally joined to an opening of the main body and closes the opening, and a regulating member that has an abutment portion that abuts against the top surface of the lid, which is the surface opposite the main body, thereby regulating movement of the lid in a direction away from the opening, and a fixing portion fixed to the main body. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a power storage device with improved safety. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the electricity storage device according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing the configuration of the restricting member and its surroundings according to the embodiment. [Figure 4] FIG. 4 is a plan view of the energy storage element according to the embodiment. [Figure 5] FIG. 5 is a first cross-sectional view showing the structural relationship between the restricting member and the exterior body according to the embodiment. [Figure 6] FIG. 6 is a second cross-sectional view showing the structural relationship between the restricting member and the exterior body according to the embodiment. [Figure 7] FIG. 7 is a schematic diagram showing the positional relationship between the restricting member and the joint portion according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] An energy storage device according to one embodiment of the present invention comprises a main body that houses an energy storage element, an exterior body having a lid that is integrally joined to an opening of the main body and closes the opening, and a regulating member that has an abutment portion that abuts against the top surface of the lid, which is the surface opposite the main body, thereby regulating movement of the lid in a direction away from the opening, and a fixing portion fixed to the main body.

[0010] According to this configuration, the lid is integrally joined to the opening of the main body, ensuring high airtightness at the opening. In this case, when gas is released from the energy storage element, the internal pressure of the lid increases rapidly, resulting in the lid being subjected to a large internal pressure acting in a direction that would cause the lid to be removed from the main body. However, in the energy storage device according to this aspect, if the internal pressure of the lid increases and causes the lid to deform or displace, such as by expanding or moving, the abutting portion of the restricting member abuts against the upper surface of the lid, thereby suppressing the deformation or displacement of the lid. Furthermore, because the restricting member is fixed to the main body by the fixing portion, the abutting portion ensures its effectiveness as a member to prevent the lid from slipping off or a member to suppress deformation of the lid. Thus, the energy storage device according to this aspect can improve safety.

[0011] The main body portion may house a plurality of the storage elements arranged in a line in a first direction, and the abutment portion of the regulating member may be arranged in the center of the edge portion of the cover body in the first direction in a second direction that intersects with the first direction when viewed from above the cover body.

[0012] According to this configuration, the abutting portion is disposed to abut against the center in the second direction of the edge portion of the lid in the first direction (the edge portion extending in the second direction), which is most likely to bulge. Therefore, the bulge (deformation) of the lid can be more efficiently suppressed. This contributes to improving the safety of the power storage device.

[0013] The fixing portion may extend to a position on the side of the main body portion beyond the center of the main body portion in a third direction, which is the alignment direction of the lid body and the main body portion.

[0014] According to this configuration, the fixing portion is disposed over a relatively wide range in the third direction, and can therefore also function as a member that protects or reinforces the wall portion of the main body, which also contributes to improving the safety of the power storage device.

[0015] The power storage device may further include a reinforcing member disposed outside a wall of the main body and fixed to the main body, and the fixing portion may be fixed to the reinforcing member.

[0016] With this configuration, the reinforcing member can suppress bulging of the wall portion, and the restricting member can suppress deformation or displacement of the lid body. In other words, the combination of the restricting member and the reinforcing member can achieve a higher reinforcing effect for the entire exterior body. This can further improve the safety of the energy storage device. Because the restricting member is directly fixed to the reinforcing member, operations such as welding and fastening can be easily performed.

[0017] The cover body and the main body may be joined at a joint located on the periphery of the opening, and at least a portion of the area where the abutment portion is located when viewed from above on the cover plate may overlap with the joint.

[0018] With this configuration, the abutting portion is located directly above the portion where the lid and the main body are joined by welding, adhesive, or the like, so the abutting portion can effectively prevent damage such as cracking of the joint. This reduces the possibility of internal gas leakage due to damage to the joint, which contributes to improving the safety of the power storage device.

[0019] The energy storage device may further include a reinforcing member separate from the regulating member, which is arranged outside the wall of the main body and fixed to the main body, and the fixing portion extends to the side of the main body to a position beyond the center of the main body in the alignment direction of the lid body and the main body, and is fixed to the reinforcing member.

[0020] According to this configuration, the restricting member and the reinforcing member are separate bodies (separate members), allowing for a high degree of freedom in the shape and size of the restricting member, allowing the restricting member to be shaped or sized to better suitably regulate the position of the lid. Because the restricting member is fixed to the reinforcing member, the restricting member and the reinforcing member are structurally placed in a relationship that enhances the rigidity of each other. In other words, the combination of the restricting member and the reinforcing member provides a reinforcing effect for the entire exterior body. Furthermore, because the fixing portion is arranged over a relatively wide range in the height direction, it can also function as a member that protects or reinforces the wall portion of the main body. These factors contribute to improving the safety of the energy storage device.

[0021] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated.

[0022] In the following description and drawings, the X-axis direction is defined as the arrangement direction of multiple energy storage elements, the direction in which the long sides of the containers of the energy storage elements face each other, or the thickness direction of the container. The Y-axis direction is defined as the arrangement direction of the electrode terminals of one energy storage element, or the direction in which the short sides of the containers of the energy storage elements face each other. The Z-axis direction is defined as the arrangement direction of the main body and the lid in the exterior body of the energy storage device, the arrangement direction of the energy storage elements and the bus bars, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect each other (orthogonal in the following embodiments and their modifications). Depending on the usage mode, the Z-axis direction may not be the up-down direction, but for convenience of explanation, the following description will be made assuming that the Z-axis direction is the up-down direction.

[0023] Hereinafter, the X-axis direction may be referred to as the first direction, and the Y-axis direction may be referred to as the second direction. Furthermore, the Z-axis direction may be referred to as the third direction or height direction. In the following embodiments, expressions indicating relative directions or attitudes, such as parallel and perpendicular, may be used, but these expressions also include cases where the directions or attitudes are not strictly those of the same kind. "Two directions are parallel" does not only mean that the two directions are completely parallel, but also means that the two directions are substantially parallel, i.e., that there is a difference of about a few percent. In the following description, the "positive side of the X-axis direction" refers to the side of the arrow on the X-axis, and the "negative side of the X-axis direction" refers to the side opposite the positive side of the X-axis. The same applies to the Y-axis and Z-axis directions.

[0024] (Embodiment) [1. General description of the power storage device] First, an overall description of a power storage device 1 according to an embodiment will be given with reference to Figures 1 and 2. Figure 1 is a perspective view showing the appearance of the power storage device 1 according to an embodiment. Figure 2 is an exploded perspective view of the power storage device 1 according to an embodiment.

[0025] The power storage device 1 is a device that can be charged with electricity from an external source and can discharge electricity to the outside, and in this embodiment has a substantially rectangular parallelepiped shape. The power storage device 1 may be a battery module (battery assembly) used for power storage, power supply, or the like. Specifically, the power storage device 1 may be used as a battery for driving or starting the engine of a mobile object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline-powered automobile. Examples of the electric railway vehicle include a train, a monorail, and a linear motor car. The power storage device 1 may also be used as a stationary battery for home use or a power generator, etc.

[0026] As shown in FIGS. 1 and 2 , the energy storage device 1 includes a plurality of energy storage elements 20, an exterior body 10 that houses the plurality of energy storage elements 20, and a reinforcing member 100 attached to the exterior body 10. In this embodiment, eight energy storage elements 20 are housed in the exterior body 10. The number of energy storage elements 20 included in the energy storage device 1 is not limited to eight. The energy storage device 1 may include one or more energy storage elements 20. In this embodiment, one energy storage element row 24 is formed by the plurality of energy storage elements 20 arranged in the X-axis direction. The energy storage element row 24 may include spacers, insulating films, etc., not shown.

[0027] The exterior body 10 has a main body 12 that houses the energy storage element array 24, and a lid 11, and a bus bar plate 17 is arranged between the energy storage element array 24 housed in the main body 12 and the lid 11. The bus bar plate 17 holds a plurality of bus bars 33, which are covered by bus bar covers 70 and 75. A connection unit 80 including a control circuit and the like is arranged between the bus bar plate 17 and the lid 11.

[0028] The exterior body 10 is a rectangular (box-shaped) container (module case) that forms the outer shell of the energy storage device 1. In other words, the exterior body 10 is a member that fixes the energy storage element array 24, the bus bar plate 17, etc. in predetermined positions and protects them from impacts and the like. The exterior body 10 is formed from an insulating material 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), polyethersulfone (PES), ABS resin, or a composite material thereof, or a metal with an insulating coating.

[0029] The lid 11 of the exterior housing 10 is a rectangular member that closes the opening 15 of the main body 12, and has a positive electrode external terminal 91 and a negative electrode external terminal 92. The external terminals 91 and 92 are electrically connected to the plurality of energy storage elements 20 via the connection unit 80 and the bus bar 33, and the energy storage device 1 charges with electricity from the outside and discharges electricity to the outside via these external terminals 91 and 92. The external terminals 91 and 92 are formed of a conductive member made of metal, such as aluminum or an aluminum alloy.

[0030] The cover 11 is provided with a ventilation chamber (not shown) through which gas passing from the inside or outside of the exterior body 10 passes, and an exhaust pipe 90 that connects the inside of the ventilation chamber to the outside of the exterior body 10. Gas inside the exterior body 10 is released to the outside of the exterior body 10 via the ventilation chamber and the exhaust pipe 90. More specifically, the ventilation chamber is provided with a valve member that opens when the pressure inside the exterior body 10 (internal pressure) rises to a predetermined value. Therefore, even if foreign matter such as water or dust flows into the ventilation chamber through the exhaust pipe 90 under normal circumstances, the valve member substantially prevents the foreign matter from flowing into the interior of the exterior body 10. Furthermore, when the internal pressure of the exterior body 10 reaches or exceeds a predetermined value due to the discharge of gas from the energy storage element 20, the valve member opens, and the gas inside the exterior body 10 is released from the ventilation chamber to the outside of the exterior body 10 through the exhaust pipe 90.

[0031] The main body 12 of the exterior body 10 is a rectangular cylindrical housing (casing) with a bottom and an opening 15 formed therein for accommodating the energy storage element array 24. With the opening 15 closed by the lid 11, the periphery of the opening 15 and the lid 11 are joined by, for example, thermal welding. This ensures airtightness at the opening 15.

[0032] The energy storage elements 20 are secondary batteries (single cells) that can charge and discharge electricity, and more specifically, non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries. The energy storage elements 20 have a flattened rectangular parallelepiped (square) shape, and in this embodiment, eight energy storage elements 20 are arranged in the X-axis direction as described above.

[0033] In this embodiment, the energy storage element 20 includes a metal container 21. The container 21 is a rectangular case having a pair of opposing long sides 21a and a pair of opposing short sides 21b. The container 21 contains an electrode assembly, a current collector, an electrolyte, and the like. In this embodiment, the multiple energy storage elements 20 are aligned in a row in the X-axis direction with their long sides 21a facing the X-axis direction (with their short sides 21b parallel to the X-axis direction).

[0034] The cover plate 21c of the container 21 is provided with metal electrode terminals 22 (positive electrode terminal and negative electrode terminal) electrically connected to the electrode body inside the container 21. The cover plate 21c of the container 21 is further provided with a gas exhaust valve 23 for exhausting gas inside the container 21 to the outside. The gas exhaust valve 23 has the function of opening (opening the valve) to exhaust gas inside the container 21 to the outside of the container 21 when the internal pressure of the container 21 increases due to evaporation of the electrolyte inside the container 21. A gas exhaust valve 23 having such a function is provided for each of the multiple energy storage elements 20. In the present embodiment, as shown in FIG. 2, each of the multiple energy storage elements 20 is arranged in an orientation in which the gas exhaust valve 23 faces the positive side in the Z-axis direction.

[0035] The energy storage element 20 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 20 may also be a primary battery that allows stored electricity to be used without the user having to charge it. In addition, although the present embodiment illustrates the energy storage element 20 having a rectangular parallelepiped (cornered) shape, the shape of the energy storage element 20 is not limited to a rectangular parallelepiped shape, and may be a polygonal prism shape, a cylindrical shape, an elongated cylindrical shape, or the like other than a rectangular parallelepiped shape. Furthermore, a laminate-type energy storage element may be provided in the energy storage device 1 as the energy storage element 20.

[0036] The bus bar 33 is a rectangular plate-like member that is held by the bus bar plate 17 and placed on at least two energy storage elements 20 to electrically connect the electrode terminals 22 of the at least two energy storage elements 20. The material of the bus bar 33 is not particularly limited, and the bus bar 33 may be formed of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or stainless steel, or a combination thereof, or a conductive material other than a metal. In this embodiment, five bus bars 33 are used to connect two energy storage elements 20 in parallel to form four sets of energy storage element groups, and the four sets of energy storage element groups are connected in series. Furthermore, there is no particular limit to the manner in which the eight energy storage elements 20 are electrically connected, and all eight energy storage elements 20 may be connected in series by seven bus bars.

[0037] The connection unit 80 is a unit having a plurality of bus bars and a control board, etc., and electrically connects the energy storage element array 24 to the external terminals 91 and 92. The control board of the connection unit 80 has a plurality of electrical components, and these electrical components form a detection circuit that detects the state of each energy storage element 20, a control circuit that controls charging and discharging, etc. In this embodiment, the connection unit 80 is fixed to the bus bar plate 17.

[0038] Bus bar plate 17 is a resin member that holds bus bars 33. In the present embodiment, bus bar plate 17 is a member that holds multiple bus bars 33, connection unit 80, and other wiring (not shown), and regulates the positions of these members. Bus bar plate 17 also has multiple bus bar openings 17a that hold each of the multiple bus bars 33 and expose a portion of each of the multiple bus bars 33 to the side of the multiple energy storage elements 20.

[0039] A path forming portion 19 is provided at the center of the bus bar plate 17 in the Y axis direction, extending in the X axis direction along the arrangement of the gas discharge valves 23 of the multiple energy storage elements 20 and protruding toward the positive side in the Z axis direction. The path forming portion 19 covers all of the gas discharge valves 23 from the positive side in the Z axis direction. As shown in FIG. 2 , path outlets 18 are provided at the longitudinal ends of the path forming portion 19 on both the positive side and the negative side in the X axis direction. Therefore, gas discharged from the energy storage elements 20 mainly passes through the path outlets 18 and is released to the outside of the exterior body 10 via the above-mentioned ventilation chamber and exhaust pipe 90. The bus bar plate 17 configured in this manner is fixed to the main body 12 of the exterior body 10 by a predetermined method such as adhesive bonding or heat welding.

[0040] Each of the bus bar covers 70 and 75 is a resin member that covers the plurality of bus bars 33 from above, and serves to electrically insulate the plurality of bus bars 33 from the connection unit 80.

[0041] The reinforcing member 100 is a member that reinforces the exterior body 10. In the present embodiment, the reinforcing member 100 is disposed so as to surround the exterior body 10, and when the exterior body 10 attempts to expand due to an increase in internal pressure, the reinforcing member 100 can suppress the expansion.

[0042] The energy storage device 1 further includes a regulating member 200 fixed to the main body 12 of the exterior housing 10. In this embodiment, as shown in FIGS. 1 and 2, a plurality of regulating members 200 are fixed to the main body 12 via the reinforcing member 100, and these regulating members 200 mainly serve to hold down the lid 11. Each regulating member 200 has a contact portion 201 and a fixing portion 202. In this embodiment, three regulating members 200 are fixed to the reinforcing member 100, and in order to distinguish between these three regulating members 200, different reference numerals (210, 220, 230) are assigned as shown in FIG. 2. In the following description, matters describing the "regulating member 200" and its components (the contact portion 201, the fixing portion 202) apply to each of the regulating members 210, 220, and 230. Below, the regulating member 200 and its peripheral configuration will be further described with reference to FIGS. 3 to 7.

[0043] [2. Configuration of the control member and its surroundings] FIG. 3 is a perspective view showing a regulating member 200 and its surrounding configuration according to an embodiment. FIG. 3 illustrates a state in which the reinforcing member 100, the regulating member 200, and the spacers 151 and 152 are separated from the exterior housing 10. FIG. 4 is a plan view (viewed from the positive side in the Z-axis direction) of the energy storage device 1 according to an embodiment. FIG. 5 is a first cross-sectional view showing the structural relationship between the regulating member 200 according to an embodiment and the exterior housing 10. FIG. 5 illustrates an end portion on the negative side in the Y-axis direction in the V-V cross section of FIG. 4. FIG. 6 is a second cross-sectional view showing the structural relationship between the regulating member 200 according to an embodiment and the exterior housing 10. FIG. 6 illustrates an end portion on the negative side in the X-axis direction in the VI-VI cross section of FIG. 4. FIG. 7 is a schematic diagram showing the positional relationship between the regulating member 200 according to an embodiment and a joint 14.

[0044] As shown in FIG. 2 and FIGS. 3 to 6, the restricting member 200 has an abutting portion 201 that abuts against the top surface 11a of the lid 11, which is the surface opposite to the main body 12, and a fixing portion 202 that is fixed to the main body 12. The abutting portion 201 abuts against the top surface 11a, thereby restricting movement of the lid 11 in a direction away from the opening 15 (see FIG. 2). The restricting member 200 is formed of a metal such as iron or an aluminum alloy. In this embodiment, the energy storage device 1 is provided with three restricting members 200 (210, 220, and 230) as shown in FIGS. 2 and 3. That is, the restricting member 210 has the abutting portion 211 and the fixing portion 212, the restricting member 220 has the abutting portion 221 and the fixing portion 222, and the restricting member 230 has the abutting portion 231 and the fixing portion 232. The fixing portions 212, 222, and 232 of the three restricting members 210, 220, and 230, respectively, are fixed to the main body portion 12. Specifically, the fixing portions 212, 222, and 232 are fixed to the main body portion 12 via the reinforcing member 100. This fixing is achieved by welding or fastening with bolts or rivets.

[0045] The contact portion 201 may be in direct contact with the upper surface 11a, or may be in indirect contact with the upper surface 11a via another member therebetween.

[0046] The reinforcing member 100 is a ring-shaped member in a top view (when viewed from the positive side in the Z-axis direction) that is formed to fit along the four wall portions 13 of the exterior body 10. In this embodiment, as shown in FIG. 3 , the four wall portions 13 of the exterior body 10 are divided into wall portions 13a and 13c that form the short side surfaces of the exterior body 10, and wall portions 13b and 13d that form the long side surfaces of the exterior body 10. That is, the fixing portion 212 of the restricting member 210 is disposed opposite to the wall portion 13b. The fixing portion 222 of the restricting member 220 is disposed opposite to the wall portion 13a. The fixing portion 232 of the restricting member 230 is disposed opposite to the wall portions 13c and 13d.

[0047] Like the restricting member 200, the reinforcing member 100 is a member made of a metal such as iron or an aluminum alloy, and as shown in Fig. 3, is fixed to the exterior body 10 with spacers 151 and 152 interposed between the exterior body 10 and the reinforcing member 100. The spacers 151 and 152 are members made of mica or resin, and protect the exterior body 10 from the reinforcing member 100, which has higher rigidity than the exterior body 10, and also electrically insulate the exterior body 10 from the reinforcing member 100. As these members, a mica molded product or, like the exterior body 10, an electrically insulating resin such as PP, PC, or PE is used.

[0048] In this embodiment, as shown in Fig. 4, the contact portions 201 of the multiple restricting members 200 are arranged so as to press the peripheral portion of the top surface 11a of the lid body 11 downward (toward the negative Z-axis direction). Furthermore, the top surface 11a is a substantially rectangle having four sides when viewed from above, and an area including the center of each of the four sides is pressed down by the three restricting members 200. Therefore, even if an increase in the internal pressure of the exterior body 10 causes the lid body 11 to deform or displace so as to come off the main body 12, the deformation or displacement is suppressed by the three restricting members 200.

[0049] As shown in FIGS. 5 and 6 , the lid 11, whose movement in a direction away from the main body 12 is restricted by the abutment portion 201 of the restricting member 200, is joined to the main body 12 at a joint 14. The joining method used is a joining method that makes the lid 11 impossible to detach after joining (in other words, a joining method that does not assume detachment). In other words, after the lid 11 is joined to the main body 12, it is virtually impossible to remove the lid 11 from the main body 12 without causing destruction, breakage, or deformation of at least one of the lid 11 and the main body 12. Furthermore, the joint 14 formed by heat welding or the like is located on the periphery of the opening 15 (see FIG. 2 ) of the main body 12, as shown in FIG. 7 . This allows the exterior body 10 to ensure high airtightness at the opening 15.

[0050] As described above, the energy storage device 1 according to this embodiment includes an exterior body 10 having a main body 12 that houses an energy storage element 20 and a lid 11 that is integrally joined to an opening 15 of the main body 12 and closes the opening 15, and a restricting member 200. The restricting member 200 has an abutting portion 201 that abuts against an upper surface 11a of the lid 11, which is the surface opposite to the main body 12, to restrict movement of the lid 11 in a direction away from the opening 15, and a fixing portion 202 that is fixed to the main body 12.

[0051] According to this configuration, since the lid 11 is integrally joined to the opening 15 of the main body 12, the exterior body 10 can ensure high airtightness at the position of the opening 15. In this case, when gas is discharged from the energy storage element 20, the internal pressure of the exterior body 10 increases rapidly, and as a result, the lid 11 is subjected to a large internal pressure that acts in a direction to remove the lid 11 from the main body 12. Specifically, when the energy storage element 20 opens and gas is discharged, the internal pressure of the exterior body 10, which is in an airtight or semi-airtight state, increases rapidly. In this case, the discharge of gas from the exhaust pipe 90 may not keep up with the increase in internal pressure, and the internal pressure of the exterior body 10 may increase or remain at a high level. In this case, the high internal pressure applied to the lid 11 may cause damage, such as cracks, to the joint 14, which is the joint between the lid 11 and the main body 12. However, in the energy storage device 1 according to this embodiment, when an increase in the internal pressure of the exterior body 10 causes deformation or displacement such as expansion or movement of the lid body 11, the abutting portion 201 of the restricting member 200 abuts against the upper surface 11a of the lid body 11, thereby suppressing the deformation or displacement of the lid body 11. Furthermore, because the restricting member 200 is fixed to the main body 12 at the fixing portion 202, the abutting portion 201 is effective as a member for preventing the lid body 11 from slipping off or a member for suppressing deformation. In this way, the energy storage device 1 according to this embodiment can improve safety.

[0052] In this embodiment, a plurality of energy storage elements 20 arranged side by side in a first direction (X-axis direction) are housed in main body 12. When lid 11 is viewed from the side of top surface 11a, contact portion 201 of restricting member 200 is arranged at the center, in a second direction (Y-axis direction) intersecting with the first direction (X-axis direction), of the edge portion of lid 11 in the first direction (X-axis direction).

[0053] As described above, in this embodiment, the abutting portion 201 is arranged to abut on the center portion in the Y-axis direction of the edge portion in the X-axis direction of the lid 11 (the edge portion extending in the Y-axis direction), which is most likely to bulge. Therefore, the bulge (deformation) of the lid 11 can be more efficiently suppressed. This contributes to improving the safety of the energy storage device 1.

[0054] In this embodiment, as shown in Figures 1 to 3, the fixing portion 202 is extended on the side of the main body portion 12 from the side of the lid body 11 to a position beyond the center in the third direction (Z-axis direction), which is the alignment direction of the lid body 11 and the main body portion 12.

[0055] According to this configuration, the fixing portion 202 is disposed over a relatively wide range in the Z-axis direction, and can therefore also function as a member that protects or reinforces the wall portion 13 of the main body portion 12. This also contributes to improving the safety of the energy storage device 1.

[0056] The energy storage device 1 according to this embodiment further includes a reinforcing member 100 that is arranged outside the wall portion 13 of the main body portion 12 and fixed to the main body portion 12. The fixing portion 202 is fixed to the reinforcing member 100.

[0057] According to this configuration, the reinforcing member 100 can suppress the bulging of the wall portion 13, and the restricting member 200 can suppress the deformation or displacement of the lid body 11. In other words, the combination of the restricting member 200 and the reinforcing member 100 can provide a reinforcing effect for the entire exterior body 10. This can further improve the safety of the energy storage device 1. In addition, since the restricting member 200 is directly fixed to the reinforcing member 100, operations such as welding or fastening can be easily performed.

[0058] Furthermore, the fixing portion 202 of the restricting member 200 also functions to improve the rigidity of the reinforcing member 100. Specifically, as shown in FIG. 6, the fixing portion 202 is disposed on the outside of the reinforcing member 100 and joined to the outer surface of the reinforcing member 100 by welding or the like. Therefore, the restricting member 200 functions as a member that improves the rigidity of the reinforcing member 100 or a member that increases the thickness of the reinforcing member 100. In other words, the fixing portion 202 of the restricting member 200 can improve the reinforcing function of the reinforcing member 100. Furthermore, as shown in FIG. 6, a rib 13e provided on the outer surface of the wall portion 13 of the main body 12 is disposed at a position facing the upper end surface of the reinforcing member 100. Therefore, the rib 13e functions to position the reinforcing member 100 during manufacturing of the energy storage device 1, and also functions as a portion that restricts upward movement of the reinforcing member 100 (toward the positive side in the Z-axis direction) during use of the energy storage device 1. Therefore, even if a large force is applied upward to the abutting portion 201, the reinforcing member 100 to which the restricting member 200 is fixed abuts against the rib 13e, making it substantially impossible for the reinforcing member 100 to move upward. As a result, the abutting portion 201 can more reliably suppress deformation or displacement of the lid 11. In FIG. 6, the reinforcing member 100 is configured by two plate-shaped members overlapping each other in the thickness direction, but this configuration is an example, and the reinforcing member 100 may also be configured from a single material.

[0059] In this embodiment, as shown in Figures 5 to 7, the lid 11 and the main body 12 are joined at a joint 14 located on the periphery of the opening 15. When viewed from the top surface 11a side, at least a part of the arrangement area of ​​the contact portions 201 overlaps with the joint 14. Specifically, as shown in Figures 5 to 7, each of the arrangement areas of the four contact portions 201 (contact portion 211, contact portion 221, and two contact portions 231) overlaps with a part of the extension direction of the joint 14 and overlaps with all or a part of the width direction of the joint 14 which is perpendicular to the extension direction.

[0060] As described above, in this embodiment, the abutting portion 201 is located directly above the portion (joint portion 14) where the lid 11 and the main body 12 are joined by welding, adhesion, or the like. Therefore, the abutting portion 201 can effectively prevent damage such as cracking of the joint portion 14. This reduces the possibility of internal gas leakage or the like occurring due to damage to the joint portion 14. This contributes to improving the safety of the energy storage device 1.

[0061] Focusing on the relationship between the restricting member 200 and the reinforcing member 100, the energy storage device 1 according to this embodiment can also be described as follows. The energy storage device 1 includes a reinforcing member 100 that is separate from the restricting member 200 and that is disposed outside the wall 13 of the main body 12 and fixed to the main body 12. The fixing portion 202 extends from the lid 11 side on the side of the main body 12 to a position beyond the center in the height direction (Z-axis direction) that is the alignment direction of the lid 11 and the main body 12, and is fixed to the reinforcing member 100.

[0062] According to this configuration, the regulating member 200 and the reinforcing member 100 are separate bodies (separate members), allowing for a high degree of freedom in the shape and size of the regulating member 200. Therefore, the regulating member 200 can be shaped or sized to better suitably regulate the position of the lid 11. Furthermore, because the regulating member 200 is fixed to the reinforcing member 100, the regulating member 200 and the reinforcing member 100 are structurally positioned to enhance each other's rigidity. In other words, the combination of the regulating member 200 and the reinforcing member 100 can provide a greater reinforcing effect for the entire exterior body 10. Furthermore, because the fixing portion 202 is disposed over a relatively wide range in the height direction, it can also function as a member that protects or reinforces the wall portion 13 of the main body 12. These factors contribute to improving the safety of the power storage device.

[0063] (Variation) The above describes the power storage device according to the present invention based on the embodiment. However, the present invention is not limited to the above embodiment. As long as it does not deviate from the spirit of the present invention, various modifications that a person skilled in the art can make to the above embodiment are also included in the scope of the present invention.

[0064] In this embodiment, three restricting members 200 are arranged so as to press down on each of the four sides of lid 11 in top view, but one restricting member 200 may press down on only one side of lid 11. Consider a case where the area or volume of joint 14 is relatively small due to constraints such as the shape of main body 12 or lid 11, and the joint strength of one of the four sides of lid 11 is weaker than the others. In this case, one restricting member 200 may be arranged on exterior body 10 so as to press down only that one side. This reduces the possibility of defects such as damage to joint 14 between lid 11 and main body 12.

[0065] In this embodiment, as shown in FIGS. 3 and 4, one of the three restricting members 200, restricting member 230, is configured to press two adjacent sides of lid 11 in top view. However, separate restricting members 200 may be arranged on each of these two sides. In other words, the shape, number, and layout of restricting members 200 are not limited to those shown in FIGS. 1 to 7. A restricting member 200 having fixing portions 202 arranged on the outer sides of two walls 13a and 13c (see FIG. 3) connected to the bottom side of main body 12 may be fixed to exterior body 10. In this case, a single restricting member 200 that presses two opposing sides of the four sides of lid 11 in top view can be fabricated by bending a single metal plate. Furthermore, a portion of the restricting member 200 located outside the bottom surface of the main body 12 (the connecting portion of the two fixing portions 202) functions as a portion that restricts the upward movement of the two contact portions 201. Therefore, the restricting member 200 can achieve a higher effect of suppressing the bulging (deformation) of the lid 11.

[0066] The fixing portion 202 may be formed in a rectangular ring shape in top view, and arranged to surround the outer surfaces of the four wall portions 13 (13a to 13d) of the main body 12, and the fixing portion 202 may have four abutment portions 201 that press the four sides of the lid 11. In other words, one regulating member 200 having a shape similar to the shape obtained by combining the reinforcing member 100 and three regulating members 200 according to the present embodiment (see FIG. 3) may be fixed to the exterior body 10. In other words, the regulating member 200 and the reinforcing member 100 do not have to be separate members. In other words, one of the regulating member 200 and the reinforcing member 100 may be provided integrally with the other.

[0067] In this way, it is sufficient for the energy storage device 1 to have at least one regulating member 200, and it is sufficient for one regulating member 200 to have one or more abutting portions 201. Furthermore, it is sufficient for one abutting portion 201 to be arranged so as to abut against the upper surface 11a of the lid 11. In other words, it is sufficient for one abutting portion 201 to be provided on the regulating member 200 so as to press at least a portion of the upper surface 11a of the lid 11.

[0068] The reinforcing member 100 and the restricting member 200 do not necessarily have to be made of metal. The reinforcing member 100 and the restricting member 200 may be made of a highly rigid non-metallic material such as fiber-reinforced plastic. This allows the weight of the electricity storage device 1 to be reduced.

[0069] The energy storage device 1 does not necessarily have to include the reinforcing member 100. By including at least the restricting member 200 as a member that suppresses deformation or displacement of the lid 11, the energy storage device 1 can improve safety as described above. Furthermore, when the energy storage device 1 does not include the reinforcing member 100, the restricting member 200 may be fixed to the main body 12 by fixing the fixing portion 202 to the main body 12 by engaging, fitting, embedding, bonding, welding, fastening, or the like.

[0070] Any combination of the above-described components is also included within the scope of the present invention. [Industrial Applicability]

[0071] The present invention can be applied to an electricity storage device including an electricity storage element 20 such as a lithium ion secondary battery. [Explanation of symbols]

[0072] 1. Energy storage device 10. Exterior body 11 Lid 11a Top surface 12 Main body 13, 13a, 13b, 13c, 13d wall section 13e Rib 14 Joint 15 Opening 20 Energy storage element 100 Reinforcing member 200, 210, 220, 230 Regulating member 201, 211, 221, 231 Contact part 202, 212, 222, 232 Fixed part

Claims

1. an exterior body including a main body that houses an energy storage device and a lid that is integrally joined to an opening of the main body and closes the opening; a restricting member having an abutting portion that abuts against an upper surface of the lid body, which is the surface opposite to the main body portion, to restrict movement of the lid body in a direction away from the opening, and a fixing portion that is fixed to the main body portion; a reinforcing member disposed outside the wall of the main body and fixed to the main body, The fixing portion is fixed to the reinforcing member. Energy storage device.

2. The main body accommodates a plurality of the energy storage elements arranged side by side in a first direction, the abutment portion of the restricting member is disposed at a center portion in a second direction intersecting with the first direction of an edge portion of the lid body in a top view of the lid body, The electricity storage device according to claim 1.

3. The fixing portion is provided on the side of the main body portion and extends to a position beyond a center portion of the main body portion in a third direction which is an arrangement direction of the lid body and the main body portion. The electricity storage device according to claim 1 or 2.

4. the lid and the main body are joined at a joint located on the periphery of the opening, At least a part of an arrangement area of ​​the abutment portion in a top view of the lid body overlaps with the joint portion. The electricity storage device according to any one of claims 1 to 3.

5. an exterior body including a main body that houses an energy storage device and a lid that is integrally joined to an opening of the main body and closes the opening; a restricting member having an abutting portion that abuts against an upper surface of the lid body, which is the surface opposite to the main body portion, to restrict movement of the lid body in a direction away from the opening, and a fixing portion that is fixed to the main body portion; a reinforcing member disposed outside the wall of the main body and fixed to the main body, the reinforcing member being separate from the restricting member; The fixing portion extends to a position on the side of the main body portion beyond a center portion of the main body portion in an arrangement direction of the lid body and the main body portion, and is fixed to the reinforcing member. Energy storage device.

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