Cover plate structure of secondary battery

Abstract

The present disclosure relates to a secondary battery cover plate structure, comprising: a top cover plate having a first pole via hole; the pole is arranged on the top cover plate in an insulating manner; the lower support is provided with a second pole via hole and is provided with a buckling part, the upper end of the buckling part extends outwards to form a buckling outer edge, a clamping groove is formed between the buckling outer edge and the upper surface of the lower support, and the height of the clamping groove is larger than the thickness of the inner edge of the first pole via hole, so that after the top cover plate and the lower support are buckled, the first pole via hole is clamped in the clamping groove. A gap is reserved between the buckling outer edge and the top cover plate; the sealing element is arranged between the top cover plate and the post terminal, and a part of the sealing element extends to be filled in the gap; and the pole cap is arranged on the outer side of the pole in a surrounding manner. According to the cover plate structure, the machining precision and assembling precision requirements of the buckle structure can be reduced, the machining efficiency and the yield of the cover plate structure can be improved, and the buckling stability of the top cover plate and the lower support can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery top covers, and in particular to a secondary battery cover plate structure. Background Art

[0002] In the existing power battery structure, such as the common square aluminum shell battery, it generally includes a shell, a battery cell and a cover plate structure. The battery cell is arranged in the shell, and the cover plate structure is used to close the shell. The cover plate structure usually includes a lower bracket, a top cover plate, a sealing ring, a fixing frame and positive and negative bipolar columns.

[0003] In the traditional cover plate structure, the positive and negative poles are placed in the mold, and then the lower bracket, top cover plate and other components are placed in the mold in sequence. The pole caps formed by injection molding connect the various components into one. This method has low processing efficiency and requires high precision in the placement of components.

[0004] To solve the above problems, the inventor filed a Chinese patent application in 2022 with patent number CN217848116U, entitled A battery top cover assembly for a secondary battery and a secondary battery. In the patent application, the lower bracket and the top cover plate are connected by a snap-fit ​​structure, which can improve the processing efficiency of the cover plate structure. However, in the process of actual application of the snap-fit ​​structure for production, the inventor found that since the snap-fit ​​structure of the lower bracket is tightly snapped to the inner edge of the first pole through-hole of the top cover plate, this structure has very high requirements for processing accuracy and assembly accuracy. The height of the card slot formed under the snap-fit ​​structure is required to be basically equal to the inner edge thickness of the first pole through-hole, so that the lower bracket and the top cover plate can be stably snapped together. In the actual production process, the height of the card slot is often too small, resulting in the inability to snap together, which affects the processing efficiency and yield rate. Utility Model Content

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention aims to provide a secondary battery cover plate structure. The present invention can reduce the processing accuracy and assembly accuracy requirements of the buckle structure, help improve the processing efficiency and yield rate of the cover plate structure, and improve the stability of the buckle connection between the top cover plate and the lower bracket.

[0006] A secondary battery cover structure disclosed in the present disclosure includes:

[0007] A top cover plate having a first pole through hole penetrating along a thickness direction;

[0008] A pole, which is insulated and arranged on the top cover plate and located at the first pole through hole;

[0009] A lower bracket, which has a second pole through hole penetrating in the thickness direction, the position of the second pole through hole corresponds to the position of the first pole through hole, the lower bracket is formed with a buckle portion on the outer side of the second pole through hole, the upper end of the buckle portion extends outward to form a buckling outer edge, a slot is formed between the buckling outer edge and the upper surface of the lower bracket, the height of the slot is greater than the inner edge thickness of the first pole through hole, so that the buckle portion passes through the first pole through hole, so that after the top cover plate and the lower bracket are buckled, a gap is left between the buckling outer edge and the top cover plate;

[0010] A sealing member is disposed between the top cover plate and the pole and is located outside the buckle portion, and a portion of the sealing member extends to fill the gap;

[0011] A pole cap is disposed around the outside of the pole and is connected to the top cover plate and the pole respectively, so that the top cover plate and the pole are insulated from each other.

[0012] Preferably, the secondary battery cover structure further includes:

[0013] A fixing frame is arranged on the top cover plate and is located outside the first pole through hole. The fixing frame has a third pole through hole corresponding to the first pole through hole and used to accommodate the pole. The pole is partially embedded in the fixing frame.

[0014] Preferably, a positioning groove matched with the fixing frame is formed on the outer side of the first pole through hole on a side of the top cover plate away from the lower bracket, and the fixing frame is installed in the positioning groove.

[0015] Preferably, the bottom surface of the fixing frame is welded to the bottom wall of the positioning groove, and part of the side surfaces of the fixing frame are welded to the side walls of the positioning groove.

[0016] Preferably, the secondary battery cover structure also includes a connector, the lower end of the pole extends through the second pole through hole to be exposed outside the lower surface of the lower bracket, and the connector is connected to the lower surface of the lower bracket and also to the exposed part of the pole.

[0017] Preferably, the connecting member is in a sheet shape, one end of which is connected to the lower surface of the lower bracket, and the other end is formed with a connecting hole adapted to the lower end of the pole, and the connecting hole is sleeved on the outer side of the lower end of the pole and connected.

[0018] Preferably, the buckle portion extends along the outer side of the second pole through hole, the buckle outer edge has a plurality of locations, the buckle outer edges at the plurality of locations are evenly distributed on the buckle portion, and the cross section of the buckle outer edge is semicircular, so that the outer side surface of the buckle outer edge is an arc-shaped surface;

[0019] The sealing member is formed with a filling portion at a position corresponding to the gap, the filling portion protruding toward the direction where the gap is located.

[0020] Preferably, the lower bracket is hollowed out in the middle of its length direction to form a plurality of elastic shrinkage holes.

[0021] The advantages of the secondary battery cover structure disclosed in the present invention are:

[0022] 1. The height of the card slot is set to be greater than the inner edge thickness of the first pole through hole, so that a large gap is left between the outer edge of the card slot and the top cover plate after buckling. When the seal and the pole are subsequently installed, the seal is squeezed from top to bottom by the pole, so that part of the seal fills the gap. The structure makes full use of the elastic deformable characteristics of the seal and the relative position of the pole and the seal, overcomes the technical prejudice that the traditional snap-fit ​​requires equal sizes, and fills the gap formed by the seal. The depth of the card slot can be greater than the inner edge thickness of the first pole through hole, so that the buckle is assembled. The outer edge can be conveniently buckled to the inner edge of the first pole through hole, which greatly reduces the processing accuracy and assembly accuracy requirements of the buckle structure, avoids the phenomenon that the buckle cannot be buckled due to the small height of the card slot in the actual production process, and helps to improve the processing efficiency and the yield rate of the cover plate. In addition, the seal is a soft elastic material, which is filled between the buckled outer edge and the top cover plate to play a role similar to that of an elastic gasket. Compared with the rigid contact of the buckle directly buckled in the prior art, the flexible contact formed by the seal can make the assembly of the lower bracket and the top cover plate more tight and stable, and reduce the risk of loosening of the top cover plate and the lower bracket.

[0023] 2. The present invention uses oblique welding to weld the bottom surface and part of the side surface of the fixing frame to the top cover plate. Compared with the structure of welding the bottom surface alone in the prior art, this structure has higher stability, making the connection between the fixing frame and the top cover plate more stable and not easy to fall off. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a secondary battery cover structure according to this embodiment;

[0025] Figure 2 yes Figure 1 Exploded view of;

[0026] Figure 3 yes Figure 1 Sectional view at the pole position;

[0027] Figure 4 is a schematic diagram of the structure of the top cover plate of this embodiment;

[0028] Figure 5 is a schematic structural diagram of the lower bracket described in this embodiment;

[0029] Figure 6 is a schematic structural diagram of the buckle portion of this embodiment;

[0030] Figure 7 is a schematic structural diagram of the fixing frame described in this embodiment;

[0031] Figure 8 is a schematic structural diagram of the connecting member described in this embodiment;

[0032] Fig. 9 This is a schematic diagram of the structure of the top cover plate of this embodiment with an explosion-proof valve installed;

[0033] Fig.10 yes Fig. 9 Schematic diagram of the structure after the lower bracket is assembled;

[0034] Fig.11 yes Fig.10 Schematic diagram of the structure after installing the seal;

[0035] Fig.12 yes Fig.11 Schematic diagram of the structure after adding poles;

[0036] Fig.13 yes Fig.12 Schematic diagram of the structure after the fixing frame is installed;

[0037] Fig.14 yes Fig.13 Schematic diagram of welding points;

[0038] Fig.15 yes Fig.13 Schematic diagram of the structure after the polar cap is formed by injection molding;

[0039] Fig.16 yes Fig.15 Schematic diagram of the structure after applying the protective film;

[0040] Fig.17 yes Fig.16 Structural schematic diagram of adding connecting parts;

[0041] Fig.18 It is a cross-sectional view of the negative electrode column described in this embodiment.

[0042] Explanation of the reference numerals: 1-top cover plate, 11-first pole through hole, 12-positioning groove, 2-pole, 2a-aluminum part, 2b-copper part, 3-lower bracket, 31-second pole through hole, 32-buckle part, 321-buckle outer edge, 33-elastic shrinkage hole, 4-seal, 5-pole cap, 6-fixing frame, 61-third pole through hole, 7-connector, 71-connecting hole, 8-explosion-proof valve, 9-protective film, A-side wall welding point, B-bottom wall welding point. DETAILED DESCRIPTION

[0043] like Figure 1-Figure 18 As shown, a secondary battery cover structure described in the present disclosure includes:

[0044] The top cover plate 1 is generally a square plate structure, and has a first pole through hole 11 penetrating along the thickness direction, for the pole 2 to pass through, so that the pole 2 can be electrically connected to the battery cell inside the battery housing. In the bipolar pole structure, the number of the first pole through holes 11 is two, which are respectively distributed at both ends of the length direction of the top cover plate 1 to correspond to the positive pole and the negative pole, respectively.

[0045] The poles 2 are usually two in number, one is a positive pole and the other is a negative pole. The shape and size of the poles 2 are usually corresponding to the first pole vias 11 and are made of conductive materials. For the negative pole, Fig.18 As shown, the upper part is required to be made of aluminum material, that is, the upper part is the aluminum part 2a, and the lower part is made of copper material, that is, the lower part is the copper part 2b. In this embodiment, the pole 2 is a cylindrical structure. In other optional embodiments, the pole 2 can be a quadrangular prism or other special-shaped structures, which is not limited in this embodiment.

[0046] The pole 2 is arranged on the top cover plate 1 and is located at the first pole through hole 11 .

[0047] The lower bracket 3 is usually made of plastic material to have good insulation performance. The lower bracket 3 is formed with a second pole through hole 31 at a position corresponding to the first pole through hole 11. The second pole through hole 31 is also adapted to the pole 2 and is also provided for the pole 2 to pass through. The lower bracket 3 is formed with an upwardly protruding snap portion 32 on the outer side of the second pole through hole 31. For example, for the cylindrical pole 2, the snap portion 32 is in a circular ring shape, and the upper end of the snap portion 32 extends outward to form a snap-fit ​​outer edge 321, so that a snap groove is formed between the snap-fit ​​outer edge 321 and the upper surface of the lower bracket 3, and the height of the snap groove is greater than the inner edge thickness of the first pole through hole 11. For example, the height of the snap groove is 0.2mm-0.5mm greater than the inner edge thickness of the first pole through hole 11. In this way, when the lower bracket 3 is assembled with the top cover plate 1, after the snap portion 32 passes through the first pole through hole 11, a large gap is left between the snap-fit ​​outer edge 321 and the top cover plate 1. This matching size makes the assembly between the top cover plate 1 and the lower bracket 3 simple.

[0048] The seal 4 is arranged between the top cover plate 1 and the pole 2. Specifically, for the cylindrical pole 2 of this embodiment, the seal 4 is a sealing ring structure, and the seal 4 is sleeved on the outside of the buckle portion 32. When the pole 2 is not installed, the seal 4 is not squeezed and is naturally sleeved on the outside of the buckle portion 32. When the pole 2 is installed and fixed by injection molding, the inner edge of the seal 4 is squeezed and filled into the gap between the buckled outer edge 321 and the top cover plate 1 due to the squeezing effect of the pressure of the pole 2, so that a tight fit is formed between the top cover plate 1, the lower bracket 3 and the seal 4.

[0049] The pole cap 5 is usually formed by an injection molding process, is disposed around the outside of the pole 2, and is connected to the pole 2 and the top cover plate 1 respectively, so that the top cover plate 1 and the pole 2 are insulated from each other.

[0050] Furthermore, in this embodiment, the secondary battery cover structure further includes:

[0051] The fixing frame 6 is in the shape of a hollow circular ring, and has an inner edge extending inward at the upper end. The fixing frame 6 is arranged on the top cover plate 1 and is located outside the first pole through hole 11. The fixing frame 6 has a third pole through hole 61 corresponding to the first pole through hole 11 and used to accommodate the pole 2. The pole 2 is partially embedded in the fixing frame 6. The fixing frame 6 is made of metal material and connected to the top cover plate 1 by welding. The fixing frame 6 is used to limit the pole 2 to prevent the pole 2 from dislocating upward. In a specific embodiment, a plurality of reinforcement holes are opened on the side of the fixing frame 6, so that when the pole cap 5 is formed by injection molding, the colloid can enter the reinforcement hole to form a glue column to reinforce the connection between the fixing frame 6 and the pole cap 5.

[0052] Furthermore, in the present embodiment, a side of the top cover plate 1 away from the lower bracket 3, i.e., the upper surface, is formed with a positioning groove 12 adapted to the fixing frame 6 on the outer side of the first pole through hole 11. For example, when the pole 2 is cylindrical, the positioning groove 12 is annular, and the lower end of the fixing frame 6 is embedded in the positioning groove 12.

[0053] More specifically, the bottom surface of the fixing frame 6 is welded to the bottom wall of the positioning groove 12 to form a bottom wall welding point B, and part of the side surface of the fixing frame 6, specifically the lower side surface, is welded to the side wall of the positioning groove 12 to form a side wall welding point A. The structure in which both the side wall and the bottom wall are welded can effectively strengthen the connection between the fixing frame 6 and the top cover plate 1.

[0054] Furthermore, in this embodiment, the secondary battery cover plate structure also includes a connector 7, and the lower end of the pole 2 extends through the second pole through hole 31 to be exposed outside the lower surface of the lower bracket 3. The connector 7 is connected to the lower surface of the lower bracket 3 and is also connected to the exposed portion of the pole 2. Specifically, in this embodiment, the length of the pole 2 is increased so that the lower end of the pole 2 can be exposed outward after the pole 2 is installed in the top cover plate 1 and the lower bracket 3, and then the exposed portion of the pole 2 is connected to the lower bracket 3 through the connector 7, thereby limiting the upward movement of the pole 2, making it difficult for the pole 2 to separate upward from the top cover plate 1, thereby improving the stability of the installation of the pole 2.

[0055] More specifically, the connecting piece 7 is in the shape of a long sheet, one end of the connecting piece 7 is welded to the lower surface of the lower bracket 3, and the other end is formed with a connecting hole 71 adapted to the lower end of the pole 2. The connecting hole 71 is sleeved on the outer side of the lower end of the pole 2 and welded to the lower end of the pole 2, and then the pole 2 and the lower bracket 3 are connected into an integral structure through the connecting piece 7, reducing the risk of the pole 2 detaching upward from the top cover plate 1.

[0056] Further, in this embodiment, the buckle portion 32 extends along the outer side of the second pole through hole 31. For example, for a cylindrical pole 2, the buckle portion 32 extends along the circular second pole through hole 31 and finally forms a circular ring. The buckle outer edge 321 has several locations, for example, four locations. The buckle outer edges 321 at the four locations are evenly distributed on the buckle portion 32, that is, they are distributed at equal angles. This distribution method will enable the buckle outer edge 321 to have a uniform limiting effect on the seal 4. The cross section of the buckle outer edge 321 is semicircular, so that the outer side surface of the buckle outer edge 321 is an arc surface, that is, the buckle outer edge 321 presents a structure with narrow upper and lower ends and wide middle part. This structure will facilitate the seal 4 to pass through the buckle outer edge 321 and be mounted on the buckle portion 32 below, and after passing through, the seal 4 can also be limited to prevent the seal 4 from dislocating upward.

[0057] The seal 4 is formed with a filling portion (not shown in the figure) protruding in the direction of the gap at a position corresponding to the gap formed by the buckled outer edge 321 and the top cover plate 1. The filling portion extends to the gap with a certain thickness, so that the seal 4 can be more easily protruded at the lower inner position and filled into the gap when squeezed by the pole 2, and it is also beneficial for the seal 4 to achieve tight filling in the gap.

[0058] Furthermore, in the present embodiment, a plurality of elastic shrinkage holes 33 are formed in the middle portion of the lower bracket 3 in the length direction thereof. Since the lower bracket 3 is made of plastic material and has a certain material elasticity, when assembled with the top cover plate 1, it is easy to have a certain dimensional error due to external factors such as temperature changes, resulting in an inability to be assembled with the top cover plate 1. Therefore, in the present embodiment, an elastic shrinkage hole 33 is hollowed out in the middle portion of the lower bracket 3, so that the length of the lower bracket 3 can be fine-tuned through the elastic shrinkage hole 33 therein, so that the lower bracket 3 is adapted to the size of the top cover plate 1, which further reduces the processing accuracy requirements and assembly accuracy requirements of the lower bracket 3 and the top cover plate 1, and improves the fault tolerance of the assembly.

[0059] The present disclosure sets the height of the card slot to be greater than the inner edge thickness of the first pole through hole 11, so that a large gap is left between the outer edge 321 of the card slot and the top cover plate 1 after buckling. When the seal 4 and the pole 2 are subsequently installed, the seal 4 is squeezed from top to bottom by the pole 2, so that part of the seal 4 is filled into the gap. The present structure makes full use of the elastic deformable characteristics of the seal 4 and the relative position of the pole 2 and the seal 4, overcomes the technical prejudice that the traditional snap-fit ​​requires equal sizes, and fills the gap formed by the seal 4. The depth of the card slot can be greater than the inner edge thickness of the first pole through hole 11, so that the buckling during assembly The outer edge 321 can be conveniently buckled to the inner edge of the first pole through hole 11, which greatly reduces the processing accuracy and assembly accuracy requirements of the buckle structure, avoids the phenomenon that the buckle cannot be buckled due to the small height of the card slot in the actual production process, and helps to improve the processing efficiency and the yield rate of the cover plate. In addition, the seal 4 is a soft elastic material, which is filled between the buckled outer edge 321 and the top cover plate 1 and can play a role similar to that of an elastic gasket. Compared with the rigid contact of the buckle directly buckled in the prior art, the flexible contact formed by the seal 4 can make the assembly of the lower bracket 3 and the top cover plate 1 more tight and stable, and reduce the risk of loosening of the top cover plate 1 and the lower bracket 3.

[0060] The present invention uses oblique welding to weld the bottom surface and part of the side surface of the fixing frame 6 to the top cover plate 1. Compared with the structure of welding the bottom surface alone in the prior art, this structure has higher stability, making the connection between the fixing frame 6 and the top cover plate 1 more stable and not easy to fall off.

[0061] This embodiment also provides a method for processing a secondary battery cover structure, comprising the following steps:

[0062] S01. Prepare suitable top cover plate 1, pole 2, lower bracket 3 and fixing frame 6 for use; specifically, the top cover plate 1, pole 2 and fixing frame 6 can be made by stamping of metal materials, and the lower bracket 3 can be made by injection molding of plastic materials.

[0063] S02, such as Fig. 9As shown, the explosion-proof valve 8 is installed in the explosion-proof valve 8 installation hole on the back of the top cover plate 1;

[0064] S03, such as Fig.10 As shown, the lower bracket 3 is connected to the top cover plate 1, so that the end of the buckle portion 32 of the lower bracket 3 away from the lower bracket 3 passes through the first pole through hole 11 of the top cover plate 1, and the buckle outer edge 321 is buckled to the upper side of the inner edge of the first pole through hole 11, so that a gap is left between the buckle outer edge 321 and the top cover plate 1;

[0065] S04, such as Fig.11 As shown, the seal 4 is installed on the top cover plate 1 and is located on the outside of the buckle portion 32;

[0066] S05, such as Fig.12 As shown, the pole 2 is installed in the first pole through hole 11 of the top cover plate 1;

[0067] S06, such as Fig.13 , Fig.14 As shown, a fixing frame 6 is installed on the outer side of the pole 2, and the fixing frame 6 is connected to the top cover plate 1;

[0068] S07, such as Fig.15 As shown, the integrated structure formed by the top cover plate 1, the seal 4, the pole 2 and the fixing frame 6 is placed in a mold and the pole cap 5 is formed by injection molding on the outside of the pole 2; specifically, during the injection molding process, the pole 2 is subjected to the downward pressure of the injection mold, and the pressure causes the pole 2 to squeeze the seal 4 downward, so that the bottom of the inner edge of the seal 4 extends outward and fills the gap between the buckled outer edge 321 and the top cover plate 1, and after injection molding, since the position of the pole 2 remains fixed, the seal 4 will not recover the deformation upward, and the bottom of the inner edge of the seal 4 will remain filled in the gap.

[0069] S08, such as Fig.16 , 17 As shown, the obtained top cover assembly is marked, and a protective film 9 is attached to the explosion-proof valve 8, and a connector 7 is welded on the back of the lower bracket 3, and then a helium test and an insulation withstand voltage test are performed. After passing the test, the secondary battery cover plate structure is obtained.

[0070] More specifically, in step S06, if Fig.14 As shown, the bottom surface of the fixing frame 6 is welded to the bottom wall of the positioning groove 12 and the lower side surface of the fixing frame 6 is welded to the side wall of the positioning groove 12 by using an oblique welding process from the oblique outer side of the fixing frame 6 .

[0071] The processing method of this embodiment belongs to the same inventive concept as the above-mentioned secondary battery cover plate structure, which can be understood by referring to the above description and will not be described again here.

[0072] In the description of the present disclosure, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0073] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present disclosure.

Claims

1. A secondary battery cover structure, characterized in that: include: A top cover plate having a first pole through hole penetrating along a thickness direction; A pole, which is insulated and arranged on the top cover plate and located at the first pole through hole; A lower bracket, which has a second pole through hole penetrating in the thickness direction, the position of the second pole through hole corresponds to the position of the first pole through hole, the lower bracket is formed with a buckle portion on the outer side of the second pole through hole, the upper end of the buckle portion extends outward to form a buckling outer edge, a slot is formed between the buckling outer edge and the upper surface of the lower bracket, the height of the slot is greater than the inner edge thickness of the first pole through hole, so that the buckle portion passes through the first pole through hole, so that after the top cover plate and the lower bracket are buckled, a gap is left between the buckling outer edge and the top cover plate; A sealing member is disposed between the top cover plate and the pole and is located outside the buckle portion, and a portion of the sealing member extends to fill the gap; A pole cap is disposed around the outside of the pole and is connected to the top cover plate and the pole respectively, so that the top cover plate and the pole are insulated from each other.

2. The secondary battery cover structure according to claim 1, characterized in that: Also includes: A fixing frame is arranged on the top cover plate and is located outside the first pole through hole. The fixing frame has a third pole through hole corresponding to the first pole through hole and used to accommodate the pole. The pole is partially embedded in the fixing frame.

3. The secondary battery cover structure according to claim 2, characterized in that: A positioning groove matched with the fixing frame is formed on the outer side of the first pole through hole on one side of the top cover plate away from the lower bracket, and the fixing frame is installed in the positioning groove.

4. The secondary battery cover structure according to claim 3, characterized in that: The bottom surface of the fixing frame is welded to the bottom wall of the positioning groove, and part of the side surface of the fixing frame is welded to the side wall of the positioning groove.

5. The secondary battery cover structure according to claim 1, characterized in that: It also includes a connecting piece, the lower end of the pole extends through the second pole through hole to be exposed outside the lower surface of the lower bracket, and the connecting piece is connected to the lower surface of the lower bracket and also connected to the exposed part of the pole.

6. The secondary battery cover structure according to claim 5, characterized in that: The connecting piece is in the shape of a sheet, one end of which is connected to the lower surface of the lower bracket, and the other end is formed with a connecting hole adapted to the lower end of the pole, and the connecting hole is sleeved on the outer side of the lower end of the pole and connected.

7. The secondary battery cover structure according to claim 1, characterized in that: The buckle portion extends along the outer side of the second pole through hole, the buckle outer edge has a plurality of locations, the buckle outer edges at the plurality of locations are evenly distributed on the buckle portion, and the cross section of the buckle outer edge is semicircular, so that the outer side surface of the buckle outer edge is an arc-shaped surface; The sealing member is formed with a filling portion at a position corresponding to the gap, the filling portion protruding toward the direction where the gap is located.

8. The secondary battery cover structure according to claim 1, characterized in that: The lower bracket is hollowed out in the middle of its length direction to form a plurality of elastic shrinkage holes.

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