A rivet component and an energy storage cell comprising the rivet component

Abstract

Examples of a rivet component and an energy storage cell comprising the rivet component are described. In an example, the rivet component includes a planar portion including a depression formed on a first surface of the planar portion. The rivet component further includes a hollow shaft which is extending orthogonally away from a base member of the depression. Such rivet component is to be installed on a cell body which includes a first end and a second end. To install, the rivet component is positioned on a top surface of the first end so that the planar portion rest on the top surface of the first end with the depression and the hollow shaft passes through or inserted into an opening to be flanged in contact with a bottom surface of the first end to integrate the rivet component with the cell body.

Description

A RIVET COMPONENT AND AN ENERGY STORAGE CELL COMPRISING THE RIVET COMPONENTBACKGROUND

[0001] Energy storage devices, such as cells or batteries, are typically used in variety of electrical and mechanical devices to power different components of these devices. Examples of such devices include, but are not limited to mobile phones, electronic cameras, automobiles, watches, etc. Generally, such cells include a metallic shell accommodating current collector, insulation plate, gasket, rivet, and other components. To provide a sealed input or a leak proof entry into the cell for insertion of material, such as electrolyte, a rivet, which is made up of sheet metal, having a planar surface is welded with the current collector on top of the cell in an opening.BRIEF DESCRIPTION OF DRAWINGS

[0002] The detailed description is provided with reference to the accompanying figures, wherein:

[0003] FIG. 1 illustrates a side view of a rivet component, in accordance with one example of the present subject matter;

[0004] FIG. 2A illustrates a side view of a rivet component positioned on a top surface of a cell body of an energy storage cell, in accordance with one example of the present subject matter;

[0005] FIG. 2B illustrates a side view of a rivet component installed on a top surface of the cell body of an energy storage cell, in accordance with one example of the present subject matter;

[0006] FIG. 2C illustrates an isometric view of an energy storage cell with a rivet component installed, in accordance with an example of the present subject matter;

[0007] FIG. 3A illustrates a perspective view of an energy storage cell with terminals of a bus bar attached, in accordance with one example of the present subject matter; and

[0008] FIG. 3B-3C illustrates isometric views of an energy storage cell with terminals of a bus bar attached onto it, in accordance with one example of the present subject matter.

[0009] It may be noted that throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and / or implementations consistent with the description; however, the description is not limited to the examples and / or implementations provided in the drawings.DETAILED DESCRIPTION

[0010] As would be understood, the rapid progress of the global economy and technology has advanced human civilization resulting in transportation of peoples and goods from one place to another. Generally, during transportation, internal combustion engine vehicles are used which lead to tremendous damage to the global ecological environment. One of the solutions to environment problems caused by such transportation is to use new energy vehicles which does not affect the environment. For example, vehicles powered by electric rechargeable energy storage batteries or cells are used nowadays to curb environmental pollution. Such energy storage cells or batteries storing energy to power different electrical and mechanical devices may also be used to power other types of loads as well.

[0011] Such energy storage cells include, among other components, a metallic shell or can, a current collector, and a rivet. In such energy storage cells, in one example, a jelly roll on top of which the current collector is connected or welded is inserted into the metallic can. The metallic can itself includes the sheet metal rivet which is stamped on the top surface of the metallic can. Thereafter, the planar portion of such sheet metal rivet, which comes in contact with the current collector, is welded with the current collector to act as a terminal for the energy storage cell. It may be noted that, the planar portion of sheet metal rivet, which is welded with the current collector, is comparatively thinner which leads tofailure while extracting high current from the cell. Further, such connection of rivet as terminal onto the cell lacks protection from potential leakage, does not provide better packaging robustness, does not provide better thermal exchange properties, etc.

[0012] Accordingly, it is desirable to provide such a rivet component installable onto an energy storage cell in connection with the current collector which does not fail during extraction of high current, provide protection from potential leakage, having better packaging robustness, and provide better thermal exchange properties.

[0013] Examples of a rivet component and an energy storage cell comprising the rivet component are described. In an example, the rivet component includes a planar portion which further includes a first surface and a second surface. In one example, a first thickness of the planar portion is about 1 mm. Such first thickness of the planar portion enables proper sealing ability, provide structural stability, improves current carrying capacity and ensures good contact with external bus bar terminals. The planar portion further includes a depression formed on the first surface of the planar portion. The depression is defined by a side wall and a base member which is to extend certain portion of the planar portion to a depth. For example, in case of cylindrical depression, the side walls are walls of cylinder, and the base member is the flat base of such cylinder. In an example, a second thickness of the base member is about 0.8mm. Such second thickness of the base member of the depression enables laser welding to happen to connect the rivet component with a current collector and provides structural stability as well. However, the depression may be formed of any shape, e.g., cuboidal, semi-spherical, etc., without deviating from the scope of the present subject matter.

[0014] Continuing further, the rivet component includes a hollow shaft which is extending orthogonally from away from the base member of the depression and away from planar portion as well. In an example, a third thickness of the side walls of the hollow shaft is less than that of the first thickness and the second thickness. Such rivet component is used to be installed on a cell can or cell body of an energy storage cell. In an example, the energy storage cell includes the cellbody including a first end and a second end. The first end further includes a top surface and a bottom surface with an opening formed either in center or at any other position on the first end.

[0015] To install the rivet component onto the energy storage cell, the rivet component is positioned on the top surface of the first end of the cell body. Once positioned, the planar portion of the rivet component rest on the top surface of the first end of the cell body with the depression and the hollow shaft passes through or inserted into the opening formed on the top surface of the first end of the cell body. In an example, the opening formed on the first end of the cell body is of such a dimension that it accommodates or lets the depression, and the hollow shaft passes through it to extend into the cell body. In another example, while installing the rivet component onto the cell body, the rivet component further includes a gasket which is accommodated around the outer surface of the rivet component. In an example, the gasket is made up of a insulation material, such as rubber or plastic, which provides an insulation to the rivet component with respect to other components of the energy storage cells.

[0016] Returning to the present example, once the rivet component is positioned, the hollow shaft which is extending into the cell body is flanged in contact with the bottom surface of the first end of the cell body to integrate the rivet component with the cell body or to seal the rivet component onto the cell body of the energy storage cell. Once flanged, the base member of the depression which is formed on the planar portion is welded to a current collector. For example, a jelly roll with the current collector attached on its top surface is inserted into the cell body from the second end of the cell body. While inserting, a protrusion formed on the current collector comes in contact with the base member of the depression formed on the rivet component. In an example, the dimension of the protrusion of the current collector is similar to that of the depression to provide a complete contact between the two. Once contacted, the base member is welded to the protrusion of the current collector using one of laser welding and ultrasonic welding. In an example, the welding is performed from the first surface of the rivet component to insert into the depression andthereby weld the base member of the depression with the protrusion of the current collector.

[0017] It may be noted that the examples as described above have been described in the context that a rivet component is integrated with the first end of the cell body with the current collector entering from the second end. The same should not be construed as a limitation and in another example, the rivet component may be integrated with the second end and the current collector is inserted from the first end without deviating from the scope of the present subject matter.

[0018] The above-described rivet component on installation onto the energy storage cell provide various advantages over the conventionally available rivets. For example, since the present rivet component is formed in the form of a billet providing a suitable thickness of different structures, the rivet component is able to withstand failure caused at the time of high current extraction from the energy storage cell. Further, the present rivet component provides protection from potential leakage, having better packaging robustness, provide better thermal exchange properties, and provide better integrity during thermal runaway process.

[0019] The above aspects are further described in conjunction with the figures, and in associated description below. It should be noted that the description and figures merely illustrate principles of the present subject matter. Therefore, various assembly that encompass the principles of the present subject matter, although not explicitly described or shown herein, may be devised from the description and are included within its scope.

[0020] An example rivet component is depicted in FIG.1. FIG. 1 illustrates a side view of a rivet component 100, in accordance with one implementation of the present subject matter. In one example, the rivet component 100 includes a planar portion 102 having a first surface 104 and a second surface 106. In an example, the planar portion 102, as depicted in FIG. 1 A-1 B, is a circular plate having a first thickness. The value of the first thickness, in one example, is 1 mm. This first thickness is of such value that it provides improved sealing ability, improved structural robustness, improves current carrying capacity (when rivetcomponent acts as a terminal of an energy storage cell), and ensures good contact or weldability when connected with the bus bar terminals.

[0021] Continuing further, the planar portion 102 of the rivet component 100 further includes a depression 108 formed on the first surface 104. In an example, the depression 108 is defined by a side wall 1 10 and a base member 1 12 which is to extend the planar portion 102 to a depth of about 0.65 mm. For example, in case of a cylindrical depression, the side wall 1 10 of the depression are side walls of cylinder and the base member 1 12 is the base of the cylinder. In an example, the base member 112 of the depression 108 is of a second thickness having value 0.8 mm. It may be noted that, such value of second thickness of the base member 1 12 enables proper laser welding and provides structural stability as well. In one example, such depression 108 on the planar portion 102 is formed by one of a machining process, cold forging process, and metal injection molding process. For example, the rivet component 100 is formed as a billet instead of a sheet metal material as compared to conventional rivets.

[0022] Returning to the present example, the rivet component 100 further includes a hollow shaft 1 14 which extending away from the base member 1 12 and away from the planar portion 102 as well. In case of a circular planar portion and a cylindrical depression, the hollow shaft 114 is also of cylindrical shape. It may be noted that, although, the planar portion 102 is depicted as circular plate, however, it may be of any shape. Further, the depression 108 and the hollow shaft 1 14 are depicted as having cylindrical extension, however, any other shape such as cuboidal may also be used without deviating from the scope of the present subject matter.

[0023] The rivet component 100 is to be installed onto an energy storage cell. While installing the rivet component 100 onto the energy storage cell, the rivet component 100 is, initially, positioned on top and in contact with a top surface of a cell body of the energy storage cell and then integrated onto the cell body by converting the hollow shaft into flanges which comes in contact with a bottom surface of the cell body. The detailed description of installation of rivet component 100 onto the energy storage cell is depicted in conjunction with FIG. 2A-2C.

[0024] FIG. 2A-2B illustrates different views of an energy storage cell while installing the rivet component. Specifically, FIG. 2A depicts a side of a first end of a cell body with a rivet component positioned, FIG. 2B depicts a side view of a first end of the cell with the rivet component integrated, and FIG. 2C depicts an isometric view of an energy storage cell with the rivet component integrated and welded, in accordance with an example of the present subject matter.

[0025] As depicted in FIG. 2C, an energy storage cell, such as energy storage cell 200, includes a cell body 202 or a cell can. In an example, the cell body 202 may take any shape, e.g., cylindrical, cuboidal, prismatic, etc. In another example, the cell body 202 is made up of a metallic material. The cell body 202 includes a first end 204 and a second end 206 with the first end 204 including a top surface 208 and a bottom surface (not visible in FIG. 2C). In an example, the top surface 208 of the first end 204 of the cell body 202 further includes an opening (not shown in FIG. 2C). In an example, such opening may be formed at either centre of the first end 204 or at any other position based on the requirement and structural ability of the energy storage cell 200.

[0026] While installing a rivet component, such as rivet component 100, on the energy storage cell 200, the rivet component 100 is initially positioned on the top surface 208 of the first end 204 of the cell body 202. For example, as depicted in FIG. 2A, the rivet component 100 is positioned on top surface 208 of the first end 204 of the cell body 202. Once positioned, the the planar portion 102 of the rivet component 100 rest on the top surface 208 of the first end 204 of the cell body 202 with the depression 108 and the hollow shaft 1 14 passes through or inserted into the opening formed on the top surface 208 of the first end 204 of the cell body 202. In an example, the opening formed on the first end 204 of cell body 202 is of such a dimension that it accommodates or lets the depression 108 and the hollow shaft 1 14 passes through it to extend inside the cell body 202. In one example, while installing the rivet component 100 onto the cell body 202, the rivet component 100 further includes a gasket, such as gasket 116, which is accommodated around the outer surface of the rivet component 100. In an example, gasket 1 16 is made up of an insulation material, such as rubber orplastic, which provides an insulation to the rivet component 100 with respect to other components of the energy storage cell 200.

[0027] Returning to the present example, once the rivet component 100 is positioned on the top surface 208 of the first end 204 of the cell body 202, as depicted in FIG. 2B and 2C, the hollow shaft 1 14 which is extending into the cell body 202 is flanged in contact with the bottom surface of the first end 204 of the cell body 202 to integrate the rivet component 100 with the cell body 202 or to seal the rivet component 100 onto the cell body 202 of the energy storage cell 200. Once flanged, the base member 112 of depression 108 which is formed on the planar portion 102 is welded to a current collector. For example, a jelly roll 214 with the current collector 210 attached on its top surface is inserted into the cell body 202 from the second end 206. Once inserted, a protrusion 212 formed on the current collector 210 comes in contact with the base member 1 12 of the depression 108 formed on the rivet component 100. In an example, the dimension of protrusion 212 of the current collector 210 is similar to that of the depression to provide a complete contact between the two components.

[0028] Once contacted, the base member 112 is welded to the protrusion 212 of the current collector 210 using laser welding. In an example, the laser from the laser welding penetrates the contacted surfaces from the first surface 104 of the rivet component 100 to insert into the depression and thereby weld the base member 112 with the protrusion 212 of the current collector 210. As a result of such welding, a junction is formed between the rivet component 100 and the current collector 210 which acts as a cathode or anode. The welded structure thus formed is able to withstand the failure which may have been caused during high current extraction. Further, such welded structure along with the gasket provide protection from potential leakage, have better packaging robustness, and provide better thermal exchange properties as well.

[0029] The depression 108 formed on the rivet component 100 which is installed onto the energy storage cell 200 may be used to accommodate or connect to an input terminal of a bus bar. The usage of depression 108 as a connecting point to the bus bar terminals is depicted in conjunction with FIG. 3A- 3C.

[0030] FIG. 3A illustrates a perspective view of an energy storage cell with terminals attached and FIG. 3B-3C illustrates isometric views of an energy storage cell with terminals attached onto it, in accordance with one example of the present subject matter. As depicted in FIG. 3A-3C, an energy storage cell, such as energy storage cell 200 is connected to a bus bar. The bus bar includes a positive terminal 302 and a negative terminal 304. It may be noted that, alternatively, the 302 may be the negative terminal and the 304 may be the positive terminal. The positive terminal 302 is connected or accommodated into the depression 108 formed on the rivet component 100 so as to make the rivet component 100 as the positive terminal. On the other hand, the negative terminal 304 is connected to the top surface 208 of the first end 204 of the cell body 202 of the energy storage cell 200 via welding or any other process.

[0031] As depicted in FIG. 3B-3C, the positive terminal 302 includes a planar element 306 and an engaging member 308 protruding away from the planar element 306. In an example, the planar element 306 along with the engaging member 308 is engaged or accommodated into the depression 108 of the rivet component 100 so as to make the rivet component 100 to act as the positive terminal. Similar to this, the negative terminal 304 includes a pair of contacting member 310 which is to be contacted onto the top surface 208 of the first end 204 of the cell body 202 so as to make the rest of the top surface 208 of the first end 204 to act as the negative terminal. In another example, the opposite implementation, i.e., the rivet component 100 to act as negative terminal and the rest of the top surface 208 as positive terminal is also possible without deviating from the scope of the present subject matter.

[0032] It may be noted that the examples as described above have been described in context of a cylindrical energy storage cell. However, the same should not be construed as a limitation and the approaches as described above may be implemented with any other shapes of cells as well without deviating from the scope of the present subject matter.

[0033] Although aspects and other examples have been described in a language specific to structural features and / or methods, the present subject matter is not necessarily limited to such specific features or elements asdescribed. Rather, the specific features are disclosed as examples and should not be construed to limit the scope of the present subject matter.

Claims

I / We Claim:1 . A rivet component (100) comprising: a planar portion (102) comprising a first surface (104) and a second surface (106), wherein the first surface (104) of the planar portion (102) comprises a depression (108) defined by a side wall (1 10) and a base member (112) to extend the planar portion (102) to a depth; and a hollow shaft (1 14) extending orthogonally away from the base member (112) of the depression (108) and the planar portion (102).

2. The rivet component (100) as claimed in claim 1 , wherein a first thickness of the planar portion (102) is 1 mm.

3. The rivet component (100) as claimed in claim 1 , wherein a second thickness of the base member (1 12) of the depression (108) is 0.8 mm.

4. The rivet component (100) as claimed in claim 1 , wherein the rivet component (100) is to be installed on top and in contact with a first end (204) of a cell body (202) of an energy storage cell (200), wherein on installing, the planar portion (102) of the rivet component (100) rest on a top surface (208) of the first end (204) of the cell body (202) with the depression (108) and the hollow shaft (114) inserted into an opening formed on the top surface (208) of the first end (204) of the cell body (202).

5. The rivet component (100) as claimed in claim 1 , wherein the hollow shaft (114) of the rivet component (100) is flanged in contact with a bottom surface of the first end (204) of the cell body (202) to integrate the rivet component (100) with the cell body (202).

6. The rivet component (100) as claimed in claim 5, wherein when installed on the cell body (202) and the hollow shaft (114) is flanged in contact with the bottom surface of the first end (204) of the cell body (202), the base member (1 12) of the depression (108) which is formed on the planar portion (102) is welded with a current collector (210) comprised in the cell body (202) using one of laser welding and ultrasonic welding.

7. The rivet component (100) as claimed in claim 1 , wherein the rivet component (100) further comprises a gasket (1 16) to be accommodated around the outer surface of the rivet component (100) to provide an insulation to the rivetcomponent (100) with respect to other components of the energy storage cell (200).

8. The rivet component (100) as claimed in claim 1 , wherein a shape of the depression (108) formed on the first surface (104) of the planar portion (102) is one of a cylindrical, cuboidal, and semi-spherical.

9. The rivet component (100) as claimed in claim 1 , wherein the depression (108) on the first surface (104) of the planar portion (102) is formed by one of machining, cold forging, and metal injection molding process.

10. An energy storage cell (200) comprising: a cell body (202) comprising a first end (204) with an opening and a second end (206); and a rivet component (100) positioned on a top surface (208) of the first end (204) of the cell body (202), wherein on positioning, a planar portion (102) of the rivet component (100) rest on the top surface (208) of the first end (204) of the cell body (202) with a depression (108) and a hollow shaft (1 14) of the rivet component (100) passes through the opening, wherein the hollow shaft (114) is flanged onto a bottom surface of the first end (204) of the cell body (202) to integrate the rivet component (100) with the cell body (202).1 1. The energy storage cell (200) as claimed in claim 10, wherein the rivet component (100) comprises: the planar portion (102) comprising a first surface (104) and a second surface (106), wherein the first surface (104) of the planar portion (102) comprises the depression (108) defined by a side wall (1 10) and a base member (112) to extend the planar portion (102) to a depth; and the hollow shaft (1 14) extending orthogonally away from the base member (112) of the depression (108) and the planar portion (102).

12. The energy storage cell (200) as claimed in claim 1 1 , wherein a first thickness of the planar portion (102) is 1 mm and a second thickness of the base member (1 12) of the depression (108) is 0.8 mm.

13. The energy storage cell (200) as claimed in claim 1 1 , wherein the depression (108) of the rivet component (100) is used as an input point to connect one of a positive and a negative terminal from a bus bar.

14. The energy storage cell (200) as claimed in claim 10, wherein the rivet component (100) further comprises a gasket (1 16) to be accommodated around the outer surface of the rivet component (100) to provide an insulation to the rivet component (100) with respect to other components of the energy storage cell (200).

15. The energy storage cell (200) as claimed in claim 10, wherein when the rivet component (100) is positioned on the cell body (202) and the hollow shaft (1 14) is flanged in contact with the bottom surface of the first end (204) of the cell body (202), the base member (1 12) of the depression (108) is welded with a current collector (210) comprised in the cell body (202) using one of laser welding and ultrasonic welding.

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