Lithium battery top cover structure

Abstract

The utility model discloses a lithium battery top cover structure, which relates to the technical field of lithium batteries, comprises a top cover provided with an explosion-proof hole, and is characterized in that the explosion-proof hole is sequentially provided with a protective cover, an explosion-proof membrane and a deformation layer from top to bottom, and the protective cover, the explosion-proof membrane and the deformation layer are all connected onto the top cover; the surface of the protective cover is provided with air holes, the deformation layer is of a downward arched structure, the deformation layer comprises a first metal layer and a second metal layer arranged on the first metal layer, the thermal expansion coefficient of the first metal layer is larger than that of the second metal layer, and the thermal expansion coefficient of the second metal layer is larger than that of the first metal layer. A plurality of sharp knives are uniformly distributed on the surface of the second metal layer; according to the utility model, the safety reaction can be performed at the initial stage of battery heating, the corresponding reaction can be continuously performed according to the heating condition of the battery, the accident risk of battery heat is effectively avoided, the structure is simple, and the safety coefficient is higher.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically a lithium battery top cover structure. Background Technology

[0002] With the development of electric vehicles, the demand for lithium batteries is gradually increasing. Lithium batteries are a type of battery that uses lithium metal or lithium alloy as the negative electrode material and a non-aqueous electrolyte solution. Lithium batteries mainly consist of a casing, cells, and a top cover. The top cover is usually equipped with an explosion-proof valve to ensure the safety performance of the battery. When the internal gas pressure of the battery reaches a critical value, the explosion-proof valve is activated to release the gas from the battery.

[0003] The aforementioned explosion-proof structure using an explosion-proof valve has certain drawbacks: when the battery heats up or heats up to a certain extent, the explosion-proof valve cannot dissipate the heat from the battery. It can only be activated when the battery heats up to its limit and the gas pressure reaches a critical value. Therefore, there is a certain delay in battery thermal protection, which increases the risk of battery combustion and explosion accidents. Utility Model Content

[0004] This utility model discloses a lithium battery top cover structure to solve the technical problem of delayed battery thermal protection.

[0005] To solve the above-mentioned technical problems, the present invention proposes the following optimized technical solution:

[0006] A lithium battery top cover structure includes a top cover with an explosion-proof hole. The explosion-proof hole has a protective cover, an explosion-proof film, and a deformable layer arranged sequentially from top to bottom. The protective cover, the explosion-proof film, and the deformable layer are all connected to the top cover. The surface of the protective cover has ventilation holes. The deformable layer has a downward arched structure and includes a first metal layer and a second metal layer disposed on the first metal layer. The thermal expansion coefficient of the first metal layer is greater than that of the second metal layer. The surface of the second metal layer is uniformly covered with a plurality of sharp blades.

[0007] Furthermore, the protective cover is welded to the top surface of the top cover, and the protective cover covers the explosion-proof hole.

[0008] Furthermore, the protective cover is a cylindrical structure that is narrow at the top and wide at the bottom, with an opening at the bottom.

[0009] Furthermore, the number of vent holes is set to several, and the several vent holes are located on the side of the protective cover.

[0010] Furthermore, the first metal layer is a copper sheet, and the second metal layer is an iron sheet.

[0011] Furthermore, the first metal layer and the second metal layer are connected by welding.

[0012] Furthermore, the explosion-proof membrane is a sheet-like structure with the same cross-sectional shape as the explosion-proof hole, and the diameter of the explosion-proof membrane is larger than the diameter of the explosion-proof hole.

[0013] Furthermore, the explosion-proof film is made of aluminum.

[0014] The present invention has the following advantages over the prior art:

[0015] The lithium battery top cover structure provided by this utility model has a number of sharp blades evenly spaced in the deformable layer, and the deformable layer has a downward arched structure, that is, the sharp blades on the deformable layer gradually approach the explosion-proof membrane from the center to the edge. When the battery generates heat, the deformation of the first metal layer is greater than that of the second metal layer, so the deformable layer arches upward. Since the sharp blades on the edge of the deformable layer are closer to the explosion-proof membrane than the sharp blades in the center, the sharp blades on the edge of the deformable layer pierce the explosion-proof membrane first to release heat and vent gas from the battery. When the battery continues to heat up, the sharp blades on the deformable layer gradually pierce the explosion-proof membrane from the edge to the center to increase the release of heat and the venting of gas. It can make a safety response in the early stage of battery heating and can continuously make corresponding responses according to the battery heating situation, effectively avoiding the accident risk of battery overheating. The structure is simple and has a higher safety factor. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a cross-sectional view of the structure of this utility model.

[0018] In the diagram: 1. Top cover; 2. Explosion-proof hole; 3. Protective cover; 4. Explosion-proof membrane; 5. Deformable layer; 6. Ventilation hole; 7. Sharp blade. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] See Figures 1-2A lithium battery top cover structure includes a top cover 1, the top cover 1 having an explosion-proof hole 2, the explosion-proof hole 2 having a protective cover 3, an explosion-proof membrane 4 and a deformable layer 5 arranged sequentially from top to bottom, the protective cover 3, the explosion-proof membrane 4 and the deformable layer 5 being connected to the top cover 1; the surface of the protective cover 3 is provided with vent holes 6, the deformable layer 5 has a downward arched structure, the deformable layer 5 includes a first metal layer and a second metal layer disposed on the first metal layer, the thermal expansion coefficient of the first metal layer is greater than the thermal expansion coefficient of the second metal layer, and the surface of the second metal layer is uniformly covered with a plurality of sharp blades 7.

[0021] In the above technical solution, the top cover 1 is placed over the opening of the lithium battery casing, and the lithium battery is placed inside the casing. When the lithium battery heats up, the deformation layer deforms, specifically the deformation of the first metal layer is greater than that of the second metal layer. Therefore, the deformation layer arches upward. Since the sharp edges 7 of the deformation layer are closer to the explosion-proof film 4, the sharp edges 7 of the deformation layer first pierce the explosion-proof film 4 to release battery heat and vent gas. At this time, the sharp edges 7 in the center of the deformation layer have not yet pierced the explosion-proof film 4. When the lithium battery continues to heat up, the deformation layer continues to deform, and the deformation layer continuously pierces the explosion-proof film 4 from the sharp edges 7 to the sharp edges 7 in the center, so as to better release battery heat and vent gas. The sharp edges 7 can be controlled to pierce the explosion-proof film 4 according to the heat of the battery. The higher the heat of the battery, the larger the area of ​​the explosion-proof film 4 pierced, achieving a suitable piercing area that matches the battery's heat. This effectively avoids the risk of battery overheating accidents, and the explosion-proof function is flexibly controlled using a simple structure.

[0022] In this embodiment, the protective cover 3 is welded to the top surface of the top cover 1. The protective cover 3 covers the explosion-proof hole 2, which serves to prevent dust and textile debris from falling in, and to prevent the explosion-proof film 4 from being damaged.

[0023] In this embodiment, the protective cover 3 is a cylindrical structure with an opening at the bottom, narrow at the top and wide at the bottom, used to cover the explosion-proof membrane 4 and the explosion-proof hole 2, which is aesthetically pleasing and reasonable.

[0024] In this embodiment, the number of ventilation holes 6 is set to several, and the several ventilation holes 6 are located on the side of the protective cover 3, which serves to prevent debris from falling from top to bottom, and also allows air to be released and heat dissipated through the ventilation holes 6 on the side.

[0025] In this embodiment, the first metal layer is a copper sheet and the second metal layer is an iron sheet. Copper has a greater coefficient of thermal expansion than iron, and the deformation layer arches upward when heated.

[0026] In this embodiment, the first metal layer and the second metal layer are connected by welding.

[0027] In this embodiment, the explosion-proof membrane 4 is a sheet-like structure with the same cross-sectional shape as the explosion-proof hole 2. The diameter of the explosion-proof membrane 4 is larger than the diameter of the explosion-proof hole 2, that is, the explosion-proof membrane 4 can cover the explosion-proof hole 2 and play the role of sealing the explosion-proof hole 2.

[0028] In this embodiment, the explosion-proof film 4 is made of aluminum. The aluminum explosion-proof film 4 can be welded to the top cover 1 and can be pierced by a sharp knife 7.

[0029] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A lithium battery top cover structure, comprising a top cover, wherein the top cover is provided with an explosion-proof hole, characterized in that, The explosion-proof hole is provided with a protective cover, an explosion-proof membrane, and a deformation layer from top to bottom. The protective cover, the explosion-proof membrane, and the deformation layer are all connected to the top cover. The surface of the protective cover is provided with vent holes. The deformation layer has a downward arched structure. The deformation layer includes a first metal layer and a second metal layer disposed on the first metal layer. The thermal expansion coefficient of the first metal layer is greater than that of the second metal layer. The surface of the second metal layer is evenly covered with a number of sharp blades.

2. The lithium battery top cover structure according to claim 1, characterized in that, The protective cover is welded to the top surface of the top cover, and the protective cover covers the explosion-proof hole.

3. The lithium battery top cover structure according to claim 1, characterized in that, The protective cover is a cylindrical structure that is narrow at the top and wide at the bottom, with an opening at the bottom.

4. The lithium battery top cover structure according to claim 1, characterized in that, The number of vent holes is set to several, and the several vent holes are located on the side of the protective cover.

5. The lithium battery top cover structure according to claim 1, characterized in that, The first metal layer is a copper sheet, and the second metal layer is an iron sheet.

6. The lithium battery top cover structure according to claim 1, characterized in that, The first metal layer and the second metal layer are connected by welding.

7. The lithium battery top cover structure according to claim 1, characterized in that, The explosion-proof membrane is a sheet-like structure with the same cross-sectional shape as the explosion-proof hole, and the diameter of the explosion-proof membrane is larger than the diameter of the explosion-proof hole.

8. A lithium battery top cover structure according to claim 1, characterized in that, The explosion-proof film is made of aluminum.

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