JP2015069763A - Power storage unit and power storage module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage unit and a power storage module which allow improvement in reliability.SOLUTION: A power storage unit 10 comprises: a case 30 which has a box-shaped body member 50 provided with an opening 51 and a lid member 60 welded to the body member 50 so as to seal the opening 51; an electrode assembly 20, housed in the case 30, which has a positive electrode 21 and a negative electrode 22 laminated on top of each other; and a first portion 70 which is arranged opposite to a lateral face 31 so as to restrict the deformation of the lateral face 31 where a welded portion M between the body member 50 and the lid member 60 of the case 30 is arranged. A recess 71 opened to the lateral face 31 side at a position opposite to the welded portion M is formed in the first portion 70.

Description

  The present invention relates to a power storage unit and a power storage module.

  Patent Document 1 describes a nonaqueous electrolyte secondary battery. This nonaqueous electrolyte secondary battery includes an outer can, an electrode body inserted into the outer can, and a sealing body that seals an opening of the outer can. Further, the electrode body is inserted into the outer can in a state where at least a part thereof is covered with a push-in guide plate made of an alloy having a spring property.

Japanese Patent Laid-Open No. 9-120836

  By the way, in the secondary battery as described above, the outer can (and the sealing body) may be deformed as a result of the pressure inside the outer can fluctuating due to, for example, gas generated in the outer can during power generation. . On the other hand, when the outer can and the sealing body are welded to each other, the strength of the welded portion is generally weaker than that of the raw material. For this reason, it is desirable to suppress the stress due to deformation of the outer can from being applied to the welded portion and to improve the reliability.

  For this purpose, for example, it is conceivable to suppress deformation of the side surface by disposing a restraining plate or the like on the side surface of the outer can where the welded portion is disposed. However, if a bead is formed in the welded portion, the restraint plate may come into contact with the bead and float from the side surface, and as a result, it may be difficult to effectively suppress deformation of the side surface. In that case, the stress due to the deformation of the outer can cannot be sufficiently prevented from being applied to the welded portion, and the reliability may be impaired.

  This invention is made | formed in view of such a situation, and it aims at providing the electrical storage unit and electrical storage module which can improve reliability.

  An electricity storage unit according to the present invention includes a box-shaped main body member having an opening, a case having a lid member welded to the main body member so as to seal the opening, and a positive electrode and a negative electrode stacked on each other. The electrode assembly housed in the case and a first surface disposed opposite to the first surface so as to restrict deformation of the first surface on which the welded portion between the main body member and the lid member in the case is disposed. And a concave portion that opens to the first surface side at a position facing the welded portion. The concave portion is formed on the first regulating member.

  In this power storage unit, a case for accommodating the electrode assembly includes a box-shaped main body member having an opening and a lid member welded to the main body so as to seal the opening of the main body member. And a 1st control member is arrange | positioned facing a 1st surface so that a deformation | transformation of the 1st surface in which the welding part of the main body member and cover member in a case is arrange | positioned may be controlled. In particular, the first restricting member is formed with a recess opening on the first surface side at a position facing the welded portion of the case. For this reason, when the first restricting member is disposed opposite to the first surface, the bead formed in the welded portion of the case is disposed (relieved) in the recess of the first restricting member, It is difficult to contact the first regulating member. Therefore, it is possible to effectively suppress (restrict) the deformation of the first surface by the first restricting member, and to suppress the stress due to the deformation of the case from being applied to the welded portion. Therefore, reliability can be improved.

  In the electricity storage unit according to the present invention, the first surface is a surface orthogonal to the stacking direction of the positive electrode and the negative electrode, and the first regulating member has a plate shape extending along the first surface. May be. In this case, the first surface of the case is a surface orthogonal to the stacking direction of the positive electrode and the negative electrode. The surface orthogonal to the stacking direction of the positive electrode and the negative electrode in the case is considered to be wider than the other surfaces in the case due to the shape of the positive electrode and the negative electrode, and the deformation amount is also large. Therefore, by restricting the deformation of the first surface with the first restricting member, it is possible to effectively suppress the stress due to the deformation of the case from being applied to the welded portion.

  The power storage unit according to the present invention further includes a second restricting member disposed to face the second surface so as to restrict deformation of the second surface different from the first surface in the case. Also good. In this case, in addition to the restriction of the deformation of the first surface, the deformation of the second surface different from the first surface is also restricted. Therefore, it can suppress reliably that the stress by a deformation | transformation of a case applies to a welding part.

  In the power storage unit according to the present invention, the first restricting member and the second restricting member may be configured integrally. In this case, by fixing one of the first and second restricting members to the case, the other of the first and second restricting members can also be fixed to the case. .

  The power storage module according to the present invention is a power storage module including a plurality of power storage units arranged along a predetermined direction, and the power storage unit seals the box-shaped main body member having the opening and the opening. In this way, a case including a lid member welded to a main body member, an electrode assembly including a positive electrode and a negative electrode laminated on each other and housed in the case, and a welded portion between the main body member and the lid member in the case are disposed. A first restricting member disposed to face the first surface so as to restrict deformation of the first surface, and the first restricting member includes a first restricting member at a position facing the welded portion. 1 is formed with a recess opening on the surface side. This power storage module includes a plurality of power storage units as described above. Therefore, reliability can be improved for the same reason as described above.

  In the power storage module according to the present invention, the first regulating member may be shared between the power storage units adjacent to each other along a predetermined direction. In this case, the structure can be simplified and the number of parts can be reduced.

  In the power storage module according to the present invention, the power storage units are arranged along the stacking direction of the positive electrode and the negative electrode, and the first surface is a surface orthogonal to the stacking direction of the positive electrode and the negative electrode. The member may have a plate shape extending along the first surface. In this case, as described above, by restricting the deformation of the first surface that is considered to have a relatively large deformation amount in the case, it is possible to reliably suppress the stress due to the deformation of the case from being applied to the welded portion. is there.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical storage unit and electrical storage module which can improve reliability can be provided.

It is typical sectional drawing which shows the structure of the electrical storage module which concerns on this embodiment. It is a perspective view of the electrical storage unit shown by FIG. FIG. 3 is a schematic partial sectional view taken along line III-III in FIG. 2. It is a side view of the electrical storage unit shown by FIG. FIG. 5 is a schematic partial cross-sectional view illustrating a modification example of the power storage module and the power storage unit illustrated in FIG. 1.

  Hereinafter, an embodiment of a power storage unit and a power storage module according to the present invention will be described in detail with reference to the drawings. In addition, below, the same code | symbol is attached | subjected to the same elements or the corresponding elements, and the overlapping description is abbreviate | omitted. Moreover, the dimensional ratio in each figure may differ from an actual thing.

  FIG. 1 is a schematic cross-sectional view showing the configuration of the power storage module according to this embodiment. In FIG. 1 (and other drawings), an orthogonal coordinate system S is shown. As shown in FIG. 1, the power storage module 1 includes a plurality of (here, four) power storage units 10. The power storage units 10 are arranged along a predetermined direction (y-axis direction in the orthogonal coordinate system S: a stacking direction of a positive electrode and a negative electrode described later). The power storage unit 10 is, for example, a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery.

  FIG. 2 is a perspective view of the power storage unit shown in FIG. FIG. 3 is a schematic partial sectional view taken along line III-III in FIG. FIG. 4 is a side view of the power storage unit shown in FIG. As illustrated in FIGS. 1 to 4, the power storage unit 10 includes an electrode assembly 20, a case 30, and a restricting member (first restricting member, second restricting member) 40. The electrode assembly 20 is accommodated in the case 30. The regulating member 40 is disposed outside the case 30 and at least partially contacts the case 30. 2 to 4 exemplify the power storage unit 10 located on the outermost part (the leftmost side in the drawing) of the power storage module 1 in a predetermined direction among the plurality of power storage units 10.

  The electrode assembly 20 includes a plurality of positive electrodes 21 and a plurality of negative electrodes 22, and a plurality of separators 23 disposed between the positive electrodes 21 and the negative electrodes 22. The positive electrode 21 and the negative electrode 22 are alternately stacked along a predetermined direction (y-axis direction in the orthogonal coordinate system S) via the separator 23. The positive electrode 21, the negative electrode 22, and the separator 23 have a sheet shape extending in a direction orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22.

  The positive electrode 21 includes a metal foil 21a and a positive electrode active material layer 21b provided on both surfaces of the metal foil 21a. The metal foil 21a is, for example, an aluminum foil. The positive electrode active material layer 21b includes, for example, a positive electrode active material and a binder. Examples of the positive electrode active material include composite oxide, metallic lithium, and sulfur. The composite oxide includes, for example, at least one of manganese, nickel, cobalt, and aluminum and lithium.

The negative electrode 22 includes a metal foil 22a and a negative electrode active material layer 22b provided on both surfaces of the metal foil 22a. The metal foil 22a is, for example, a copper foil. The negative electrode active material layer 22b includes, for example, a negative electrode active material and a binder. Examples of the negative electrode active material include carbon such as graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, SiO _x (0.5 ≦ x ≦ 1.5) and the like, and boron-added carbon and the like.

  The separator 23 is a porous film made of a polyolefin-based resin such as polyethylene (PE) and polypropylene (PP), and a woven or non-woven fabric made of polypropylene, polyethylene terephthalate (PET), methylcellulose, or the like.

  The case 30 houses the electrode assembly 20. An insulating film (not shown) is provided on the inner side surface of the case 30. The electrode assembly 20 is in contact with the inner surface of the case 30 through the insulating film. The case 30 is filled with an electrolytic solution L. Examples of the electrolyte solution L include organic solvent-based or non-aqueous electrolyte solutions.

  Case 30 includes a main body member 50 and a lid member 60. The main body member 50 and the lid member 60 (that is, the case 30) are made of aluminum, for example. The main body member 50 has a rectangular box shape with one side opened. That is, the main body member 50 has an opening 51. The main body member 50 includes a pair of side surfaces 52 that face each other and a pair of side surfaces 53 that face each other and connect the side surfaces 52 to each other.

  The side surface 52 is a surface orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20 (that is, a surface parallel to the xz plane). Therefore, the positive electrode 21 and the negative electrode 22 extend along the side surface 52 in the case 30. The side surface 53 is a surface parallel to the stacking direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20 and the height direction (z-axis direction in the orthogonal coordinate system S) of the positive electrode 21 and the negative electrode 22 (ie, y−). a plane parallel to the z-plane). The side surface 52 is configured wider than the side surface 53 due to the shape of the positive electrode 21 and the negative electrode 22 (electrode assembly 20).

  The lid member 60 has a rectangular plate shape. The lid member 60 is welded to the main body member 50 so as to seal the opening 51 of the main body member 50. The lid member 60 includes a back surface 61 disposed on the main body member 50 side (inside the case 30) and a front surface 62 opposite to the back surface 61 when welded to the main body member 50. The back surface 61 and the front surface 62 are surfaces parallel to the stacking direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20 and the width direction (x-axis direction of the orthogonal coordinate system S) of the positive electrode 21 and the negative electrode 22 (that is, a plane parallel to the xy plane).

  From both ends in the longitudinal direction of the surface 62 (the lid member 60), a positive terminal EP electrically connected to the positive electrode 21 of the electrode assembly 20 and a negative electrode electrically connected to the negative electrode 22 of the electrode assembly 20 Terminal EN protrudes. In addition, a safety valve (not shown) is formed at the center in the longitudinal direction of the surface 62 (lid member 60).

  The lid member 60 includes a pair of side surfaces 63 that connect the back surface 61 and the surface 62 to each other, and a pair of side surfaces 64 that connect the back surface 61 and the surface 62 to each other and connect the side surfaces 63 to each other. The side surface 63 is a surface orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20. The side surface 63 is flush with the side surface 52 of the main body member 50 in a state where the main body member 50 and the lid member 60 are welded to each other.

  The side surface 64 is a surface parallel to the stacking direction of the positive electrode 21 and the negative electrode 22 and the height direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20. The side surface 64 is flush with the side surface 53 of the main body member 50 in a state where the main body member 50 and the lid member 60 are welded to each other. The side surface 63 is configured wider than the side surface 64.

  The side surface 52 of the main body member 50 and the side surface 63 of the lid member 60 constitute a pair of side surfaces (first surfaces) 31 of the case 30. The side surface 31 of the case 30 is a surface orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20. Further, the side surface 53 of the main body member 50 and the side surface 64 of the lid member 60 constitute a side surface 32 different from the side surface 31 of the case 30. The side surface 32 is a surface parallel to the stacking direction of the positive electrode 21 and the negative electrode 22 and the height direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20. Since the side surface 52 and the side surface 63 are configured to be wider than the side surface 53 and the side surface 64, respectively, the side surface 31 of the case 30 is also configured to be wider than the side surface 32.

  On the other hand, the surface 62 of the lid member 60 constitutes an upper surface (a surface (second surface) different from the side surfaces 31, 32) 33 of the case 30. The upper surface 33 of the case 30 is a surface parallel to the stacking direction of the positive electrode 21 and the negative electrode 22 and the width direction of the positive electrode 21 and the negative electrode 22 in the electrode assembly 20. Here, the upper surface 33 of the case 30 is configured to be narrower than the side surface 31 and wider than the side surface 32.

  A welded portion M between the main body member 50 and the lid member 60 is disposed on the side surface 31 and the side surface 32 of the case 30. More specifically, the welded part M is formed over the entire circumference of the side surfaces 31 and 32 (outer side surfaces) of the case 30. In other words, the lid member 60 is welded to the main body member 50 so as to cover the main body member 50 from the height direction of the electrode assembly 20, and the welded portion M (joint interface) thereof includes the side surface 31 and the side surface of the case 30. 32 (not exposed on the upper surface 33). A bead B may be formed on the welded part M.

  The restriction member 40 includes a first part (first restriction member) 70 and a second part (second restriction member) 80. The first portion 70 and the second portion 80 (that is, the restriction member 40) are made of, for example, aluminum. The first portion 70 is disposed to face the side surface 31 of the case 30. The first portion 70 has a rectangular plate shape and extends along the side surface 31. The first portion 70 extends on the side surface 31 over a wider range than the positive electrode 21 and the negative electrode 22. That is, the first portion 70 covers the positive electrode 21 and the negative electrode 22 (and the welded portion M) when viewed from the stacking direction of the positive electrode 21 and the negative electrode 22.

  The first portion 70 is formed with a recess 71 that opens to the side surface 31 at a position facing the welded portion M (omitted in FIGS. 2 and 4). The recess 71 is a groove extending along the welded part M over the entire width of the first part 70. Therefore, the bead B formed in the welded part M is disposed in the recess 71. That is, the recess 71 functions as a relief groove for the bead B. Here, the first portion 70 is fixed to the case 30 in a state in which the first portion 70 is in contact with the side surface 31 in most of the portions excluding the recess 71.

  The first portion 70 is pressed against the side surface 31 of the case 30. Accordingly, the first portion 70 restricts deformation of the side surface 31 (particularly outward deformation). That is, the 1st part 70 is arrange | positioned facing the side surface 31 (and contacting) so that the deformation | transformation of the side surface 31 in which the welding part M in the case 30 is arrange | positioned is controlled. The first portion 70 functions as a restraining plate that applies pressure to the electrode assembly 20 via the side surface 31.

  Here, the first portion 70 is shared between the power storage units 10 adjacent to each other along the stacking direction of the positive electrode 21 and the negative electrode 22 (that is, 1 between the pair of power storage units 10 adjacent to each other. Two first portions 70 are arranged). Therefore, the first portion 70 includes a first surface 72 that faces the side surface 31 of the case 30 of one power storage unit 10 among the power storage units 10 adjacent to each other, and a side surface of the case 30 of the other power storage unit 10. And a second surface 73 facing 31. And the recessed part 71 is formed in both the 1st surface 72 and the 2nd surface 73 in the position which opposes the welding part M of each electrical storage unit 10. As shown in FIG.

  The second portion 80 is disposed to face the upper surface 33 of the case 30. The second portion 80 has a rectangular plate shape and extends along the upper surface 33 of the case 30. The second portion 80 is formed integrally with the first portion 70 by being connected to the first portion 70 at the end portion on the side surface 31 side (that is, the first portion 70 and the second portion 70 are connected to the first portion 70). The portions 80 are not separate from each other but are integrated). Therefore, the restricting member 40 is formed in an L-shaped cross section by the first portion 70 and the second portion 80 as a whole.

  For example, the second portion 80 is in contact with the upper surface 33 or at a distance from the upper surface 33 so as to contact the upper surface 33 and restrict the deformation when at least the upper surface 33 starts to deform. It is disposed close to the upper surface 33. The second portion 80 is fixed to the case 30 in such a state. That is, the second portion 80 is disposed so as to face the upper surface 33 so as to restrict deformation of the upper surface 33 different from the side surface 31 in the case 30. Since the second portion 80 is integrated with the first portion 70, the second portion 80 is fixed to the case 30 by fixing the first portion 70 to the case 30. Can do.

  Here, the second portion 80 extends over substantially the entire upper surface 33 in the direction intersecting the longitudinal direction of the upper surface 33 (the stacking direction of the positive electrode 21 and the negative electrode 22). On the other hand, the second portion 80 extends only in the center of the upper surface 33 so as to avoid the positive terminal EP and the negative terminal EN in the longitudinal direction of the upper surface 33. An opening 81 is formed at the center of the second portion 80 so as to expose the safety valve.

  Here, as described above, the power storage unit 10 located on the outermost part (the leftmost side in the drawing) of the power storage module 1 among the plurality of power storage units 10 is illustrated. Therefore, here, in the stacking direction of the positive electrode 21 and the negative electrode 22, another power storage unit 10 (hereinafter referred to as an adjacent unit) is disposed on one side of the power storage unit 10, and no adjacent unit is disposed on the other side. Therefore, the first portion 70 shared with the adjacent unit is disposed on one side surface 31 of the case 30, but the first portion 70 is not disposed on the other side surface 31.

  Therefore, in the power storage module 1, a regulating member 90 is separately provided on the side surface 31 in order to regulate the deformation of the side surface 31 where the first portion 70 of the case 30 of the power storage unit 10 is not disposed. . The restricting member 90 has the same configuration as that of the first portion 70 of the restricting member 40 (that is, a recess 71 for releasing the bead B of the welded portion M is formed).

  On the other hand, among the power storage units 10, the power storage unit 10 located on the outermost side (the rightmost side in the drawing) of the power storage module 1 is also provided with an adjacent unit on one side and an adjacent unit on the other side. Not placed. Therefore, the first portion 70 disposed on one side surface 31 of the case 30 of the power storage unit 10 is shared with an adjacent unit, but the other side surface 31 of the case 30 of the power storage unit 10. The first portion 70 disposed above is not shared. For this reason, in the 1st part 70 of the electrical storage unit 10, the recessed part 71 should just be provided only in the 1st surface 72. FIG.

  The power storage units 10 configured as described above are fixed to each other in the stacked direction of the positive electrode 21 and the negative electrode 22 in a state where a plurality of the power storage units 10 are arranged with the first portion 70 of the regulating member 40 interposed therebetween, thereby configuring the power storage module 1. doing. The power storage unit 10 can be fixed, for example, by sandwiching a plurality of power storage units 10 arranged in a row with a pair of plate members and fastening the plate members with bolts or the like. By fixing the storage units 10 in this manner, the first portion 70 can be fixed between the storage units 10 adjacent to each other.

  As described above, the power storage module 1 according to this embodiment includes a plurality of power storage units 10. In each power storage unit 10, the case 30 that houses the electrode assembly 20 is welded to the main body member 50 so as to seal the box-shaped main body member 50 having the opening 51 and the opening 51 of the main body member 50. And the lid member 60 made. And the 1st part 70 of the control member 40 is arrange | positioned facing the side surface 31 so that the deformation | transformation of the side surface 31 in which the welding part M of the main body member 50 and the cover member 60 in the case 30 is arrange | positioned. .

  In particular, the first portion 70 is formed with a recess 71 that opens to the side surface 31 at a position facing the welded portion M of the case 30. For this reason, when the first portion 70 is disposed facing the side surface 31, the bead B formed in the welded portion M of the case 30 is disposed in the recess 71 of the first portion 70 (released). ), It is difficult to contact the first portion 70. Therefore, the floating from the side surface 31 of the first portion 70 due to the contact with the bead B is suppressed. For this reason, the deformation of the side surface 31 can be effectively suppressed (restricted) by the first portion 70, and the stress due to the deformation of the case 30 can be suppressed from being applied to the welded portion M. Therefore, according to the power storage module 1 (and the power storage unit 10), reliability can be improved.

  Further, in the power storage unit 10, the first portion 70 of the regulating member 40 is disposed on the side surface 31 that is orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22 in the case 30 and is relatively wide and has a large amount of deformation. Arranges and regulates its deformation. For this reason, it can suppress effectively that the stress by a deformation | transformation of case 30 is added to the welding part M. FIG.

  In the power storage unit 10, the first portion 70 of the regulating member 40 is in contact with and pressed against the side surface 31 orthogonal to the stacking direction of the positive electrode 21 and the negative electrode 22 in the case 30. For this reason, it is possible to apply pressure to the electrode assembly 20 using the first portion 70 (that is, the first portion 70 can function as a restraining plate). Further, the electrode assembly 20 can be dissipated using the first portion 70.

  Further, in the power storage unit 10, the second portion 80 of the regulating member 40 is disposed to face the upper surface 33 so as to regulate not only the side surface 31 of the case 30 but also the upper surface 33. For this reason, the deformation of the upper surface 33 is also suppressed, and the stress due to the deformation of the case can be reliably suppressed from being applied to the welded part M.

  Moreover, in the electrical storage unit 10, the 1st part 70 and the 2nd part 80 of the control member 40 are mutually comprised integrally. Therefore, if the first portion 70 is fixed to the case 30 as described above, the second portion 80 can also be fixed to the case 30.

  Further, in the power storage module 1, the first portion 70 of the regulating member 40 is shared between the power storage units 10 adjacent to each other. For this reason, while being able to simplify the structure of the electrical storage module 1, the number of parts of the electrical storage module 1 can be reduced.

  The above embodiment describes one embodiment of the power storage unit and the power storage module according to the present invention. Therefore, the power storage unit and the power storage module according to the present invention are not limited to the power storage unit 10 and the power storage module 1 described above. In the power storage unit and the power storage module according to the present invention, the above-described power storage unit 10 and the power storage module 1 can be arbitrarily changed without changing the gist of each claim.

  FIG. 5 is a schematic partial cross-sectional view showing a modification of the power storage module and the power storage unit shown in FIG. As shown in FIG. 5A, the power storage unit 10 can have a regulating member 40 </ b> A instead of the regulating member 40. The restricting member 40 </ b> A includes a pair of first portions 70 disposed to face the side surfaces 31 so as to restrict the deformation of the pair of side surfaces 31 of the case 30. A pair of 1st part 70 and 2nd part 80 are mutually comprised integrally. Therefore, the regulating member 40A is formed in a U-shaped cross section as a whole.

  Further, as illustrated in FIG. 5B, the power storage unit 10 can include a regulating member 40 </ b> B instead of the regulating member 40. The restriction member 40 </ b> B has one first portion 70 and one second portion 80, similar to the restriction member 40, but the first portion 70 and the second portion 80 are separate. It differs from the restricting member 40 in that it is configured as described above. Thus, the 1st part 70 and the 2nd part 80 do not necessarily need to be integral.

  5C, in the power storage module 1, the first portion 70 of the regulating member 40 is shared between the power storage units 10 adjacent to each other in the stacking direction of the positive electrode 21 and the negative electrode 22. It does not have to be converted. In this case, if the first portion 70 and the regulating member 90 of the regulating member 40 are interposed between the neighboring electrical storage units 10 in order to set the escape of the beads B of the respective electrical storage units 10. Good.

  In addition, the regulating member 40 further includes another portion arranged to face the side surface 32 so as to regulate the deformation of the side surface 32 of the case 30 (a surface parallel to the stacking direction of the positive electrode 21 and the negative electrode 22). May be. In that case, since the side surface 32 of the case 30 is a surface on which the welded portion M is disposed, a recess that opens to the side surface 32 side at a position facing the welded portion M is also formed on the other portion. It is desirable to form. Further, the regulating member 40 may not have the second portion 80.

  Moreover, in the said embodiment, the case where the 1st part 70 of the limitation member 40 contacted and pressed the side surface 31 of the case 30 was demonstrated. However, since the first portion 70 only needs to be able to regulate the deformation of the side surface 31, the first portion 70 does not necessarily have to be in contact with the side surface 31 and pressed. In other words, the first portion 70 may be disposed close to the side surface 31 while being separated from the side surface 31 so as to come into contact with the side surface 31 and regulate the deformation when the side surface 31 starts to deform. Further, the entire regulation member 40 may be fixed to the case 30 by fixing the second portion 80 instead of the first portion 70 to the case 30.

  Further, the second portion 80 of the regulating member 40 may not extend over the entire upper surface 33 in the direction intersecting the longitudinal direction of the upper surface 33. From the viewpoint of restricting the deformation of the upper surface 33, the second portion 80 only needs to extend beyond at least the center position in the direction intersecting the longitudinal direction of the upper surface 33. Similarly, the first portion 70 does not necessarily extend so as to cover the positive electrode 21 and the negative electrode 22 when viewed from the stacking direction of the positive electrode 21 and the negative electrode 22.

  Further, the material of the regulating member 40 is not limited to the above-described aluminum, and any material can be used. However, the material of the regulating member 40 is a material having at least a hardness comparable to the hardness of the material of the case 30 or a hardness higher than the hardness of the material of the case 30 from the viewpoint of regulating the deformation of the case 30. Preferably there is.

  Here, in the said embodiment, the case where the welding part M of the main body member 50 and the cover member 60 was arrange | positioned at the outer side surface (the side surface 31 and the side surface 32) of the case 30 was demonstrated. However, the present invention can also be applied when the welded portion M between the main body member 50 and the lid member 60 is disposed on the upper surface 33 (or the bottom surface) of the case 30. In that case, the second portion 80 (in this case, facing the upper surface 33 so as to regulate the deformation of the upper surface 33 on which the welded portion M of the main body member 50 and the lid member 60 in the case 30 is disposed). What is necessary is just to arrange | position a 1st control member. Moreover, what is necessary is just to form the recessed part opened to the upper surface 33 side in the position facing the welding part M with respect to the 2nd part 80. FIG.

  Furthermore, the present invention can be applied to an arbitrary power storage device such as an arbitrary secondary battery or an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 1 ... Power storage module, 10 ... Power storage unit, 20 ... Electrode assembly, 21 ... Positive electrode, 22 ... Negative electrode, 30 ... Case, 31 ... Side surface (first surface), 33 ... Upper surface (second surface), 50 ... Main body member 51... Opening portion 60... Lid member 70... First portion (first regulating member) 71... Recessed portion 80.

Claims (7)

A box-shaped main body member having an opening, and a case having a lid member welded to the main body member so as to seal the opening;
An electrode assembly having a positive electrode and a negative electrode laminated on each other and housed in the case;
A first restricting member disposed to face the first surface so as to restrict deformation of the first surface on which the welded portion between the main body member and the lid member in the case is disposed; Prepared,
The first restricting member is formed with a recess that opens to the first surface side at a position facing the welded portion.
A power storage unit characterized by that. The first surface is a surface orthogonal to the stacking direction of the positive electrode and the negative electrode,
The first restricting member has a plate shape extending along the first surface.
The power storage unit according to claim 1. A second restricting member disposed to face the second surface so as to restrict deformation of the second surface different from the first surface in the case;
The power storage unit according to claim 2. The first restricting member and the second restricting member are integrally formed.
The power storage unit according to claim 3. A power storage module comprising a plurality of power storage units arranged along a predetermined direction,
The power storage unit is
A box-shaped main body member having an opening, and a case including a lid member welded to the main body member so as to seal the opening;
An electrode assembly including a positive electrode and a negative electrode stacked on each other, and housed in the case;
A first restricting member disposed to face the first surface so as to restrict deformation of the first surface on which the welded portion between the main body member and the lid member in the case is disposed; Have
The first restricting member is formed with a recess that opens to the first surface side at a position facing the welded portion.
The electrical storage module characterized by the above-mentioned. The first restriction member is shared between the power storage units adjacent to each other along the predetermined direction.
The power storage module according to claim 5. The power storage units are arranged along the stacking direction of the positive electrode and the negative electrode,
The first surface is a surface orthogonal to the stacking direction of the positive electrode and the negative electrode,
The first restricting member has a plate shape extending along the first surface.
The power storage module according to claim 5 or 6.

Images