CN212625813U

CN212625813U - Secondary battery top cap and secondary battery thereof

Info

Publication number: CN212625813U
Application number: CN202021462668.5U
Authority: CN
Inventors: 邓平华; 谭婷; 王雷
Original assignee: Jiangxi Bestley New Energy Technology Co ltd
Current assignee: Jiangxi Bestley New Energy Technology Co ltd
Priority date: 2020-07-22
Filing date: 2020-07-22
Publication date: 2021-02-26
Anticipated expiration: 2030-07-22

Abstract

The utility model provides a secondary battery top cap and secondary battery thereof, wherein, the secondary battery top cap includes: the top cover plate, connect the first electrode unit and the second electrode unit of top cover plate, the top cover plate is equipped with first electrode and introduces the hole, and first electrode unit is including wearing to establish the first utmost point post that the hole was introduced to first electrode, and the top cover plate below is insulating to set up the connection piece, and the top surface of connection piece and the bottom surface of first utmost point post are face-to-face contact. Compared with the prior art, the utility model discloses a connection piece of secondary cell top cap is located the below of top cap piece, and after first utmost point post wore to establish first electrode and introduces the hole, face-to-face contact was realized with the top surface of connection piece in its bottom surface, when carrying out laser welding, the welding operation of being convenient for, and the face of weld be face-to-face contact, and its welding area is big, and joint strength is high, can prevent to become invalid because of rosin joint or the poor secondary cell who arouses of welding. Meanwhile, the connecting sheet is used for connecting the electrode assembly in the pole and the battery cell instead of the straw hat type thin sheet body, and the processing is particularly simple and convenient.

Description

Secondary battery top cap and secondary battery thereof

Technical Field

The utility model relates to an energy storage apparatus field especially relates to a secondary battery top cap and secondary battery thereof.

Background

With the development of modern society and the enhancement of environmental awareness of people, more and more driving power supplies of electric tools and new energy vehicles develop towards the directions of high capacity and high safety, which provides a wide space for the application and development of secondary batteries.

The secondary battery generally employs an adaptor to connect the electrode post and the electrode assembly, and the adaptor is generally fixed to the electrode post by laser welding. However, the adaptor is generally a thin sheet body formed in a shape of a straw hat by drawing, which is difficult to process, and the adaptor is laser-welded with the bottom of the pole by penetrating into the pole hole, so that the welding position is not easy to operate, and cold welding or poor welding is easily caused in the welding process. When the secondary battery receives impact, the adapter is easily separated from the pole, so that the secondary battery fails.

SUMMERY OF THE UTILITY MODEL

In order to ensure the welding firmness between the pole and the connecting piece, the secondary battery is prevented from losing efficacy. The utility model discloses an aspect provides a secondary battery top cap, include: the top cover plate, connect the first electrode unit and the second electrode unit of top cover plate, the top cover plate is equipped with first electrode and introduces the hole, first electrode unit is including wearing to establish the first utmost point post in hole is introduced to first electrode, the insulating connection piece that sets up in top cover plate below, the top surface of connection piece with the bottom surface of first utmost point post is the face-to-face contact.

Compared with the prior art, the utility model discloses a connection piece of secondary cell top cap is located the below of top cap piece, and after first utmost point post wore to establish first electrode and introduces the hole, face-to-face contact was realized with the top surface of connection piece in its bottom surface, when carrying out laser welding, the welding operation of being convenient for, and the face of weld be face-to-face contact, and its welding area is big, and joint strength is high, can prevent to become invalid because of rosin joint or the poor secondary cell who arouses of welding. Meanwhile, the connecting sheet is used for connecting the electrode assembly in the pole and the battery cell instead of the straw hat type thin sheet body, and the processing is particularly simple and convenient.

Preferably, the first electrode post includes a terminal plate and a post portion connected to the terminal plate and penetrating the first electrode introduction hole, and a top surface of the connecting piece is in surface-to-surface contact with a bottom surface of the post portion.

Preferably, the top surface and/or the bottom surface of the connecting piece are/is provided with grid surfaces formed by surface treatment, the distance between adjacent grids in the grid surfaces is 0.005-10 mm, and the grids in the grid surfaces are regular patterns of parallelograms, triangles or concentric circles or irregular patterns of fish scale patterns and wave patterns. More preferably, the surface treatment may be laser, etching or sand blasting, and the surface treatment is used to form a grid surface to improve roughness. After the surface treatment, the surface roughness Ra of the connecting sheet with the grid surface is 0.1-6.0 mu m. Within the roughness range, the light reflection rate can be reduced to avoid insufficient soldering and poor welding caused by light reflection, so that the welding goodness is improved, and the welding strength of the switching piece and the pole post, and the welding strength of the switching piece and the pole ear of the battery cell are ensured.

Preferably, the connecting pieces are of plate-shaped structures and are consistent in size in the vertical direction, the plate-shaped connecting pieces are easier to process, and the occupied size in the vertical direction is small.

Preferably, the connecting piece includes contact site, branching portion and is located the transition portion between contact site and the branching portion, the top surface of contact site with the bottom surface of first utmost point post is a face-to-face contact, the both ends of transition portion to keeping away from the direction extension of contact site forms the branching portion. Form two branching department and be favorable to electric core when a plurality of, the electrode tab of electric core and the connection piece be connected, more accurate, be convenient for separate the utmost point ear of a plurality of electric cores and carry out laser or ultrasonic welding on the branching department of difference.

Preferably, the transition portion and the bifurcation portion are enclosed to form a hollow groove with an opening far away from the contact portion and an arc-shaped groove bottom. The formation of the hollow groove structure is beneficial to the operation of laser or ultrasonic welding of the lugs and the bifurcate parts of a plurality of electric cores.

Preferably, the first electrode unit further comprises a connecting assembly, a sealing element and an injection molding part enclosed in the first pole, the connecting assembly is provided with a first connecting piece fixed on the top cover plate and a second connecting piece connected with the first connecting piece and embedded into the injection molding part, and the sealing element is arranged between the first connecting piece and the first pole. The first connecting piece and the top cover plate are fixed, so that the assembly of the pole and the top cover plate can be completed, the process is simple, and complicated sealing and assembling processes are not needed.

Preferably, a lower insulating member for isolating the top cover sheet from the connecting sheet is fixed to the lower portion of the top cover sheet.

The utility model discloses another aspect provides a secondary battery, include electric core, hold the casing and the sealing of electric core the top cap of casing, the top cap is aforementioned secondary battery top cap. The secondary battery has high connection strength between the first pole and the connecting sheet, and can prevent failure of the secondary battery caused by insufficient soldering or poor soldering.

Drawings

Fig. 1 is a plan view of an embodiment of a secondary battery top cap according to the present invention.

Fig. 2 is a bottom view of an embodiment of a secondary battery top cap according to the present invention.

Fig. 3 is an exploded view of the secondary battery top cover of the present invention in one direction.

Fig. 4 is an exploded view of the secondary battery top cover of the present invention in the other direction.

Fig. 5 is a cross-sectional view taken along a-a of fig. 1.

Fig. 6 is an enlarged view of the circled area in fig. 5.

Fig. 7 is a first schematic view of a connecting sheet of a secondary battery top cap according to the present invention.

Fig. 8 is a second schematic view of a connecting sheet of a secondary battery top cap according to the present invention.

Fig. 9 is a third schematic view of a connection piece of a secondary battery top cap according to the present invention.

Fig. 10 is a fourth schematic view of a connection piece of a secondary battery top cap according to the present invention.

Fig. 11 is a fifth schematic view of a connecting sheet of a secondary battery top cap according to the present invention.

Fig. 12 is a sixth schematic view of a connection piece of a secondary battery top cap according to the present invention.

Fig. 13 is a seventh schematic view of a connecting sheet of a secondary battery top cover according to the present invention.

Fig. 14 is an eighth schematic view of a connecting sheet of a secondary battery top cover according to the present invention.

Fig. 15 is a ninth schematic view of a connecting sheet of a secondary battery top cover according to the present invention.

Fig. 16 is a tenth schematic view of a connection piece of a secondary battery top cap according to the present invention.

Fig. 17 is an eleventh schematic view of a connecting sheet of a secondary battery top cap according to the present invention.

Description of the elements

100-secondary battery top cover; 1-top cover sheet; 11-a first electrode lead-in hole; 13-a second electrode introduction hole; 15-explosion-proof valve mounting holes; 2-second electrode unit/positive electrode unit; 21-positive pole column; 23-a positive first connection member; 25-positive second connection; 27-positive seal; 29-positive injection molding; 3-first electrode unit/negative electrode unit; 31-a negative electrode post; 311-terminal plate; 313-a column portion; 33-a first connector; 35-a second connector; 37-a seal; 39-injection molding; 4-an explosion-proof valve assembly; 41-explosion-proof valve; 43-explosion-proof valve protection plate; 5-liquid injection hole; 6-lower insulation; 61-a clamping part; 7/7 a-connecting piece; 71-a contact portion; 73-a transition; 75-bifurcation part

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be noted that, in general, the secondary battery is placed vertically, one side of the secondary battery top cover, which extends out and is connected with the outside, is an upper side, i.e., a top direction, and the other side is a lower side, i.e., a bottom direction.

The secondary battery top cap and the secondary battery thereof according to the present invention will be described with reference to the accompanying drawings.

Referring to fig. 1 to 5, the secondary battery includes a battery cell, a case for accommodating the battery cell, and a secondary battery top cover 100 for sealing the case, wherein the secondary battery top cover 100 is welded to the case to be sealed, and a secondary battery electrolyte for infiltrating the battery cell is injected into the case. The secondary battery top cap 100 includes a top cap sheet 1, and a first electrode unit 3, a second electrode unit 2, a liquid injection hole 5, and an explosion-proof valve assembly 4 provided on the top cap sheet 1. The top cover plate 1 is provided with a first electrode introducing hole 11, a second electrode introducing hole 13 and an explosion-proof valve mounting hole 15, the first electrode introducing hole 11 is connected with the first electrode unit 3, and the second electrode introducing hole 13 is connected with the second electrode unit 2. The explosion-proof valve assembly 4 comprises an explosion-proof valve 41 and an explosion-proof valve protection sheet 43, the explosion-proof valve 41 is arranged in the explosion-proof valve mounting hole 15, and the explosion-proof valve protection sheet 43 is arranged above the explosion-proof valve 41. A lower insulator 6 is provided below the top cover plate 1 to electrically insulate the top cover plate 1 from the cells in the housing.

The first electrode unit 3 may be either a positive electrode unit or a negative electrode unit, as shown in the figure. As shown in fig. 3-6, the negative electrode unit 3 includes the negative electrode post 31, a connecting assembly, sealing member 37 and enclose the injection molding 39 of locating the negative electrode post 31, the connecting assembly has the first connecting piece 33 that is fixed in the top cover plate 1 and the second connecting piece 35 that connects the first connecting piece 33 and imbeds the injection molding 39, sealing member 37 is between first connecting piece 33 and negative electrode post 31, only need to fix first connecting piece 33 and top cover plate 1, can accomplish the equipment of negative electrode post 31 and top cover plate 1, its process is simple, need not loaded down with trivial details sealed and assembly process. The first connecting piece 33 and the second connecting piece 35 can be integrally formed or can be in split type welding connection, and the connection strength among all the parts of the secondary battery top cover 100 can be improved through the action of the first connecting piece 33, the second connecting piece 35 and the injection molding piece 39.

The negative electrode post 31 has a terminal plate 311 and a cylindrical portion 313 connected to the terminal plate 311 and penetrating the first electrode introduction hole 11, the terminal plate 311 and the cylindrical portion 313 may be welded together by two metal blocks, generally, the terminal plate 311 is made of an aluminum material for connection with the outside, the cylindrical portion 313 is made of a copper material, and the cylindrical portion 313 may be a cylinder or a prism. The part of terminal plate 311 is wrapped by injection molding 39, so that injection molding 39 can be firmly fitted with terminal plate 311. The bottom end of the terminal plate 311 and the top of the column 313 abut the seal 37. According to practical requirements, the projection in the vertical direction of the column 313 may be significantly smaller than the terminal plate 311, so that a larger gap is formed between the column 313 and the first connecting member 33.

The utility model discloses in adopt a unique connection structure to remove the negative pole utmost point ear of realizing electric core and be connected between the negative pole utmost point post 31, as shown in fig. 5 ~ 6, first utmost point post 31 wears to establish first electrode and introduces hole 11, and cover plate 1 below is insulating to set up connection piece 7, and the top surface of connection piece 7 and the bottom surface of first utmost point post 31 are a face-to-face contact. More precisely, the column portion 313 penetrates the first electrode introducing hole 11 and its bottom surface is in surface-to-surface contact with the top surface of the connecting member 7. The lower insulating member 6 is fixed to the lower portion of the top cover piece and extends upward around the first electrode introducing hole 11 to form a catching portion 61 that is caught to the first connecting member 33. The lower insulator 6 isolates the tab 7 from the top cover sheet 1 and forms a large gap in the horizontal direction with the column portion 313.

Furthermore, the top surface and/or the bottom surface of the connecting piece 7 are/is provided with grid surfaces formed by surface treatment, the distance between adjacent grids in the grid surfaces is 0.005-10 mm, and the grids in the grid surfaces are regular patterns of parallelograms, triangles or concentric circles or irregular patterns of fish scale patterns and wave patterns. The grid surface may be only arranged on the top surface or the bottom surface of the connecting sheet 7, or both the top surface and the bottom surface may be provided with the grid surface, of course, the grid surface may be fully distributed on the whole top surface or the bottom surface, or may be partially arranged. As shown in fig. 7 to 10 and 13 to 17, the mesh surface is formed by covering the entire bottom surface of the connecting piece 7, and the mesh shape of the mesh surface is triangular in fig. 9, and parallelogram in fig. 7 to 8 and 10 (in which fig. 7 is square, and fig. 8 and 10 are both rhomboid). Fig. 13 and 14 are concentric circles spaced at different intervals, and fig. 16 is a wave pattern. Of course, in the actual use process, the shape of the mesh is not limited to this, and other regular patterns such as trapezoid, pentagram, hexagon, etc., or parallel lines as shown in fig. 15, a fishing net shape as shown in fig. 17, or irregular patterns such as fish scale, involute, etc. may be used, that is, as long as a plurality of regularly arranged meshes can be formed. As shown in fig. 11 and 12, a mesh area is provided only in a part of the bottom surface of the connecting plate 7, that is, only in the area to be welded to the cell tab. The surface treatment may be laser, etching or sand blasting, and the roughness is increased by forming a grid surface through the surface treatment. After the surface treatment, the surface roughness Ra of the connecting sheet 7 with the grid surface is 0.1-6.0 μm. Within the roughness range, the light reflection rate can be reduced to avoid insufficient soldering and poor welding caused by light reflection, so that the welding goodness is improved, and the welding strength of the adapter plate 7, the negative pole post 31, the adapter plate 7 and the battery core pole ear is ensured. The connecting sheet 7 is of a plate-shaped structure and is consistent in size along the vertical direction, the plate-shaped connecting sheet 7 is easier to process, and the occupied size in the vertical direction is small.

As shown in fig. 7 to 12, the connecting piece 7 includes a contact portion 71, a branch portion 75, and a transition portion 73 located between the contact portion 71 and the branch portion 75, a top surface of the contact portion 71 is in surface-to-surface contact with a bottom surface of the first pole 31, and both ends of the transition portion 73 extend in a direction away from the contact portion 71 to form the branch portion 75. Form two parts 75 that branch and be favorable to the electric core to be a plurality of times, the electrode tab of electric core and the connection piece 7 be connected, more accurate, be convenient for separate the utmost point ear of a plurality of electric cores and carry out laser or ultrasonic welding on the part 75 that branches of difference. Transition portion 73 and branching portion 75 enclose to be set up the opening and keep away from contact 71 and the tank bottom is curved hollow groove, forms hollow groove structure and is favorable to the utmost point ear of a plurality of electric cores and branching portion 75 to carry out laser or ultrasonic welding operation.

The positive electrode unit 2 and the negative electrode unit 3 can be the same or different, both can be electrically insulated from the top cover sheet 1, the negative electrode unit 3 can be electrically insulated from the top cover sheet 1, and the positive electrode unit 2 is electrically connected with the top cover sheet 1. The positive electrode unit 2 and the negative electrode unit 3 can be of the same structure, the second electrode unit 2 comprises a positive electrode post 21, a connecting assembly, a positive sealing element 27 and a positive electrode injection molding member 29 enclosed in the positive electrode post 21, the connecting assembly is provided with a positive electrode first connecting piece 23 fixed on the top cover plate 1 and a positive electrode second connecting piece 25 connected with the positive electrode first connecting piece 23 and embedded into the positive electrode injection molding member 29, and the positive sealing element 27 is arranged between the positive electrode first connecting piece 23 and the positive electrode post 21. The positive pole 21 penetrates through the second electrode lead-in hole 13, the connecting sheet 7a is arranged below the top cover sheet 1 in an insulating mode, and the top surface of the connecting sheet 7a is in surface-to-surface contact with the bottom surface of the positive pole 21. However, in order to solve the problems of overcharge and puncture of the secondary battery during the use of the secondary battery, the positive electrode unit 2 and the top cover sheet 1 are usually electrically conducted to form an external short circuit, so that when the positive electrode unit 2 is prepared by injection molding, conductive particles, such as conductive carbon or conductive metal, are added to the injection molding material, so that the positive electrode post 21 and the positive electrode second connecting member 23 are electrically connected through the conductive positive electrode injection molding member 29, and then the positive electrode unit and the top cover sheet 1 are electrically conducted through the electrical connection of the positive electrode second connecting member 25 and the top cover sheet 1. Of course, the structures of the positive electrode unit 2 and the negative electrode unit 3 may be different, and if the structures of the partial positive sealing member 27, the positive electrode post 21, the positive first connecting member 23, the positive second connecting member 25 and the positive injection-molded member 29 are adjusted based on the actual requirements, the structures of the positive electrode unit 2 and the negative electrode unit 3 may not be completely symmetrical.

It should be noted that the above-mentioned embodiments illustrate rather than limit the scope of the invention, and that modifications of various equivalent forms of the invention, which may occur to those skilled in the art after reading the present application, fall within the scope of the appended claims.

Claims

1. A secondary battery top cap, comprising: the top cover plate, connect the first electrode unit and the second electrode unit of top cover plate, the top cover plate is equipped with first electrode and introduces the hole, its characterized in that, first electrode unit is including wearing to establish the first utmost point post in hole is introduced to first electrode, the insulating connection piece that sets up in top cover plate below, the top surface of connection piece with the bottom surface of first utmost point post is face-to-face contact.

2. The secondary battery top cap according to claim 1, wherein the first terminal post includes a terminal plate and a post portion connecting the terminal plate and penetrating the first electrode introduction hole, and a top surface of the connecting piece and a bottom surface of the post portion are in surface-to-surface contact.

3. The secondary battery top cap according to claim 1, wherein the top surface and/or the bottom surface of the connecting tab has a mesh surface formed by surface treatment, and a distance between adjacent meshes in the mesh surface is 0.005 to 10 mm.

4. The secondary battery top cap according to claim 3, wherein the shape of the mesh in the mesh plane is a regular pattern of parallelograms, triangles or concentric circles, or an irregular pattern of fish scale or wave patterns.

5. The secondary battery top cap according to claim 3, wherein the connection tab having a mesh surface has a surface roughness Ra of 0.1 to 6.0 μm.

6. The secondary battery top cap according to claim 1, wherein the connecting tabs are plate-like structures and are uniform in size in the vertical direction.

7. The secondary battery top cap of claim 1, wherein the connecting tab comprises a contact portion, a branch portion and a transition portion between the contact portion and the branch portion, wherein a top surface of the contact portion is in surface-to-surface contact with a bottom surface of the first terminal, and two ends of the transition portion extend away from the contact portion to form the branch portion.

8. The secondary battery top cap according to claim 7, wherein the transition portion and the branch portion enclose a hollow groove opened away from the contact portion and having an arc-shaped groove bottom.

9. The secondary battery top cap of claim 1, wherein the first electrode unit further comprises a connection assembly, a sealing element and an injection molding member surrounding the first terminal post, the connection assembly comprises a first connection member fixed to the top cap plate and a second connection member connected to the first connection member and embedded in the injection molding member, and the sealing element is arranged between the first connection member and the first terminal post.

10. A secondary battery, comprising an electric core, a shell for accommodating the electric core and a top cover for sealing the shell, wherein the top cover is the secondary battery top cover of any one of claims 1 to 9.