Negative pole, top cover assembly and battery

Abstract

The utility model belongs to the technical field of batteries, and discloses a negative pole, a top cover assembly and a battery. The negative pole comprises a copper base block and an aluminum pole body, the copper base block comprises a first surface and a second surface, a first groove is formed in the first surface, the part, close to the bottom of the groove, of the side wall of the first groove is concaved inwards to form an exhaust cavity, so that a groove body with a trapezoidal section is formed in the first surface, and the aluminum pole body comprises an aluminum pole body and a boss. The aluminum column body is provided with a first groove, the aluminum column body is provided with a boss, the boss is inserted into the first groove, and the bottom face of the boss abuts against the groove bottom of the first groove in an attached mode. And the exhaust cavity, a first gap between the opening of the first groove and the boss and a second gap between the opening end face of the first groove and the bottom face of the aluminum column body can jointly form an exhaust channel allowing gas generated by welding to be exhausted outwards. Therefore, accumulation of gas on a bonding interface of the copper substrate block and the aluminum column body is avoided, and the welding strength of the copper substrate block and the aluminum column body is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a negative pole, a top cover assembly and a battery. Background Art

[0002] Today, batteries are widely used in power tools and new energy vehicles due to their excellent properties, such as high capacity. In addition to high capacity, these batteries must also have excellent safety to meet usage standards and requirements.

[0003] The negative electrode column material of the top cover assembly of existing batteries is often made of copper-aluminum composite materials. During the processing, there are limited processing methods due to the difference in plasticity of the two materials. Therefore, the negative electrode column needs to be made of special materials such as copper-aluminum friction welding, or copper-aluminum composite plates, to meet the requirements of aluminum on the outside of the battery and copper on the inside of the battery. The current friction welding operation method is specifically as follows: the copper block contacts the surface of the aluminum rod, the copper block rotates, the aluminum rod is radially fixed, and approaches the copper block axially. After the two are close together, they can move relative to each other to generate heat, thereby melting the aluminum, allowing aluminum atoms to penetrate into the copper block under the action of heat. However, when the copper rod and the aluminum block move relative to each other, there is a problem that the gas in the gap between the copper rod and the aluminum block cannot be discharged in time, resulting in gas accumulation at the interface between the two, which causes cracks to appear after the copper block and the aluminum rod cool down, thereby affecting the welding strength.

[0004] Based on the above, there is an urgent need for a negative electrode column, a top cover assembly and a battery to solve the problems existing in the prior art. Utility Model Content

[0005] The first purpose of the present utility model is to provide a negative electrode column that can promptly and effectively discharge the gas generated during the friction welding process, thereby preventing cracks from occurring on the joint surface of the copper block and the aluminum rod, thereby improving the welding strength of the negative electrode column and enhancing the reliability of the negative electrode column.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] The negative electrode column includes a copper base block and an aluminum column, the copper base block includes a first surface and a second surface arranged opposite to each other, the first surface is provided with a first groove, and the part of the side wall of the first groove close to the bottom of the first groove is recessed inward to form an exhaust cavity, so as to form a groove body with a trapezoidal cross-section on the first surface, the aluminum column includes an aluminum column body and a boss, the aluminum column body is provided with the boss, the boss is inserted into the first groove, and the bottom surface of the boss is in contact with the bottom of the first groove. When the copper base block and the aluminum column are welded by friction welding, the exhaust cavity, the first gap between the open part of the first groove and the boss, and the second gap between the open end face of the first groove and the bottom surface of the aluminum column body can jointly form an exhaust channel for the gas generated by welding to be discharged to the outside.

[0008] Preferably, the cross-sectional shape of the boss is trapezoidal, and the horizontal cross-sectional area of the boss gradually decreases in the direction pointing toward the copper base block.

[0009] Preferably, a portion of the sidewall of the first groove away from the groove bottom of the first groove is flat, so as to form a groove body with a cylindrical cross-section on the first surface.

[0010] Preferably, a second groove is further provided on the first surface, and one side wall of the second groove is connected to the first groove.

[0011] Preferably, at least two second grooves are circumferentially formed on the first surface with the first groove as the center.

[0012] Preferably, four second grooves are circumferentially arranged on the first surface with the first groove as the center.

[0013] Preferably, the depth of the second groove is less than or equal to the depth of the first groove.

[0014] Preferably, the horizontal cross-sectional shape of the second groove includes any one of a rectangle, a triangle, a semicircle and a trapezoid.

[0015] The negative electrode provided by the present invention has the following beneficial effects: the negative electrode is provided with a first groove, and a portion of the first groove sidewall near the groove bottom is recessed inward to form a venting cavity. This allows gases generated by thermal decomposition or material evaporation caused by the high temperature at the welding interface during friction welding between the aluminum column body and the copper base block to be discharged from the bonding interface between the two, thereby preventing gas accumulation and ensuring the weld strength between the copper base block and the aluminum column. Furthermore, during the friction welding process, the portion of the boss in contact with the bottom of the first groove melts and diffuses into the venting cavity, allowing the copper base block to wrap around the boss, thereby significantly increasing the physical connection strength between the copper base block and the aluminum column.

[0016] The second purpose of the present invention is to provide a top cover assembly that can improve the safety and reliability of the top cover assembly.

[0017] To achieve this purpose, the present invention adopts the following technical solutions:

[0018] The top cover assembly includes a top cover plate, positive electrode plastic, negative electrode plastic, a sealing ring, an insulating bracket, an explosion-proof valve assembly, a positive electrode column and the above-mentioned negative electrode column. Two mounting holes are provided on the top cover plate for respectively mounting the positive electrode column and the negative electrode column. The positive electrode plastic is arranged around the positive electrode column, and the negative electrode plastic is arranged around the negative electrode column. A sealing ring is sandwiched between the positive electrode column and the top cover plate, and between the negative electrode column and the top cover plate. The explosion-proof valve assembly is arranged on the top cover plate, and the insulating bracket is fixed to the bottom of the top cover plate.

[0019] The beneficial effects of the top cover assembly provided by the present invention are as follows: since the above-mentioned negative pole is installed on the top cover plate of the top cover assembly, and in the negative pole column, a first groove is provided on the first surface of the copper base block, and a boss is provided on the aluminum column, which is inserted into the first groove, when the aluminum column and the copper base block are friction welded, the gas generated at the interface between the two will be discharged from the first groove and will not accumulate at the position of the interface between the two, thereby ensuring the welding strength and improving the safety and reliability of the top cover assembly.

[0020] The third object of the present invention is to provide a battery that can enhance the overall performance stability of the battery and the user experience.

[0021] To achieve this purpose, the present invention adopts the following technical solutions:

[0022] A battery comprises a cell, an insulating shell and the above-mentioned top cover assembly, wherein the cell is accommodated in the cavity of the insulating shell, the sealing cover of the top cover assembly is arranged on the insulating shell, and the welding area of the top cover plate of the top cover assembly is welded to the positive electrode tab or the negative electrode tab on the cell.

[0023] The beneficial effects of the battery provided by the present invention are as follows: since the battery uses a top cover assembly including the negative electrode provided by this embodiment, the stability of the electrode can be ensured, thereby enhancing the overall performance stability of the battery and the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the negative electrode column provided by an embodiment of the present utility model;

[0025] Figure 2 This is a cross-sectional view of the negative electrode column provided by an embodiment of the present utility model when the copper base block and the aluminum column are not friction welded;

[0026] Figure 3 This is a cross-sectional view of the negative electrode column provided by the embodiment of the present invention after the copper base block and the aluminum column are friction-welded and excess waste is removed;

[0027] Figure 4 yes Figure 2 A partial enlarged view of point A in the middle;

[0028] Figure 5 yes Figure 3 A partial enlarged view of point B in the middle;

[0029] Figure 6 This is a front view of the aluminum column provided by the embodiment of the present utility model before friction welding;

[0030] Figure 7 It is a top view of the copper base block provided by an embodiment of the present utility model.

[0031] In the picture:

[0032] 101, first gap; 102, second gap;

[0033] 1. Copper base block; 11. First groove; 111. Exhaust cavity; 12. Second groove;

[0034] 2. Aluminum column; 21. Aluminum column body; 22. Boss. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0036] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0039] The following is combined with Figure 1 To the attached Figure 7 The negative electrode column, top cover assembly and battery provided by the present invention are specifically introduced with reference to specific embodiments.

[0040] At present, batteries generally include a cell, an insulating shell and a top cover assembly. Among them, the cell is accommodated in the cavity of the insulating shell, and the sealing cover of the top cover assembly is arranged at the opening of the insulating shell to seal the insulating shell. The insulating shell can be made of insulating materials such as plastic (such as polypropylene, polyethylene, etc.), and the present invention is not limited to this. The top cover assembly includes a top cover plate and a pole. The pole includes a positive pole and a negative pole. Two mounting holes for mounting the positive pole and the negative pole are provided on the top cover plate. The positive pole tab on the cell is connected to the positive pole, or the negative pole tab is connected to the negative pole, thereby achieving electrical conduction between the inside and the outside of the battery while preventing a short circuit. A pressure relief groove is also provided on the top cover plate, and an explosion-proof valve assembly is provided on the pressure relief groove. When the internal air pressure of the battery is high, the battery will open the explosion-proof valve assembly and discharge the gas from the pressure relief groove to the insulating shell.

[0041] The negative electrode posts of existing batteries are often made of copper-aluminum composite materials. Due to the difference in plasticity between the two materials during processing, the negative posts are often manufactured using copper-aluminum friction welding or special materials such as copper-aluminum composite plates to meet the requirement of aluminum on the exterior and copper on the interior. However, the existing technology has the following drawbacks: when the copper rod and aluminum block move relative to each other, the generated gas cannot be discharged in a timely manner, resulting in gas accumulation at the interface between the two. This can cause cracks in the copper block and aluminum rod after cooling, thus affecting the weld strength.

[0042] In order to solve the above technical problems, the present embodiment provides a negative electrode column, such as Figures 1 to 5 As shown, the negative electrode column comprises a copper base block 1 and an aluminum column 2. The copper base block 1 comprises a first surface and a second surface disposed opposite each other. A first groove 11 is provided at the center of the first surface. An annular exhaust cavity 111 is formed inwardly on the sidewalls of the first groove 11, near the bottom of the groove, to form a groove with a trapezoidal cross-section. Furthermore, the aluminum column 2 comprises an aluminum body 21 and a boss 22. The bottom surface of the aluminum body 21 is provided with the boss 22, which is inserted into the first groove 11, and the bottom surface of the boss 22 abuts against the bottom of the first groove 11. When the copper base block 1 and the aluminum column 2 are welded by friction welding, the gas generated from the welding interface between the boss 22 and the first groove 11 will be discharged into the first groove 11 through the exhaust cavity 111, the first gap 101 between the open part of the first groove 11 and the boss 22, and the second gap 102 between the open end surface of the first groove 11 and the bottom surface of the aluminum column body 21, thereby avoiding the accumulation of gas at the interface between the two.

[0043] Therefore, the negative electrode column is provided with a first groove 11, and a vent cavity 111 is formed inwardly on the sidewall of the first groove 11 near the bottom of the groove. This allows gases generated by thermal decomposition or material evaporation caused by the high temperature at the welding interface during friction welding between the aluminum column body 21 and the copper base block 1 to be discharged from the bonding interface between the two, thereby preventing gas accumulation and ensuring the weld strength between the copper base block 1 and the aluminum column 2. During the friction welding process, the portion of the boss 22 in contact with the bottom of the first groove 11 will melt and diffuse into the vent cavity 111, allowing the copper base block 1 to wrap around the boss 22, thereby significantly increasing the physical connection strength between the copper base block 1 and the aluminum column 2.

[0044] It should be noted that, in other embodiments, the portion of the side wall of the first groove 11 away from the bottom of the first groove 11 is flat, so as to form a groove body with a cylindrical cross-section on the first surface. Through this arrangement, the bonding area between the side wall of the first groove 11 and the side wall of the aluminum column 2 can be increased, thereby improving the connection strength between the copper base block 1 and the aluminum column 2 in the radial direction, and can also reduce the stress on the aluminum column 2, thereby preventing the aluminum column 2 from bending and deforming during use.

[0045] Optionally, in this embodiment, reference Figure 6 As shown, the cross-section of the boss 22 is trapezoidal, and the horizontal cross-sectional area of the boss 22 gradually decreases as it points toward the copper base block 1. This increases the connection area between the boss 22 and the aluminum column 21, thereby improving the connection strength between the boss 22 and the aluminum column 21. This effectively prevents fractures between the boss 22 and the aluminum column 21 due to heat and stress when the boss 22 and the aluminum column 21 rotate during friction welding, thereby effectively improving the safety of the production process.

[0046] Optionally, in this embodiment, reference Figure 7 As shown, a second groove 12 is also formed on the first surface, one sidewall of which is connected to the first groove 11. The provision of the second groove 12 increases the exhaust space on the copper base block 1, thereby further facilitating exhaust. Furthermore, the partially molten structure of the aluminum column 2 can diffuse into the second groove 12, thereby securing the aluminum column 2 through the second groove 12, thereby helping to increase the anti-twist capability of the aluminum column 2.

[0047] In this embodiment, continue to refer to Figure 7 As shown, with the first groove 11 as the center, four second grooves 12 are circumferentially opened on the first surface, which can not only meet the anti-twisting ability requirements of the aluminum column 2 under actual working conditions, but also reduce the grooving pressure, ensuring the production efficiency while improving the structural strength of the entire negative electrode column.

[0048] Of course, in other embodiments, four, five or even more second grooves 12 may be provided on the first surface, and the present invention is not limited thereto. Preferably, at least two second grooves 12 are provided on the first surface.

[0049] Optionally, in this embodiment, the horizontal cross-section of the second groove 12 is rectangular for ease of production. Of course, in other embodiments, the horizontal cross-section of the second groove 12 can also be trapezoidal, semicircular, or triangular, etc., and the present invention is not limited thereto.

[0050] Optionally, in this embodiment, the depth of the second groove 12 is less than or equal to the depth of the first groove 11. This not only avoids the situation where the second groove 12 is opened too deep, resulting in the weakening of the structural strength of the copper base block 1, but also ensures that the limiting function of the second groove 12 on the aluminum column 2 can meet the anti-twisting capability requirements.

[0051] The production principle of the negative electrode column provided in this embodiment is as follows: first, four second grooves are punched around the first groove, then the copper base block is cleaned and the center portion is cut to form the first groove; secondly, the boss at the bottom of the aluminum column is aligned with the first groove and then inserted into the first groove; thirdly, the copper base block and the aluminum column are friction welded; finally, the excess waste on the copper base block is processed and removed, and finally a negative electrode column is formed. Figure 1 or Figure 3 Negative post shown.

[0052] This embodiment also provides a top cover assembly, which, in addition to the above-mentioned top cover plate, positive pole, and explosion-proof valve assembly, also includes a positive pole upper plastic, a negative pole upper plastic, a sealing ring, an insulating bracket, and the negative pole provided in this embodiment. The top cover plate is a plain aluminum sheet with a mounting hole on each side, one mounting hole for mounting the positive pole and the other for mounting the negative pole; the positive pole upper plastic surrounds the positive pole and is fixed to the upper surface of the top cover plate; the negative pole upper plastic surrounds the negative pole and is fixed to the upper surface of the top cover plate; and a sealing ring is sandwiched between the positive pole and the top cover plate, and between the negative pole and the top cover plate, preferably a rubber ring; and the insulating bracket is fixed to the bottom of the top cover plate to electrically insulate the top cover plate from the battery cell.

[0053] In the negative electrode column of the top cover assembly, a first groove 11 is provided on the first surface of the copper base block 1, and a boss 22 is provided on the aluminum column 2, and the boss 22 is inserted into the first groove 11. Therefore, when the aluminum column 2 and the copper base block 1 are friction welded, the gas generated at the interface between the two will be discharged from the first groove 11 and will not accumulate at the position of the interface between the two, thereby ensuring the welding strength and improving the safety and reliability of the top cover assembly.

[0054] This embodiment also provides a battery comprising the aforementioned battery cell, an insulating housing, and the top cover assembly provided in this embodiment. Because the battery utilizes the top cover assembly including the negative electrode provided in this embodiment, the stability of the electrode is ensured, thereby enhancing the overall performance stability of the battery and the user experience.

[0055] Throughout this specification, references to terms such as "some embodiments" and "other embodiments" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0056] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A negative electrode column, characterized in that: The invention comprises a copper base block (1) and an aluminum column (2), wherein the copper base block (1) comprises a first surface and a second surface arranged opposite to each other, wherein the first surface is provided with a first groove (11), and a portion of the side wall of the first groove (11) close to the bottom of the first groove (11) is inwardly recessed to form an exhaust cavity (111), so as to form a groove body with a trapezoidal cross-section on the first surface, and the aluminum column (2) comprises an aluminum column body (21) and a boss (22), wherein the aluminum column body (21) is provided with the boss (22), and the boss (22) is inserted into the In the first groove (11), the bottom surface of the boss (22) is in contact with the bottom of the first groove (11). When the copper base block (1) and the aluminum column (2) are welded by friction welding, the exhaust cavity (111), the first gap (101) between the open end of the first groove (11) and the boss (22), and the second gap (102) between the open end surface of the first groove (11) and the bottom surface of the aluminum column body (21) can jointly form an exhaust channel for exhausting welding gas.

2. The negative electrode column according to claim 1, characterized in that: The cross-sectional shape of the boss (22) is trapezoidal, and the horizontal cross-sectional area of the boss (22) gradually decreases in the direction pointing toward the copper base block (1).

3. The negative electrode column according to claim 1, characterized in that: A portion of the side wall of the first groove (11) away from the groove bottom of the first groove (11) is flat, so as to form a groove body with a cylindrical cross-section on the first surface.

4. The negative electrode column according to any one of claims 1 to 3, characterized in that: A second groove (12) is also provided on the first surface, and one side wall of the second groove (12) is connected to the first groove (11).

5. The negative electrode column according to claim 4, characterized in that: With the first groove (11) as the center, at least two second grooves (12) are circumferentially formed on the first surface.

6. The negative electrode column according to claim 5, characterized in that: Four second grooves (12) are circumferentially formed on the first surface.

7. The negative electrode column according to claim 4, characterized in that: The opening depth of the second groove (12) is less than or equal to the opening depth of the first groove (11).

8. The negative electrode column according to claim 4, characterized in that: The horizontal cross-sectional shape of the second groove (12) includes any one of a rectangle, a triangle, a semicircle and a trapezoid.

9. Top cover assembly, characterized in that, It includes a top cover plate, positive electrode plastic, negative electrode plastic, a sealing ring, an insulating bracket, an explosion-proof valve assembly, a positive electrode column and a negative electrode column as described in any one of claims 1 to 8, the top cover plate is provided with two mounting holes for respectively mounting the positive electrode column and the negative electrode column, the positive electrode plastic is surrounded by the positive electrode column, the negative electrode plastic is surrounded by the negative electrode column, a sealing ring is sandwiched between the positive electrode column and the top cover plate, and between the negative electrode column and the top cover plate, the explosion-proof valve assembly is arranged on the top cover plate, and the insulating bracket is fixed to the bottom of the top cover plate.

10. A battery, characterized in that It includes a battery cell, an insulating shell and a top cover assembly as described in claim 9, wherein the battery cell is accommodated in the cavity of the insulating shell, the sealing cover of the top cover assembly is provided on the insulating shell, and the welding area of the top cover plate of the top cover assembly is welded to the positive electrode tab or the negative electrode tab on the battery cell.

Images