Secondary battery and electronic device

Abstract

The utility model provides a secondary battery which comprises a shell which comprises an end wall which is provided with a first assembly hole; the upper plastic is in contact with the surface, facing the outside of the shell, of the end wall, and the upper plastic is provided with a second assembly hole corresponding to the first assembly hole; the pole comprises an outer riveting flange and a columnar part, the columnar part penetrates through the first assembly hole and the second assembly hole, the outer riveting flange is connected with one end, located outside the shell, of the columnar part, and the outer riveting flange and the end wall clamp the upper plastic together; and the metal sheet is arranged between the upper plastic and the outer riveting flange. The utility model aims to provide a secondary battery and an electronic device so as to at least improve the connection strength of a riveting pole and a shell.

Description

Technical Field

[0001] This utility model relates to a secondary battery and an electronic device. Background Technology

[0002] In the field of new energy power batteries, the application of rechargeable batteries is becoming increasingly widespread. These batteries (such as lithium-ion batteries) can be used in vehicles, energy storage, mobile phones, tablets, wearable devices, power banks, e-cigarettes, digital products, power tools, power units, and other electronic devices. Improving the stability of battery structures is a key research direction in battery technology development. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a secondary battery and electronic device to at least improve the connection strength between the riveted terminal and the housing.

[0004] To achieve the above objectives, this utility model provides a secondary battery, comprising: a casing, including an end wall having a first mounting hole; an upper plastic plate in contact with the surface of the end wall facing the outside of the casing, wherein the upper plastic plate has a second mounting hole corresponding to the first mounting hole; an electrode post, including an outer riveted flange and a columnar portion, the columnar portion passing through the first and second mounting holes, the outer riveted flange being connected to one end of the columnar portion located outside the casing and together with the end wall clamping the upper plastic plate; and a metal sheet disposed between the upper plastic plate and the outer riveted flange.

[0005] In some embodiments, the hardness of the external riveted flange is greater than the hardness of the columnar portion.

[0006] In some embodiments, the thickness of the metal sheet is T1, where 0.1 mm < T1 < 0.8 mm.

[0007] In some embodiments, the sum of the thicknesses of the metal sheet and the outer riveted flange is T2, 0.8 mm. <T2<2.0mm。

[0008] In some embodiments, a metal sheet is disposed around the columnar portion, and the diameter D2 of the outer periphery of the metal sheet is smaller than the diameter D1 of the outer riveted flange, 0.05mm < D1 - D2 < 0.5mm.

[0009] In some embodiments, the metal sheet and the columnar portion are in clearance fit, the inner periphery diameter of the metal sheet is D3, and the outer diameter of the columnar portion is D4. <D3-D4<0.4mm。

[0010] In some embodiments, the flange width of the pole post is (D2-D4) / 2, where 0.3mm < (D2-D4) / 2 < 2.5mm.

[0011] In some embodiments, the surface of the outer riveted flange facing the outside of the housing has a recessed area located between the outer edge of the outer riveted flange and the outer periphery of the metal sheet. The flatness of the terminal plane except for the recessed area is less than 0.1 mm.

[0012] In some embodiments, the secondary battery further includes: a sealing ring; and an electrode assembly accommodated in the housing. The sealing ring is disposed inside the housing facing the electrode assembly; a lower plastic, surrounding the columnar portion and contacting the surface of the end wall facing the inside of the housing; wherein, the width from the compressed edge of the sealing ring to the first assembly hole is W1, 0.8 mm < W1 < 3.0 mm, and wherein, after compression, at least part of the sealing ring contacts the lower plastic.

[0013] In some embodiments, the inner riveted flange of the terminal is connected to one end of the columnar portion located inside the housing and jointly clamps the lower plastic with the end wall. The distance between the inner periphery of the lower plastic and the outer periphery of the inner riveted flange is W2, 0.2 mm < W2 < 4.0 mm.

[0014] An embodiment of the present application further provides an electronic device, including the secondary battery of any one of the above.

[0015] The beneficial technical effect of the present utility model is that: in the embodiment of the present application, the metal sheet is disposed between the upper plastic and the outer riveted flange, which can at least improve the connection strength between the riveted terminal and the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Shows a top view schematic diagram of the secondary battery according to an embodiment of the present application.

[0018] Figure 2 Shows along Figure 1 The cross-sectional schematic diagram taken along the AA line in

[0019] Figure 3 Shows a schematic diagram when the electronic device according to an embodiment of the present application is a vehicle.

[0020] Figure 4 Shows a three-dimensional schematic diagram of the secondary battery according to an embodiment of the present application.

[0021] Figure 5A And Figure 5B Shows Figure 2 The enlarged schematic diagram of the B area in

[0022] Figure 6 It shows Figure 5B A magnified view of region C in the middle. Detailed Implementation

[0023] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0024] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0025] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0026] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0027] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0028] Figure 1 A top view schematic diagram of a secondary battery according to an embodiment of this application is shown. Figure 2 It shows along Figure 1 A schematic diagram of the cross-section taken by line AA. See also Figure 1 and Figure 2This application provides a secondary battery 100, which includes a housing 200, an electrode assembly located within the housing 200, a current collector, and terminal posts 50 mounted on the housing 200. The housing 200 includes an end wall 111 and side walls surrounding the end wall 111. The housing 200 can be formed in various ways, such as integral stamping, integral casting, or separate welding, as long as a stable seal and electrical connection can be established. A receiving cavity is formed within the housing 200 to accommodate the electrode assembly, electrolyte, current collector, and other necessary battery components. Specifically, the diameter of the housing 200 can be determined according to the specific dimensions of the electrode assembly. The housing 200 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent rusting during long-term use, a rust-preventive material such as metallic nickel can be plated onto the surface of the housing 200. The secondary battery 100 can be a cylindrical battery, such as a 4680 cylindrical battery with a height of 80mm and a diameter of 46mm; or a battery with a height of 15mm and a diameter of 46mm.

[0029] Electrode assemblies are components in the secondary battery 100 where electrochemical reactions occur. The housing 200 may contain one or more electrode assemblies. The electrode assembly is a wound or stacked electrode assembly, including a stacked and / or wound positive electrode, a first separator, a negative electrode, and a second separator. The positive electrode includes a positive current collector and a positive active material layer coated on the positive current collector. A first coated area coated with the positive active material layer and a first uncoated area without the positive active material layer are formed on the positive current collector. The first coated area and the first uncoated area are arranged along the height direction of the electrode assembly. The first uncoated area extends beyond the separator at one end in the height direction of the secondary battery 100, forming a bent positive electrode tab. The negative electrode includes a negative current collector and a negative active material layer coated on the negative current collector. A second coated area with the negative active material layer and a second uncoated area without the negative active material layer are formed on the negative current collector. The second coated area and the second uncoated area are arranged along the height direction of the electrode assembly. The second uncoated area also extends towards one end of the secondary battery 100 in the height direction to the outside of the separator, forming a bent negative electrode tab. The first separator and the second separator are disposed between the positive electrode and the negative electrode to isolate the positive and negative active material layers. Taking the lithium-ion secondary battery 100 as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The material of the negative current collector can be copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the first separator and the second separator can be PP (polypropylene) or PE (polyethylene), etc. To protect and insulate the electrode assembly, an insulating film can be wrapped around the outside of the electrode assembly. The insulating film can be synthesized from PP, PE, PET, PVC or other polymer materials.

[0030] This utility model provides an electronic device 1000. In some embodiments, the electronic device 1000 may include a battery pack, a battery array 1002, an electric vehicle, an energy storage cabinet, etc. For ease of explanation, the following embodiments use a vehicle as an example to illustrate the electronic device 1000. See also... Figure 3The vehicle's interior is equipped with a battery pack 1002. Another electronic device 1000, such as the battery pack 1002, can be located at the bottom, head, or tail of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's movement or the operation of its internal electrical components. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner's suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0031] Figure 4 A perspective view of a secondary battery 100 according to an embodiment of this application is shown. Figure 5A and Figure 5B It shows Figure 2 Enlarged diagram of region B in the middle. Figure 6 It shows Figure 5B A magnified view of region C. See also Figure 5A , Figure 5B and Figure 6In some embodiments, the end wall 111 has a first mounting hole 1110, the upper plastic 121 contacts the surface of the end wall 111 facing the outside of the housing 200, and the lower plastic 131 contacts the surface of the end wall 111 facing the inside of the housing 200. The upper plastic 121 has a second mounting hole 1210 corresponding to the first mounting hole 1110, and the lower plastic 131 has a third mounting hole corresponding to the first mounting hole 1110 and the second mounting hole 1210. In some embodiments, the pole post 50 includes an outer riveting flange 51, a columnar portion 52, and an inner riveting flange 53. The outer riveting flange 51 is located outside the housing 200, and the columnar portion 52 passes through the first mounting hole 1110 and the second mounting hole 1210. The outer riveting flange 51 is connected to the end of the columnar portion 52 of the electrode post 50 located outside the housing 200. The inner riveting flange 53 is connected to the end of the columnar portion 52 of the electrode post 50 located inside the housing 200. The inner riveting flange 53 and the end wall 111 together clamp the lower plastic 131, and the outer riveting flange 51 and the end wall 111 together clamp the upper plastic 121. The inner riveting flange 53 of the electrode post 50 contacts the surface of the lower plastic 131 facing the electrode assembly / the surface away from the end wall 111 and fixes the lower plastic 131 to the inner side of the end wall 111 facing the inside of the housing 200. The outer riveting flange 51 of the electrode post 50 contacts the surface of the upper plastic 121 away from the end wall 111 and fixes the lower plastic 131 to the outer side of the end wall 111 away from the inside of the housing 200. The upper plastic 121 and the lower plastic 131 surround the columnar portion 52. The metal sheet 311 is disposed between the upper plastic 121 and the outer riveted flange 51. Since the pole post 50 is externally riveted, the outer riveted flange 51 is formed on the outside of the housing 200. In the prior art, the flange size for external riveting of the pole post is limited, the flanged edge has a large R angle, and the external dimensions are unstable.

[0032] To avoid the above problems, an internal riveting structure solution can be adopted to ensure the stability and accuracy of the dimensions related to the customer interface. However, the steps of adopting the internal riveting structure solution are numerous, the process is complex, and the stability of samples between different batches is poor. According to an embodiment of the present application, by means of the metal sheet 311 disposed between the upper plastic 121 and the outer riveting flange 51, at least the connection strength between the riveting pole 50 and the housing 200 can be improved. Additionally, the flange size can be enlarged, and the R angle at the edge after flanging can be reduced, so that the dimensions related to the customer interface are stable and the strength of the pole 50 is increased. In some embodiments, the hardness of the outer riveting flange 51 is greater than the hardness of the columnar part 52. It can be understood that by applying a large pressure to flatten the outer riveting flange 51, the metal hardness of the outer riveting flange 51 is increased, that is, the riveting strength of the outer riveting flange 51 is increased, making the outer riveting flange 51 not easily deformed after riveting, and ensuring that the accumulated pressure of the outer riveting flange 51 on the sealing component located inside the secondary battery 100 is large enough to ensure sealing. The hardness measured at a point in the middle position in the radial direction of the outer riveting flange 51 can be used as the hardness of the riveting flange, and the hardness measured in the central region of the columnar part 52 can be used as the hardness of the columnar part 52. Further, since the metal sheet 311 is disposed between the outer riveting flange 51 and the upper plastic 121, in order to prevent the pole 50 from cracking during bending, the transition angle 511 between the outer riveting flange 51 and the columnar part 52 can be set as a non-right-angle transition to form at least a reserved material extrusion space 512 spaced apart from the metal sheet 311. Further, the corner 3111 of the metal sheet 311 corresponding to the transition angle 511 can also be set as a non-right-angle transition to further increase the reserved material extrusion space 512. The thickness of the metal sheet 311 is T1, 0.1mm < T1 < 0.8mm, preferably, 0.3mm < T1 < 0.5mm. In some embodiments, the sum of the thickness of the metal sheet 311 and the outer riveting flange 51 is T2, 0.8mm < T2 < 2.0mm, preferably, 1.2mm < T2 < 1.6mm. The metal sheet 311 is disposed around the columnar part 52, and the diameter D2 of the outer perimeter of the metal sheet 311 is smaller than the diameter D1 of the outer riveting flange 51, 0.05mm < D1 - D2 < 0.5mm, preferably, 0.1mm < D1 - D2 < 0.3mm. It can be understood that there can be a clearance fit between the metal sheet and the columnar part. The diameter of the inner perimeter of the metal sheet is D3, and the outer diameter of the columnar part 52 is D4, D3 > D4, and 0 < D3 - D4 < 0.4mm, preferably, 0 < D3 - D4 < 0.2mm. It can be understood that the flanging width of the pole 50 is (D2 - D4) / 2, 0.3mm < (D2 - D4) / 2 < 2.5mm, preferably, 1mm < (D2 - D4) / 2 < 1.5mm.It can be understood that since the diameter D1 of the outer riveted flange 51 is greater than the diameter D2 of the outer periphery of the metal sheet 311, during the riveting process, the outer edge of the outer riveted flange 51 that extends beyond the outer periphery area of the metal sheet 311 will be collapsed, thus forming a recessed area on the surface of the outer riveted flange 51 facing the outside of the housing 200. It can be understood that the flatness of the flat surface of the terminal 50 except for the recessed area is less than 0.1 mm. The flat surface of the terminal is also the top flat surface where the terminal 50 protrudes outside the housing 200 of the secondary battery 100. The above content can also be understood as that the recessed area does not protrude from the flat surface of the terminal, thus not affecting the welding with the busbar when multiple secondary batteries 100 are connected in series or parallel. The good flatness of the flat surface of the terminal 50 except for the recessed area enables a good fitting effect between the secondary battery 100 and the busbar. In some embodiments, the secondary battery 100 further includes a sealing ring 411. The sealing ring 411 is disposed inside the housing 200 facing the electrode assembly. The width from the compressed edge of the sealing ring 411 to the first assembly hole 1110 is W1, and 0.8 mm < W1 < 3.0 mm. Preferably, 1.2 mm < W1 < 2.3 mm. In some embodiments, after being compressed, at least part of the sealing ring 411 contacts the edge of the lower plastic 131 facing away from the columnar portion 52. In some embodiments, the distance between the inner periphery of the lower plastic 131 and the outer periphery of the inner riveted flange 53 is W2, and 0.2 mm < W2 < 4.0 mm. As a preference, the range of W2 is within 0.5 mm < W2 < 2.5 mm.

[0033] An embodiment of the present application further provides an electronic device 1000, including the secondary battery 100 of any one of the above, and the electronic device 1000 can have the beneficial effects described above regarding the secondary battery 100.

[0034] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A secondary battery characterized by comprising: The secondary battery comprises: a case including an end wall having a first fitting hole; an upper plastic in contact with a surface of the end wall facing outside of the case, wherein the upper plastic has a second fitting hole corresponding to the first fitting hole; a pole including an outer riveting flange and a columnar portion, the columnar portion passing through the first fitting hole and the second fitting hole, the outer riveting flange being connected to an end of the columnar portion located outside of the case and clamping the upper plastic together with the end wall; a metal sheet disposed between the upper plastic and the outer riveting flange.

2. The secondary battery according to claim 1, characterized by The hardness of the outer riveting flange is greater than the hardness of the columnar portion.

3. The secondary battery according to claim 1, characterized by The thickness of the metal sheet is T1, 0.1mm < T1 < 0.8mm.

4. The secondary battery according to claim 3, characterized by The sum of the thicknesses of the metal sheet and the outer riveting flange is T2, 0.8mm < T2 < 2.0mm.

5. The secondary battery according to claim 1, characterized by The metal sheet is disposed around the columnar portion, the outer periphery of the metal sheet having a diameter D2 less than the diameter D1 of the outer riveting flange, 0.05mm < D1-D2 < 0.5mm.

6. The secondary battery according to claim 5, characterized by The metal sheet is in clearance fit with the columnar portion, the inner periphery of the metal sheet having a diameter D3, and the outer diameter of the columnar portion being D4, 0 < D3-D4 < 0.4mm. The flange width of the pole is (D2-D4) / 2, 0.3mm < (D2-D4) / 2 < 2.5mm.

7. The secondary battery according to claim 6, characterized by The surface of the outer riveting flange facing outside of the case has a recessed area between the outer edge of the outer riveting flange and the outer periphery of the metal sheet, the flatness of the pole plane except the recessed area being less than 0.1mm. The secondary battery further comprises:

8. The secondary battery according to claim 6, characterized by a sealing ring; and an electrode assembly accommodated in the case, the sealing ring being disposed inside of the case facing the electrode assembly; 9. The secondary battery according to claim 1, characterized by a lower plastic surrounding the columnar portion and in contact with a surface of the end wall facing inside of the case; wherein the width of the edge of the sealing ring after compression to the first fitting hole is W1, 0.8mm < W1 < 3.0mm, and wherein the sealing ring after compression is at least partially in contact with the lower plastic. The inner riveting flange of the pole is connected to an end of the columnar portion located inside of the case and clamps the lower plastic together with the end wall, the distance between the inner periphery of the lower plastic and the outer periphery of the inner riveting flange being W2, 0.2mm < W2 < 4.0mm. The secondary battery comprises any one of claims 1 to 10. The secondary battery comprises any one of claims 1 to 10. ​ 10. The secondary battery according to claim 9, characterized by ​ ​ 11. An electronic device, comprising: ​

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