Power battery shell

Abstract

The utility model discloses a power battery shell, which comprises a shell side wall and a shell bottom wall, the shell side wall and the shell bottom wall are fixedly connected or integrally formed to form the power battery shell for accommodating a battery cell, and the shell bottom wall comprises a structural part, and a first welding part and a plurality of second welding parts which are distributed on the structural part; the bottom surface of the first welding part is lower than the plane where the bottom surface of the structural part is located, and the first welding part is welded with the busbar; the second welding part is welded with one end face of one tab or one end face of one bus bar of the battery cell; according to the utility model, the first welding part protruding out of the battery bottom shell is designed, so that the busbar can be in better contact with the bottom surface of the first welding part, namely the welding plane, a gap between the first welding part and the busbar is prevented, the phenomenon of pseudo soldering is reduced, and the welding yield is improved.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically a power battery casing. Background Technology

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage. A lithium-ion power battery generally includes an internal structure and an external structure. The internal structure mainly includes electrode arrays, while the external structure mainly includes a cover and a casing. The casing provides space for the electrode arrays, and the cover and casing are welded together to fix the electrode arrays within the internal space. Currently, when assembling lithium-ion batteries into packs, busbars are used to connect different cells together. In existing technologies, the two welding points between the individual cell and the busbar are located on the top cover and the bottom cover of the individual cell, respectively. Because the bottom cover is a planar structure, gaps may exist between the busbar and the bottom cover during welding, leading to incomplete welds and weak welds, posing potential safety hazards. Summary of the Invention

[0003] The purpose of this utility model is to provide a power battery casing to solve the problems of incomplete welding and weak welding in the prior art, and this utility model can improve the safety of the battery.

[0004] To achieve the above objectives, the technical solution of this utility model is: a power battery casing, including a side wall and a bottom wall, wherein the side wall and the bottom wall are fixedly connected or integrally formed to form a cavity structure that accommodates a battery cell with one end open; the bottom wall includes a structural part and a first welding part and a plurality of second welding parts distributed on the structural part; the bottom surface of the first welding part is lower than the plane where the bottom surface of the structural part is located; the first welding part is welded to a busbar; the second welding parts are welded to one of the tabs or one end face of the battery cell.

[0005] Furthermore, the first welded portion is located at the center of the structural portion, and the second welded portion is distributed around the first welded portion.

[0006] Furthermore, the thickness of the first welded portion is greater than or equal to the thickness of the structural portion, and the first welded portion is a protruding structure formed by a local outward protrusion of the structural portion.

[0007] Furthermore, the thickness of the second welded portion is less than or equal to the thickness of the structural portion, and the second welded portion is a groove-shaped structure formed by a local inward recess of the structural portion.

[0008] Furthermore, an explosion-proof valve is provided on the bottom wall of the shell.

[0009] Furthermore, the explosion-proof valve is provided with explosion-proof markings, which are located on the inner or outer surface of the explosion-proof valve.

[0010] Furthermore, the front projection of the explosion-proof valve does not interfere with the front projection of the manifold.

[0011] Compared with the prior art, the advantages and positive effects of this utility model are as follows: By designing a first welding part that protrudes from the bottom of the battery casing, this utility model facilitates better contact between the busbar and the bottom surface of the first welding part, i.e., the welding plane, preventing gaps between the first welding part and the busbar, reducing the phenomenon of incomplete soldering, and improving the welding yield.

[0012] The first welding part of the battery bottom shell of this utility model has a simple structure. Compared with the traditional battery, which requires a separate terminal post to be designed at the bottom of the shell for connecting the busbar, the structure is extremely simple, with fewer production steps and lower cost. Compared with the same-side outlet tab, the method of directly welding the busbar at the bottom results in a shorter circuit path, lower internal resistance, and improved product performance.

[0013] The front projection of the explosion-proof valve and the front projection of the manifold of this utility model do not interfere with each other. The explosion-proof valve and the manifold are staggered to prevent the explosion-proof valve from impacting the manifold when it bursts open. The gas will not be blocked by the manifold when depressurizing, thus achieving better depressurization and improving battery safety. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a bottom view of the present invention;

[0017] Figure 3 For the present utility model Figure 2 Cross-sectional view at point AA;

[0018] Figure 4 For the present utility model Figure 3 Enlarged view of point B;

[0019] Figure 5 This is a schematic diagram of the present invention being welded to a battery cell and a busbar.

[0020] In the diagram: 1. Bottom wall of the shell; 11. Structural part; 111. First welded part; 112. Second welded part; 113. Explosion-proof valve; 1131. Explosion-proof groove; 2. Side wall of the shell; 3. Busbar; 4. Battery cell. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] like Figures 1-5 As shown; a power battery casing includes a side wall 2 and a bottom wall 1, which are integrally stamped to form a cavity structure with one end open to accommodate the battery cell. Alternatively, the side wall 2 and the bottom wall 1 can also be fixedly connected together by welding.

[0023] To improve welding yield and convenience, the bottom wall 1 of the shell includes a structural part 11 and a first welding part 111 and three second welding parts 112 distributed on the structural part 11. The first welding part 111 is a protruding structure formed by a partial outward protrusion of the structural part 11. The bottom surface of the first welding part 111 is lower than the plane where the bottom surface of the structural part 11 is located. The first welding part 111 is welded to the busbar 3 through the bottom surface of the protruding structure. The protruding structure of the first welding part 111 can facilitate better contact between the busbar 3 and the bottom surface of the first welding part 111, that is, the welding plane, reducing the phenomenon of incomplete welding and improving welding yield.

[0024] In this embodiment, in order to further improve the welding yield, the thickness of the first welding part 111 is greater than or equal to the thickness of the structural part 11 to prevent burn-through.

[0025] In this embodiment, the first welding part 111 is located at the center of the structural part 11 and is positioned between the busbar 3 and the first welding part 111, which facilitates subsequent welding work. Three second welding parts 112 are distributed around the first welding part 111. The second welding parts 112 are welded to one of the tabs of the battery cell 4. In some other embodiments, if a busbar is also provided between the bottom wall 1 of the casing and the battery cell 4, the second welding part 112 is welded to one end face of the busbar, and the other end face of the busbar is welded to one of the tabs of the battery cell 4.

[0026] In this embodiment, in order to facilitate welding, the thickness of the second welding part 112 is less than or equal to the thickness of the structural part 11. The second welding part 112 is a groove-shaped structure formed by a partial inward recess of the structural part 11. Therefore, the side of the second welding part 112 located on the inner side of the bottom wall 1 of the shell can be better welded to one of the tabs of the battery cell 4 or one end face of the busbar.

[0027] In this embodiment, to improve safety, an explosion-proof valve 113 is provided on the bottom wall 1 of the casing, and an explosion-proof groove 1131 is provided on the explosion-proof valve 113. When the explosion-proof valve 113 bursts open, it can burst along the explosion-proof groove 1131, reducing the risk of tearing the casing and further improving the safety performance of the battery cell. In terms of the design of the position of the explosion-proof groove 1131, the explosion-proof groove 1131 can be located on the inner surface or the outer surface of the explosion-proof valve 113.

[0028] In this embodiment, in order to prevent the explosion-proof valve 113 from impacting the manifold 3 when it bursts open, and also to ensure that the gas is not blocked by the manifold 3 during depressurization and achieve better depressurization, the front projection of the explosion-proof valve 113 and the front projection of the manifold 3 do not interfere with each other.

[0029] Based on the embodiments of this utility model, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without creative effort should be considered as such.

[0030] It is included within the protection scope of this utility model.

Claims

1. A power battery casing, comprising a side wall and a bottom wall, wherein the side wall and the bottom wall are fixedly connected or integrally formed to form a cavity structure that accommodates a battery cell with one end open, characterized in that: The bottom wall of the shell includes a structural part and a first welded part and several second welded parts distributed on the structural part; The bottom surface of the first welded part is lower than the plane where the bottom surface of the structural part is located, and the first welded part is welded to the busbar; The second welding part is welded to one of the tabs of the battery cell or one of the end faces of the busbar.

2. The power battery casing according to claim 1, characterized in that: The first welded part is located at the center of the structural part, and the second welded part is distributed around the first welded part.

3. The power battery casing according to claim 1, characterized in that: The thickness of the first welded part is greater than or equal to the thickness of the structural part, and the first welded part is a convex structure formed by a local outward protrusion of the structural part.

4. The power battery casing according to claim 1, characterized in that: The thickness of the second welded part is less than or equal to the thickness of the structural part, and the second welded part is a groove-shaped structure formed by a local inward recess of the structural part.

5. The power battery casing according to claim 1, characterized in that: An explosion-proof valve is installed on the bottom wall of the shell.

6. The power battery casing according to claim 5, characterized in that: The explosion-proof valve is provided with explosion-proof markings, which are located on the inner or outer surface of the explosion-proof valve.

7. The power battery casing according to claim 5, characterized in that: The front projection of the explosion-proof valve does not interfere with the front projection of the manifold.

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