JP2014049318A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity of a power storage device while restraining deterioration of productivity of the power storage device.SOLUTION: A secondary battery 10 is formed such that a layered electrode assembly 11 formed by laminating a positive electrode 12, a negative electrode 16 and a separator 20 insulating them is housed in a case 21. The case 21 is a square-shaped case on the bottom wall of which four side walls 22b, 22c, 22d, 22e stand. The power storage device comprises plate-like reinforcing members 30 covering side walls 22b, 22d along a lamination direction of the electrode assembly 11, and restraining members 31 for restraining movement of the reinforcing members 30 in a direction for approaching the electrode assembly 11 from the side walls 22b, 22d.

Description

  The present invention relates to a power storage device including a case in which an electrode assembly is accommodated.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. A secondary battery has, for example, a positive electrode, a negative electrode, and an electrode assembly that is layered by alternately laminating separators that insulate them. And such an electrode assembly is accommodated in the case.

Japanese Patent Laid-Open No. 09-12083

  The case may be deformed when a large pressure is applied. If the electrode assembly inside the case is deformed as the case is deformed, the positive electrode and the negative electrode may be short-circuited. In order to provide the power storage device with sufficient pressure resistance, for example, it is conceivable to mold the case with a highly rigid material. However, when the case is molded from a material having high rigidity, the press molding method normally used as the case molding method cannot be used. Although the case molding can be performed even with a material having high rigidity by the cut-out molding method, the time required for molding the case becomes longer than the press molding, and the productivity of the power storage device is reduced.

  The present invention has been made paying attention to such problems existing in the prior art, and its purpose is to improve the rigidity of the power storage device while suppressing the decrease in the productivity of the power storage device. is there.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, there is provided a layered electrode assembly in which a positive electrode, a negative electrode, and a separator that insulates them are stacked on a rectangular case having four side walls standing on a bottom wall. In the power storage device accommodated so that each surface of the assembly faces the inner surface of the case, a plate-shaped reinforcing member that covers the first side wall and the second side wall along the stacking direction among the side walls, and The gist includes a first side wall and a regulating member that regulates movement of the reinforcing member in a direction approaching the electrode assembly from the second side wall.

  When the first side wall and the second side wall along the stacking direction of the electrode assembly among the four side walls of the case are deformed by receiving pressure, pressure is applied to the side surfaces of the respective layers of the electrode assembly. Thus, when pressure is applied to the side surfaces of each layer of the electrode assembly, for example, the pressure is applied to the surface of each layer of the electrode assembly by receiving pressure from the side wall along the direction orthogonal to the stacking direction of the electrode assembly. The assembly is likely to be deformed.

  According to the above configuration, when pressure is applied to the first side wall and the second side wall along the stacking direction of the electrode assembly, pressure is applied to the plate-like reinforcing member that covers the first side wall and the second side wall. However, the reinforcement member is restricted by the restriction member from receiving the pressure and approaching the electrode assembly. For this reason, it can suppress that the pressure provided to the 1st side wall and 2nd side wall of a case acts on the side surface of each layer of an electrode assembly. Further, the operation of providing the reinforcing member and the regulating member can be performed in a shorter time than the operation of molding the case with a highly rigid material. Accordingly, it is possible to improve the rigidity of the power storage device while suppressing a decrease in productivity of the power storage device.

  The invention according to claim 2 is characterized in that, in the power storage device according to claim 1, the regulating member is in contact with or close to the surface of the reinforcing member on the electrode assembly side.

  According to the above configuration, even when the first side wall and the second side wall of the case are deformed by receiving pressure, the reinforcing member approaches the electrode assembly due to the deformation due to the contact between the reinforcing member and the regulating member. The movement of the reinforcing member in the same direction can be restricted before or immediately after the movement. Therefore, deformation of the electrode assembly can be further suppressed, and the rigidity of the power storage device can be further improved.

  According to a third aspect of the present invention, in the power storage device according to the first or second aspect, the restriction member includes a third side wall along a direction orthogonal to the stacking direction of the electrode assembly, The gist is to form a plate that covers the four side walls.

  For example, when pressure is applied to the surface of each layer of the electrode assembly by receiving pressure from the third side wall along the direction orthogonal to the stacking direction of the electrode assembly among the four side walls of the case and the fourth side wall, The deformation of the electrode assembly itself may occur to a lesser extent than when pressure is applied to the side surface of each layer of the assembly.

  According to the above configuration, since the regulating member has a plate shape covering the third side wall and the fourth side wall along the direction orthogonal to the stacking direction of the electrode assembly, the pressure applied to the surface of each layer of the electrode assembly In contrast, it can be provided with rigidity by a restricting member. Therefore, the rigidity of the power storage device can be further improved.

  According to a fourth aspect of the present invention, in the power storage device according to any one of the first to third aspects, the regulating member is made of a metal material, and an insulating member is provided between the regulating member and the electrode assembly. The gist of this is the interposition.

  According to the said structure, the rigidity of an electrical storage apparatus can be improved with the control member which consists of metal materials. Further, since the insulating member is interposed between the regulating member and the electrode assembly, the electrode assembly can be insulated from the regulating member. The insulating member may be interposed between the restricting member and the electrode assembly by interposing an insulating film separate from the restricting member or the electrode assembly, or by coating the surface of the restricting member with an insulating material. May be performed.

  The invention according to claim 5 is the power storage device according to any one of claims 1 to 4, wherein the power storage device is a secondary battery.

  According to the present invention, it is possible to improve the rigidity of the power storage device while suppressing a decrease in productivity of the power storage device.

The disassembled perspective view of the secondary battery in embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the structure of an electrode assembly. The perspective view of a reinforcement member and a control member. Sectional drawing which shows the state which has arrange | positioned the reinforcement member and the control member between the electrode assembly and the side wall of a case. Sectional drawing which shows the state which has arrange | positioned the reinforcement member and the control member between the electrode assembly in another embodiment, and the side wall of a case.

Hereinafter, a first embodiment in which the present invention is embodied in a lithium ion secondary battery mounted on a vehicle such as an industrial vehicle or a passenger vehicle will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the secondary battery 10 includes an electrode assembly 11 and an aluminum case 21 that accommodates the electrode assembly 11. The case 21 includes a rectangular case main body 22 in which an opening 22 a into which the electrode assembly 11 can be inserted is formed, and a rectangular plate-shaped lid 23 that closes the opening 22 a of the case main body 22. The case main body 22 includes a bottom wall 22f and four side walls 22b, 22c, 22d, and 22e provided upright on the bottom wall 22f. In addition, an electrolytic solution is injected into the case 21.

  The electrode assembly 11 is electrically connected to an electrode terminal including a positive electrode terminal 26 and a negative electrode terminal 27 that exchange electricity with the electrode assembly 11. The positive electrode terminal 26 and the negative electrode terminal 27 are exposed to the outside of the case 21 through a pair of opening holes 23 a arranged in parallel with the lid 23 at a predetermined interval. Further, ring-shaped insulating members 26 a and 27 a for insulating from the case 21 are attached to the positive terminal 26 and the negative terminal 27, respectively.

  As shown in FIG. 3, the electrode assembly 11 includes a sheet-like positive electrode 12 and a sheet-like negative electrode 16. The positive electrode 12 includes a positive metal foil (in this embodiment, an aluminum foil) 13 and a positive electrode active material layer 14 formed by applying a positive electrode active material on both surfaces thereof. A positive electrode tab 15 made of a region not coated with the positive electrode active material is provided on a part of the edge of the positive electrode metal foil 13 so as to protrude. The negative electrode 16 has a negative electrode metal foil (copper foil in this embodiment) 17 and a negative electrode active material layer 18 formed by applying a negative electrode active material on both surfaces thereof. A negative electrode tab 19 made of a region where the negative electrode active material is not applied is provided on a part of the edge of the negative electrode metal foil 17 so as to protrude. The electrode assembly 11 is formed as a layered body having a separator 20 interposed between the positive electrode 12 and the negative electrode 16 to insulate them. The electrode assembly 11 is configured by laminating a plurality of positive electrodes 12 and a plurality of negative electrodes 16. That is, the electrode assembly 11 is provided with a plurality of sets each including the positive electrode 12, the negative electrode 16, and the separator 20.

  As shown in FIG. 1, the positive electrode tabs 15 are collected in the stacking direction of the electrode assemblies 11 to form a positive electrode tab group, and a positive electrode conductive member 24 is joined to the positive electrode tab group. The negative electrode tabs 19 are collected in the stacking direction of the electrode assembly 11 to form a negative electrode tab group, and the negative electrode conductive member 25 is joined to the negative electrode tab group. The positive electrode conductive member 24 is connected to the positive electrode terminal 26, and the negative electrode conductive member 25 is connected to the negative electrode terminal 27. As a result, the positive electrode tab group and the positive electrode terminal 26 are electrically connected via the positive electrode conductive member 24, and the negative electrode tab group and the negative electrode terminal 27 are electrically connected via the negative electrode conductive member 25. Further, in a state where the electrode assembly 11 is accommodated in the case main body 22, the lid 23 and the case main body 22 are joined, and the opening 22 a of the case main body 22 is closed by the lid 23 and sealed. A secondary battery 10 is configured.

  The electrode assembly 11 includes surfaces 11e and 11f in the stacking direction of the electrode assembly 11, and side surfaces 11a and 11c, an upper surface 11d, and a lower surface 11b in a direction orthogonal to the stacking direction of the electrode assembly 11. Here, the side surfaces 11 a and 11 c of the electrode assembly 11 include side surfaces 12 a and 16 a of respective layers such as the positive electrode 12 and the negative electrode 16. Further, the upper surface 11 d includes an upper surface 12 b where the positive electrode tab 15 in the positive electrode 12 is provided and an upper surface 16 b where the negative electrode tab 19 in the negative electrode 16 is provided. The lower surface 11b is composed of a lower surface 12c opposite to the upper surface 12b of the positive electrode 12, and a lower surface 16c opposite to the upper surface 16b of the negative electrode 16.

  The electrode assembly 11 is accommodated so that each surface thereof faces the inner surface of the case main body 22. That is, in a state where the electrode assembly 11 is accommodated in the case main body 22, the side surfaces 11a and 11c and the surfaces 11e and 11f of the electrode assembly 11 face the side walls 22b, 22c, 22d and 22e of the case main body 22. Yes. The upper surface 11 d of the electrode assembly 11 faces the lid 23 of the case 21, and the lower surface 11 b faces the bottom wall 22 f of the case body 22. In the case body 22, the electrode assembly 11 is accommodated such that the bottom wall 22 f and the lower surface 11 b of the electrode assembly 11 are parallel to each other along the stacking direction of the electrode assembly 11. In the state where the electrode assembly 11 is accommodated in the case body 22, two opposing side walls 22 c and 22 e out of the four side walls 22 b, 22 c, 22 d and 22 e of the case body 22 are stacked with the electrode assembly 11. Opposite in direction. Further, the other two side walls 22 b and 22 d of the case main body 22 face each other in a direction orthogonal to the stacking direction of the electrode assembly 11.

  As shown in FIG. 4, the secondary battery 10 includes two rectangular plate-shaped reinforcing members 30 and two rectangular plate-shaped regulating members 31. As shown by a two-dot chain line in FIG. 1, the reinforcing member 30 and the regulating member 31 are accommodated in the case body 22 so as to form a square cylinder. The reinforcing member 30 and the regulating member 31 are both made of a metal composite material having a higher elastic modulus than aluminum, and the thickness thereof is thinner than the thickness of the side walls 22b, 22c, 22d, and 22e of the case body 22 of the case 21. Further, the reinforcing member 30 and the regulating member 31 have the same thickness. The reinforcing member 30 has first and second side walls 22b, 22c, 22d, and 22e of the case body 22 that have surfaces 30a and 30b in the stacking direction of the electrode assembly 11, and the second side walls 22b, 22c, 22d, and 22e. It is about the same size as the side wall 22d. The restricting member 31 has a third side wall 22c whose surfaces 31a and 31b are in the direction perpendicular to the stacking direction of the electrode assembly 11 among the four side walls 22b, 22c, 22d and 22e of the case body 22. And the size of the fourth side wall 22e.

  As shown in FIGS. 4 and 5, in a state where the reinforcing member 30 is accommodated in the case 21, the surface 30 a of one reinforcing member 30 faces the first side wall 22 b of the case main body 22 and the other reinforcing member The surface 30a of the member 30 and the second side wall 22d of the case main body 22 are positioned so as to face each other. Similarly, in a state where the regulating member 31 is housed in the case 21, the surface 31 a of one regulating member 31 faces the third side wall 22 c of the case body 22, and the surface 31 a of the other regulating member 31 and the case The main body 22 is positioned so as to face the fourth side wall 22e. In the case 21, the surface 30 b on the electrode assembly 11 side of one reinforcing member 30 faces the side surface 11 a of the electrode assembly 11, and the surface 30 b on the electrode assembly 11 side of the other reinforcing member 30. The electrode assembly 11 is positioned so as to face the side surface 11c. Similarly, in the case 21, the surface 31 b of one regulating member 31 faces the surface 11 e of the electrode assembly 11, and the surface 31 b of the other regulating member 31 faces the surface 11 f of the electrode assembly 11. Is located. That is, the two reinforcing members 30 are provided so as to cover the first side wall 22b and the second side wall 22d along the stacking direction of the electrode assembly 11, respectively. The two restricting members 31 are provided so as to cover the third side wall 22c and the fourth side wall 22e along the direction orthogonal to the stacking direction of the electrode assembly 11, respectively.

  As shown in FIG. 1, the reinforcing member 30 has the same direction as the length L1 along the stacking direction of the electrode assembly 11 in a state where the electrode assembly 11 and the reinforcing member 30 are accommodated in the case 21. The length L3 along is long. As shown in FIG. 5, in a state where the electrode assembly 11 and the reinforcing member 30 are accommodated in the case 21, both ends of the reinforcing member 30 in the same direction are predetermined on both sides in the stacking direction of the electrode assembly 11. Only the length is protruding.

  As shown in FIG. 1, the regulating member 31 is compared with a length L <b> 2 along the direction orthogonal to the stacking direction of the electrode assembly 11 in a state where the electrode assembly 11 and the regulating member 31 are accommodated in the case 21. The length L4 along the same direction is long. Here, the length L2 of the electrode assembly 11 indicates the length of the positive electrode 12 or the negative electrode 16 along the direction orthogonal to the stacking direction of the electrode assembly 11. As shown in FIG. 5, in a state where the electrode assembly 11 and the regulating member 31 are accommodated in the case 21, the regulating member 31 in the same direction is formed on both sides in the direction orthogonal to the stacking direction of the electrode assembly 11. Both ends protrude from the side surface 12a of the positive electrode 12 and the side surface 16a of the negative electrode 16 by a predetermined length.

  When the reinforcing member 30 and the restricting member 31 are accommodated in the case 21, the side surfaces 31 d of the two restricting members 31 protrude from both sides of the electrode assembly 11 in the stacking direction. It is in contact with 30b. Further, the side surfaces 31 f of the two regulating members 31 are in contact with the surface 30 b of the other reinforcing member 30 that protrudes on both sides of the electrode assembly 11 in the stacking direction. In this way, when the surface 30b and the side surfaces 31d and 31f are in contact with each other, the side surface 11a, The reinforcing member 30 is positioned in a state where the 11c and the reinforcing member 30 are separated from each other. When the electrode assembly 11, the reinforcing member 30, and the restricting member 31 are accommodated in the case 21, the reinforcing member 30 and the restricting member 31 are composed of the two restricting members 31 by the two reinforcing members 30. 11 are positioned so as to be sandwiched from both sides in a direction orthogonal to the stacking direction.

  When the reinforcing member 30 is accommodated in the case 21, the side surface 30 c faces the lid 23 of the case 21, and the side surface 30 e faces the bottom wall 22 f of the case main body 22. Further, when the regulating member 31 is accommodated in the case 21, the side surface 31 c faces the lid 23 of the case 21, and the side surface 31 e faces the bottom wall 22 f of the case main body 22.

  In addition, a sheet-like insulating member 40 for insulating the electrode assembly 11 from the case 21, the reinforcing member 30, and the regulating member 31 is attached to the electrode assembly 11. That is, when the electrode assembly 11, the reinforcing member 30, and the restricting member 31 are accommodated in the case 21, between the reinforcing member 30 and the electrode assembly 11, and between the restricting member 31 and the electrode assembly 11. In addition, sheet-like insulating members 40 are interposed between the lid 23 of the case 21 and the electrode assembly 11 and between the bottom wall 22f of the case body 22 and the electrode assembly 11, respectively.

Next, the operation of this embodiment will be described.
If the reinforcing member 30 and the regulating member 31 are not housed in the case 21, if the first side wall 22b and the second side wall 22d of the case 21 along the stacking direction of the electrode assembly 11 are deformed by receiving pressure, Pressure is applied to the side surfaces 12 a and 16 a of each layer of the electrode assembly 11. When pressure is applied to the side surfaces 12a and 16a of each layer of the electrode assembly 11 in this way, for example, pressure is received from the third side wall 22c and the fourth side wall 22e of the case 21 along the direction orthogonal to the stacking direction of the electrode assembly 11. The electrode assembly 11 is more likely to be deformed than when pressure is applied to the surface of each layer of the electrode assembly 11. Specifically, when a pressure is partially applied to the first side wall 22b and the second side wall 22d of the case 21, the side surface 12a of each layer of a part of the electrode assembly 11 that faces the portion to which the pressure is applied. , 16a will receive pressure. Since the side surfaces 12a and 16a are small in thickness, the positive electrode 12 and the negative electrode 16 having the side surfaces 12a and 16a that have been subjected to pressure are likely to be deformed.

  In the present embodiment, when pressure is applied to the first side wall 22b and the second side wall 22d of the case 21 along the stacking direction of the electrode assembly 11, the reinforcing member 30 that covers the first side wall 22b and the second side wall 22d is applied to the reinforcing member 30. Although pressure is applied, the restriction member 31 restricts the reinforcement member 30 from approaching the electrode assembly 11 from the first side wall 22b or the second side wall 22d under the pressure. Specifically, if the first side wall 22b of the case 21 is deformed by receiving pressure, first, pressure is applied to one reinforcing member 30 that covers the first side wall 22b. And the direction which approaches the electrode assembly 11 from one reinforcement member 30 to the two regulation members 31 via the side surface 31d of the regulation member 31 which is contacting the surface 30b of the reinforcement member 30 (the arrow direction of FIG. 5) ) Pressure is applied. At this time, the side surface 31 d of the regulating member 31 functions as a pressure receiving surface that receives the pressure applied from the reinforcing member 30. Here, since the regulating member 31 is made of a composite material of a metal having a higher elastic modulus than aluminum, deformation is hardly caused even when subjected to a large pressure. Furthermore, since the side surface 31 f of the regulating member 31 is in contact with the surface 30 b of the other reinforcing member 30, movement in the direction approaching the other reinforcing member 30 is restricted. Thereby, the movement of the one reinforcing member 30 in the direction approaching the electrode assembly 11 from the first side wall 22b is restricted by the restriction member 31.

  In the above description, the first side wall 22b is the second side wall 22d, the one reinforcing member 30 is the other reinforcing member 30, the other reinforcing member 30 is the one reinforcing member 30, the side surface 31d is the side surface 31f, and the side surface 31f is the side member 31f. By replacing each of the side surfaces 31d, the operation in the case where the second side wall 22d of the case 21 is deformed by receiving pressure will be described.

  In the present embodiment, even if the third side wall 22c and the fourth side wall 22e of the case 21 are deformed by receiving pressure, the regulating member 31 that covers the third side wall 22c and the fourth side wall 22e is not easily deformed. For this reason, the restriction member 31 suppresses pressure from being applied to the surface of the electrode assembly 11 from the third side wall 22c and the fourth side wall 22e of the case 21. Therefore, for example, even when pressure is applied from the third side wall 22c and the fourth side wall 22e of the case 21 along the direction orthogonal to the stacking direction of the electrode assemblies 11, the deformation of the electrode assembly 11 is suppressed. Can do.

As described above, according to the present embodiment, the following effects can be obtained.
(1) According to the present embodiment, when pressure is applied to the first side wall 22b and the second side wall 22d of the case 21 along the stacking direction of the electrode assembly 11, the first side wall 22b and the second side wall 22d are Although pressure is applied to the covering plate-shaped reinforcement member 30, the restriction member 31 restricts the reinforcement member 30 from approaching the electrode assembly 11 under the pressure. For this reason, it can suppress that the pressure provided to the 1st side wall 22b and the 2nd side wall 22d of case 21 acts on the side surfaces 12a and 16a of each layer of the electrode assembly 11. FIG. Further, the operation of providing the reinforcing member 30 and the regulating member 31 can be performed in a shorter time than the operation of molding the case 21 with a highly rigid material. Therefore, it is possible to improve the rigidity of the secondary battery 10 while suppressing a decrease in productivity of the secondary battery 10.

  (2) According to this embodiment, even when the first side wall 22b and the second side wall 22d of the case 21 are deformed by receiving pressure, the reinforcing member 30 and the regulating member 31 are in contact with each other. Before the reinforcing member 30 moves in the direction approaching the electrode assembly 11, the movement of the reinforcing member 30 in the same direction can be restricted. Therefore, the deformation of the electrode assembly 11 can be further suppressed, and the rigidity of the secondary battery 10 can be further improved.

  (3) According to the present embodiment, the regulating member 31 has a plate shape covering the third side wall 22c and the fourth side wall 22e of the case 21 along the direction orthogonal to the stacking direction of the electrode assembly 11, The regulation member 31 can provide rigidity even with respect to the pressure on the surface of each layer of the electrode assembly 11. Therefore, the rigidity of the secondary battery 10 can be further improved.

  (4) According to this embodiment, the rigidity of the secondary battery 10 can be improved by the regulating member 31 made of a metal material. Further, since the insulating member 40 is interposed between the regulating member 31 and the electrode assembly 11, the electrode assembly 11 can be insulated from the regulating member 31.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
A punching metal may be adopted as the reinforcing member 30. In such a form, the weight can be suppressed while the rigidity of the reinforcing member 30 is maintained. And the secondary battery 10 with a large energy density per weight can be obtained. Similarly, a punching metal can be adopted as the restricting member 31, and the same effect can be obtained even in such a form.

  ○ Instead of providing the sheet-like insulating member 40, the reinforcing member 30 and the regulating member 31 may be coated with an insulating material to insulate the reinforcing member 30, the regulating member 31 and the electrode assembly 11 from each other. . In short, it is only necessary that the surface of the reinforcing member 30 and the regulating member 31 on the electrode assembly 11 side is insulated.

  As the metal material of the reinforcing member 30 and the regulating member 31, it is also possible to employ a metal material having a modulus of elasticity comparable to the material of the case 21, such as aluminum, or a metal material having a low modulus of elasticity. In such a case, it is desirable to increase the thickness of the reinforcing member 30 or the regulating member 31.

  The reinforcing member 30 may be made of a material other than a metal material such as ceramics. In addition, if the insulation between the reinforcing member 30 and the electrode assembly 11 is not necessary depending on the material of the reinforcing member 30, the insulating member between the reinforcing member 30 and the electrode assembly 11 may be omitted.

  The regulating member 31 may be made of a material other than a metal material such as ceramics. If insulation between the regulating member 31 and the electrode assembly 11 is unnecessary depending on the material of the regulating member 31, the insulating member 40 between the regulating member 31 and the electrode assembly 11 may be omitted.

  O Although the reinforcing member 30 and the regulating member 31 are separate bodies, they may be composed of one member having four side walls. That is, this one member may be accommodated in the case main body 22 so as to form a frame shape. Two members having two side walls corresponding to one reinforcing member 30 and one regulating member 31 may be provided. Furthermore, it is good also considering the two reinforcement members 30 and the two control members 31 as one member by combinations other than these. With such a form of the member, the work efficiency when interposing between the side wall 22b, 22c, 22d, 22e of the case 21 and the electrode assembly 11 is improved, so that the productivity of the secondary battery 10 is improved. Can do.

  The restriction member 31 may be smaller than the third side wall 22c and the fourth side wall 22e of the case 21. However, in this embodiment, it is assumed that the size of the regulating member 31 along the direction orthogonal to the stacking direction of the electrode assembly 11 is substantially the same as that of the third side wall 22c and the fourth side wall 22e, and the side surfaces 31d and 31f are reinforced. By adopting a configuration that contacts the member 30 or a configuration that fixes the regulating member 31 in the case 21, the movement of the regulating member 31 in the direction perpendicular to the stacking direction of the electrode assembly 11 is regulated. Must be configured. Also in such a form, as shown in FIG. 1, the electrode assembly 11 and the regulating member 31 are accommodated in the case 21 and the length of the regulating member 31 is smaller than the length L <b> 2 of the electrode assembly 11. The length L4 needs to be longer. In a state where the electrode assembly 11 and the regulating member 31 are accommodated in the case 21, both ends of the regulating member 31 in the same direction are side surfaces of the positive electrode 12 on both sides in a direction orthogonal to the stacking direction of the electrode assembly 11. 12a and 16a of the negative electrode 16 need to protrude by a predetermined length. Even in such a configuration, the movement of the reinforcing member 30 in the direction approaching the electrode assembly 11 can be restricted by bringing the surface 30b of the reinforcing member 30 into contact with the side surfaces 31d and 31f of the restricting member 31.

  Although the two reinforcing members 30 and the two restricting members 31 are used, the number of the reinforcing members 30 and the restricting members 31 is not limited to this. For example, when one reinforcing member 30 and two restricting members 31 are used, it is necessary to fix the restricting member 31 in the case 21 so that the restricting member 31 does not move due to the movement of the reinforcing member 30. It becomes.

  ○ The lid 23 of the case 21 together with the reinforcing member 30 positioned so as to cover the first side wall 22b and the second side wall 22d as in the above-described embodiment, depending on the location where the pressure in the case 21 may be applied. Alternatively, the reinforcing member 30 may be provided so as to face the bottom wall 22f. According to such a form, it can suppress that the pressure provided to the lid | cover 23 or the bottom wall 22f acts on the side surfaces 12a and 16a of each layer of the electrode assembly 11. When the reinforcing member 30 is provided on the lid 23, the positive electrode tab 15 and the negative electrode tab 19 can be protruded from the electrode assembly 11 toward the lid 23 through the hole by providing a hole in the reinforcing member 30. It is necessary to.

  When the reinforcing member 30 and the regulating member 31 are accommodated in the case 21, the side surfaces 31d and 31f of the regulating member 31 and the surface 30b of the reinforcing member 30 may be close to each other. However, even in such a form, as shown in FIG. 1, the electrode assembly 11 and the regulating member 31 are accommodated in the case 21 and compared with the length L2 of the electrode assembly 11. The length L4 needs to be longer. In a state where the electrode assembly 11 and the regulating member 31 are accommodated in the case 21, both ends of the regulating member 31 in the same direction are side surfaces of the positive electrode 12 on both sides in a direction orthogonal to the stacking direction of the electrode assembly 11. 12a and the side surface 16a of the negative electrode 16 need to protrude by a predetermined length. Even in such a configuration, the movement of the reinforcing member 30 in the direction approaching the electrode assembly 11 can be restricted by bringing the surface 30b of the reinforcing member 30 into contact with the side surfaces 31d and 31f of the restricting member 31.

  The reinforcing member 30 and the regulating member 31 may have the same thickness as the side walls 22b, 22c, 22d, and 22e, or larger than the side walls 22b, 22c, 22d, and 22e. It is good.

The reinforcing member 30 and the regulating member 31 may have different thicknesses.
A plurality of types of reinforcing members 30 and regulating members 31 having different thicknesses are prepared, and the reinforcing members 30 and regulating members 31 having appropriate thicknesses are prepared according to the space between the case main body 22 and the lid 23 and the electrode assembly 11. Can be selected and provided between the case main body 22 and the lid 23 and the electrode assembly 11. In particular, the thickness along the stacking direction of the electrode assembly 11 is uneven coating of the active material on the positive electrode 12 and the negative electrode 16 and uneven pressing performed by applying pressure from both sides of the electrode assembly 11 in the stacking direction. Depending on the situation. Therefore, when the electrode assembly 11 is produced, it is difficult to make the thickness along the stacking direction of the electrode assembly 11 constant. For this reason, by changing the thickness of the regulating member 31 according to the thickness along the stacking direction of the electrode assembly 11, or adopting a material having a different elastic modulus according to the thickness of the regulating member 31, Regardless of the thickness of the electrode assembly 11 along the stacking direction, the rigidity of the secondary battery 10 can be improved.

The regulating member 31 does not have to be rectangular, and the shape can be freely set as long as the movement of the reinforcing member 30 in the direction approaching the electrode assembly 11 can be regulated.
The regulating member 31 does not have to be plate-shaped. For example, as shown in FIG. 6, the regulating member 131 may be fixed in the case 21 and have a shape protruding into the case 21. Specifically, the restricting member 131 is located at a total of four locations on both sides of the third side wall 22c of the case body 22 and both sides of the fourth side wall 22e in the direction orthogonal to the stacking direction of the electrode assembly 11. ing. Further, the regulating member 131 is positioned such that the side surface 131d is in contact with or close to the surface 30b of the reinforcing member 30. The regulating member 131 has one end fixed to the third side wall 22c and the fourth side wall 22e of the case body 22 and the other end protruding so as to be in contact with or close to the surface 30b of the reinforcing member 30. Yes. Also by such a restricting member 131, the side surface 131d of the restricting member 131 functions as a pressure receiving surface that receives the pressure applied from the reinforcing member 30, thereby restricting the movement of the reinforcing member 30 in the direction approaching the electrode assembly 11. Can do. In FIG. 6, a predetermined gap is provided between the reinforcing member 30 and the side surfaces 11a and 11c of the electrode assembly 11, and the restriction member 131 is provided so that the other end of the restriction member 131 protrudes into this gap. May be. And the fixing location of the end of the regulating member 131 is not limited to the third side wall 22c and the fourth side wall 22e of the case body 22, but may be other locations in the case 21, such as the bottom wall 22f and the lid 23. is there.

  The restriction members 31 and 131 face the electrode assembly 11 of the reinforcement member 30 as long as the movement of the reinforcement member 30 in the direction approaching the electrode assembly 11 from the first sidewall 22b and the second sidewall 22d can be restricted. It may be in contact with or close to a part other than the surface 30b.

  ○ Instead of the case 21 illustrated in FIG. 2, the case main body 22 of the case 21 is composed of a bottom wall 22e and four side walls 22b, 22d, 22f, and 23 erected on the bottom wall 22e. It is also possible. In such a case 21, a lid 22c is provided so as to close the opening formed by the side walls 22b, 22d, 22f, and 23. And in the state which accommodated the electrode assembly 11 in the case 21 of this form, it covers so that the side walls 22b and 22d may be covered between the side walls 22b and 22d of the case main body 22 and the side surfaces 11a and 11c of the electrode assembly 11. A reinforcing member 30 can be provided. Further, the regulating members 31 and 131 can be provided between the bottom wall 22e of the case body 22 and the lid 22c of the case 21 and the surfaces 11e and 11f of the electrode assembly 11. The effect similar to the said embodiment can be acquired also by such a form.

As the electrode assembly 11, it is also possible to adopt a wound body in which a strip-shaped separator is interposed between a strip-shaped positive electrode and a strip-shaped negative electrode, and these are wound.
In the above embodiment, the positive electrode active material layer 14 may be provided only on one side of the positive electrode 12. At this time, it is necessary to laminate the positive electrode 12 so that the positive electrode active material layer 14 faces the negative electrode active material layer 18.

  In the above embodiment, the negative electrode active material layer 18 may be provided only on one side of the negative electrode 16. At this time, the negative electrode 16 needs to be laminated so that the negative electrode active material layer 18 faces the positive electrode active material layer 14.

  The secondary battery 10 is a lithium ion secondary battery, but is not limited thereto, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer and the negative electrode active material layer and transfer charge.

The present invention may be embodied in a power storage device such as an electric double layer capacitor.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The positive electrode, the negative electrode, and the separator are in the form of a sheet, and the electrode assembly is a laminate in which the positive electrode, the negative electrode, and the separator are laminated. The power storage device according to any one of the above.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Electrode assembly, 12 ... Positive electrode, 16 ... Negative electrode, 20 ... Separator, 21 ... Case, 22 ... Case main body, 22b ... First side wall, 22c ... Third side wall, 22d ... First 2 side walls, 22e ... 4th side wall, 22f ... bottom wall, 23 ... lid, 30 ... reinforcing member, 31 ... regulating member.

Claims (5)

A layered electrode assembly in which a positive electrode, a negative electrode, and a separator that insulates them are stacked on a rectangular case with four side walls standing on the bottom wall, each surface of the electrode assembly is connected to the case. In the power storage device accommodated so as to face the inner surface,
A plate-like reinforcing member that covers the first side wall and the second side wall along the stacking direction among the side walls;
A power storage device comprising: the first side wall; and a regulating member that regulates movement of the reinforcing member in a direction approaching the electrode assembly from the second side wall.   The power storage device according to claim 1, wherein the restricting member is in contact with or close to a surface of the reinforcing member on the electrode assembly side.   3. The power storage device according to claim 1, wherein the restricting member has a plate shape that covers a third side wall and a fourth side wall along a direction orthogonal to the stacking direction of the electrode assembly among the side walls. The restriction member is made of a metal material,
The power storage device according to claim 1, wherein an insulating member is interposed between the regulating member and the electrode assembly.   The power storage device according to claim 1, wherein the power storage device is a secondary battery.