JP2017027819A - Secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of a secondary battery, by reducing the temperature gradient of an electrode body.SOLUTION: A first collector 40P is configured so that the calorific value per unit time is larger than that of a second collector 40N. A first insulation member 1 and a second insulation member 2 have different configurations so that the amount of heat transferred from the first collector 40P to a battery container 10 via the first insulation member 1 in the unit time is larger than the amount of heat transferred from the second collector 40N to the battery container 10 via the second insulation member 2 in the unit time.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a secondary battery.

  In recent years, secondary batteries with large capacity (Wh) have been developed as power sources for hybrid electric vehicles and pure electric vehicles, and among them, prismatic lithium ion secondary batteries with high energy density (Wh / kg). Is attracting attention. As an example of such a secondary battery, when the positive electrode active material such as lithium is suppressed from being deposited on the battery container, and when the battery container is short-circuited with a metal outer case surrounding the battery container, Has been disclosed (see Patent Document 1 below).

  A power storage element described in Patent Document 1 is made of a metal battery container that houses a power generation element including a positive electrode plate and a negative electrode plate, and penetrates the battery container and is electrically connected to the positive electrode plate. A positive electrode terminal, a negative electrode terminal penetrating the battery container and electrically connected to the negative electrode plate, a positive electrode side sealing member that seals between the battery container and the positive electrode terminal, and the battery A negative electrode side sealing member that seals between the container and the negative electrode terminal; This power storage element is characterized in that one of the positive electrode side sealing member and the negative electrode side sealing member is a conductive material having a resistance value larger than that of the battery container, and the other is an insulating material. .

  In the electric storage element, since either the positive electrode terminal or the negative electrode terminal is electrically connected to the battery container, the electric potential of the battery container is approximately the same as the positive electrode terminal or the negative electrode terminal. Therefore, it can suppress that an active material precipitates in a battery container. Moreover, since the sealing member is used for the electrical connection between the battery case and the terminal, the potential of the battery case can be made substantially the same as that of the terminal only by replacing the parts (replacement of the sealing member). No increase in parts. In addition, since the sealing member that connects the battery container and the terminal has a higher resistance value than the battery container, even if the battery container is short-circuited with a metal outer case that surrounds the battery container, the sealing member is externally connected via the battery container. It is possible to suppress a short-circuit current flowing through the case.

JP2015-43282A

  In the electric storage element described in Patent Document 1, the positive electrode current collector that electrically connects the positive electrode terminal and the positive electrode plate is made of, for example, an aluminum alloy plate, and the negative electrode current collector that electrically connects the negative electrode terminal and the negative electrode plate. The electric body is made of, for example, a copper alloy. Inner seal members having the same configuration are disposed between the positive and negative electrode current collectors and the lid of the case that houses the power generation element (see FIGS. 4 and 5, reference numerals 81P and 81N). ). Such a storage element is connected to the positive electrode current collector and the negative electrode current collector when the positive electrode current collector having a relatively large electric resistance becomes higher in temperature than the negative electrode current collector having a relatively small electric resistance. In addition, the temperature gradient of the power generation element may increase, and the storage element may deteriorate.

  This invention is made | formed in view of the said subject, and it aims at reducing the temperature gradient of the electrode body as a power generation element, and suppressing deterioration of a secondary battery.

  In order to achieve the above object, the secondary battery of the present invention includes an electrode body, a battery container that accommodates the electrode body, an external terminal provided on the battery container, and the external terminal connected to the electrode body. A first current collector plate and a second current collector plate; a first insulating member disposed between the first current collector plate and the battery container; and a gap between the second current collector plate and the battery container. A secondary battery comprising: a second insulating member disposed; wherein the first current collector plate has a configuration that generates more heat per unit time than the second current collector plate; The insulating member and the second insulating member are configured such that the amount of heat per unit time moving from the first current collector plate to the battery container via the first insulating member passes through the second insulating member. It has a different configuration that is greater than the amount of heat per unit time that travels from the plate to the battery container.

  According to the secondary battery of the present invention, the calorific value of the unit time is smaller than the calorific value of the unit time moving from the second current collector plate having a small calorific value per unit time to the battery container via the second insulating member. The amount of heat per unit time that moves from the large first current collector plate to the battery container via the first insulating member increases. As a result, the temperature difference between the first current collector plate and the second current collector plate is reduced, the temperature gradient of the electrode body between the first current collector plate and the second current collector plate is reduced, and the secondary current is reduced. Battery deterioration can be suppressed.

1 is an external perspective view of a secondary battery according to Embodiment 1 of the present invention. The disassembled perspective view of the secondary battery shown in FIG. FIG. 3 is an exploded perspective view of a lid assembly for the secondary battery shown in FIG. 2. The expanded sectional view which follows the IV-IV line of FIG. Sectional drawing explaining the assembly procedure of the cover assembly shown in FIG. Sectional drawing explaining the assembly procedure of the cover assembly shown in FIG. Sectional drawing explaining the assembly procedure of the cover assembly shown in FIG. The disassembled perspective view of the electrode body of the secondary battery shown in FIG. The external appearance perspective view of the cover assembly of the secondary battery which concerns on Embodiment 2 of this invention. The expanded sectional view of the positive electrode external terminal vicinity of the secondary battery which concerns on Embodiment 3 of this invention. The expanded sectional view of the negative electrode external terminal vicinity of the secondary battery which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of a secondary battery of the present invention will be described in detail with reference to the drawings. In addition, in order to make an understanding of this invention easy, the reduced scale of each part in drawing may be changed suitably. In the following description, up, down, left, and right are convenient directions for explaining the positional relationship between the members, and do not necessarily correspond to the vertical direction or the horizontal direction.

[Embodiment 1]
FIG. 1 is an external perspective view of a secondary battery 100 according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of the secondary battery 100 shown in FIG. Although details will be described later, in the secondary battery 100 of the present embodiment, the amount of heat q1 per unit time for moving from the positive electrode current collector plate 40P to the battery container 10 is the unit time for moving from the negative electrode current collector plate 40N to the battery container 10. The greatest feature is that the insulating members 1 and 2 (see FIG. 3) between the current collector plates 40 and the battery container 10 have different configurations so as to be greater than the amount of heat q2.

  The battery container 10 includes a bottomed rectangular tube-shaped battery can 11 having an opening 11 d at the top, and a battery lid 12 that closes the opening 11 d of the battery can 11, and accommodates an electrode body 30. The battery container 10 can be manufactured by, for example, aluminum or an aluminum alloy, and the battery can 11 can be manufactured by, for example, deep-drawing these materials. The battery can 11 includes a generally rectangular flat bottom wall 11b, a pair of rectangular wide side walls 11a along the longitudinal direction of the bottom wall 11b, and a pair of rectangular narrow side walls 11c along the short direction of the bottom wall 11b. Have.

  The battery lid 12 is a flat plate member having a substantially rectangular planar shape. For example, the battery lid 12 is joined over the entire circumference of the opening 11d of the battery can 11 by laser welding, thereby closing the opening 11d of the battery can 11. doing. The battery lid 12 constitutes a lid assembly 50 by assembling an external terminal 20 and a current collector plate 40 at both ends in the longitudinal direction. The battery lid 12 is provided with a gas discharge valve 13 and a liquid injection port 14 at an intermediate portion in the longitudinal direction.

  The gas discharge valve 13 is formed by, for example, pressing the battery lid 12 to make it thin, or joining a thin film member to an opening provided in the battery lid 12 by laser welding or the like. The gas discharge valve 13 is cleaved when the internal pressure of the battery container 10 rises above a predetermined pressure to reduce the internal pressure of the battery container 10. The liquid injection port 14 is provided for injecting the non-aqueous electrolyte into the battery container 10 in which the battery can 11 is closed by the battery lid 12. After the non-aqueous electrolyte is injected, the injection plug 15 is inserted by, for example, laser welding. It is sealed by joining.

  3 is an exploded perspective view of the lid assembly 50 shown in FIG. 4 is an enlarged cross-sectional view of the negative electrode external terminal 20N and its peripheral members shown in FIG. 3 cut along a line IV-IV parallel to the longitudinal direction of the battery cover 12. As shown in FIG. In the secondary battery 100 of the present embodiment, the positive electrode external terminal 20P and the positive electrode current collector plate 40P, and the negative electrode external terminal 20N and the negative electrode current collector plate 40N have a substantially mirror image configuration. Therefore, below, each structure of the negative electrode external terminal 20N shown in FIG. 4 is demonstrated in detail, and the description about each structure of the positive electrode external terminal 20P is abbreviate | omitted suitably.

  The lid assembly 50 mainly includes a pair of external terminals 20, a battery lid 12, a pair of insulating members 1 and 2, and a pair of current collector plates 40. The pair of external terminals 20 is provided on the battery lid 12 which is a part of the battery case 10, and one is a positive external terminal 20P and the other is a negative external terminal 20N. Each external terminal 20 includes a terminal portion 21, an external insulator 22, a connection member 23, and a gasket 24.

  The material of the terminal portion 21 and the connection member 23 of the positive external terminal 20P is, for example, aluminum or an aluminum alloy, and the material of the terminal portion 21 and connection member 23 of the negative external terminal 20N is, for example, copper or a copper alloy. The material of the external insulator 22 is an insulating resin such as polypropylene (PP), for example, and the material of the gasket 24 is an insulating material such as tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA). Resin.

  The terminal portion 21 is a substantially rectangular plate-like member whose long side is the longitudinal direction of the battery lid 12. The terminal portion 21 has a circular through hole 21a provided in the center portion, a concave portion 21b provided on the lower surface facing the battery lid 12, and a pair of groove portions 21c provided adjacent to the concave portion 21b. doing. The through hole 21a is provided at a position communicating with the hole 23d of the connection member 23 that engages with the recess 21b. The recess 21 b is formed in a circular shape corresponding to the shape of the upper surface of the connection member 23 facing the terminal portion 21, and engages a part of the flange portion 23 b of the connection member 23.

  The groove portion 21 c is provided on both sides of the recess portion 21 b in the long side direction of the terminal portion 21, and extends so as to cross the terminal portion 21 in the short side direction of the terminal portion 21. The groove 21c is provided between the welded portion Bw and the recessed portion 21b of the bus bar B (see FIG. 5C) that is welded to the upper surface of the terminal portion 21. When pressure is applied from the bus bar B to the upper surface of the terminal portion 21, the terminal portion 21 is bent at the groove portion 21c to relieve the pressure acting on the gasket 24 and suppress deformation of the gasket 24.

  The external insulator 22 is disposed between the terminal portion 21 and the battery lid 12 to electrically insulate them. The external insulator 22 includes a circular through hole 22a provided at the center, a recess 22b provided on the surface facing the terminal portion 21, and a pair of engagement recesses provided on the surface facing the battery lid 12. 22c. The through hole 22 a is inserted through the connection member 23, and the flange portion 23 b of the connection member 23 and the flange portion 24 b of the gasket 24 are disposed inside. The recess 22b engages and holds the terminal portion 21 inside. The engaging recess 22 c engages with a cylindrical protrusion 12 b provided on the battery lid 12, and positions the external insulator 22 on the battery lid 12.

  The connecting member 23 includes a shaft portion 23a, a flange portion 23b provided at one end of the shaft portion 23a, a cylindrical portion 23c provided at the other end of the shaft portion 23a, and a hole provided in a central portion of the flange portion 23b. 23d and a hole 23e provided in the cylindrical portion 23c. The shaft portion 23a is provided in a columnar shape, the flange portion 23b is provided in a disk shape at the end portion on the terminal portion 21 side, and the cylindrical portion 23c is provided in a cylindrical shape at the end portion on the current collector plate 40 side of the shaft portion 23a. ing.

  The gasket 24 has a cylindrical cylindrical portion 24a, a flange portion 24b provided at an end portion of the cylindrical portion 24a on the terminal portion 21 side, and a through hole 24c through which the connecting member 23 is inserted. In the gasket 24, the flange portion 24 b is disposed between the flange portion 23 b of the connection member 23 and the upper surface of the battery lid 12, and the cylindrical portion 24 a is disposed between the shaft portion 23 a of the connection member 23 and the through hole 12 a of the battery lid 12. The connection member 23 and the battery lid 12 are electrically insulated from each other.

  The battery lid 12 includes through holes 12 a provided at both ends in the longitudinal direction, a protrusion 12 b provided adjacent to the through hole 12 a on the upper surface facing the external insulator 22, and a lower surface facing the insulating member 2. And an engaging recess 12c provided corresponding to the protrusion 12b. The through hole 12 a is formed in a cylindrical shape through which the shaft portion 23 a of the connection member 23 and the cylindrical portion 24 a of the gasket 24 are inserted. The protruding portion 12 b is formed in a columnar shape that engages with the engaging recess 22 c of the external insulator 22. The engagement recess 12 c is formed in a bottomed cylindrical shape that engages the protrusion 2 b of the insulating member 2. In addition, an annular groove 12 d is formed around the through hole 12 a on the upper surface of the battery lid 12.

  Of the pair of current collector plates 40, the positive electrode current collector plate 40P is made of, for example, aluminum or an aluminum alloy, and the negative electrode current collector plate 40N is made of, for example, copper or a copper alloy. Each current collecting plate 40 includes a base portion 41 disposed substantially parallel to the battery lid 12 and a pair of connection pieces 42 connected to electrodes constituting the electrode body 30.

  The base 41 of the current collector plate 40 is formed in a substantially rectangular plate shape with the long side direction of the battery lid 12 as the long side direction and the short side direction of the battery lid 12 as the short side direction, and is inserted through the connection member 23 of the external terminal 20. A through hole 41a is provided. The connection piece 42 of the current collector plate 40 is provided at the longitudinal end of the base 41 on the longitudinal end of the battery lid 12, and is bent downward from both sides in the short direction of the base 41, so that the battery can 11 is widened. It forms in a pair of plate shape which hangs down toward the bottom wall 11b of the battery can 11 along the side wall 11a. Insulating members 1 and 2 are disposed between the base 41 of each current collector plate 40 and the battery lid 12, respectively, and the current collector plate 40 is electrically insulated from the battery lid 12.

  Here, the positive electrode current collector plate 40P connecting the positive electrode external terminal 20P to the electrode body 30 is a first current collector plate, and the negative electrode current collector plate 40N connecting the negative electrode external terminal 20N to the electrode body 30 is a second current collector plate. Then, the first current collector plate has a configuration that generates more heat per unit time than the second current collector plate. More specifically, in the secondary battery 100 of the present embodiment, the resistivity of the metal material of the positive electrode current collector plate 40P, which is the first current collector plate, is the metal of the negative electrode current collector plate 40N, which is the second current collector plate. Higher than material resistivity.

That is, when the material of the positive electrode current collector plate 40P as the first current collector plate is aluminum, the resistivity ρp is ρp = 2.65 × 10 ⁻⁸ [Ωm]. When the material of the negative electrode current collector plate 40N as the second current collector plate is copper, the resistivity ρn is ρn = 1.68 × 10 ⁻⁸ [Ωm]. When the dimensions of the current collector plates 40 are the same, the cross-sectional area S and the length L of the current path are equal. Therefore, the resistance Rp of the positive current collector 40P and the resistance Rn of the negative current collector 40N are as follows: It can represent with Formula (1) and (2).

Rp = ρp × (L / S) (1)
Rn = ρn × (L / S) (2)

  Therefore, assuming that the currents I flowing through the current collector plates 40 are equal, the calorific value Qp per unit time of the positive electrode current collector plate 40P and the calorific value Qn per unit time of the negative electrode current collector plate 40N are respectively expressed by the following equations (3). And (4). Further, the ratio Qp / Qn of the calorific value Qp per unit time of the positive current collector plate 40P which is the first current collector and the calorific value Qn per unit time of the negative current collector 40N which is the second current collector is as follows: (5).

Qp = I ² × Rp (3)
Qn = I ² × Rn (4)
Qp / Qn = ρp / ρn = 1.58 (5)

That is, when the material of the positive electrode current collector plate 40P is aluminum and the material of the negative electrode current collector plate 40N is copper, the positive electrode current collector plate 40P that is the first current collector plate is the negative electrode current collector plate that is the second current collector plate. The heat generation amount Qn per unit time of the electric plate 40N is about 1.58 times larger and the heat generation amount Qp per unit time is larger. The physical properties of aluminum at 25 ° C. include, for example, a thermal conductivity of about 236 [W / (mK)], a specific heat of about 913 [J / (kg · K)], and a density of about 2700 [kg / m. ³ ]. The physical properties of copper at 25 ° C. include, for example, a thermal conductivity of about 350 [W / (m · K)], a specific heat of about 385 [J / (kg · K)], and a density of about 8900 [kg]. / M ³ ].

  The secondary battery 100 of the present embodiment includes insulating members 1 and 2 between the current collector plates 40 and the battery lid 12, respectively. The insulating members 1 and 2 are disposed between the current collector plate 40 and the battery lid 12, one surface is in contact with the base 41 of the current collector plate 40 so that heat can be transferred, and the other surface is heat transferred to the battery lid 12. The current collector plate 40 and the battery lid 12 are electrically insulated from each other. In the secondary battery of the secondary battery 100 of the present embodiment, the insulating member 1 disposed between the positive current collector plate 40P, which is the first current collector plate, and the battery lid 12 of the battery container 10 is used as the first insulating member. The insulating member 2 disposed between the negative electrode current collector plate 40N, which is the second current collector plate, and the battery lid 12 of the battery container 10 is referred to as a second insulating member.

  In the secondary battery 100 of this embodiment, the first insulating member and the second insulating member have different configurations, that is, the amount of heat per unit time that moves from the first current collector plate to the battery container 10 via the first insulating member. Is characterized by having a different configuration that is greater than the amount of heat per unit time that travels from the second current collector plate to the battery container 10 via the second insulating member. In other words, in the secondary battery 100, the amount of heat q1 [W] per unit time in which the positive-side insulating member 1 and the negative-side insulating member 2 move from the positive current collector plate 40P to the battery lid 12 via the insulating member 1. ] Has a different configuration than the amount of heat q2 [W] per unit time that moves from the negative electrode current collector plate 40N to the battery lid 12 via the insulating member 2.

  More specifically, in the secondary battery 100 of the present embodiment, the thermal resistivity 1 / λp of the positive-side insulating member 1 that is the first insulating member is that of the negative-side insulating member 2 that is the second insulating member. Thermal resistivity is lower than 1 / λn. More specifically, the material of the insulating member 1 as the first insulating member is, for example, a thermal conductivity λp of about 0.5 [W / (mK)] and a thermal resistivity 1 / λp of about 2.0 [W / (mK)]. The material of the insulating member 2 which is polyethylene of about mK / W] and the second insulating member is, for example, a thermal conductivity λn of about 0.1 [W / (mK)], and a thermal resistivity 1 / λn. It is a polypropylene of about 10.0 [mK / W].

The amount of heat q1, q2 [W] per unit time moving from each current collecting plate 40 to the battery lid 12 via the insulating members 1, 2 is Ap, An [m ^2]. ], The thicknesses of the insulating members 1 and 2 are tp and tn [m], respectively, and the temperature differences between the current collectors 40 and the battery lid 12 are ΔKp and ΔKn [K], respectively, (7).

q1 = λp × (ΔKp / tp) × Ap (6)
q2 = λn × (ΔKn / tn) × An (7)

  In the secondary battery 100 of the present embodiment, the insulating members 1 and 2 are formed in the same shape and dimensions. That is, the insulating members 1 and 2 have the same thicknesses tp and tn, the same dimension in the longitudinal direction, that is, the lengths lp and ln, and the same dimension in the lateral direction, that is, the widths wp and wn. Heat transfer areas Ap and An in contact with 12 are equal. Therefore, the ratio q1 / q2 of the calorie q1, q2 [W] per unit time moving to the battery lid 12 via the insulating members 1, 2 can be expressed by the following formula (8).

  q1 / q2 = (λp / λn) × (ΔKp / ΔKn) = 5.0 × ΔKp / ΔKn (8)

  Therefore, if the temperature differences ΔKp and ΔKn between the current collector plates 40 and the battery lid 12 are equal, the amount of heat q1 [W] per unit time moving to the battery lid 12 via the insulating member 1 is equal to the insulating member 2. The amount of heat q2 [W] per unit time of movement to the battery lid 12 via the battery increases by about 5 times. Further, when the temperature difference ΔKp between the positive electrode current collector plate 40P and the battery lid 12 is larger than the temperature difference ΔKn between the negative electrode current collector plate 40N and the battery lid 12, the unit time for moving to the battery lid 12 via the insulating member 1 The amount of heat q1 [W] is greater than five times the amount of heat q2 [W] per unit time moving to the battery lid 12 via the insulating member 2.

  The insulating member 2 is a substantially rectangular plate-like member in which the longitudinal direction of the battery lid 12 is a long side direction and the short side direction of the battery lid 12 is a short side direction in a plan view. The insulating member 2 includes a through hole 2a provided in the center, a protrusion 2b provided on a surface in contact with the battery lid 12, and an engagement convex portion 2c provided on a surface in contact with the base 41 of the current collector plate 40. And have.

  The through hole 2 a is provided in a circular shape through which the shaft portion 23 a of the connection member 23 and the cylindrical portion 24 a of the gasket 24 are inserted. The protrusion 2 b is formed in a columnar shape that engages with the engagement recess 12 c of the battery lid 12. The engaging convex portion 2c extends so as to cross the insulating member 2 in the lateral direction, and a current collector is provided between a pair of engaging convex portions 2c provided at intervals in the longitudinal direction of the insulating member 2. It is provided so that the base 41 of the board 40 may be engaged.

  Next, the assembly procedure of the lid assembly 50 shown in FIG. 3 will be described. 5A, 5B, and 5C are process diagrams for explaining an assembly procedure of the lid assembly 50. FIG. The negative electrode external terminal 20N and the negative electrode current collector plate 40N have a mirror image symmetric configuration. Therefore, in the following, the assembly procedure of each component on the negative electrode external terminal 20N side shown in FIG. 4 will be described in detail, and the description of the assembly procedure of each component on the positive electrode external terminal 20P side will be omitted as appropriate.

  First, as shown in FIG. 5A, the flange portion 23b of the connecting member 23 is engaged with the concave portion 21b on the lower surface of the terminal portion 21, and laser welding is performed between the peripheral portion of the concave portion 21b and the peripheral portion of the flange portion 23b. And the terminal portion 21 and the connection member 23 are electrically connected. Next, as shown in FIG. 5B, the terminal portion 21 is fitted into the recess 22b of the external insulator 22, and the flange portion 23b of the connecting member 23 is disposed inside the through hole 22a of the external insulator 22 and connected. The member 23 is inserted through the through hole 24 c of the gasket 24.

  In this state, the connection member 23 is inserted into the through hole 12a of the battery lid 12, the protrusion 12b of the battery lid 12 is engaged with the engagement recess 22c of the external insulator 22, and the external insulator 22 is placed on the battery lid 12. And the flange portion 24b of the gasket 24 electrode body 30 is disposed inside the through hole 22a of the external insulator 22. Thereby, the external insulator 22 is arrange | positioned between the terminal part 21 and the battery cover 12, and insulates these electrically. The gasket 24 has a flange portion 24 b sandwiched between the flange portion 23 b of the connection member 23 and the battery lid 12, and a cylindrical portion 24 a has an outer peripheral surface of the shaft portion 23 a of the connection member 23 and a through hole 12 a of the battery lid 12. Between the connecting member 23 and the battery lid 12.

  Next, the cylindrical portion 23c of the connecting member 23 that passes through the through hole 12a of the battery lid 12 is inserted into the through hole 2a of the insulating member 2, and the protrusion 2b of the insulating member 2 is inserted into the engagement recess 12c of the battery lid 12. Insert and engage. Then, the cylindrical portion 23 c of the connection member 23 is inserted into the through hole 41 a of the base portion 41 of the current collector plate 40, and the base portion 41 of the current collector plate 40 is engaged between the pair of engaging convex portions 2 c of the insulating member 2. . In this state, using the mold D1 and the mold D2, the cylindrical portion 23c of the connecting member 23 is plastically deformed and expanded in diameter to form a disk-shaped caulking portion 23f shown in FIG. 5C.

  More specifically, as shown in FIG. 5B, the flat pressing surface of the mold D1 is brought into contact with the upper surface of the terminal portion 21, and the protrusion D1a provided on the pressing surface of the mold D1 is inserted into the through hole of the terminal portion 21. 21a and the hole 23d of the connection member 23 are inserted. In this state, the conical tip portion of the mold D2 is press-fitted into the hole 23e of the cylindrical portion 23c of the connection member 23, so that the cylindrical portion 23c of the connection member 23 is plastically deformed and expanded so as to be spread outward. Diameter. At this time, by inserting the protrusion D1a of the mold D1 into the through hole 21a of the terminal portion 21 and the hole 23d of the connection member 23, the connection member 23 is accurately positioned with respect to the mold D2, and the cylindrical portion 23c is accurately positioned. It can be plastically deformed well.

  Next, as shown in FIG. 5C, the mold D2 is replaced with the mold D3 to form a disk-shaped caulking portion 23f. The mold D3 is formed in a concave shape having a flat surface D3a and an inclined surface D3b around the flat surface D3a. The cylindrical portion 23c plastically deformed by the mold D2 is further pressed and plastically deformed to form a disk shape corresponding to the mold D3. A caulking portion 23f is formed. As a result, the step portion between the shaft portion 23 a and the cylindrical portion 23 c of the connection member 23 abuts on the base portion 41 of the current collector plate 40, the flange portion 24 b of the gasket 24 is appropriately compressed, and the groove portion 12 d of the battery lid 12. It is elastically deformed inward and is in close contact with the battery lid 12. Further, the insulating member 2 is appropriately tightened between the battery lid 12 and the base portion 41 of the current collector plate 40, and is in close contact with the battery lid 12 and the base portion 41 of the current collector plate 40.

  The caulking portion 23f is in contact with the lower surface of the base portion 41 of the current collector plate 40, and the peripheral portion is joined to the lower surface of the base portion 41 of the current collector plate 40 by laser welding. Accordingly, the terminal portion 21 of the external terminal 20 and the current collector plate 40 are electrically connected via the connection member 23. As described above, the external terminal 20 and the current collector plate 40 are electrically connected to each other in a state of being electrically insulated from the battery lid 12, and the respective members are integrally fixed to the battery lid 12, A lid assembly 50 is configured. As shown in FIG. 2, the lid assembly 50 supports the electrode body 30 in the battery container 10 by joining the electrode body 30 to the current collector plate 40.

  FIG. 6 is an exploded perspective view showing a state in which the end portion on the winding end side of the electrode body 30 of the secondary battery 100 shown in FIG. 2 is developed. The electrode body 30 is a flat wound electrode group in which a long strip-like positive electrode 31 and a negative electrode 32 are wound around a winding axis A with long strip-shaped separators 33 and 34 interposed therebetween.

  The electrode body 30 includes a pair of flat portions 30a in which a positive electrode 31 and a negative electrode 32 are flatly stacked, and a pair of semi-cylindrical shapes in which the positive electrode 31 and the negative electrode 32 are bent and stacked on both sides of the flat portion 30a. It has the curved part 30b. The pair of curved portions 30b are formed on both sides of the electrode body 30 in the height direction perpendicular to the winding axis A direction and the thickness direction. The electrode body 30 is inserted into the battery can 11 such that the winding axis A is parallel to the bottom wall 11 b and the wide side wall 11 a of the battery can 11, and the pair of flat portions 30 a are the pair of wide side walls 11 a of the battery can 11. The pair of curved portions 30 b are disposed to face the battery lid 12 and the bottom wall 11 b of the battery can 11.

  The separators 33 and 34 insulate the positive electrode 31 and the negative electrode 32, and the separator 34 is wound outside the negative electrode 32 wound around the outermost periphery. The separators 33 and 34 can be made of, for example, a polyolefin-based resin material. Specifically, the separators 33 and 34 are made of a porous resin material containing at least one of a polypropylene resin material and a polyethylene resin.

  The positive electrode 31 includes a positive electrode foil 31a that is a positive electrode current collector, and a positive electrode mixture layer 31b formed by applying a positive electrode active material mixture on both surfaces of the positive electrode foil 31a. One side in the width direction of the positive electrode 31 is an uncoated portion where the positive electrode mixture layer 31b is not formed, and is a foil exposed portion 31c where the positive foil 31a is exposed. The positive electrode 31 has a foil exposed portion 31c disposed on the opposite side of the winding axis A direction from the foil exposed portion 32c of the negative electrode 32, and is wound around the winding axis A.

  The positive electrode 31 is, for example, a positive electrode active material mixture kneaded by adding a conductive material, a binder and a dispersion solvent to the positive electrode active material, and applied to both surfaces of the positive electrode foil 31a except for one side in the width direction. It can be produced by drying, pressing and cutting. As the positive electrode foil 31a, for example, an aluminum foil having a thickness of about 10 μm to 20 μm can be used. The thickness of the positive electrode mixture layer 31b not including the thickness of the positive electrode foil 31a is, for example, about 90 μm.

As a material of the positive electrode active material mixture, for example, 100 parts by weight of lithium manganate (chemical formula LiMn ₂ O ₄ ) is used as the positive electrode active material, 10 parts by weight of flaky graphite as the conductive material, and 10% by weight as the binder. Part of polyvinylidene fluoride (hereinafter referred to as PVDF) and N-methylpyrrolidone (hereinafter referred to as NMP) can be used as a dispersion solvent. The positive electrode active material is not limited to the above-described lithium manganate. For example, another lithium manganate having a spinel crystal structure, or a lithium manganese composite oxide partially substituted or doped with a metal element may be used. Further, as the positive electrode active material, lithium cobaltate or lithium titanate having a layered crystal structure, and a lithium-metal composite oxide obtained by substituting or doping a part thereof with a metal element may be used.

  The negative electrode 32 includes a negative electrode foil 32a that is a negative electrode current collector, and a negative electrode mixture layer 32b that is formed by applying a negative electrode active material mixture on both surfaces of the negative electrode foil 32a. One side in the width direction of the negative electrode 32 is an uncoated portion where the negative electrode mixture layer 32b is not formed, and is a foil exposed portion 32c where the negative foil 32a is exposed. The negative electrode 32 is wound around the winding axis A, with the foil exposed portion 32c being disposed on the opposite side of the foil exposed portion 31c of the positive electrode 31 in the winding axis A direction.

  The negative electrode 32 is, for example, applied to a negative electrode active material mixture kneaded by adding a binder and a dispersion solvent to the negative electrode active material on both sides of the negative electrode foil 32a except one side in the width direction, dried, pressed, It can be produced by cutting. As the negative electrode foil 32a, for example, a copper foil having a thickness of about 5 μm to 10 μm can be used. The thickness of the negative electrode mixture layer 32b not including the thickness of the negative electrode foil 32a is, for example, about 70 μm.

As a material for the negative electrode active material mixture, for example, 100 parts by weight of amorphous carbon powder as the negative electrode active material, 10 parts by weight of PVDF as the binder, and NMP as the dispersion solvent can be used. The negative electrode active material is not limited to the above-mentioned amorphous carbon, and natural graphite capable of inserting and removing lithium ions, various artificial graphite materials, carbonaceous materials such as coke, and compounds such as Si and Sn (for example, , SiO, TiSi ₂ or the like), or a composite material thereof. The particle shape of the negative electrode active material is not particularly limited, and a particle shape such as a scale shape, a spherical shape, a fiber shape, or a lump shape can be appropriately selected.

  The binder used for the positive electrode mixture layer 31b and the negative electrode mixture layer 32b is not limited to PVDF. Examples of the binder include polytetrafluoroethylene (PTFE), polyethylene, polystyrene, polybutadiene, butyl rubber, nitrile rubber, styrene butadiene rubber, polysulfide rubber, nitrocellulose, cyanoethyl cellulose, various latexes, acrylonitrile, and vinyl fluoride. Polymers such as vinylidene fluoride, propylene fluoride, chloroprene fluoride, and acrylic resins, and mixtures thereof may be used.

  In the direction of the winding axis A of the electrode body 30, the width of the negative electrode mixture layer 32 b of the negative electrode 32 is wider than the width of the positive electrode mixture layer 31 b of the positive electrode 31. A negative electrode 32 is wound around the innermost and outermost periphery of the electrode body 30. Accordingly, the positive electrode mixture layer 31b is sandwiched between the negative electrode mixture layer 32b from the innermost periphery to the outermost periphery of the electrode body 30.

  The electrode body 30 is provided with electrode foil laminated portions 31d and 32d for joining the current collector plate 40 to both ends in the winding axis A direction. More specifically, a foil laminated portion 31d of the positive electrode 31 in which the foil exposed portion 31c of the positive electrode 31 is wound and laminated is provided at one end portion in the winding axis direction X of the electrode body 30. A foil laminated portion 32d of the negative electrode 32 is provided at the other end portion in the rotational axis direction X. The foil exposed portion 32c of the negative electrode 32 is wound and laminated. The foil laminated portions 31d and 32d are bundled in two on one side and the other side of the winding axis A in the thickness direction of the electrode body 30, and are each collected by, for example, ultrasonic pressure welding or resistance welding. The pair of 40 connection pieces 42 are joined to one and the other.

  Here, as shown in FIG. 6, in the winding axis A direction of the electrode body 30, the widths of the separators 33 and 34 are wider than the width of the negative electrode mixture layer 32 b, but the foils of the positive electrode 31 and the negative electrode 32 are exposed. The portions 31c and 32c protrude outward in the width direction from the end portions in the width direction of the separators 33 and 34, respectively. Therefore, the separators 33 and 34 do not hinder when the foil laminated portions 31 d and 32 d of the positive electrode 31 and the negative electrode 32 are bundled and joined to the current collector plate 40.

  As described above, the electrode body 30 is electrically connected to the external terminal 20 via the current collector plate 40 joined to the foil laminate portions 31d and 32d. More specifically, in the electrode body 30, the positive electrode 31 is electrically connected to the positive external terminal 20P via the positive current collector 40P, and the negative electrode 32 is connected to the negative external terminal 20N via the negative current collector 40N. Is electrically connected. The electrode body 30 is fixed to the lid assembly 50 via the current collector plate 40 and supported by the lid assembly 50.

  As shown in FIG. 2, the electrode body 30 supported by the lid assembly 50 is covered with the current collector plate 40 and covered with the insulating case 60 so as to be insulated from the battery can 11. It is inserted inside the can 11. The material of the insulating case 60 is an insulating resin material such as polypropylene, for example. The lid assembly 50 is formed by joining the battery lid 12 over the entire circumference of the opening 11d of the battery can 11 by, for example, laser welding in a state where the opening 11d of the battery can 11 is closed by the battery lid 12. The electrode body 30 is sealed in the container 10.

Thereafter, a non-aqueous electrolyte is injected into the battery container 10 through the liquid injection port 14 of the battery lid 12, and the liquid injection plug 15 is joined to the liquid injection port 14 by, for example, laser welding to seal the battery container 10. As the nonaqueous electrolytic solution to be injected into the battery container 10, for example, a nonaqueous electrolytic solution in which a lithium salt such as lithium hexafluorophosphate (LiPF ₆ ) is dissolved in a carbonate organic solvent such as ethylene carbonate is used. be able to.

  As illustrated in FIG. 5C, the secondary battery 100 is connected to, for example, a plurality of other secondary batteries 100 in series by joining the bus bar B to the terminal portion 21 of the external terminal 20. The secondary battery 100 is charged by storing the externally generated power supplied to the external terminal 20 and the current collector plate 40 in the electrode body 30, and supplies the power stored in the electrode body 30 to the external device from the external terminal 20. .

  Here, as described above, the secondary battery 100 of the present embodiment has a configuration in which the heat generation amount Qp of the positive electrode current collector plate 40P per unit time is larger than the heat generation amount Qn of the negative electrode current collector plate 40N per unit time. doing. Therefore, at the time of charging / discharging of the secondary battery 100, the temperature of the positive electrode current collector plate 40P tends to rise more than the temperature of the negative electrode current collector plate 40N. When the temperature difference between the positive electrode current collector plate 40P and the negative electrode current collector plate 40N increases, the temperature gradient of the electrode body 30 connected thereto increases, and the positive electrode 31 and the negative electrode 32 constituting the electrode body 30 There is a risk of deterioration.

  Therefore, in the secondary battery 100 of the present embodiment, the amount of heat q1 per unit time that the insulating member 1 and the insulating member 2 move from the positive electrode current collector plate 40P to the battery container 10 via the insulating member 1 is the insulating member 2. And having a different configuration that is greater than the amount of heat q2 per unit time that moves from the negative electrode current collector plate 40N to the battery case 10. Thereby, the temperature rise of the positive electrode current collector plate 40P having a large calorific value Qp is suppressed, the temperature difference between the positive electrode current collector plate 40P and the negative electrode current collector plate 40N is reduced, and the deterioration of the secondary battery 100 is suppressed. be able to.

  Further, in the secondary battery 100 of the present embodiment, since the insulating members 1 and 2 have different configurations as described above, the thermal resistivity 1 / λp of the insulating member 1 that is the first insulating member is the second insulating material. It is made to become lower than the thermal resistivity 1 / λn of the insulating member 2 which is a member. Thus, in order to make the insulating members 1 and 2 have different configurations in which the amount of heat q1 radiated through the insulating member 1 is larger than the amount of heat q2 radiated through the insulating member 2, the material of the insulating members 1 and 2 is different. It is possible to use the insulating members 1 and 2 having the same size and shape by making different.

  Further, in the secondary battery 100 of the present embodiment, the thermal resistivity 1 / λp of the insulating member 1 that is the first insulating member is made lower than the thermal resistivity 1 / λn of the insulating member 2 that is the second insulating member. Therefore, the material of the insulating member 1 is polyethylene, and the material of the insulating member 2 is polypropylene. Thereby, the temperature rise of the positive electrode current collector plate 40P having a large calorific value Qp is suppressed by a material that can be normally used as the insulating members 1 and 2, and the temperature between the positive electrode current collector plate 40P and the negative electrode current collector plate 40N is suppressed. The difference can be reduced and deterioration of the secondary battery 100 can be suppressed.

  In the secondary battery 100 of the present embodiment, the first current collector plate is the positive electrode current collector plate 40P, the second current collector plate is the negative electrode current collector plate 40N, and the resistance of the metal material of the positive electrode current collector plate P The rate ρp is higher than the resistivity ρn of the metal material of the negative electrode current collector plate 40N. Therefore, the material of the positive electrode current collector plate P can be commonly used aluminum or aluminum alloy, and the material of the negative electrode current collector plate 40N can be generally used copper or copper alloy.

  Moreover, since the electrical storage element described in the above-mentioned patent document 1 electrically connects either the positive electrode terminal or the negative electrode terminal to the battery container, the potential between the battery container and the external environment is The potential difference is relatively large. Therefore, there exists a subject that a battery container becomes easy to corrode compared with the case where a positive electrode terminal and a negative electrode terminal are electrically insulated with respect to a battery container. On the other hand, in the secondary battery 100 of this embodiment, both the positive external terminal 20P and the negative external terminal 20N are insulated from the battery container 10 by the external insulator 22 and the gasket 24. Therefore, according to the secondary battery 100 of the present embodiment, the corrosion of the battery container 10 can be suppressed as compared with the power storage element of Patent Document 1.

  As described above, according to the secondary battery 100 of the present embodiment, the temperature gradient of the electrode body 30 can be reduced and deterioration of the positive electrode 31 and the negative electrode 32 can be suppressed.

[Embodiment 2]
Hereinafter, the secondary battery according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 7 is a perspective view showing the lid assembly 50A of the present embodiment.

  In the secondary battery of this embodiment, the thickness Tp of the positive electrode current collector plate 40P is thicker than the thickness Tn of the negative electrode current collector plate 40N, and the arrangement of the insulating member 1 and the insulating member 2 is reversed. This is different from the secondary battery 100 described in the first embodiment. Since the other points of the secondary battery of the present embodiment are the same as those of the secondary battery 100 described in the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  In the secondary battery of the present embodiment, the thickness Tn of the negative electrode current collector plate 40N is made thinner than the thickness Tp of the positive electrode current collector plate 40P, and the thickness Tp of the positive electrode current collector plate 40P is equal to the negative electrode current collector plate 40N. It is thicker than 1.58 times the thickness Tn. For example, if the thickness Tp of the positive electrode current collector plate 40P is twice the thickness Tn of the negative electrode current collector plate 40N, the cross-sectional area S of the current path in the positive electrode current collector plate 40P is This is twice the cross-sectional area S of the current path. Therefore, based on the above formulas (1) to (4), the ratio Qn / Qp between the calorific value Qn per unit time of the negative electrode current collector plate 40N and the calorific value Qp per unit time of the positive electrode current collector plate 40P is as follows: (9)

                  Qn / Qp = (ρn / ρp) × 2 = 1.27 (9)

  That is, when the material of the positive electrode current collector plate 40P is aluminum and the material of the negative electrode current collector plate 40N is copper, the negative electrode current collector plate 40N is approximately 1 than the calorific value Qp per unit time of the positive electrode current collector plate 40P. It has a structure with a large calorific value Qn per unit time of about 27 times.

  Therefore, in the secondary battery of the present embodiment, contrary to the secondary battery 100 of the first embodiment, the negative electrode current collector plate 40N is the first current collector plate, and the positive electrode current collector plate 40P is the second current collector plate. And That is, in the secondary battery of the present embodiment, the negative electrode current collector plate 40N that is the first current collector plate has a configuration that generates more heat per unit time than the positive electrode current collector plate 40P that is the second current collector plate. ing.

  Further, in the secondary battery of this embodiment, the arrangement of the insulating member 1 and the insulating member 2 is replaced, and the insulating member 1 as the first insulating member having a relatively low thermal resistivity 1 / λp is replaced with the negative electrode current collector plate 40N. Between the positive electrode current collector plate 40P and the battery cover 12, the second insulating member having a relatively high thermal resistivity 1 / λn.

  That is, the insulating member 1 that is the first insulating member and the insulating member 2 that is the second insulating member are units that move from the negative current collector plate 40N that is the first current collector plate to the battery case 10 via the insulating member 1. The amount of heat q1 per hour is different from the amount of heat q2 per unit time moving from the positive current collector plate 40P, which is the second current collector plate, to the battery container 10 via the insulating member 2.

  Therefore, according to the secondary battery of the present embodiment, similarly to the secondary battery 100 of the first embodiment, the amount of heat q1 radiated from the negative electrode current collector plate 40N, which is likely to become higher temperature during charging / discharging, to the battery container 10 is changed to the positive electrode. The amount of heat radiated from the current collector plate 40P to the battery case 10 is increased to suppress the temperature rise of the negative electrode current collector plate 40N having a large calorific value Qn, and between the positive electrode current collector plate 40P and the negative electrode current collector plate 40N. A temperature difference can be reduced and deterioration of the secondary battery 100 can be suppressed.

[Embodiment 3]
Hereinafter, the secondary battery according to Embodiment 3 of the present invention will be described with reference to FIGS. 8A and 8B with reference to FIGS. FIG. 8A is an enlarged cross-sectional view in the vicinity of the positive electrode external terminal 20P of the secondary battery of the present embodiment, and FIG. 8B is an enlarged cross-sectional view in the vicinity of the negative electrode external terminal 20N of the secondary battery of the present embodiment.

  In the secondary battery of this embodiment, the thickness tp of the insulating member 1 as the first insulating member is thinner than the thickness tn of the insulating member 2 as the second insulating member, and the material of the insulating member 1 and the insulating member 2 is the same. Is the same as the secondary battery 100 described in the first embodiment. Since the other points are the same as those of the secondary battery 100 described in the first embodiment, the same portions are denoted by the same reference numerals and the description thereof is omitted.

  In the secondary battery of this embodiment, the material of the insulating member 1 and the material of the insulating member 2 are both polypropylene, and the thermal conductivities λp and λn of the insulating members 1 and 2 are equal. Accordingly, assuming that the heat transfer areas Ap and An in contact with the current collector plate 40 and the battery lid 12 are equal, the unit that moves from each current collector plate 40 to the battery lid 12 via the insulating members 1 and 2. The ratio of the amount of heat q1 / q2 [W] per hour can be expressed by the following equation (10) based on the equations (6) and (7).

            q1 / q2 = (ΔKp / ΔKn) × (tn / tp) (10)

  Therefore, for example, when the temperature difference ΔKp between the positive electrode current collector plate 40P and the battery lid 12 is 1.2 times the temperature difference ΔKn between the negative electrode current collector plate 40N and the battery lid 12, the second insulation The thickness tn of the insulating member 2 that is a member can be made thicker than 1.2 times the thickness tp of the insulating member 1 that is the first insulating member. As a result, the insulating member 1 and the insulating member 2 have the amount of heat q1 per unit time moving from the positive current collector plate 40P to the battery container 10 via the insulating member 1 from the negative current collector plate 40N via the insulating member 2. It has a different configuration that is greater than the amount of heat q2 per unit time of movement to the battery container 10.

  Therefore, according to the secondary battery of the present embodiment, similarly to the secondary battery 100 of the first embodiment, the amount of heat q1 to be radiated from the positive electrode current collector plate 40P, which is likely to become a higher temperature during charging / discharging, to the battery container 10, The amount of heat radiated from the negative electrode current collector plate 40N to the battery case 10 is increased to suppress the temperature rise of the positive electrode current collector plate 40P having a large calorific value Qp, and between the positive electrode current collector plate 40P and the negative electrode current collector plate 40N. The temperature difference can be reduced, and deterioration of the secondary battery 100 can be suppressed.

  In the secondary battery of this embodiment, the insulating member 1 is made thinner by making the thickness tp of the insulating member 1 as the first insulating member thinner than the thickness tn of the insulating member 2 as the second insulating member. The configuration in which the amount of heat q1 radiated through the insulating member 2 is greater than the amount of heat q2 radiated through the insulating member 2 has been described. However, in the configuration in which the amount of heat q1 radiated through the insulating member 1 is greater than the amount of heat q2 radiated through the insulating member 2, the thickness tp of the insulating member 1 as the first insulating member is the second insulating member. The configuration is not limited to be thinner than the thickness tn of the insulating member 2. For example, the same effect can be obtained by making the heat transfer area Ap of the insulating member 1 as the first insulating member larger than the heat transfer area An of the insulating member 2 as the second insulating member.

  That is, when the material of the insulating member 1 and the material of the insulating member 2 are both polypropylene, the thickness tp of the insulating member 1 as the first insulating member is equal to the thickness tn of the insulating member 2 as the second insulating member. Then, the ratio of the amount of heat q1, q2 [W] per unit time moving from each current collector plate 40 to the battery lid 12 via the insulating members 1, 2 is based on the above formulas (6) and (7). It can be represented by the following formula (11).

            q1 / q2 = (ΔKp / ΔKn) × (Ap / An) (11)

  Therefore, for example, when the temperature difference ΔKp between the positive electrode current collector plate 40P and the battery lid 12 is 1.2 times the temperature difference ΔKn between the negative electrode current collector plate 40N and the battery lid 12, the first insulation The heat transfer area Ap of the insulating member 1 which is a member can be made larger than 1.2 times the heat transfer area of the insulating member 2 which is the second insulating member. The heat transfer areas Ap and An can be adjusted by making at least one of the lengths lp and ln and the widths wp and wn of the insulating members 1 and 2 different. As a result, the insulating member 1 and the insulating member 2 have the amount of heat q1 per unit time moving from the positive current collector plate 40P to the battery container 10 via the insulating member 1 from the negative current collector plate 40N via the insulating member 2. It has a different configuration that is greater than the amount of heat q2 per unit time of movement to the battery container 10, and the same effect as the secondary battery of this embodiment can be obtained.

  The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Insulation member (1st insulation member), 2 Insulation member (2nd insulation member), 2a Through-hole, 2b Protrusion part, 2c Engagement convex part, 10 Battery container, 11 Battery can, 11a Wide side wall, 11b Bottom wall, 11c narrow side wall, 11d opening, 12 battery cover, 12a through hole, 12b protrusion, 12c recess, 13 gas discharge valve, 14 injection port, 15 injection plug, 20 external terminal, 20N negative external terminal, 20P positive external Terminal, 21 Terminal portion, 21a Through hole, 21b Recess, 21c Groove, 22 External insulator, 22a Through hole, 22b Recess, 22c Recess, 23 Connection member, 23a Shaft, 23b Flange, 23c Cylindrical, 23d Hole, 23e hole, 23f caulking part, 24 gasket, 24a cylindrical part, 24b flange part, 24c through-hole, 30 electrode body, 30a flat part, 30 Curved portion, 31 positive electrode, 31a positive foil, 31b positive electrode mixture layer, 31c foil exposed portion, 32 negative electrode, 32a negative electrode foil, 32b negative electrode mixture layer, 32c foil exposed portion, 33 separator, 34 separator, 40 current collector Plate, 40P positive current collector plate (first current collector plate / second current collector plate), 40N negative current collector plate (second current collector plate / first current collector plate), 41 base, 41a through hole, 42 connection piece , 50 Lid assembly, 60 Insulation case, 100 Secondary battery, Qp Unit time of heat generation, Qn Unit time of heat generation, q1 Unit time of heat, q2 Unit time of heat, 1 / λp Heat of first insulating member Resistivity, 1 / λn thermal resistivity of the second insulating member, tp thickness of the first insulating member, tn thickness of the second insulating member, Ap heat transfer area of the first insulating member, transfer of the An second insulating member Thermal area, weld Bw, D1 mold, D1 Projections, D2 mold, Tp positive collector plate thickness, the thickness of the Tn negative collector plate

Claims (8)

An electrode body; a battery container that houses the electrode body; an external terminal provided in the battery container; a first current collector plate and a second current collector plate that connect the external terminal to the electrode body; A secondary battery comprising: a first insulating member disposed between one current collecting plate and the battery container; and a second insulating member disposed between the second current collecting plate and the battery container. Because
The first current collector plate has a configuration that generates more heat per unit time than the second current collector plate,
The first insulating member and the second insulating member are configured such that the amount of heat per unit time that moves from the first current collector plate to the battery container via the first insulating member passes through the second insulating member. 2. A secondary battery having a different configuration than the amount of heat per unit time of movement from the current collector plate to the battery container.   2. The secondary battery according to claim 1, wherein a thermal resistivity of the first insulating member is lower than a thermal resistivity of the second insulating member.   The secondary battery according to claim 1, wherein a thickness of the first insulating member is thinner than a thickness of the second insulating member.   The secondary battery according to claim 1, wherein a heat transfer area of the first insulating member is larger than a heat transfer area of the second insulating member.   The secondary battery according to claim 2, wherein the material of the first insulating member is polyethylene, and the material of the second insulating member is polypropylene. The first current collector plate is a positive electrode current collector plate, the second current collector plate is a negative electrode current collector plate,
The secondary battery according to claim 1, wherein a resistivity of the metal material of the positive electrode current collector plate is higher than a resistivity of the metal material of the negative electrode current collector plate. The first current collector plate is a negative electrode current collector plate, the second current collector plate is a positive electrode current collector plate,
The secondary battery according to claim 1, wherein a thickness of the positive electrode current collector plate is thicker than a thickness of the negative electrode current collector plate.   The secondary battery according to claim 6 or 7, wherein a material of the positive electrode current collector plate is aluminum or an aluminum alloy, and a material of the negative electrode current collector plate is copper or a copper alloy.

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