Secondary battery cell

Abstract

A secondary battery cell according to one embodiment of the present invention may comprise: a case forming an internal space; an electrode assembly including a negative plate, a positive plate, and a separator interposed between the negative plate and the positive plate, and disposed in the internal space; the cover plate assembly is combined to at least one side of the shell, the electrode assembly can comprise a negative electrode lug and a positive electrode lug which extend in one direction from the negative electrode plate and the positive electrode plate respectively, the cover plate assembly can comprise a connecting part, and the connecting part is electrically connected with the negative electrode lug and the positive electrode lug. And includes an elastic portion.

Description

Technical Field

[0001] The invention relates to a secondary battery core. Background Art

[0002] In recent years, the demand for secondary batteries as energy sources has increased dramatically.

[0003] A secondary battery is a battery that can be reversibly charged and discharged.

[0004] The secondary battery may include an electrode assembly and a shell containing the electrode assembly, wherein the electrode assembly is formed by repeatedly stacking a positive electrode plate and a negative electrode plate and a separator interposed between the positive electrode plate and the negative electrode plate. In addition, depending on the form of the shell, the secondary battery may further include a cap plate assembly, which is welded to the electrode assembly to seal the shell.

[0005] For example, the electrode uncoated portion of the electrode assembly can be welded to the current collector, and the current collector can be welded to the cap assembly. In particular, the rivet connection structure of the current collector and the cap assembly in the prior art has the possibility of defects due to the large number of welds at the sealing part. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] The object of the present invention is to provide a secondary battery cell which simplifies the welding process when sealing a shell.

[0008] (II) Technical solution

[0009] A secondary battery cell according to one embodiment of the present invention may include: a shell forming an internal space; an electrode assembly including a negative electrode plate, a positive electrode plate and a separator inserted between the negative electrode plate and the positive electrode plate and arranged in the internal space; and a cover assembly coupled to at least one side of the shell, the electrode assembly may include a negative electrode tab and a positive electrode tab extending from the negative electrode plate and the positive electrode plate in one direction respectively, the cover assembly may include a connecting component, the connecting component is electrically connected to the negative electrode tab and the positive electrode tab, and includes an elastic portion.

[0010] According to an embodiment of the present invention, the elastic portion may have elasticity in a direction in which the cover plate assembly is coupled to the housing.

[0011] According to an embodiment of the present invention, the elastic part may be composed of one or more coil springs or leaf springs.

[0012] According to one embodiment of the present invention, the cover plate assembly may include: a cover plate coupled to the shell; a terminal plate arranged on one side of the cover plate; and an insulating plate arranged on at least one side of one side and the other side of the cover plate, and the connecting component may be arranged to pass through the cover plate, the terminal plate and the insulating plate.

[0013] According to one embodiment of the present invention, the terminal plate may be electrically connected to the negative electrode tab or the positive electrode tab through the connecting component.

[0014] According to an embodiment of the present invention, the connection member may include a first portion that contacts the elastic portion and the terminal plate.

[0015] According to an embodiment of the present invention, the connecting component may further include a second portion, and the second portion is in contact with the elastic portion and the negative electrode tab or the positive electrode tab.

[0016] According to an embodiment of the present invention, the cover plate assembly may further include a sealing component, wherein the sealing component is disposed between the cover plate and the connecting component.

[0017] According to one embodiment of the present invention, the cap plate, the terminal plate and the insulating plate may include a through hole, the connection member is disposed in the through hole, and the connection member may be assembled in the through hole.

[0018] According to one embodiment of the present invention, the cover plate assembly may include: a first cover plate assembly, which is arranged on one side of the length direction of the shell and includes a first terminal plate electrically connected to the negative electrode tab; and a second cover plate assembly, which is arranged on the other side of the length direction of the shell and includes a second terminal plate electrically connected to the positive electrode tab.

[0019] (III) Beneficial effects

[0020] The secondary battery cell according to one embodiment of the present invention requires a reduced number of welding times when sealing a case, so the manufacturing process becomes simple and defects caused by welding can be minimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view of a secondary battery cell according to an embodiment of the present invention.

[0022] Figure 2 is a schematic exploded perspective view of a secondary battery cell according to an embodiment of the present invention.

[0023] Figure 3 is a cross-sectional view in the length direction of a secondary battery cell according to an embodiment of the present invention.

[0024] Figure 4 It is shown Figure 3 The cover plate assembly is shown before and after being combined.

[0025] Figure 5 is a cross-sectional view in the length direction of a secondary battery cell according to another embodiment of the present invention.

[0026] Figure 6 It is shown Figure 5 The cover plate assembly is shown before and after being combined.

[0027] Figure 7 is a diagram schematically showing an energy storage device including a secondary battery cell according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the concept of the present invention is not limited to the embodiments described.

[0029] For example, those skilled in the art who understand the concept of the present invention can easily propose other embodiments included in the scope of the concept of the present invention by adding, changing or deleting components, and these embodiments are also included in the scope of the concept of the present invention.

[0030] In the following description, when it is mentioned that a certain component is "connected" to another component, it means not only including the case where the certain component is directly connected to the other component, but also including the case where the certain component is indirectly connected to the other component via other components. In addition, unless otherwise stated to the contrary, "including" a certain component means that other components can be included, rather than excluding other components.

[0031] In addition, the terms including ordinal numbers such as "first" and "second" used in this specification are used to describe various components, but the components are not limited by the terms, and the terms are only used to distinguish one component from another component. For example, within the scope of the present invention, the first component can be named as the second component, and similarly, the second component can also be named as the first component.

[0032] A secondary battery cell according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0033] Figure 1 is a three-dimensional diagram of a secondary battery cell according to an embodiment of the present invention, Figure 2 is a schematic exploded perspective view of a secondary battery cell according to an embodiment of the present invention.

[0034] As shown, a secondary battery cell 100 according to an embodiment of the present invention may be a prismatic secondary battery cell, and may include a case 110 , a first cap plate assembly 120 , a second cap plate assembly 130 , and a vent 140 .

[0035] The housing 110 may form the appearance of the secondary battery cell 100 and may be made of aluminum or a material containing aluminum. However, the material of the housing 110 is not limited thereto. In addition, since the secondary battery cell 100 of the present invention is a prismatic type, the housing 110 may have a flat prismatic shape.

[0036] The housing 110 may contain an electrode assembly 10 and an electrolyte (not shown) therein. The electrode assembly 10 may include a negative electrode plate, a positive electrode plate, and an insulator, i.e., a separator, interposed between the negative electrode plate and the positive electrode plate. The electrode assembly 10 may be configured as a stack type in which negative electrode plates, positive electrode plates, and separators are alternately stacked, or a jelly roll type in which stacked negative electrode plates, positive electrode plates, and separators are wound together.

[0037] The first and second cap plate assemblies 120 and 130 may be coupled to the housing 110. For example, the secondary battery cell 100 may have a two-terminal tab structure in which electrode tabs are respectively provided at both ends of the housing 110. In the case of having a two-terminal tab structure, as shown in the drawings, the first and second cap plate assemblies 120 and 130 may be coupled to both sides of the housing 110 in the length direction, respectively.

[0038] The negative electrode plate and the positive electrode plate can be coated with negative electrode active materials or positive electrode active materials on the collector plate, respectively. For example, the negative electrode plate can be coated with graphite or the like on the collector plate of copper or nickel material, and the positive electrode plate can be coated with transition metal oxide active materials on the collector plate of aluminum material.

[0039] In addition, the negative electrode plate and the positive electrode plate may include uncoated portions that are not coated with negative electrode active material or positive electrode active material at both ends of the collector plate in the length direction, and the uncoated portions of the negative electrode plate may be connected to each other to form a negative electrode tab 12a, and the uncoated portions of the positive electrode plate may be connected to each other to form a positive electrode tab 13a.

[0040] This specification focuses on a secondary battery cell 100 having a two-end tab structure in which cover assemblies are respectively coupled to both sides of the shell 110 in the length direction. However, as another example, the secondary battery cell 100 may include a single cover assembly, which may be coupled to one side of the shell 110 in the height direction.

[0041] In addition, as shown in the figure, the exhaust part 140 may be coupled to the housing 110. The exhaust part 140 may be configured to exhaust gas or the like generated inside the housing 110. For example, the exhaust part 140 may be configured to rupture when the internal pressure of the housing 110 rises due to the gas or the like. On the other hand, in addition to the housing 110, the exhaust part 140 may also be coupled to a cover plate as a component of the cover plate assembly.

[0042] Next, refer to Figures 3 to 6 A cover plate assembly according to an embodiment of the present invention is described.

[0043] Figure 3 is a cross-sectional view in the length direction of a secondary battery cell according to an embodiment of the present invention, Figure 4 It is shown Figure 3 The diagram of the cover plate assembly before and after combination shown, Figure 5 is a cross-sectional view in the length direction of a secondary battery cell according to another embodiment of the present invention, Figure 6 It is shown Figure 5 The cover plate assembly is shown before and after being combined.

[0044] The first and second cover plate assemblies 120, 130 may be respectively coupled to both sides of the length direction of the housing 110. For example, the secondary battery cell 100 may be provided with negative pole tabs and positive pole tabs on both sides of the length direction, and the first and second cover plate assemblies 120, 130 may be coupled to the housing 110 and electrically connected to the negative pole tabs or the positive pole tabs, respectively. Therefore, the components made of conductive materials in the components of the first and second cover plate assemblies 120, 130 may be charged as negative electrodes or positive electrodes. In an embodiment of the present invention, the first cover plate assembly 120 may include a component charged as a negative electrode, and the second cover plate assembly 130 may include a component charged as a positive electrode.

[0045] Reference Figure 3 and Figure 5 The first and second cap plate assemblies 120, 130 according to the embodiment of the present invention may include first and second cap plates 121, 131, first and second terminal plates 122, 132, first and second insulating plates 123, 133, first and second connecting members 124, 134, and first and second sealing members 125, 135, respectively. The first and second cap plate assemblies 120, 130 may be coupled to the housing 110 in a state where the assemblies have been assembled.

[0046] The first and second cover plates 121, 131 are components of the first and second cover plate assemblies 120, 130 that are directly coupled to the housing 110, and may be made of aluminum or a material containing aluminum. In order to couple the first and second cover plate assemblies 120, 130 to the housing 110, laser welding may be performed along edge portions of the first and second cover plates 121, 131.

[0047] The first and second terminal plates 122, 132 may be disposed on one side of the first and second cover plates 121, 131. For example, the first and second terminal plates 122, 132 may be disposed on opposite sides of the first and second cover plates 121, 131 facing the inner space of the housing 110. In addition, the first and second terminal plates 122, 132 may be electrically connected to the negative electrode tab and the positive electrode tab, respectively, and may be charged as a negative electrode or a positive electrode. For example, the first terminal plate 122 may be charged as a negative electrode, and the second terminal plate 132 may be charged as a positive electrode.

[0048] The first and second insulating plates 123 and 133 may be disposed on at least one side of the first and second cap plates 121 and 131. For example, the first insulating plate 123 may be disposed on one side and the other side of the cap plate 121, and the second insulating plate 133 may be disposed only on one side of the cap plate 131. More specifically, the first insulating plate 123 of the first cap plate assembly 120 may include a first inner insulating plate 123a disposed on one side (inner side) of the first cap plate 121 and a first outer insulating plate 123b disposed on the other side (outer side) of the first cap plate 121, and the first outer insulating plate 123b may be disposed between the first cap plate 121 and the first terminal plate 122. On the other hand, the second insulating plate 133 of the second cap plate assembly 130 may include only the second inner insulating plate 133 disposed on one side (inner side) of the second cap plate 131, and no insulating plate may be disposed between the second cap plate 131 and the second terminal plate 132.

[0049] In this regard, the first and second cover plates 121, 131 may include a placement groove for placing the first and second insulating plates 123, 133. For example, since the first insulating plates 123a, 123b are disposed on one side and the other side of the first cover plate 121, the first cover plate 121 may include a placement groove on both sides thereof. On the other hand, since the second insulating plate 133 is disposed only on one side of the second cover plate 131, the second cover plate 131 may include a placement groove on one side thereof. In addition, similarly, the first external insulating plate 123b may include a placement groove on one side thereof so as to place the first terminal plate 122, and the first terminal plate 122 may be placed in the placement groove of the first external insulating plate 123b.

[0050] As shown, the first and second connection members 124, 134 may be arranged to penetrate the first and second cover plates 121, 131, the first and second terminal plates 122, 132, and the first and second insulating plates 123, 133. For example, the first and second cover plates 121, 131, the first and second terminal plates 122, 132, and the first and second insulating plates 123, 133 may include holes, respectively, and each hole may be arranged to overlap each other to form a single through hole. The first and second connection members 124, 134 may be fixedly arranged in the through hole in a press-fit manner.

[0051] One end of the first and second connection parts 124, 134 can pass through the through hole from the first and second terminal plates 122, 132 sides disposed on the outermost sides of the first and second cover plate assemblies 120, 130 and contact the negative electrode tab 12a or the positive electrode tab 13a. In addition, in the state where the first and second connection parts 124, 134 are assembled in the through hole, the other ends of the first and second connection parts 124, 134 can contact the first and second terminal plates 122, 132. That is, the first and second terminal plates 122, 132 can be structurally connected to the two end tabs 12a, 13a through the first and second connection parts 124, 134. In addition, since the first and second connection parts 124, 134 are made of conductive materials, the first and second terminal plates 122, 132 can be electrically connected to the two end tabs 12a, 13a and charged as negative or positive electrodes. The first and second connection parts 124, 134 can provide a path for current flow.

[0052] According to an embodiment of the present invention, the first and second connecting parts 124, 134 may be rivet-type or pin-type. In addition, according to an embodiment of the present invention, the first and second connecting parts 124, 134 may include elastic parts 1241, 1341. For example, the elastic parts 1241, 1341 may be composed of a coil spring or a leaf spring. The elastic parts 1241, 1341 may have elasticity in the length direction of the housing (or the combination direction of the first and second cover plate assemblies 120, 130).

[0053] According to one embodiment of the present invention, the elastic part 1241, 1341 may be applied to the middle part of the first and second connecting parts 124, 134. For example, the first and second connecting parts 124, 134 may include a first part 1242, 1342 in contact with the first and second terminal plates 122, 132 and a second part 1243, 1343 in contact with the two end tabs 12a, 13a, and the elastic part 1241, 1341 may be arranged between the first part 1242, 1342 and the second part 1243, 1343. As another embodiment, the first and second connecting parts 124, 134 may include a first part 1242, 1342 in contact with the first and second terminal plates 122, 132 and an elastic part 1241, 1341, and the second part 1243, 1343 may be arranged on the side of the two end tabs 12a, 13a. In this case, the elastic part 1241, 1341 may be in contact with the second part 1242, 1342.

[0054] The first and second sealing parts 125, 135 may be disposed in the through hole to wrap a portion of the first and second connecting parts 124, 134 assembled in the through hole. For example, the first and second sealing parts 125, 135 may be disposed in holes formed in the first and second cover plates 121, 131 to wrap a portion of the first and second connecting parts 124, 134 disposed in the holes. The first and second sealing parts 125, 135 may be made of a material having elasticity and insulation. The first and second sealing parts 125, 135 may seal the through hole and electrically insulate the first and second connecting parts 124, 134 from the first and second cover plates 121, 131.

[0055] The first and second cover plate assemblies 120, 130 described above can be assembled in the following manner: first and second sealing components 125, 135 are provided in holes formed in the first and second cover plates 121, 131, first and second terminal plates 122, 132 and first and second (internal) insulating plates 123, 133 are provided on one side and the other side of the first and second cover plates 121, 131, respectively (in the case of the first cover plate assembly 120, the first external insulating plate 123b can be provided on one side of the first cover plate 121 together with the terminal plate 122), and then the first and second connecting components 124, 134 are assembled in the through holes formed in the assembly. The first and second connecting components 124, 134 can be fixed in a state assembled in the through holes even if they are not welded separately.

[0056] The assembled first and second cap plate assemblies 120, 130 can be respectively coupled to both sides of the length direction of the housing 110 to close the housing 110 while being connected to the negative electrode tab 12a and the positive electrode tab 13a. In a state where the first and second cap plate assemblies 120, 130 are arranged to cover both sides of the length direction of the housing 110, the first and second cap plate assemblies 120, 130 can be coupled to the housing 110 by laser welding. In a state where the first and second cap plate assemblies 120, 130 are arranged to close both sides of the length direction of the housing 110, the first and second connection parts 124, 134 can be in contact with and supported by the two end tabs 12a, 13a, and the elastic parts 1241, 1341 can be compressed in the length direction of the housing 110. Therefore, the first and second terminal plates 122, 132 and the two end tabs 12a, 13a can be connected to each other, and separate welding is not required. In addition, the electrode assembly 10 may be fixed by adjusting the pressure applied to the two end tabs 12 a and 13 a by changing the number and / or specifications of the elastic portions 1241 and 1341 .

[0057] On the other hand, the first and second cap plate assemblies 120 and 130 may be provided with a plug 150 for sealing the electrolyte injection port. The electrolyte may be injected into the inner space of the housing 110 through the electrolyte injection port.

[0058] Figure 7 FIG. 1 is a diagram schematically showing an energy storage device including a secondary battery cell according to an embodiment of the present invention.

[0059] Reference Figure 7 , the energy storage device 1 may include a plurality of secondary battery cells 100. Figure 7 As shown, the energy storage device 1 may be a battery pack, but is not limited thereto. For example, the energy storage device 1 may also be a unit smaller than a battery pack, such as a battery module.

[0060] Reference Figure 7 The energy storage device 1 may include a housing 10 provided with a space for accommodating a plurality of battery cells 100. For example, the plurality of battery cells 100 provided in each separated space of the housing 10 may be a battery module. In addition, a battery management system (BMS) 200 for controlling the plurality of battery cells 100 or the battery module may be provided on one side of the housing 10. Although not shown in the figure, a cover may be coupled to the upper portion of the housing 10.

[0061] As described above, according to the embodiments of the present invention, the number of welding times required during the assembly of the secondary battery cell 100 is reduced, so the manufacturing process becomes simple and defects caused by welding can be minimized.

[0062] Above, the configuration and features of the present invention are described based on the embodiments according to the present invention, but the present invention is not limited thereto. It is obvious to those skilled in the art that various changes or modifications can be made within the concept and scope of the present invention. Therefore, such changes or modifications belong to the appended claims.

Claims

1. A secondary battery cell, comprising: A shell, forming an internal space; an electrode assembly, comprising a negative electrode plate, a positive electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate, and disposed in the internal space; as well as a cover assembly coupled to at least one side of the housing, The electrode assembly includes a negative electrode tab and a positive electrode tab extending from the negative electrode plate and the positive electrode plate in one direction respectively. The cap plate assembly includes a connecting component, which is electrically connected to the negative electrode tab and the positive electrode tab and includes an elastic portion.

2. The secondary battery cell according to claim 1, wherein: The elastic portion has elasticity in a direction in which the cap plate assembly is coupled to the housing.

3. The secondary battery cell according to claim 1, wherein: The elastic part is composed of one or more coil springs or leaf springs.

4. The secondary battery cell according to claim 1, wherein: The cover plate assembly comprises: a cover plate coupled to the housing; a terminal board, disposed on one side of the cover plate; and an insulating plate, arranged on at least one of one side and the other side of the cover plate, The connection member is provided to penetrate the cap plate, the terminal plate, and the insulating plate.

5. The secondary battery cell according to claim 4, wherein: The terminal plate is electrically connected to the negative electrode tab or the positive electrode tab through the connecting component.

6. The secondary battery cell according to claim 5, wherein: The connection member includes a first portion that contacts the elastic portion and the terminal plate.

7. The secondary battery cell according to claim 6, wherein: The connecting member further includes a second portion, the second portion being in contact with the elastic portion and the negative electrode tab or the positive electrode tab.

8. The secondary battery cell according to claim 5, wherein: The cover plate assembly further includes a sealing component disposed between the cover plate and the connecting component.

9. The secondary battery cell according to claim 5, wherein: The cap plate, the terminal plate and the insulating plate include through holes, and the connecting member is disposed in the through holes. The connecting member is fitted in the through hole.

10. The secondary battery cell according to claim 5, wherein: The cover plate assembly comprises: A first cover plate assembly, disposed on one side of the housing in the length direction and comprising a first terminal plate electrically connected to the negative electrode tab; and The second cover plate assembly is arranged on the other side of the shell in the length direction and includes a second terminal plate electrically connected to the positive electrode tab.

11. An energy storage device, comprising: A plurality of secondary battery cells according to claim 1, The plurality of secondary battery cells are electrically connected to each other.

12. The energy storage device according to claim 11, wherein: The elastic part is composed of one or more coil springs or leaf springs.

13. The energy storage device according to claim 11, wherein: The cover plate assembly comprises: a cover plate coupled to the housing; a terminal board, disposed on one side of the cover plate; and an insulating plate, arranged on at least one of one side and the other side of the cover plate, The connection member is provided to penetrate the cap plate, the terminal plate, and the insulating plate.

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