Battery

Abstract

Provided is a battery (1) that has a safety valve (a rupture valve (80)) that has relatively high durability but can efficiently discharge gas from inside the battery (1) when ruptured. A battery (1) includes a charging / discharging body (10), a packaging body (50) that houses the charging / discharging body (10), and a safety valve (a rupture valve (80)) that is provided to the packaging body (50) and opens from the inside of the packaging body (50) toward the outside when the pressure inside the packaging body (50) has reached at least a prescribed value. The rupture valve (80) is thinner than the packaging body (50). A ring-shaped edge part (81) of the rupture valve (80) that connects to the packaging body (50) includes a first edge part (81a) that is arc-shaped and a second edge part (81b) that is linear or has a larger radius than the first edge part (81a). A groove is provided in at least the first edge part (81a).

Description

[Technical Field]

[0001] The present invention relates to a battery. [Background technology]

[0002] BACKGROUND ART Conventionally, a safety valve is known that opens from the inside to the outside when the pressure inside a battery reaches or exceeds a predetermined value, thereby discharging gas from the battery (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 111742 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for battery safety vents that have relatively high durability and that efficiently release gas inside the battery when ruptured. [Means for solving the problem]

[0005] The battery of the present invention includes a charging / discharging unit, an exterior housing that houses the charging / discharging unit, and a safety valve that is provided in the exterior housing and opens from the interior of the exterior housing to the exterior when the pressure inside the exterior housing reaches a predetermined value or higher. The thickness of the safety valve is thinner than the thickness of the exterior housing. The annular edge of the safety valve that is continuous with the exterior housing includes a first edge formed in an arc shape and a second edge formed with a larger radius than the first edge or formed in a linear shape. At least the first edge has a groove. [Effects of the Invention]

[0006] The present invention can provide a battery having a safety vent that has relatively high durability and can efficiently release gas inside the battery when it is ruptured. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a battery 1 of a first embodiment. [Figure 2] FIG. 2 is a cross-sectional perspective view showing the periphery of a negative electrode terminal 42 of the battery 1 according to the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the periphery of a negative electrode terminal 42 of the battery 1 according to the first embodiment. [Figure 4] FIG. 2 is a cross-sectional perspective view showing the periphery of a positive electrode terminal 41 of the battery 1 according to the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view showing the periphery of a positive electrode terminal 41 of the battery 1 according to the first embodiment. [Figure 6] 1 is an exploded perspective view showing a battery 1 according to a first embodiment. [Figure 7] 1 is a perspective view showing a charging / discharging unit 10 of a battery 1 according to a first embodiment. [Figure 8] 1 is a cross-sectional view showing a part of a charging / discharging body 10 of a battery 1 according to a first embodiment. [Figure 9] FIG. 4 is a cross-sectional view showing a part of a charging / discharging body 110 of a modified example of the battery 1 of the first embodiment. [Figure 10] FIG. 2 is an exploded perspective view showing the periphery of a negative electrode terminal 42 of the battery 1 according to the first embodiment. [Figure 11] FIG. 2 is an exploded perspective view showing the lid 52 and sealing plug 53 of the battery 1 of the first embodiment. [Figure 12] FIG. 2 is an exploded perspective view showing the periphery of a positive electrode terminal 41 of the battery 1 according to the first embodiment. [Figure 13] 3 is a perspective view showing the periphery of a split valve 80 of the battery 1 of the first embodiment, viewed from the side of the charge / discharge body 10. FIG. [Figure 14] 3 is a cross-sectional view showing the periphery of a split valve 80 of the battery 1 of the first embodiment. FIG. [Figure 15] 1 is a perspective view showing a simulation of deformation of a split valve 80 of the battery 1 of the first embodiment, viewed from the side of the charging / discharging body 10. FIG. [Figure 16] 4 is a cross-sectional view showing a simulation of deformation of the split valve 80 of the battery 1 of the first embodiment. FIG. [Figure 17]4 is a plan view showing a simulation of deformation of the split valve 80 of the battery 1 of the first embodiment, viewed from the charging / discharging body 10 side. FIG. [Figure 18] FIG. 10 is a cross-sectional view showing the periphery of a split valve 180 of a battery 2 according to a second embodiment. [Figure 19] FIG. 10 is a cross-sectional view showing the periphery of a split valve 280 of a battery 3 according to a third embodiment. [Figure 20] FIG. 10 is a cross-sectional view showing the periphery of a split valve 380 of a battery 4 according to a fourth embodiment. [Figure 21] FIG. 13 is a cross-sectional view showing the periphery of a split valve 480 of a battery 5 in a first modified example of the fourth embodiment. [Figure 22] 10 is a perspective view showing the periphery of a split valve 580 of a battery 6 according to a fifth embodiment, viewed from the side of the charge / discharge body 10. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Each embodiment of the present invention will be described with reference to the drawings. To facilitate understanding of each embodiment, the size and proportions of components may be exaggerated in the drawings. In each embodiment, the same components are assigned the same reference numerals, and redundant description will be omitted. Each embodiment uses a left-handed XYZ Cartesian coordinate system with the X, Y, and Z axes as its coordinate axes. The arrows on the X, Y, and Z axes indicate the positive direction of the coordinate axis. The X axis is the coordinate axis along the longitudinal direction of a rectangular parallelepiped battery. The Y axis is the coordinate axis along the lateral direction of the battery. The Z axis is the coordinate axis along the height direction of the battery. The plane formed by the X and Y axes is referred to as the XY plane, the plane formed by the Y and Z axes is referred to as the YZ plane, and the plane formed by the X and Z axes is referred to as the XZ plane. However, the positional relationships expressed in the XYZ Cartesian coordinate system are merely relative positional relationships.

[0009] [First embodiment] (Configuration of Battery 1 of First Embodiment) The configuration of a battery 1 of the first embodiment will be described with reference to FIGS.

[0010] 1 to 14, the battery 1 includes a charging / discharging unit 10 that charges and discharges electricity, a current collector 20 connected to the charging / discharging unit 10, a current interrupter 30 connected to the current collector 20, an external terminal 40 connected to the current collector 20 or the current interrupter 30, and an exterior body 50 that houses or is attached to the components of the battery 1. The battery 1 also includes an insulator 60 that insulates the components of the battery 1 from the exterior body 50, a sealing body 70 that seals the components of the battery 1 from the exterior body 50, and a split valve 80 (safety valve) that releases gas from the inside of the exterior body 50 to the outside.

[0011] The charge / discharge unit 10 charges and discharges electricity. The charge / discharge unit 10 shown in Figures 2 to 8 includes a positive electrode 11, a negative electrode 12, a separator 13 (insulating member), and an electrolyte 14. As shown in Figure 7, the charge / discharge unit 10 is configured by winding components, in which the positive electrode 11, the separator 13, the negative electrode 12, and the separator 13 are stacked in this order, into a rectangular parallelepiped shape.

[0012] As shown in FIGS. 7 and 8, the positive electrode 11 includes a long positive electrode current collecting layer 11S (current collecting foil) and a positive electrode active material layer 11T bonded to the positive electrode current collecting layer 11S. The positive electrode current collecting layer 11S includes a current collecting portion 11a and a positive electrode tab 11b. The current collecting portion 11a is wound. The positive electrode active material layer 11T is bonded to the current collecting portion 11a. As shown in FIG. 8, the positive electrode active material layer 11T faces the entire area of ​​the current collecting portion 11a along the short side direction (Z-axis direction), for example.

[0013] 7 and 8, the positive electrode tab 11b protrudes in the short direction of the current collecting part 11a from a side edge 11c along the longitudinal direction (winding direction) of the current collecting part 11a. The positive electrode tab 11b is formed integrally with the current collecting part 11a. A plurality of positive electrode tabs 11b are formed on one current collecting part 11a.

[0014] The positive electrode tabs 11b are arranged at a so-called unequal pitch. That is, the interval between adjacent positive electrode tabs 11b in the winding direction is configured so that the interval between adjacent positive electrode tabs 11b closer to the other end 11q of the winding end of the current collecting part 11a is relatively longer than the interval between adjacent positive electrode tabs 11b closer to the one end 11p of the winding start of the current collecting part 11a. All of the positive electrode tabs 11b overlap when the current collecting part 11a is wound.

[0015] The positive electrode tab 11b may be integral with the current collecting portion 11a or may be separate from the current collecting portion 11a. The multiple terminal portions are provided on a side edge (at least one side edge) of the current collecting portion 11a along the winding direction (longitudinal direction).

[0016] The current collecting portion 11a of the positive electrode 11 is formed of, for example, aluminum or an aluminum alloy. The positive electrode active material layer 11T contains a positive electrode active material constituted by a lithium-containing composite oxide, a binder, a conductive additive, etc. The lithium-containing composite oxide contains, for example, a metal element such as nickel (Ni), cobalt (Co), or manganese (Mn), and lithium (Li).

[0017] As shown in FIGS. 7 and 8, the negative electrode 12 includes a long negative electrode current collecting layer 12S (current collecting foil) and a negative electrode active material layer 12T bonded to the negative electrode current collecting layer 12S. The negative electrode current collecting layer 12S includes a current collecting portion 12a and a negative electrode tab 12b. As shown in FIG. 8, the current collecting portion 12a of the negative electrode 12 has a width along the short side direction (Z-axis direction) greater than that of the current collecting portion 11a of the positive electrode 11. Both ends of the current collecting portion 11a of the positive electrode 11 along the short side direction are located within the range along the short side direction of the current collecting portion 12a of the negative electrode 12, with a separator 13 interposed between them. The negative electrode active material layer 12T is bonded to the current collecting portion 12a. The negative electrode active material layer 12T faces, for example, the entire area of ​​the current collecting portion 12a along the short side direction (Z-axis direction).

[0018] As shown in Figures 7 and 8, for example, the negative electrode tab 12b protrudes in the width direction of the current collecting part 12a from a side edge 12c along the longitudinal direction (winding direction) of the current collecting part 12a. When stacked with the positive electrode 11 via the separator 13, the negative electrode tab 12b protrudes in the same direction as the positive electrode tab 11b of the positive electrode 11. When stacked with the positive electrode 11 via the separator 13, the negative electrode tab 12b is separated from the positive electrode tab 11b of the positive electrode 11. The negative electrode tab 12b is formed integrally with the current collecting part 12a. A plurality of negative electrode tabs 12b are formed on one current collecting part 12a.

[0019] The negative electrode tabs 12b are arranged at unequal pitches, similar to the positive electrode tabs 11b. That is, the interval between adjacent negative electrode tabs 12b in the winding direction is configured to be relatively longer for the negative electrode tabs 12b adjacent to the side closer to the other end 12q of the winding end of the current collecting part 12a than for the negative electrode tabs 12b adjacent to the side closer to the end 12p of the winding start of the current collecting part 12a. All of the negative electrode tabs 12b overlap when the current collecting part 12a is wound.

[0020] The negative electrode tab 12b may be integral with the current collecting portion 12a or may be separate from the current collecting portion 12a. The multiple terminal portions are provided on a side edge (at least one side edge) of the current collecting portion 12a along the winding direction (longitudinal direction).

[0021] The current collecting portion 12a of the negative electrode 12 is formed of, for example, copper or a copper alloy. The negative electrode active material layer 12T contains a negative electrode active material made of a carbon-based material, a binder, a conductive additive, etc. The carbon-based material is, for example, graphite.

[0022] As shown in FIGS. 7 and 8, the separator 13 (insulator) insulates the positive electrode 11 from the negative electrode 12 while allowing lithium ions to pass through. The separator 13 is formed in an elongated shape. The separator 13 has a width along its short side (Z-axis direction) greater than that of the current collector 11a of the positive electrode 11 and the current collector 12a of the negative electrode 12. Both ends of the current collector 11a of the positive electrode 11 along the short side are located within the short side of the separator 13, and both ends of the current collector 12a of the negative electrode 12 along the short side are located within the short side of the separator 13. The separator 13 is made of a porous material. Polyethylene (PE) or polypropylene (PP) is used for the separator 13. A heat-resistant insulating material may be used instead of the separator 13. The heat-resistant insulating material may be, for example, ceramic. This configuration is known as a separator-less configuration.

[0023] The electrolyte 14 corresponds to a so-called electrolytic solution. The electrolyte 14 is impregnated in the separator 13. The electrolyte 14 contains an organic solvent, a supporting salt, and an additive. The organic solvent may be, for example, a carbonate ester. The supporting salt may be, for example, a lithium salt.

[0024] A charge / discharge body 110, which is a modified example of the charge / discharge body 10, will be described with reference to FIG. 9. The charge / discharge body 110 differs in the configuration of the positive electrode 111 from the configuration of the positive electrode 11 of the first embodiment. In the configuration of the charge / discharge body 110, the same components as those of the charge / discharge body 10 are given the same reference numerals, and their description will be omitted. The positive electrode active material layer 111T of the charge / discharge body 110 faces the current collecting part 11a except for both ends along the short side direction (Z-axis direction). The heat-resistant insulating layer 111U of the charge / discharge body 110 is bonded to both ends along the short side direction of the current collecting part 11a and to the base end portion of the positive electrode tab 11b. The heat-resistant insulating layer 111U contains, for example, ceramics.

[0025] The current collector 20 is connected to the charge / discharge body 10. The current collector 20 shown in Figures 2 to 5, 10 and 12 includes a positive electrode current collector plate 21 and a negative electrode current collector plate 22.

[0026] As shown in FIGS. 4 and 5, for example, the positive current collector plate 21 electrically connects the positive electrode tab 11b of the charge / discharge unit 10 to the positive electrode terminal 41 via the current interrupter 30. As shown in FIG. 12, for example, the positive current collector plate 21 includes a rectangular parallelepiped plate-shaped first base portion 21a, a rectangular parallelepiped plate-shaped second base portion 21b, and a connecting portion 21c that connects the first base portion 21a and the second base portion 21b in a stepped manner with different heights. A recess 21d is formed on the upper surface (the surface facing the positive direction of the Z axis) of the second base portion 21b, reducing the thickness of the second base portion 21b. A ring-shaped recessed weakened portion 21e is formed in the center of the recess 21d. The positive current collector plate 21 is made of, for example, aluminum or an aluminum alloy.

[0027] 2 and 3, the negative electrode current collector 22 electrically connects the negative electrode tab 12b of the charge / discharge body 10 to the negative electrode terminal 42. As shown in FIG. 10, the negative electrode current collector 22 includes a rectangular parallelepiped base 22a and an insertion hole 22b penetrating the base 22a. The insertion hole 22b of the negative electrode current collector 22 is inserted into the insertion hole 22b of the negative electrode current collector 22. The negative electrode current collector 22 is formed of, for example, copper or a copper alloy.

[0028] The current interrupter 30 is connected to the current collector 20, and provides electrical continuity between the current collector 20 and the positive electrode terminal 41. The current interrupter 30 shown in FIGS. 4, 5, and 12 includes a diaphragm 31, a conductive member 32, and a pair of support bases 33.

[0029] 12, the diaphragm 31 includes a curved cylindrical main body 31a, a disk-shaped first joint portion 31b provided at the tip end side (negative side of the Z axis) of the main body 31a, and a ring-shaped second joint portion 31c provided at the base end side (positive side of the Z axis) of the main body 31a. The first joint portion 31b is joined to a recess 21d of the positive current collector plate 21. The second joint portion 31c is joined to a conductive member 32. The diaphragm 31 is formed of, for example, aluminum or an aluminum alloy.

[0030] 12, the conductive member 32 is formed in a cylindrical shape. A positive electrode-side first insulating plate 62 is joined to an upper surface (surface on the positive Z-axis direction side) of the conductive member 32. A second joint portion 31c of the diaphragm 31 is joined to the periphery of a lower surface (surface on the negative Z-axis direction side) of the conductive member 32. The conductive member 32 is formed of, for example, aluminum or an aluminum alloy.

[0031] 12, the support base 33 includes a rectangular parallelepiped main body 33a extending in the short-side direction (Y-axis direction) of the battery 1, and leg portions 33b extending downward (in the negative Z-axis direction) from both sides of the main body 33a in the longitudinal direction (Y-axis direction). One support base 33 is provided on each end of the diaphragm 31 along the longitudinal direction (X-axis direction) of the battery 1. The main body 33a is attached to the positive electrode side first insulating plate 62. The leg portions 33b are attached to the second base portion 21b of the positive electrode current collector plate 21. The support base 33 is formed, for example, from insulating resin.

[0032] The external terminal 40 is connected to the current collector 20 or the current interrupter 30. The external terminal 40 shown in FIGS.

[0033] The positive electrode terminal 41 is connected to the conductive member 32 of the current interrupter 30, as shown in Fig. 5, for example. As shown in Fig. 12, for example, the positive electrode terminal 41 includes a rectangular parallelepiped plate-shaped base 41a, a cylindrical insertion portion 41b protruding downward (in the negative Z-axis direction) from the base 41a, and a cylindrical joint portion 41c protruding downward (in the negative Z-axis direction) from the periphery of the base 41a.

[0034] 12, the base 41a is in contact with the base 64a of the positive electrode-side second insulating plate 64. The insertion portion 41b is inserted into the insertion hole 64b of the positive electrode-side second insulating plate 64, the positive electrode-side insertion hole 52a of the lid 52, the insertion hole 62b of the positive electrode-side first insulating plate 62, and the insertion hole 32b of the conductive member 32.

[0035] 12, the joint portion 41c protrudes downward (in the negative direction of the Z axis) from the insertion hole 32b of the conductive member 32 and is expanded radially outward to be joined to the conductive member 32. That is, the joint portion 41c is crimped to the periphery of the insertion hole 32b of the conductive member 32. Furthermore, the joint portion 41c is welded to the periphery of the insertion hole 32b of the conductive member 32. The positive electrode terminal 41 is formed of, for example, aluminum or an aluminum alloy.

[0036] The negative electrode terminal 42 is connected to the negative electrode current collector plate 22, as shown in Fig. 3, for example. As shown in Fig. 10, for example, the negative electrode terminal 42 includes a rectangular parallelepiped plate-shaped base portion 42a, a cylindrical insertion portion 42b protruding downward (in the negative Z-axis direction) from the base portion 42a, and a cylindrical joint portion 42c protruding downward (in the negative Z-axis direction) from the periphery of the base portion 42a.

[0037] 10 , the base 42a is in contact with the base 65a of the negative electrode side second insulating plate 65. The insertion portion 42b is inserted into the insertion hole 65b of the negative electrode side second insulating plate 65, the negative electrode side insertion hole 52b of the lid 52, the insertion hole 63b of the negative electrode side first insulating plate 63, and the insertion hole 22b of the negative electrode current collector plate 22.

[0038] 10 , the joint portion 42c protrudes downward from the insertion hole 22b of the negative current collector plate 22 and is expanded radially outward to be joined to the negative current collector plate 22. That is, the joint portion 42c is crimped to the periphery of the insertion hole 22b of the negative current collector plate 22. Furthermore, the joint portion 42c is welded to the periphery of the insertion hole 22b of the negative current collector plate 22. The negative terminal 42 is formed of, for example, copper or a copper alloy.

[0039] The components of the battery 1 are housed or attached in the exterior body 50. The exterior body 50 shown in Figures 1 to 6 and 10 to 12 includes a container 51, a lid 52, and a sealing plug 53.

[0040] 2 and 6, the container 51 contains the charge / discharge unit 10 covered with an insulating cover 61 and the like. The container 51 is made of a rectangular metal can. As shown in FIG. 6, the container 51 includes an opening 51a that opens along the longitudinal direction and a container portion 51b that is continuous with the opening 51a. The container 51 is made of, for example, aluminum or an aluminum alloy.

[0041] The lid 52 seals the opening 51a of the container 51, as shown in, for example, FIGS. 2 and 6. The lid 52 faces one side 10a (side) of the charge / discharge body 10, where the positive electrode 11, the separator 13, and the negative electrode 12 are adjacent to each other. The lid 52 is formed of a long, plate-shaped metal plate. The lid 52 has a positive electrode side insertion hole 52a formed as a circular through-hole at one end in the longitudinal direction. The insertion portion 41b of the positive electrode terminal 41 is inserted into the positive electrode side insertion hole 52a. The lid 52 has a negative electrode side insertion hole 52b formed as a circular through-hole at the other end in the longitudinal direction. The insertion portion 42b of the negative electrode terminal 42 is inserted into the negative electrode side insertion hole 52b.

[0042] The lid 52 has a liquid inlet 52c formed as a circular through-hole between the positive electrode side insertion hole 52a and the negative electrode side insertion hole 52b. The electrolyte 14 is injected from the lid 52 toward the container 51 through the liquid inlet 52c. The insertion portion 53b of the sealing plug 53 is inserted into the liquid inlet 52c. The lid 52 has a split valve 80 formed in the center in the longitudinal direction. The lid 52 is welded to the container 51. The lid 52 is made of, for example, aluminum or an aluminum alloy.

[0043] 11, the sealing plug 53 seals the liquid inlet hole 52c of the lid 52. The sealing plug 53 is formed in a cylindrical shape. The sealing plug 53 includes a head portion 53a having a relatively large outer diameter and an insertion portion 53b that is continuous with the head portion 53a and has a relatively small outer diameter. The head portion 53a of the sealing plug 53 is welded to the lid 52. The sealing plug 53 is formed of, for example, aluminum or an aluminum alloy.

[0044] The insulator 60 insulates the components of the battery 1 from the exterior body 50. The insulator 60 shown in Figures 1 to 6, 10, and 12 includes an insulating cover 61, a positive electrode-side first insulating plate 62, a negative electrode-side first insulating plate 63, a positive electrode-side second insulating plate 64, and a negative electrode-side second insulating plate 65.

[0045] As shown in FIG. 6, the insulating cover 61 covers and insulates the charging / discharging unit 10. The insulating cover 61 includes a pair of opposing side surfaces (a first side surface 61a and a second side surface 61b) and an opening 61c between the first side surface 61a (one side surface) and the second side surface 61b (the other side surface) through which one side portion 10a of the charging / discharging unit 10 is exposed. The insulating cover 61 covers all but one side of the one side portion 10a of the charging / discharging unit 10. That is, the insulating cover 61 covers the other side portion 10b opposite to the one side portion 10a of the charging / discharging unit 10, and the outer periphery portion 10c located between the one side portion 10a and the other side portion 10b of the charging / discharging unit 10. The insulating cover 61 is formed into a pentahedron shape by folding a polyhedron-shaped sheet into a box shape. The insulating cover 61 is made of, for example, polypropylene.

[0046] As shown in FIG. 5, for example, the positive electrode side first insulating plate 62 insulates the positive electrode current collector plate 21 and the conductive member 32 from the lid 52. As shown in FIG. 12, for example, the positive electrode side first insulating plate 62 includes a rectangular parallelepiped base 62a, an insertion hole 62b penetrating the base 62a, and a protrusion 62c annularly extending from the side edge of the base 62a and protruding in a direction away from the surrounding lid 52. The positive electrode side first insulating plate 62 accommodates the positive electrode current collector plate 21, the conductive member 32, etc. in a space defined by the base 62a and the protrusion 62c. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 62b. The positive electrode side first insulating plate 62 is formed, for example, from insulating resin.

[0047] As shown in FIG. 3, for example, the negative electrode side first insulating plate 63 insulates the negative electrode current collector plate 22 from the lid 52. As shown in FIG. 10, for example, the negative electrode side first insulating plate 63 includes a rectangular parallelepiped base 63a, an insertion hole 63b penetrating the base 63a, and a protrusion 63c annularly extending from the side edge of the base 63a and protruding in a direction away from the surrounding lid 52. The negative electrode side first insulating plate 63 accommodates the negative electrode current collector plate 22 in a space defined by the base 63a and the protrusion 63c. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 63b. The negative electrode side first insulating plate 63 is formed of, for example, insulating resin.

[0048] As shown in FIG. 5, for example, the positive electrode side second insulating plate 64 insulates the positive electrode terminal 41 from the lid 52. As shown in FIG. 12, for example, the positive electrode side second insulating plate 64 includes a rectangular parallelepiped base 64a, an insertion hole 64b penetrating the base 64a, and a protrusion 64c annularly extending from the side edge of the base 64a and protruding in a direction away from the surrounding lid 52. The positive electrode side second insulating plate 64 accommodates the positive electrode terminal 41 in a space defined by the base 64a and the protrusion 64c. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 64b. The positive electrode side second insulating plate 64 is formed, for example, from insulating resin.

[0049] As shown in FIG. 3, for example, the negative electrode side second insulating plate 65 insulates the negative electrode terminal 42 from the lid 52. As shown in FIG. 10, for example, the negative electrode side second insulating plate 65 includes a rectangular parallelepiped base 65a, an insertion hole 65b penetrating the base 65a, and a protrusion 65c annularly extending from the side edge of the base 65a and protruding in a direction away from the surrounding lid 52. The negative electrode side second insulating plate 65 accommodates the negative electrode terminal 42 in a space defined by the base 65a and the protrusion 65c. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 65b. The negative electrode side second insulating plate 65 is formed of, for example, insulating resin.

[0050] The sealing body 70 seals the components of the battery 1 and the exterior body 50. The sealing body 70 shown in Figures 2 to 5, 10 and 12 includes a positive electrode side gasket 71 and a negative electrode side gasket 72.

[0051] As shown in FIG. 5, for example, the positive electrode side gasket 71 insulates the positive electrode side second insulating plate 64 from the lid 52. The positive electrode side gasket 71 is formed in a cylindrical shape. As shown in FIG. 12, for example, the positive electrode side gasket 71 includes a first insertion portion 71a having a relatively large outer diameter, a second insertion portion 71b continuous with the first insertion portion 71a and having a relatively small outer diameter, and an insertion hole 71c passing through the first insertion portion 71a and the second insertion portion 71b. The first insertion portion 71a of the positive electrode side gasket 71 is inserted into the insertion hole 64b of the positive electrode side second insulating plate 64. The second insertion portion 71b of the positive electrode side gasket 71 is inserted into the positive electrode side insertion hole 52a of the lid 52. The insertion portion 41b of the positive electrode terminal 41 is inserted into the insertion hole 71c. The positive electrode side gasket 71 is formed, for example, from rubber having insulating properties and elasticity.

[0052] As shown in FIG. 3, for example, the negative electrode side gasket 72 insulates the negative electrode side second insulating plate 65 from the lid 52. The negative electrode side gasket 72 is formed in a cylindrical shape. As shown in FIG. 10, for example, the negative electrode side gasket 72 includes a first insertion portion 72a having a relatively large outer diameter, a second insertion portion 71b continuous with the first insertion portion 72a and having a relatively small outer diameter, and an insertion hole 72c passing through the first insertion portion 72a and the second insertion portion 71b. The first insertion portion 72a of the negative electrode side gasket 72 is inserted into the insertion hole 65b of the negative electrode side second insulating plate 65. The second insertion portion 71b of the negative electrode side gasket 72 is inserted into the negative electrode side insertion hole 52b of the lid 52. The insertion portion 42b of the negative electrode terminal 42 is inserted into the insertion hole 72c. The negative electrode side gasket 72 is formed, for example, from rubber having insulating properties and elasticity.

[0053] 1, 6, 11, 13, and 14, split valve 80 is a safety valve. Split valve 80 opens from the inside of exterior body 50 to the outside when the pressure inside exterior body 50 reaches or exceeds a predetermined value. In other words, split valve 80 is split by the pressure of gas generated inside exterior body 50, and allows the gas to be discharged to the outside of exterior body 50.

[0054] The split valve 80 is provided, for example, in a cylindrical exhaust portion 52d formed in the lid 52 of the exterior body 50. The exhaust portion 52d and the split valve 80 are formed integrally with the lid 52 by recessing the lid 52 from the outer surface 52e side toward the inner surface 52f side of the lid 52. The exhaust portion 52d protrudes from the inner surface 52f of the lid 52 toward the charge / discharge body 10 side. The thickness of the split valve 80 is sufficiently thinner than the thickness of the exterior body 50. In other words, the thickness of the split valve 80 is sufficiently thinner than the thicknesses of the container 51 and the lid 52. An edge 81 of the split valve 80 is provided in an annular shape in the exhaust portion 52d along the inner surface 52f of the lid 52.

[0055] In split valve 80, annular edge 81 connected to exhaust portion 52d of lid 52 includes first edge 81a and second edge 81b. First edge 81a is formed in an arc shape. Second edge 81b is formed in a linear shape. Edge 81 of split valve 80 is formed in a D shape. First edge 81a has a groove.

[0056] The split valve 80 is curved convexly in a direction approaching the charging / discharging body 10. That is, the split valve 80 is curved toward the inside of the battery 1. In the split valve 80, a first curved portion 82 that curves convexly from a first edge portion 81a has a smaller curvature than a second curved portion 83 that curves convexly from a second edge portion 81b. The curvature is the reciprocal of the radius of the curved portion. The first curved portion 82 has a gentler slope than the second curved portion 83. Position P1 of a tip portion 84 of the split valve 80 is located closer to the second edge portion 81b than position P2 of the center of the split valve 80. Therefore, the edge portion 81 is formed in a rotationally asymmetric ring shape.

[0057] As a first modification of the first embodiment, edge 81 of split valve 80 may be provided in an annular shape along outer surface 52e of lid 52 in exhaust portion 52d. As a second modification of the first embodiment, edge 81 of split valve 80 may be provided in an annular shape in an internal portion of exhaust portion 52d that is spaced apart from outer surface 52e and inner surface 52f of lid 52. In the first and second modifications of the first embodiment, tip 84 of split valve 80 may be located inside exhaust portion 52d. That is, tip 84 of split valve 80 may be located between outer surface 52e and inner surface 52f of lid 52. As a third modification of the first embodiment, split valve 80 may be provided in container 51.

[0058] (Operation of split valve 80 of first embodiment) The operation of the split valve 80 of the first embodiment will now be described with reference to FIGS.

[0059] 15 to 17 show simulations of deformation of the split valve 80 under stress. The shading from Min to Max in FIGS. 15 to 17 indicates the relative magnitude of deformation of the split valve 80. Min indicates a portion of the split valve 80 that is relatively small in deformation. Max indicates a portion of the split valve 80 that is relatively large in deformation. As the pressure inside the exterior body 50 increases, the split valve 80 is subjected to a pressing force in a direction from the charging / discharging body 10 toward the outside of the lid 52. As a result, the split valve 80 deforms from a state in which it is convexly curved toward the charging / discharging body 10 toward a direction away from the charging / discharging body 10. Here, in the split valve 80, the first curved portion 82 has a smaller curvature than the second curved portion 83.

[0060] Therefore, the first curved portion 82 has lower rigidity against the pressing force from the charger / discharger 10 toward the outside of the lid 52 than the second curved portion 83. That is, the first curved portion 82 is more likely to deform from the charger / discharger 10 toward the outside of the lid 52 than the second curved portion 83. Furthermore, in the first curved portion 82, the central portion 81a1 of the first edge portion 81a has a relatively small curvature and is therefore relatively most likely to deform.

[0061] Therefore, when the pressure inside the exterior body 50 reaches or exceeds a predetermined value, the split valve 80 first splits at the center 81a1 of the first edge 81a. Next, the split valve 80 quickly splits along the groove formed in the first edge 81a from the center 81a1 toward the end 81a2 of the first edge 81a. Finally, the split valve 80 reaches a state where the first edge 81a splits but the second edge 81b does not split, or where both the first edge 81a and the second edge 81b are split.

[0062] (Effects of the split valve 80 of the first embodiment) The effects of the split valve 80 of the first embodiment will be described with reference to FIGS.

[0063] The edge 81 of the split valve 80 includes a first edge 81a and a second edge 81b. The first edge 81a is arc-shaped. The second edge 81b is linear. The first edge 81a has a groove. This configuration allows the first edge 81a and the second edge 81b to have different rigidities against pressure from the charging / discharging unit 10. That is, the arc-shaped first edge 81a is made weaker than the linear second edge 81b, thereby allowing for a relatively lower rigidity. The arc-shaped first edge 81a is supported by the linear second edge 81b. Therefore, the arc-shaped first edge 81a can have a relatively higher rigidity than conventional split valves with rotationally symmetric (circular) or bilaterally symmetric (rectangular) annular edges. That is, the split valve 80 has relatively high durability.

[0064] On the other hand, when the first edge 81a splits from a state in which it has relatively high durability, compared to a conventional split valve in which the annular edge is rotationally symmetric (circular) or bilaterally symmetric (rectangular), the time from start to finish of the split can be relatively shortened. In other words, once the split valve 80 starts to split, the state in which it maintained relatively high durability is lost, allowing the splitting to proceed at high speed. Therefore, the split valve 80 can efficiently release gas inside the battery when it splits.

[0065] Therefore, the split valve 80 of the battery 1 has relatively high durability, and can efficiently release gas inside the battery when split open.

[0066] The split valve 80 is curved in a convex shape in a direction approaching the charging / discharging unit 10. With this configuration, the split valve 80 can have a relatively high rigidity against stress received from the charging / discharging unit 10. That is, the split valve 80 can have a relatively high split pressure. Furthermore, with this configuration, the split valve 80 can withstand an increase in internal pressure of the exterior body 50 that occurs when the charging / discharging unit 10 is initially charged, for example, during the manufacture of the battery 1.

[0067] In the split valve 80, the first curved portion 82, which curves convexly from the first edge 81a, has a smaller curvature than the second curved portion 83, which curves convexly from the second edge 81b. This configuration allows the first curved portion 82 and the second curved portion 83 to have a different rigidity against pressure from the charging / discharging unit 10. That is, the first curved portion 82, which starts from the arc-shaped first edge 81a, can be made weaker than the second curved portion 83, which starts from the linear second edge 81b. Therefore, the split valve 80 can selectively split the first curved portion 82.

[0068] Position P1 of tip 84 of split valve 80 is located closer to second edge 81b than position P2 of the center of split valve 80. With this configuration, in split valve 80, it is easy to create a difference in the outer shape of first curved portion 82, which curves convexly from first edge 81a, and the outer shape of second curved portion 83, which curves convexly from second edge 81b.

[0069] Edge portion 81 is formed in a rotationally asymmetric ring shape. With this configuration, in split valve 80, it is easy to create a difference in the outer shape of first curved portion 82, which is curved convexly from first edge portion 81a, and the outer shape of second curved portion 83, which is curved convexly from second edge portion 81b.

[0070] [Second embodiment] The split valve 180 of the battery 2 of the second embodiment will be described.

[0071] (Configuration of split valve 180 of second embodiment) The configuration of a split valve 180 of the second embodiment will be described with reference to FIG.

[0072] In the second embodiment, a configuration different from the first embodiment will be described. The split valve 180 is curved convexly away from the charging / discharging body 10. That is, the split valve 180 is curved toward the outside of the battery 1. Compared to the split valve 80, the split valve 180 has a shape that is inverted symmetrical with respect to the XY plane of the lid 52. The split valve 180 includes an edge 181, a first edge 181a, a second edge 181b, a first curved portion 182, a second curved portion 183, and a tip 184. The edge 181 of the split valve 180 is annularly provided along the inner surface 52f of the lid 52 in the exhaust portion 52d. The tip 184 of the split valve 180 is located inside the exhaust portion 52d of the lid 52.

[0073] As a first modification of the second embodiment, the tip 184 of the split valve 180 may protrude from the exhaust portion 52d of the lid 52 beyond the outer surface 52e of the lid 52 toward the outside of the battery 1. As a second modification of the second embodiment, the edge 181 of the split valve 180 may be provided in an annular shape along the outer surface 52e of the lid 52 in the exhaust portion 52d.

[0074] (Effects of the split valve 180 of the second embodiment) The effect of the split valve 180 of the second embodiment will be described with reference to FIG.

[0075] The split valve 180 is curved in a convex shape in a direction away from the charge / discharge unit 10. With this configuration, the split valve 180 and the charge / discharge unit 10 can be spaced apart relatively. That is, with this configuration, the volume of the charge / discharge unit 10 inside the exterior body 50 can be relatively increased. Therefore, the energy density of the battery 2 can be increased.

[0076] [Third embodiment] The split valve 280 of the battery 3 of the third embodiment will be described.

[0077] (Configuration of split valve 280 of the third embodiment) The configuration of a split valve 280 of the third embodiment will be described with reference to FIG.

[0078] The third embodiment will describe a configuration different from the first and second embodiments. Split valve 280 extends in a plane along the outer shape of lid 52. First edge 281a and second edge 281b of edge 281 of split valve 280 are provided in an annular shape along inner surface 52f of lid 52 in exhaust portion 52d.

[0079] As a modification of the third embodiment, the edge portion 281 of the split valve 280 may be provided in an annular shape along the outer surface 52e of the lid 52 in the exhaust portion 52d.

[0080] (Effects of the split valve 280 of the third embodiment) The effect of the split valve 280 of the third embodiment will be described with reference to FIG.

[0081] The split valve 280 extends in a plane along the outer shape of the lid 52. With this configuration, the split valve 280 can be easily formed. Furthermore, with this configuration, the split valve 280 and the charge / discharge unit 10 can be spaced apart relatively. That is, with this configuration, the volume of the charge / discharge unit 10 inside the exterior body 50 can be relatively increased. Therefore, the energy density of the battery 3 can be increased.

[0082] [Fourth embodiment] The split valve 380 and other components of the battery 4 of the fourth embodiment will be described.

[0083] (Configuration of split valve 380 etc. of the fourth embodiment) The configuration of a split valve 380 and other components of the fourth embodiment will be described with reference to FIGS.

[0084] In the fourth embodiment, a configuration different from the first embodiment will be described. The first edge 381a and the second edge 381b of the edge 381 of the split valve 380 are annularly provided in the exhaust portion 52d at an inner portion spaced apart from the outer surface 52e and the inner surface 52f of the lid 52, respectively. The split valve 380 is curved convexly toward the charging / discharging body 10. The tip 484 of the split valve 480 is located inside the exhaust portion 52d of the lid 52. Therefore, the entire split valve 380 is located between the outer surface 52e and the inner surface 52f of the lid 52.

[0085] As a first modification of the fourth embodiment, the tip 384 of the split valve 380 may protrude from the exhaust portion 52d beyond the inner surface 52f of the lid 52 toward the inside of the battery 1. As a second modification of the fourth embodiment, the split valve 380 may be curved convexly in a direction away from the charging / discharging body 10. In the second modification of the fourth embodiment, the tip 384 of the split valve 380 may protrude from the exhaust portion 52d of the lid 52 beyond the outer surface 52e of the lid 52 toward the outside of the battery 1. As a third modification of the fourth embodiment, as shown in FIG. 21 , the split valve 480 may be provided in the exhaust portion 152d that is not stepped relative to the lid 152 in the height direction Z.

[0086] (Effects of the split valve 380 etc. of the fourth embodiment) The effects of the split valve 380 and the like of the fourth embodiment will be described with reference to FIGS.

[0087] At least an edge 381 of the split valve 380 is located between the opposing outer surface 52e and inner surface 52f that form the thickness portion of the lid 52. This configuration allows the split valve 380 and the charge / discharge unit 10 to be spaced apart relatively. That is, this configuration allows the volume of the charge / discharge unit 10 inside the exterior body 50 to be relatively increased. This increases the energy density of the battery 4. Furthermore, this configuration prevents interference between the split valve 380 and other components during the manufacture of the battery 4.

[0088] The entire split valve 380 is located between the outer surface 52e and the inner surface 52f. This configuration can maximize the energy density of the battery 4. Furthermore, this configuration can minimize interference between the split valve 380 and other components during battery 4 manufacturing.

[0089] [Fifth embodiment] The split valve 580 of the battery 5 of the fifth embodiment will be described.

[0090] (Configuration of split valve 580 of fifth embodiment) The configuration of a split valve 580 of the fifth embodiment will be described with reference to FIG.

[0091] In the fifth embodiment, a configuration different from the first embodiment will be described. In a split valve 580 of the fifth embodiment, a second edge portion 581b of an edge portion 581 is formed in an arc shape rather than a linear shape. The split valve 580 includes an edge portion 581, a first edge portion 581a, a second edge portion 581b, a first curved portion 582, a second curved portion 583, and a tip portion 584. The annular edge portion 581 connected to the lid 52 of the split valve 580 includes a first edge portion 581a and a second edge portion 581b. The first edge portion 581a is formed in an arc shape, similar to the first edge portion 81a. Unlike the linear second edge portion 81b, the second edge portion 581b is formed with a larger radius than the first edge portion 581a. In split valve 580, first curved portion 582 curved convexly from first edge 581a has a smaller curvature than second curved portion 583 curved convexly from second edge 581b.

[0092] The configuration of split valve 580 is applicable to the second and fourth embodiments.

[0093] (Effects of the split valve 580 of the fifth embodiment) The effect of the split valve 580 of the fifth embodiment will be described with reference to FIG.

[0094] In split valve 580, first edge 581a of edge 581 is formed in an arc shape. Second edge 581b of edge 581 is formed with a larger radius than first edge 581a. With this configuration, the split pressure of split valve 580 can be set to a predetermined value by changing the curvature of second edge 581b.

[0095] The battery of the present invention is not limited to the configurations described in the embodiments, but can be configured appropriately based on the contents described in the claims.

[0096] The battery of the present invention is not limited to lithium-ion batteries. The battery of the present invention can be applied to, for example, nickel-metal hydride batteries and lead-acid batteries. The battery of the present invention is not limited to secondary batteries. The battery of the present invention can be applied to primary batteries. The battery of the present invention is not limited to a configuration in which the charging / discharging body is sealed by a container and a lid. The battery of the present invention can be applied to a configuration in which the charging / discharging body is sealed by a laminate film. Each embodiment has been described in detail or simply to clearly explain the present invention, and it is not necessary to include all of the components described, or components not shown may be included. Furthermore, some of the components of one embodiment may be deleted, replaced with components of another embodiment, or combined with components of another embodiment. [Explanation of symbols]

[0097] 1, 2, 3, 4, 5, 6 Battery, 10 Charge / discharge body, 51 Container (exterior body), 52 Lid (exterior body), 52d Vent portion, 52e Outer surface, 52f Inner surface, 80 Split valve (safety valve), 81 Edge portion, 81a First edge portion, 81a1 Center portion, 81a2 End portion, 81b Second edge portion, 82 First curved portion, 83 Second curved portion, 84 Tip portion, 152 Lid, 152d Vent portion, 180 Split valve (safety valve), 181 Edge portion, 181 Edge portion, 181a First edge portion, 181b Second edge portion, 182 First curved portion, 183 Second curved portion, 184 Tip portion, 280 Split valve (safety valve), 281 Edge portion, 281a First edge portion, 281b Second edge, 380, split valve (safety valve), 381, edge, 381a, first edge, 381b, second edge, 384, tip, 480, split valve (safety valve), 484, tip, 580, split valve (safety valve), 581, edge, 581a, first edge, 581b, second edge, 582, first bend, 583, second bend, 584, tip.

Claims

1. A charge / discharge body; an exterior body accommodating the charge / discharge unit; a safety valve provided in the exterior body and opening from the inside to the outside of the exterior body when the pressure inside the exterior body reaches or exceeds a predetermined value; The thickness of the safety valve is smaller than the thickness of the exterior body, The annular edge portion of the safety valve connected to the outer casing includes a first edge portion formed in an arc shape, and a second edge portion formed with a larger radius than the first edge portion or formed in a linear shape, The battery, wherein the first edge includes a groove and a central portion of the first edge having a minimum curvature.

2. The safety valve is curved convexly in a direction approaching the charging / discharging body. The battery of claim 1 .

3. The safety valve is curved convexly in a direction away from the charging / discharging body. The battery of claim 1 .

4. A charge / discharge body; an exterior body accommodating the charge / discharge unit; a safety valve provided in the exterior body and opening from the inside to the outside of the exterior body when the pressure inside the exterior body reaches or exceeds a predetermined value; The thickness of the safety valve is smaller than the thickness of the exterior body, The annular edge portion of the safety valve connected to the outer casing includes a first edge portion formed in an arc shape, and a second edge portion formed with a larger radius than the first edge portion or formed in a linear shape, the first edge includes a groove; the safety valve is curved convexly toward the charging / discharging body or away from the charging / discharging body, In the safety valve, a first curved portion curved convexly from the first edge portion has a smaller curvature than a second curved portion curved convexly from the second edge portion. battery.

5. A charge / discharge body, an exterior body accommodating the charge / discharge unit; a safety valve provided in the exterior body and opening from the inside to the outside of the exterior body when the pressure inside the exterior body reaches or exceeds a predetermined value; The thickness of the safety valve is smaller than the thickness of the exterior body, The annular edge portion of the safety valve connected to the outer casing includes a first edge portion formed in an arc shape, and a second edge portion formed with a larger radius than the first edge portion or formed in a linear shape, the first edge includes a groove; the safety valve is curved convexly toward the charging / discharging body or away from the charging / discharging body, The tip of the safety valve is located closer to the second edge than the center of the safety valve. battery.

6. The safety valve extends in a plane along the outer shape of the exterior body. The battery of claim 1 .

7. The edge portion is formed in a rotationally asymmetric annular shape. The battery of claim 1 .

8. At least the edge portion of the safety valve is located between the opposing outer surface and inner surface that form the thickness portion of the exterior body. The battery of claim 1 .

9. all of the safety valves are located between the outer surface and the inner surface; The battery of claim 8.

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