Pole, cover plate assembly and battery monomer

Abstract

The utility model provides a pole, a cover plate assembly and a battery monomer, and relates to the technical field of batteries. The pole comprises a first metal piece and a second metal piece; a first concave part and a first convex part are limited on the first metal piece, and the first convex part is convexly arranged from an opening of the first concave part in the direction deviating from the first concave part; the second metal piece comprises a terminal and a second convex part, the second convex part protrudes outwards from the terminal, and a second concave part is arranged on one side, close to the second convex part, of the terminal; the first convex part is embedded in the second concave part, and the second convex part is embedded in the first concave part. According to the scheme, the combination structures of the first metal and the second metal are formed in the axial direction and the radial direction of the pole. Therefore, on the premise that the height size of the pole is fixed, the area of the combination surface between the first metal piece and the second metal piece can be increased, the electrode assembly can pull the first metal piece, the cover plate can push the first convex part towards the direction of the terminal, and then the reliability of combination between the first convex part and the terminal can be improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of batteries, in particular to a pole, a cover plate assembly and a battery cell. BACKGROUND

[0002] The pole is an important component for connecting the inside and outside of the battery cell. One end of the pole is connected with the external circuit of the battery cell, and the other end is connected with the electrode assembly inside the power battery. In order to reduce the cost and weight, the external circuit of the battery cell adopts aluminum material for current transmission. However, in the battery cell, the current collector of the negative electrode current collector and the current collector of the negative electrode sheet are of the same material, which is copper. Therefore, in order to improve the conductivity of the pole and control the weight and cost of the battery cell, a copper-aluminum composite pole is used to connect the negative electrode current collector and the external circuit. The copper material of the copper-aluminum composite pole is connected with the negative electrode current collector, and the aluminum material of the copper-aluminum composite pole is connected with the external circuit.

[0003] Because the melting points of copper and aluminum materials are different, and the flowabilities of the materials are different, the combination reliability between the copper material and the aluminum material of the pole is poor, and the copper material and the aluminum material are prone to separation from each other. CONTENT OF THE INVENTION

[0004] Embodiments of the application provide a pole, a cover plate assembly and a battery cell, which can improve the combination reliability between the copper material and the aluminum material of the pole.

[0005] In a first aspect, embodiments of the application provide a pole, which comprises a first metal piece and a second metal piece; the first metal piece defines a first recess and a first protrusion, the first protrusion is protruded from the opening of the first recess in a direction away from the first recess; the second metal piece comprises a terminal and a second protrusion, the second protrusion is protruded outward from the terminal, the terminal is provided with a second recess on the side close to the second protrusion, and the second recess is arranged around the second protrusion; wherein the first protrusion is fitted in the second recess, the second protrusion is fitted in the first recess, and the materials of the first metal piece and the second metal piece are different.

[0006] In an embodiment, a third recess is arranged on the bottom wall of the first recess, and a third protrusion is arranged on the end of the second protrusion away from the terminal, the third protrusion is fitted in the third recess.

[0007] In an embodiment, the third protrusion has a first radial dimension φ1, which gradually decreases in the direction close to the terminal.

[0008] In an embodiment, the bottom wall of the first recess is provided with a fourth protrusion, and the end of the second protrusion away from the terminal is provided with a fourth recess, the fourth protrusion is fitted in the fourth recess.

[0009] In an embodiment, the bottom wall of the first recess is arched towards the second protrusion to form a fourth protrusion in the first recess and a reverse-arched groove on the side of the first metal piece away from the second metal piece.

[0010] In an embodiment, the included angle between the groove wall of the reverse-arched groove and the axis of the pole is σ, and satisfies: 15°≤σ≤60°.

[0011] In an embodiment, the second protrusion has a second radial dimension φ2, which gradually decreases in the direction close to the terminal.

[0012] In an embodiment, in the radial direction, there is a gap between the outer circumferential surface of the first protrusion and the outer circumferential surface of the second recess, and the gap has a spacing W1, which satisfies: 0

[0013] In an embodiment, the wall thickness of the bottom wall of the first recess formed by the first metal piece is D1, the wall thickness of the side wall of the first recess formed by the first metal piece is D2, and the wall thickness of the first protrusion formed by the first metal piece is D3, and they satisfy: D1>D2>D3.

[0014] In an embodiment, 1 / 2D1≤D2

[0015] In an embodiment, the material of the first metal piece is copper material, and the material of the second metal piece is aluminum material.

[0016] In an embodiment, the thickness of the first metal piece ranges from 0.2mm to 1mm.

[0017] In an embodiment, the flow cross section of the pole is S1, which satisfies: S1≥10mm 2 , and / or the area of the side of the terminal away from the second protrusion is S2, which satisfies: 100mm 2 ≤S2≤300mm 2 .

[0018] In a second aspect, the embodiments of the present application provide a cover plate assembly, which comprises a cover plate, an upper plastic piece, a lower plastic piece, a current collecting piece, a sealing ring, and the aforementioned pole; the pole is arranged on the cover plate, and the terminal is located on one side of the cover plate, and the end of the first metal piece away from the terminal is located on the other side of the cover plate; the upper plastic piece is arranged between the terminal and the cover plate; the lower plastic piece is arranged on the other side of the cover plate; one end of the current collecting piece is connected with the first metal piece; the sealing ring is arranged between the pole and the cover plate; and the material of the first metal piece is consistent with the material of the current collecting piece.

[0019] In a third aspect, the embodiments of the present application provide a battery cell, comprising a shell, an electrode assembly and the aforementioned cover plate assembly; the shell has a receiving cavity; the electrode assembly is arranged in the receiving cavity; the cover plate is connected with the shell and seals an opening of the receiving cavity, the other end of the current collector is connected with the electrode assembly; the terminal and the first protrusion are both located on the side of the cover plate away from the electrode assembly.

[0020] The beneficial effects of the embodiments of the present application are as follows:

[0021] In the embodiments of the present application, the second protrusion is embedded in the first recess to form a bonding structure of the first metal and the second metal in the axial direction of the pole post, and the first protrusion is embedded in the second recess to form a bonding structure of the first metal and the second metal in the radial direction of the pole post. In this way, the area of the bonding surface between the first metal piece and the second metal piece can be increased under the premise of a certain pole post height, and the electrode assembly can pull the first metal piece, the cover plate can push the first protrusion towards the terminal, thereby improving the reliability of the bonding between the first metal piece and the second metal piece. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0023] Figure 1 is a structural schematic diagram of a pole post provided by the embodiments of the present application;

[0024] Figure 2 is a structural schematic diagram of a first longitudinal section of a pole post provided by the embodiments of the present application;

[0025] Figure 3 is a structural schematic diagram of another pole post provided by the embodiments of the present application;

[0026] Figure 4 is a structural schematic diagram of a second longitudinal section of a pole post provided by the embodiments of the present application;

[0027] Figure 5 is a structural schematic diagram of a third longitudinal section of a pole post provided by the embodiments of the present application;

[0028] Figure 6 is Figure 5 is an enlarged view of A in FIG. 8;

[0029] Figure 7 is Figure 2 is an enlarged view of B in FIG. 8;

[0030] Figure 8 is a structural schematic diagram of a cover plate assembly provided by an embodiment of the present application;

[0031] Figure 9 is a structural schematic diagram of another cover plate assembly provided by an embodiment of the present application.

[0032] Explanation of reference signs:

[0033] 001-pole column;

[0034] 011-first metal piece; 112-first recess; 113-first protrusion; 114-third recess; 115-fourth protrusion; 116-inverted arc-shaped groove;

[0035] 012-second metal piece; 121-terminal; 123-second protrusion; 124-second recess; 125-third protrusion; 126-fourth recess;

[0036] 002-cover plate assembly; 021-cover plate; 022-upper plastic piece; 023-lower plastic piece; 024-current collecting piece. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0038] In addition, it should be understood that the specific embodiments described herein are merely used to illustrate and explain the present application, and are not used to limit the present application. In the present application, the terms "first", "second" are used for description purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include one or more of the features.

[0039] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection or can communicate with each other; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] The terms "comprise", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a product or process that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such product or process.

[0041] In the description of the embodiments of the present application, the word "example" or "for example" is used to represent an example, an illustration, or a description. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The word "example" or "for example" is intended to present a relative concept in a clear manner.

[0042] Please refer to Figures 1-2 , Figure 1 is a structural schematic diagram of a pole column 001 provided by an embodiment of the present application, Figure 2 is a structural schematic diagram of a first longitudinal section of a pole column 001 provided by an embodiment of the present application, and the embodiment of the present application provides a pole column 001. The pole column 001 comprises a first metal piece 011 and a second metal piece 012.

[0043] The first metal piece 011 defines a first recess 112 and a first protrusion 113. The first protrusion 113 is protruded from an opening of the first recess 112 in a direction away from the first recess 112. The second metal piece 012 comprises a terminal 121 and a second protrusion 123. The second protrusion 123 is protruded outward from the terminal 121. The terminal 121 is provided with a second recess 124 on a side close to the second protrusion 123. The second recess 124 is arranged around the second protrusion 123; wherein the first protrusion 113 is fitted in the second recess 124, the second protrusion 123 is fitted in the first recess, and the materials of the first metal piece 011 and the second metal piece 012 are different.

[0044] Specifically, along the radial direction of the pole column 001, the first protrusion 113 is protruded from the opening of the first recess 112 in a direction away from the first recess 112.

[0045] In addition, one end surface of the terminal 121 is connected with the second protrusion 123 and is provided with the second recess 124.

[0046] Specifically, the first protrusion 113 extends in a ring shape around the outer periphery of the first surface; and the second recess 124 extends in a ring shape around the second protrusion 123.

[0047] It can be understood that the terminal 121 is used for abutting cooperation with a cover plate of a battery monomer, and the first metal piece 011 is arranged through the cover plate, therefore, the outer diameter of the terminal 121 is greater than the outer diameter of the first metal piece 011. Meanwhile, the first protrusion 113 and the terminal 121 are located on a side of the cover plate away from an electrode assembly.

[0048] It can be understood that the first metal piece 011 and the second metal piece 012 are arranged along the axial direction of the pole column 001. The cross-sectional shape of the pole column 001 can be circular, triangular, rectangular, polygonal, or the like. For example, the cross-sectional shape of the pole column 001 is a waist circle, as shown in Figure 3 Figure 3 is another structural schematic diagram of the pole column 001 provided by the embodiment of the present application.

[0049] It can be understood that the pole column 001 can be formed by casting, specifically, the second metal piece 012 can be cast first, and then the first metal piece 011 can be cast on the second metal piece 012, so that the first protrusion 113 is embedded in the second recess 124, and the second protrusion 123 is embedded in the first recess 112; or the second metal piece 012 can be extruded to the first metal piece 011 in a manner of piling and pressing. Thus, the first recess 112 is formed on the first metal piece 011, and the second protrusion 123 embedded in the first recess 112 is formed on the second metal piece 012, and the first metal piece 011 is extruded to the second recess 124 to form the first protrusion 113 embedded in the second recess 124.

[0050] Exemplarily, the first metal is electrically connected with the electrode assembly, specifically, the first metal is electrically connected with the negative current collector, and the material of the negative current collector is copper material. Correspondingly, the first metal is copper material, and the second metal is aluminum material.

[0051] In the embodiment, the second protrusion 123 is embedded in the first recess 112 to form the combined structure of the first metal piece 011 and the second metal piece 012 in the axial direction of the pole column 001, and the first protrusion 113 is embedded in the second recess 124 to form the combined structure of the first metal piece 011 and the second metal piece 012 in the radial direction of the pole column 001. In this way, under the premise that the height dimension of the pole column 001 is constant, the area of the combined surface between the first metal piece 011 and the second metal piece 012 can be increased, and the electrode assembly can pull the first metal piece 011, the cover plate can push the first protrusion 113 towards the terminal 121, and thus the reliability of the combination between the first metal piece 011 and the second metal piece 012 can be improved.

[0052] Specifically, the electrode assembly can pull the first metal piece 011, so that the first metal piece 011 has a tendency to move towards the battery cavity. The first protrusion 113 is located on the side of the cover plate away from the battery cavity, and is in abutting cooperation with the cover plate. Under the combined action of the abutting cooperation of the first protrusion 113 with the cover plate and the tendency of the first metal piece 011 to move towards the battery cavity, the first protrusion 113 is pushed towards the terminal 121, and thus the combination between the first metal piece 011 and the second metal piece 012 can be enhanced.

[0053] ​In addition, by arranging the terminal 121 and connecting the terminal 121 and the second protrusion 123 as a whole, the terminal 121 can be prevented from falling into the battery monomer when the pole column 001 is applied to the cover plate assembly by stopping cooperation between the terminal 121 and the cover plate of the cover plate assembly, and the terminal 121 can be formed when the second metal piece 012 is formed, thereby improving manufacturing efficiency. Compared with the scheme of welding the terminal and the column in the related art, the terminal 121 and the second protrusion 123 are connected as a whole in the embodiment, so that the welding stress can be avoided to cause poor connection reliability of the terminal 121, thereby improving the reliability of the overcurrent.

[0054] In addition, when the first metal piece 011 is copper material and the second metal piece 012 is aluminum material, the pole column 001 has a large copper material covering surface by the above arrangement, so that the electrical performance of the pole column 001 is improved based on the characteristic that the electrical conductivity of copper is better than that of aluminum. Specifically, when the overcurrent path has copper material and aluminum material, the overcurrent speed is faster when the overcurrent passes through the copper material than when the overcurrent passes through the aluminum material, so that the overcurrent speed of the pole column 001 is improved, thereby improving the electrical performance of the pole column 001.

[0055] Referring to Figure 4 , Figure 4 is a second longitudinal sectional view of the pole column 001 provided by the embodiment. In an embodiment, a third recess 114 is arranged on the bottom wall of the first recess. A third protrusion is arranged on the end of the second protrusion away from the terminal 121. The third protrusion is embedded in the third recess 114. In this way, the first metal piece 011 and the second metal piece 012 form a multi-stage embedding structure in the axial direction, thereby improving the reliability of the combination between the first metal piece 011 and the second metal piece 012.

[0056] If the pole column 001 is formed by a punch forming process, the second metal piece 012 is extruded on the first metal piece 011 to form a recess, then the position on the outer periphery of the first metal piece 011 opposite to the height of the third recess 114 is limited by clamping, so that the second metal piece 012 expands radially outward at the position of the first recess when the second metal piece 012 continues to extrude, thereby forming the first recess and the second protrusion.

[0057] Referring to Figure 4 In an embodiment, the third protrusion has a first radial dimension φ1, which gradually decreases in the direction close to the terminal 121. In this way, a reverse locking structure is formed between the third protrusion and the third recess 114, that is, the third protrusion and the third recess 114 are in stop cooperation in the axial direction of the pole column 001. In this way, the first metal piece 011 and the second metal piece 012 can be effectively prevented from being separated from each other, thereby improving the reliability of the combination between the first metal piece 011 and the second metal piece 012.

[0058] Wherein, when the third recess 114 is formed, the outer periphery of the first metal piece 011 opposite to the side of the third recess 114 close to the first recess can be positioned by a clamp, so that when the third recess 114 is formed, the second metal piece 012 extrudes the side of the third recess 114 away from the first recess, thereby realizing the gradual reduction of the first radial dimension φ1 in the direction close to the terminal 121.

[0059] Please refer to Figure 5 , Figure 5 is a third longitudinal sectional view of the pole 001 provided by the embodiments of the present application. The bottom wall of the first recess is provided with a fourth protrusion 115. The end of the second protrusion away from the terminal 121 is provided with a fourth recess 126. The fourth protrusion 115 is embedded in the fourth recess 126.

[0060] It can be understood that, since the materials of the first metal piece 011 and the second metal piece 012 are different, the flowability of the two metal materials is inconsistent. Therefore, when the pole 001 is formed by bumping, it is easy to form a wavy bonding surface at the bottom of the first recess, which has an adverse effect on the bonding of the first metal and the second metal.

[0061] Based on this, in the embodiments, by providing the fourth recess 126 and the fourth protrusion 115 embedded in the fourth recess 126, the flow of the first metal piece 011 and the second metal piece 012 can be guided based on the formation of the fourth protrusion 115, so that the bonding between the first metal piece 011 and the second metal piece 012 is more reliable.

[0062] Please refer to Figure 5 In an embodiment, the bottom wall of the first recess is arched towards the second protrusion to form the fourth protrusion 115 in the first recess and form an inverted-arched groove 116 on the side of the first metal piece 011 away from the second metal piece 012. In this way, the amount of material of the first metal piece 011 can be reduced to control the material cost of the pole 001.

[0063] Please refer to Figure 5 , Figure 6 is Figure 5 is an enlarged view of A in FIG. 11. In an embodiment, the angle between the groove wall of the inverted-arched groove 116 and the axis of the pole 001 is σ, which satisfies: 15°≤σ≤60°. In this way, the first metal piece 011 has better flowability when the second protrusion is formed, so as to improve the operability of the pole 001.

[0064] Please refer to Figure 2In an embodiment, the second protrusion 123 has a second radial dimension φ2, which gradually decreases in the direction close to the terminal 121. In this way, an undercut structure can be formed between the second protrusion and the first recess, i.e., the second protrusion and the first recess are in axial stop cooperation with each other. In this way, the first metal piece 011 and the second metal piece 012 can be effectively prevented from being separated from each other, thereby improving the reliability of the combination between the first metal piece 011 and the second metal piece 012.

[0065] In the forming of the first recess, the opposite position of the outer periphery of the first metal piece 011 to the side of the first recess close to the terminal 121 can be limited by a clamp, so that when the first recess is formed, the second metal piece 012 extrudes the side of the first recess away from the terminal 121, thereby realizing the gradual decrease of the second radial dimension φ2 in the direction close to the terminal 121.

[0066] Please refer to Figure 7 , Figure 7 is Figure 2 an enlarged view of B in FIG. 13. In an embodiment, the outer periphery surface of the first protrusion 113 and the outer periphery surface of the second recess 124 have a gap therebetween in the radial direction. The gap has a gap distance W1, which satisfies: 0 < W1 ≤ 0.1 mm.

[0067] It can be understood that the battery cell is often in a charging and discharging state, and the temperature of the battery cell is relatively high during charging and discharging. Therefore, the relevant heated components are in a thermal expansion state.

[0068] Based on this, in the present embodiment, by providing a gap between the outer periphery surface of the first protrusion 113 and the outer periphery surface of the second recess 124, and limiting the maximum value of the gap to be not greater than 0.1 mm, the requirements of the combination between the first metal piece 011 and the second metal piece 012 can be met to ensure the reliability of the structure of the pole 001, and when the first metal piece 011 and the second metal piece 012 expand, the mutual pushing force in the radial direction can be reduced to improve the internal stress state of the pole 001, and the adverse effects of thermal expansion on the connection part between the pole 001 and other components can be reduced.

[0069] Please refer to Figure 2 In an embodiment, the wall thickness of the bottom wall of the first metal piece 011 forming the first recess is D1, the wall thickness of the side wall of the first metal piece 011 forming the first recess is D2, and the wall thickness of the first metal piece 011 forming the first protrusion 113 is D3, which satisfy: D1 > D2 > D3. In this way, the side of the first metal piece 011 away from the terminal 121 has a relatively thick thickness, which is beneficial to the welding of the first metal piece 011 and the current collecting piece, and the thickness of the first protrusion 113 is relatively small, which can control the amount of material of the first metal piece 011.

[0070] In an embodiment, 1 / 2D1≤D2<D1, and / or, 1 / 2D2≤D3<D2.

[0071] It can be understood that it can be 1 / 2D1≤D2<D1, or, 1 / 2D2≤D3<D2, or, 1 / 2D1≤D2<D1, and 1 / 2D2≤D3<D2.

[0072] In the present embodiment, by limiting 1 / 2D1≤D2<D1, the wall thickness of the first recess can be avoided to be too small to be broken during forming; by limiting 1 / 2D2≤D3<D2, the thickness of the first protrusion 113 can be avoided to be too small to be broken during forming.

[0073] In an embodiment, the material of the first metal piece 011 is copper material, and the material of the second metal piece 012 is aluminum material. In this way, the low resistance requirement of the pole 001 during overcurrent can be met to reduce power loss, and the material cost of the pole 001 can be controlled to improve the economy of the pole 001.

[0074] In addition, the copper material includes but is not limited to pure copper, brass, bronze, phosphor bronze, beryllium bronze, and oxygen-free copper.

[0075] The aluminum material includes but is not limited to 1070 aluminum plate, 1060 aluminum plate, and L3 aluminum plate.

[0076] In an embodiment, the thickness of the first metal piece 011 ranges from 0.2mm to 1mm. In this way, the strength requirement of the first metal piece 011 can be met, and the material cost of the first metal piece 011 can be controlled, thereby improving the economy of the pole 001.

[0077] In an embodiment, the overcurrent section of the pole 001 is S1, which satisfies: S1≥10mm 2 , and / or, the area of the side of the terminal 121 away from the second protrusion is S2, which satisfies: 100mm 2 ≤S2≤300mm 2 .

[0078] It can be understood that in the present embodiment, S1≥10mm 2 , or, 100mm 2 ≤S2≤300mm 2 , or, S1≥10mm 2 , and 100mm 2 ≤S2≤300mm 2 .

[0079] In the embodiment, by limiting the flow cross section of the pole post 001, the basic flow capacity of the pole post 001 can be ensured to meet the flow requirement of the battery monomer; and by limiting the area of the side of the terminal 121 away from the second protrusion, the terminal 121 has sufficient area for welding with the connecting row to improve the operability of the welding of the terminal 121 with the connecting row, and the volume of the terminal 121 can be controlled to facilitate the arrangement of other components on the end cover, and the material cost of the terminal 121 can be controlled.

[0080] Please refer to Figure 8 and Figure 9 , Figure 8 is a structural schematic diagram of a cover plate assembly 002 provided by an embodiment of the present application, Figure 9 is a structural schematic diagram of another cover plate assembly 002 provided by an embodiment of the present application. Accordingly, an embodiment of the present application also provides another cover plate assembly 002. The cover plate assembly 002 includes a cover plate 021, an upper plastic part 022, a lower plastic part 023, a current collecting part 024, a sealing ring, and the aforementioned pole post 001. The pole post 001 is arranged on the cover plate 021. The terminal 121 is located on one side of the cover plate 021, and the end of the first metal part 011 away from the terminal 121 is located on the other side of the cover plate 021. The upper plastic part 022 is arranged between the terminal 121 and the cover plate 021. The lower plastic part 023 is arranged on the other side of the cover plate 021. One end of the current collecting part 024 is connected with the first metal part 011. The sealing ring is arranged between the pole post 001 and the cover plate 021. The material of the first metal part 011 is consistent with the material of the current collecting part 024.

[0081] The terminal 121 and the first protrusion 113 are located on the same side of the cover plate 021. Specifically, the side of the terminal 121 and the first protrusion 113 close to the cover plate 021 is in contact with the upper plastic part 022.

[0082] It can be understood that the pole post 001 provided by an embodiment of the present application can be used in the cover plate assembly 002 of a cylindrical battery, as shown in Figure 8 , or can be used in the cover plate assembly 002 of a square battery, as shown in Figure 9 .

[0083] In the embodiment, by using the aforementioned pole post 001, the area of the bonding surface between the first metal part 011 and the second metal part 012 can be increased based on the structure that the first metal part 011 and the second metal part 012 are embedded in each other, and the electrode assembly can pull the first metal part 011, the cover plate 021 can push the first protrusion 113 towards the terminal 121, and thus the reliability of the combination between the first metal part 011 and the second metal part 012 can be improved. In this way, the structure of the pole post 001 is reliable, and thus the structural stability of the cover plate assembly 002 can be improved.

[0084] Correspondingly, the embodiment of the present application also provides a battery cell. The battery cell comprises a shell, an electrode assembly and the aforementioned cover plate assembly 002. The shell has a receiving cavity. The electrode assembly is arranged in the receiving cavity. The cover plate 021 is connected with the shell and seals the opening of the receiving cavity. The other end of the current collector 024 is connected with the electrode assembly. The terminal 121 and the first protrusion 113 are both located on the side of the cover plate 021 away from the electrode assembly.

[0085] The electrode assembly comprises at least a positive electrode sheet, a diaphragm and a negative electrode sheet arranged in a stack.

[0086] It can be understood that the pole 001 is connected with the negative electrode sheet of the battery cell through the current collector 024.

[0087] In the embodiment, by adopting the aforementioned cover plate assembly 002, in addition to the premise that the height dimension of the pole 001 is certain, the area of the bonding surface between the first metal piece 011 and the second metal piece 012 can be increased; the first metal piece 011 can also be pulled by the electrode assembly so that the cover plate 021 can push the first protrusion 113 towards the direction of the terminal 121, thereby the reliability of the combination between the first metal piece 011 and the second metal piece 012 can be improved. In this way, the reliability of the battery cell can be improved, so that the pole 001 can meet the overcurrent requirement of the battery cell while the cost can also be controlled, which is conducive to improving the economy of the battery cell.

[0088] The above has introduced the embodiments of the present application in detail, and the specific examples have been applied in the present text to describe the principles and implementation manners of the present application. The above embodiment descriptions are only used to help understand the method of the present application and its core idea; meanwhile, for the person skilled in the art, according to the idea of the present application, the specific implementation manner and application range will have changes; in conclusion, the content of the present description should not be understood as the limitation of the present application.

Claims

1. A pole, characterized in that The first metal piece defines a first recess and a first protrusion, the first protrusion protrudes from an opening of the first recess in a direction away from the first recess; The second metal piece includes a terminal and a second protrusion, the second protrusion protrudes outward from the terminal, a second recess is provided on a side of the terminal close to the second protrusion, and the second recess is provided around the second protrusion; The first protrusion is embedded in the second recess, the second protrusion is embedded in the first recess, and the materials of the first metal piece and the second metal piece are different. A third recess is provided on a bottom wall of the first recess, and a third protrusion is provided on an end of the second protrusion away from the terminal, the third protrusion is embedded in the third recess.

2. The pole according to claim 1, characterized in that The third protrusion has a first radial dimension φ1, which gradually decreases in a direction close to the terminal.

3. The pole according to claim 2, characterized in that A fourth protrusion is provided on a bottom wall of the first recess, and a fourth recess is provided on an end of the second protrusion away from the terminal, the fourth protrusion is embedded in the fourth recess.

4. The pole according to claim 1, wherein The bottom wall of the first recess is arched towards the second protrusion to form the fourth protrusion in the first recess and form an inverted-arched groove on a side of the first metal piece away from the second metal piece.

5. The pole according to claim 4, characterized in that An included angle between a groove wall of the inverted-arched groove and an axis of the pole is σ, and 15°≤σ≤60° is satisfied.

6. The pole according to claim 5, characterized in that The second protrusion has a second radial dimension φ2, which gradually decreases in a direction close to the terminal.

7. The pole according to any one of claims 1-6, characterized in that In a radial direction, there is a gap between an outer circumferential surface of the first protrusion and an outer circumferential surface of the second recess, a distance of the gap is W1, and 0<W1≤0.1mm is satisfied.

8. The pole according to any one of claims 1-6, characterized in that A wall thickness of the bottom wall of the first recess formed by the first metal piece is D1, a wall thickness of a side wall of the first recess formed by the first metal piece is D2, and a wall thickness of the first protrusion formed by the first metal piece is D3, and D1>D2>D3 is satisfied.

9. The pole according to any one of claims 1-6, characterized in that 1 / 2D1≤D2<D1, and / or, 1 / 2D2≤D3<D2.

10. The pole according to claim 9, characterized in that The material of the first metal piece is copper material, and the material of the second metal piece is aluminum material.

11. The pole as claimed in claim 1, characterized in that The thickness of the first metal piece ranges from 0.2mm to 1mm.

12. The pole according to claim 11, characterized in that The cover plate; 13. The pole according to any one of claims 1-6, characterized in that The overcurrent section of the pole is S1, and S1≥10mm 2 , and / or the area of the side of the terminal away from the second convex part is S2, and 100mm 2 ≤S2≤300mm 2 .

14. A cover plate assembly characterized by, The pole according to any one of claims 1-13 is arranged through the cover plate, and the terminal is located on one side of the cover plate, and an end of the first metal piece away from the terminal is located on the other side of the cover plate; The upper plastic piece is arranged between the terminal and the cover plate; The lower plastic piece is arranged on the other side of the cover plate; The current collecting piece is connected to one end of the first metal piece; The sealing ring is arranged between the pole and the cover plate; The material of the first metal piece is consistent with the material of the current collecting piece. The shell has a receiving cavity; The electrode assembly is arranged in the receiving cavity; 15. A battery cell, characterized by And the cover plate assembly according to claim 14 is connected to the shell and closes an opening of the receiving cavity, the other end of the current collecting piece is connected to the electrode assembly; the terminal and the first protrusion are both located on a side of the cover plate away from the electrode assembly. ​ ​ ​

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