Cover plate, shell and battery

Abstract

The utility model discloses a cover plate, a shell and a battery, the cover plate comprises a substrate, an insulating layer and a top plate, and the substrate is provided with a first through hole; the insulating layer is arranged on one side of the substrate, and a second through hole communicated with the first through hole is formed in the insulating layer; the top plate is arranged on one side, deviating from the substrate, of the insulating layer, an explosion-proof part is arranged on the top plate, and the explosion-proof part covers the second through hole and is used for being connected with a tab; and the explosion-proof part generates plastic deformation when being stressed. According to the utility model, the explosion-proof part is connected with the tab, and the explosion-proof part can generate plastic deformation under pressure, so that the internal pressure of the battery is increased, the explosion-proof part is pushed to expand outwards and the tab is snapped if a large amount of gas is generated due to electrolyte decomposition caused by overcharge of the battery, and the circuit breaking effect is realized, so that the current flow in the battery is cut off; therefore, battery explosion and fire can be avoided, and the safety performance of the battery is effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of batteries, in particular to a cover plate, a shell and a battery. Background Art

[0002] With the continuous development of science and technology, terminal products have higher and higher requirements for the safety performance of button-type batteries. The current button-type batteries still have certain problems in their safety performance under high voltage overcharging conditions.

[0003] At present, the explosion-proof method used in button-type batteries produced in the industry is to set a notch at the bottom of the shell, and the notch is semi-circular, and the tab is connected to the outside of the notch at the bottom of the shell. When the battery is overcharged at a high voltage, the shell will crack at the notch position to release the pressure. Since the tab is connected to the outside of the notch at the bottom of the shell, the charging process cannot be interrupted, and the electrochemical reaction is still maintained inside the battery, and the safety performance is poor. Utility Model Content

[0004] The embodiments of the utility model provide a cover plate, a housing and a battery, which can prevent the battery cell from catching fire or exploding when overcharged at a high voltage, thereby improving the safety performance of the battery.

[0005] Specifically, the utility model provides a cover plate, including a substrate, an insulating layer and a top plate, wherein a first through hole is arranged on the substrate; the insulating layer is arranged on one side of the substrate, and a second through hole connected to the first through hole is arranged on the insulating layer; the top plate is arranged on the side of the insulating layer away from the substrate, and an explosion-proof part is arranged on the top plate, and the explosion-proof part covers the second through hole and is used to be connected to the pole ear; the explosion-proof part produces plastic deformation when subjected to pressure.

[0006] Optionally, the explosion-proof portion is recessed along a side of the top plate away from the insulating layer toward the first through hole to form an arc surface; the bottom of the arc surface is located in the first through hole.

[0007] Optionally, the distance between the bottom of the arc surface and the upper surface of the top plate is 0.3 mm to 0.5 mm;

[0008] The projection of the arc surface on the top plate is a circle with a radius of 1.5 mm to 3 mm.

[0009] Optionally, an angle between a tangent line at a connection point between the arc surface and the top plate and the top plate is ≤45°.

[0010] Optionally, the second through hole is coaxially arranged with the first through hole.

[0011] Optionally, the top plate and the explosion-proof part are integrally stamped and formed.

[0012] Optionally, the top plate is made of soft metal, and the soft metal includes any one of aluminum, lead, tin, and zinc.

[0013] The utility model further provides a shell, comprising a containing tube and a cover plate as described in any one of the above items, wherein an opening is arranged at one end of the containing tube, and the cover plate seals the opening of the containing tube.

[0014] Optionally, the base plate is connected to a side wall of the accommodating tube, and the top plate is located on a side of the base plate facing away from the accommodating tube.

[0015] The utility model also provides a battery, comprising a winding core and a shell as described in any one of the above items, wherein the winding core is arranged in the shell.

[0016] Optionally, the winding core includes a positive electrode lug and a negative electrode lug, and the positive electrode lug or the negative electrode lug extends along a preset straight line and is connected to a central position of the explosion-proof portion.

[0017] The beneficial effects of the utility model are:

[0018] In the cover plate, shell and battery provided by the utility model, since the explosion-proof part is connected to the pole ear and the explosion-proof part can produce plastic deformation when subjected to pressure, if the battery is overcharged and the electrolyte decomposes to produce a large amount of gas, the internal pressure of the battery will increase, and the gas will pass through the first through hole and the second through hole to push the explosion-proof part to expand outward, breaking the pole ear and achieving a circuit-breaking effect, thereby cutting off the current flow inside the battery, thereby avoiding battery explosion and fire, and effectively improving the safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 It is a schematic structural diagram of a cover plate in the first embodiment of the utility model;

[0021] Figure 2 It is a schematic structural diagram of a battery in the first embodiment of the utility model.

[0022] In the figure: 100, substrate, 110, first through hole, 200, insulating layer, 210, second through hole, 300, top plate, 310, explosion-proof part, 400, accommodating tube, 500, winding core, 510, positive electrode ear, 520, negative electrode ear. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0024] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Figure 1 Schematic diagram of the structure of the cover plate in the first embodiment of the utility model, such as Figure 1 As shown, and refer to Figure 2 The utility model provides a cover plate, characterized in that it includes a substrate 100, an insulating layer 200 and a top plate 300, wherein the substrate 100 is provided with a first through hole 110; the insulating layer 200 is arranged on one side of the substrate 100, and the insulating layer 200 is provided with a second through hole 210 connected with the first through hole 110; the top plate 300 is arranged on the side of the insulating layer 200 away from the substrate 100, and the top plate 300 is provided with an explosion-proof part 310, which covers the second through hole 210 and is used to be connected with the pole ear; the explosion-proof part 310 undergoes plastic deformation when subjected to pressure.

[0027] In the embodiment of the utility model, since the explosion-proof part 310 is connected to the pole ear, and the explosion-proof part 310 can produce plastic deformation when subjected to pressure, if the battery is overcharged and the electrolyte decomposes to produce a large amount of gas, the internal pressure of the battery will increase. The gas passes through the first through hole 110 and the second through hole 210 to push the explosion-proof part 310 to expand outward, breaking the pole ear to achieve a circuit-breaking effect, thereby cutting off the current flow inside the battery, thereby avoiding battery explosion and fire, and effectively improving the safety performance of the battery.

[0028] In an embodiment of the present invention, the explosion-proof portion 310 is recessed along a side of the top plate 300 away from the insulating layer 200 toward the first through hole 110 to form an arc surface; the bottom of the arc surface is located in the first through hole 110 .

[0029] This arrangement enables the explosion-proof portion 310 to expand upward from a concave to a convex when plastic deformation occurs, and the displacement of the bottom of the arc surface is large, thereby avoiding failure to successfully pull off the tab due to the small displacement of the bottom of the arc surface. In other words, the explosion-proof portion 310 is set as a concave, which can better pull off the tab, ensuring that the safety performance of the battery can be effectively improved.

[0030] Specifically, the distance L between the bottom of the arc surface and the upper surface of the top plate 300 is 0.3 mm to 0.5 mm. The projection of the arc surface on the top plate 300 is a circle with a radius R of 1.5 mm to 3 mm. The angle α between the tangent line at the connection between the arc surface and the top plate 300 and the top plate 300 is ≤45°. Since the angle between the tangent line at the connection between the arc surface and the cover plate and the cover plate is designed to be small enough (α≤45°), the arc surface can be smoothly flipped upward without being stuck, thereby ensuring that the explosion-proof part 310 can pull the tab off.

[0031] In one embodiment of the present invention, the second through hole 210 is coaxially arranged with the first through hole 110 to increase the cross-sectional area of ​​the connection position between the second through hole 210 and the first through hole 110, so that the rapid gas can quickly pass through the second through hole 210, thereby quickly pushing the explosion-proof part 310 to expand outward.

[0032] In one embodiment of the present invention, the top plate 300 and the explosion-proof part 310 are integrally stamped and formed without any additional connection structure to avoid connection gaps, thereby ensuring that the explosion-proof part 310 can withstand stress when the internal pressure of the battery increases.

[0033] Furthermore, the top plate 300 is made of soft metal, which includes any one of aluminum, lead, tin, and zinc. This configuration, on the one hand, utilizes the high ductility of soft metal, so that the explosion-proof part 310 can respond quickly when the internal pressure of the battery increases abnormally, and cut off the circuit in time, thereby greatly improving the safety of the battery; on the other hand, soft metal is easy to process and shape, which helps to reduce production costs and facilitate large-scale promotion and application.

[0034] In one embodiment of the present invention, the inner edge of the insulating layer 200 extends into the first through hole 110 and is located between the substrate 100 and the top plate 300 to block the electrical connection between the substrate 100 and the top plate 300 to avoid a battery short circuit.

[0035] The utility model further provides a shell, comprising a containing tube 400 and a cover plate as in any of the above embodiments, so as to have all the effects of the cover plate.

[0036] In one embodiment of the present invention, an opening is provided at one end of the accommodating tube 400, and the cover plate covers the opening of the accommodating tube 400. The base plate 100 is connected to the side wall of the accommodating tube 400, and the top plate 300 is located on the side of the base plate 100 away from the accommodating tube 400.

[0037] like Figure 2 As shown, the utility model further provides a battery, comprising a winding core 500 and a shell as in any of the above embodiments, so as to have all the effects of the shell. The winding core 500 is arranged in the shell.

[0038] In one embodiment of the utility model, the winding core 500 includes a positive electrode ear 510 and a negative electrode ear 520, and the positive electrode ear 510 or the negative electrode ear 520 is connected to the center position of the explosion-proof part 310, and the positive electrode ear 510 or the negative electrode ear 520 extends along a preset straight line without any bend in the middle, so as to facilitate the positive electrode ear 510 or the negative electrode ear 520 to be pulled apart.

[0039] When preparing the battery provided by the embodiment of the utility model, the substrate 100, the insulating layer 200 and the top plate 300 are first stamped, and the insulating layer 200 is made of PP material. Then the substrate 100 and the top plate 300 are hot-pressed and composited through the insulating layer 200, and then the pole ears of the winding core 500 are connected to the shell and the cover plate by laser welding, resistance welding or ultrasonic welding; wherein the positive pole ear 510 passes through the first through hole 110 and the second through hole 210 to connect to the center position of the explosion-proof part 310, and the negative pole ear 520 is connected to the bottom of the accommodating tube. Then the assembled winding core 500 is baked and injected with liquid; after the injection is completed, the substrate 100 is welded and sealed with the accommodating tube 400 by laser welding.

[0040] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A cover plate, characterized in that: It includes a substrate, an insulating layer and a top plate, wherein the substrate is provided with a first through hole; the insulating layer is provided on one side of the substrate, and the insulating layer is provided with a second through hole connected to the first through hole; the top plate is provided on the side of the insulating layer away from the substrate, and an explosion-proof part is provided on the top plate, the explosion-proof part covers the second through hole and is used to be connected to the pole ear; the explosion-proof part undergoes plastic deformation when subjected to pressure.

2. The cover plate according to claim 1, characterized in that: The explosion-proof portion is recessed along a side of the top plate away from the insulating layer toward the first through hole to form an arc surface; the bottom of the arc surface is located in the first through hole.

3. The cover plate according to claim 2, characterized in that: The distance between the bottom of the arc surface and the upper surface of the top plate is 0.3 mm to 0.5 mm; The projection of the arc surface on the top plate is a circle with a radius of 1.5 mm to 3 mm.

4. The cover plate according to claim 2, characterized in that: The angle between the tangent line at the connection between the arc surface and the top plate and the top plate is ≤45°.

5. The cover plate according to claim 1, characterized in that: The second through hole is coaxially arranged with the first through hole.

6. The cover plate according to claim 5, characterized in that: The top plate is made of soft metal, which includes any one of aluminum, lead, tin and zinc.

7. A housing, characterized in that: It comprises a containing tube and the cover plate according to any one of claims 1 to 6, wherein one end of the containing tube is provided with an opening, and the cover plate seals the opening of the containing tube.

8. The housing according to claim 7, characterized in that The base plate is connected to the side wall of the accommodating tube, and the top plate is located at a side of the base plate away from the accommodating tube.

9. A battery, characterized in that: It comprises a winding core and a shell as claimed in claim 7 or 8, wherein the winding core is arranged in the shell.

10. The battery according to claim 9, characterized in that The winding core includes a positive electrode ear and a negative electrode ear. The positive electrode ear or the negative electrode ear extends along a preset straight line and is connected to the center position of the explosion-proof part.

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