Pole for lithium battery, cover plate assembly and lithium battery

Abstract

The utility model discloses a pole for a lithium battery, which comprises a terminal arranged on the outer side of the pole, the body of the terminal is provided with a through hole extending along the axial direction of the terminal, and an explosion-proof sheet can be fixed in the through hole to seal the through hole. According to the lithium battery cover plate, the through hole is formed in the terminal of the pole, and the explosion-proof sheet is welded and fixed on the terminal, so that the structure of the lithium battery cover plate can be simplified, the design of a safety valve and a liquid injection hole in the production process of the battery cover plate is omitted, the manufacturing procedures of the lithium battery cover plate are reduced, and the processing cost of the cover plate is reduced. The utility model discloses a cover plate assembly and a lithium battery.

Description

Technical Field

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

[0002] With the increase in global new energy vehicle penetration and the development of the energy storage industry, global lithium-ion battery shipments increased by 91% in 2021, and the demand for lithium-ion battery structural parts also increased significantly. The global lithium-ion battery structural parts market increased from nearly 5.8 billion yuan in 2017 to 25.5 billion yuan in 2021. my country's demand for lithium battery structural parts in 2022 will also expand from 18.1 billion yuan in the previous year to 36 billion yuan. In the future, with the rapid development of lithium battery applications, market demand will continue to expand significantly.

[0003] In a broad sense, lithium battery structural parts include cell cover, shell, positive and negative soft connector, top patch, lower plastic, etc. In a narrow sense, lithium battery structural parts refer to shells and cell cover with high dimensional accuracy, high surface quality, high performance requirements and other characteristics, which play the role of transmitting energy, protecting safety, insulation, fixing and supporting cells, etc., and have specific functions such as connectivity, shock resistance, heat dissipation, corrosion resistance, antistatic, etc. according to different application environments. In order to achieve the above functional characteristics, the existing lithium battery structural parts, especially the cell cover assembly, are extremely complex and have high manufacturing and use costs. Utility Model Content

[0004] In order to overcome the defects in the prior art, the embodiments of the utility model provide a lithium battery pole, a cover plate assembly and a lithium battery, which can reduce the production process of the lithium battery cover plate, reduce the manufacturing cost of the lithium battery, and improve the process efficiency of the lithium battery production process.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] The utility model discloses a pole for a lithium battery in a first aspect. The pole comprises a terminal arranged outside the pole. The body of the terminal is provided with a through hole extending along its axial direction. An explosion-proof plate can be fixed in the through hole to close the through hole.

[0007] The present application provides a through hole on the terminal of the lithium battery pole, which is used for liquid injection during battery assembly, and an explosion-proof plate can be arranged in the through hole as a safety valve of the battery, thereby eliminating the design of the safety valve and the liquid injection hole on the cover substrate, simplifying the structure of the cover substrate, reducing the manufacturing process of the lithium battery cover, and reducing the processing cost of the lithium battery cover, while not affecting the original function of the cover.

[0008] Furthermore, a step is provided in the through hole of the terminal, the step surface of the step faces the top side of the terminal, and the step surface is provided with a welding groove for fixing the explosion-proof disk.

[0009] After the pole is installed, a protrusion is provided on one side of the terminal away from the upper surface of the cover substrate and located in the terminal through hole, the protrusion forms a step, and a welding groove is provided on the side of the step facing the top of the terminal for welding and fixing the explosion-proof plate, so that the pole can effectively relieve pressure under thermal runaway of the battery. After the explosion-proof valve opening on the cover substrate is cancelled, the battery cover still has the function of safe pressure relief.

[0010] The second aspect of the utility model discloses a lithium battery cover plate assembly, including a cover plate substrate and a pole arranged on the cover plate substrate, the pole including a terminal arranged at the top of the pole, the body of the terminal is provided with a through hole extending along its axial direction, and an explosion-proof plate can be fixed in the through hole to close the through hole.

[0011] The cover plate assembly in the above technical solution eliminates the safety valve and liquid injection hole provided on the cover plate substrate of the existing cover plate, simplifies the cover plate structure, reduces the production process of the cover plate, and reduces the processing cost.

[0012] Furthermore, a step is provided in the through hole of the terminal, the step surface of the step faces the top side of the terminal, and the step surface is provided with a welding groove for fixing the explosion-proof disk.

[0013] After the safety valve design on the cover substrate is cancelled, the explosion-proof disc is fixed to the terminal of the pole by setting a welding groove for fixing the explosion-proof disc in the terminal through hole, so that the structure of the cover substrate is simplified without affecting the original function of the cover substrate.

[0014] Furthermore, a sealing ring is provided between the terminal and the cover substrate, and an upper plastic is provided on the cover outside the terminal. The upper plastic at least covers a portion of the outer peripheral surface of the terminal to seal the covered portion of the terminal.

[0015] A sealing ring is arranged between the pole terminal and the cover plate to ensure the sealing performance inside the battery after packaging. At the same time, plastic is arranged on the periphery of the pole terminal to fix and strengthen the sealing.

[0016] Furthermore, the cross section of the terminal is circular, and the cross section of the through hole is circular.

[0017] Since the terminal through hole is separately provided in the terminal, the shape of the pole has no effect on the terminal through hole, and the pole can be provided in a variety of shapes. Preferably, the pole in the present application is provided in a cylindrical shape. Considering the complexity of the process and the fact that the requirements for the pole may be high due to the complex structure, the shape of the through hole extending along the axial direction of the terminal body can preferably be provided in a cylindrical shape to reduce the complexity of the process.

[0018] Furthermore, the cross-sectional area of ​​the through hole of the terminal is larger than the cross-sectional area of ​​the explosion-proof disk.

[0019] After the injection hole is cancelled, the electrolyte can be injected through the through hole extending axially along the terminal body during the battery production process. Since the size of the through hole is adjusted according to the size of the explosion-proof disk, the size of the through hole is larger than the size of the explosion-proof disk. There are size differences between different types of explosion-proof disks. The diameter of some types of explosion-proof disks is 18mm or larger, while the diameter of the injection hole is usually 3mm. Therefore, the size of the through hole is larger than the size of the injection hole of the existing battery cover. When injecting electrolyte, the production efficiency of the lithium battery injection process is improved, and the configuration requirements and energy consumption of the injection equipment are reduced. It is especially suitable for large battery cells and long cycle square aluminum shell batteries.

[0020] Furthermore, a boss is provided at the axial top end of the terminal, and the end surface of the boss is used to fix the explosion-proof patch.

[0021] The top of the pole terminal outside the through hole is a protrusion, which can be used to fix the explosion-proof patch. After the battery cover assembly is assembled, the explosion-proof patch is fixed on the top of the pole terminal to protect the appearance of the pole terminal and protect the function of the explosion-proof patch from being affected.

[0022] Furthermore, a substrate through hole is provided on the substrate, and the substrate through hole is correspondingly connected to a through hole on the terminal.

[0023] The substrate itself is provided with through holes, and the through holes on the terminals provided in the present application are connected to the through holes on the substrate in a corresponding manner, without affecting the original design of the poles and the substrate.

[0024] The third aspect of the utility model discloses a lithium battery, comprising a shell and an electrode assembly contained in the shell, and a lithium battery pole and cover assembly as described in any one of the first and second aspects, wherein the cover assembly covers the shell and encloses the electrode assembly in the shell.

[0025] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0026] 1. The utility model can simplify the structure of the lithium battery cover by opening a through hole on the pole terminal and fixing the explosion-proof plate on the terminal. It is no longer necessary to separately set a safety valve and open a liquid injection hole during the production process of the battery cover, thereby reducing the production process of the lithium battery cover and reducing the processing cost of the cover.

[0027] 2. During the battery production process, the utility model can inject electrolyte through the through hole extending along the axial direction of the body of the pole terminal, which can improve the efficiency of lithium battery electrolyte injection and reduce the configuration requirements and energy consumption of the injection equipment. It is particularly suitable for large-cell and long-cycle square aluminum shell batteries.

[0028] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a top view of the lithium battery cover of the utility model.

[0031] Figure 2 It is a partial cross-sectional view of the positive pole in the lithium battery cover assembly of the utility model.

[0032] The reference numerals of the above drawings are: 1, positive pole; 2, cover substrate; 3, negative pole; 4, positive terminal; 5, explosion-proof plate; 6, explosion-proof patch; 7, welding groove; 8, terminal through hole; 9, substrate through hole; 10, upper plastic; 11, sealing ring; 12, step; 13, boss DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] The directional words appearing in the following description are all directions shown in the figure, and do not limit the specific structure of the lithium battery pole and cover assembly and the lithium battery of the utility model. In the description of the utility model, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0035] The lithium battery pole provided by the embodiment of the utility model is used to be installed on the lithium battery cover plate, and the cover plate assembly is used to be installed at the shell opening of the lithium battery to seal the electrode assembly and the electrolyte in the shell. The cover plate assembly of the embodiment of the utility model can simplify the lithium battery cover plate structure, reduce the production process and processing cost of the battery cover plate, and can also inject electrolyte through the through hole extending along the axial direction of the pole terminal during the battery production process, thereby improving the production efficiency of the lithium battery injection process, reducing the configuration requirements and energy consumption of the injection equipment, and is particularly suitable for large battery cells and long-cycle square aluminum shell batteries.

[0036] In order to better understand the present invention, Figure 1 to Figure 2 The lithium battery pole and cover plate assembly according to the embodiment of the utility model is described in detail.

[0037] Figure 1 It is a top view of the lithium battery cover of the utility model. Figure 2 It is a partial cross-sectional view of the positive pole of the lithium battery cover of the utility model. It should be noted that the complete lithium battery pole and cover assembly structure diagram according to the embodiment of the utility model is not shown in the attached drawings. It should be noted that in the following description of the embodiment, "one side", "top", "bottom", "above", and "below" are all directions shown with reference to the placement position of the battery pole in the attached drawings.

[0038] like Figure 1 As shown, according to one embodiment of the utility model, a battery cover assembly includes a positive column 1, a cover substrate 2 and a negative column 3. The cover substrate 2 can be made of plastic or metal material, for example, the same plastic or metal material as the lithium battery shell can be selected. In this embodiment, the cover substrate 2 has the function of assembling and fixing the various functional components of the cover, and welding and sealing with the lithium battery shell. The cover substrate 2 is provided with pole holes for the positive pole 1 and the negative pole 3, which are used to assemble the positive pole 1 and the negative pole 3. The positive pole 1 and the negative pole 3 are arranged at intervals on the cover substrate 2. The positive pole 1 has the functions of positive current conduction, heat conduction and weak conduction with the cover, and the negative pole 3 has the functions of negative current conduction, heat conduction and insulation with the cover.

[0039] Figure 2 yes Figure 1 An enlarged view of the local structure of the positive electrode column 1 in the cover assembly, such as Figure 1 As shown, the cover plate assembly includes a positive electrode column 1 and a negative electrode column 3. In some embodiments, the electrode terminals on the positive electrode column 1 and the negative electrode column 3 can be used to set a through hole extending along the axial direction. Since the upper and lower materials of the negative terminal of the negative electrode column are different, the processing complexity will be increased when setting the terminal through hole. Therefore, it is more convenient and advantageous to set the through hole on the positive electrode column. As a preferred embodiment, the embodiment of the utility model is described in detail with the positive electrode column 1 as a preferred embodiment.

[0040] Of course, in some embodiments, without considering the complexity of terminal through-hole processing on the pole, and when it is more advantageous to set a through-hole on the negative pole, the terminal through-hole can also be set in the negative terminal, and the explosion-proof plate and explosion-proof patch can be set in the negative terminal, which is not described in detail in the present utility model.

[0041] In this embodiment, the cross-section of the positive electrode column 1 is preferably set to a circle. Since the shape setting of the positive electrode column 1 does not affect the setting of the terminal through hole 8, in the actual production process, the positive electrode column 1 can also be set to other shapes, such as square, polygonal, elliptical, etc., and the utility model does not make specific limitations here.

[0042] like Figure 2 In the cross-sectional view of the positive electrode column shown, a positive terminal 4 is provided on the outer side of the positive electrode column 1, and a terminal through hole 8 is opened in the positive terminal 4. The position of the terminal through hole 8 corresponds to the substrate through hole 9 on the cover substrate.

[0043] In the present embodiment, the top end of the positive electrode column 1 is the end of the positive electrode column 1 located on one side of the upper surface of the cover substrate 2, and a step 12 is provided in the through hole of the positive terminal 4, and the step 12 is provided at a position located at the bottom of the positive terminal 4. Specifically, in the present embodiment, the bottom of the positive terminal 4 is the portion of the positive terminal 4 close to the cover substrate.

[0044] A welding groove 7 is provided on one side of the step 12 facing the top of the positive terminal 4, which is used to fix the explosion-proof plate 5 in the terminal through hole 8, so that the explosion-proof plate 5 is welded and fixed in the positive terminal 4, so that the positive pole 1 can effectively release pressure under thermal runaway of the battery. At the same time, the explosion-proof plate 5 is arranged in the positive terminal 4, and the safety valve opening, explosion-proof plate laser welding and explosion-proof plate patch bonding processes on the battery cover are eliminated, thereby reducing the production processes of the lithium battery cover, reducing the processing cost, and achieving all functional requirements of the existing lithium battery cover.

[0045] A boss 13 is provided at the axial top end of the positive terminal 4, and the end face of the boss 13 is used to fix the explosion-proof patch 6. The diameter of the boss 13 of the positive terminal 4 is smaller than the diameter of the positive terminal 4 itself. After the battery cover assembly is assembled, the explosion-proof patch 6 is fixed to the end face of the boss 13 on the positive terminal 4, which can protect the appearance of the positive terminal 4 and protect the function of the explosion-proof patch 5 from being affected.

[0046] In some embodiments, the explosion-proof patch 6 can be fixed on the positive terminal 4 by gluing, for example, the explosion-proof patch 6 can be bonded and fixed on the boss 13 of the positive terminal 4 by glue. The present invention is not specifically limited here.

[0047] The upper plastic 10 of the lithium battery is arranged around the positive terminal 4. In one embodiment, the upper plastic 10 can be made of a high temperature resistant insulating plastic material by integral injection molding, for example, one or more materials selected from polyphenylene sulfide, perfluoroalkoxy resin or polypropylene. In this embodiment, the upper plastic 10 is arranged around the positive terminal 4, at least partially covering the positive terminal 4 to fix and seal the positive terminal 4, which can effectively prevent leakage of the electrolyte, avoid reaction with the external environment, and maintain the stability of the internal structure of the battery.

[0048] The lithium battery pole insulating seal ring 11 is usually made of an elastic polymer material with good mechanical properties, high temperature resistance, low temperature resistance, chemical corrosion resistance, and excellent electrical properties, such as fluororubber, etc., which can maintain good sealing performance and electrical insulation performance under certain use environments. In this embodiment, the seal ring 11 is arranged between the positive terminal 4 and the cover substrate 2 to seal the inside of the positive terminal 4.

[0049] The positive electrode column 1 in the present application has an explosion-proof plate 5 arranged inside the positive terminal 4 and an explosion-proof patch 6 arranged on the end face of the boss 13 of the positive terminal 4, so that the positive electrode column 1 can meet the functions of a traditional positive electrode column while also meeting the requirements of explosion-proof plate welding, explosion-proof plate patch, and battery positive electrode BUSBAR welding.

[0050] like Figure 2 As shown, a terminal through hole 8 is provided along the axial direction extending inwardly of the positive terminal 4. During the battery production process, the terminal through hole 8 can be used to inject electrolyte, eliminating the injection hole opening and grooving processes and the processing of injection hole sealing nails and welding sheets. The diameter of the terminal through hole 8 can be adjusted according to the diameter of the explosion-proof plate 5. Due to the size differences between different types of explosion-proof plates, the diameter of some types of explosion-proof plates is 18 mm or larger, while the injection hole diameter is generally 3 mm. Therefore, the size of the terminal through hole 8 is larger than that of the existing injection hole, and the efficiency of injecting electrolyte is higher, which can reduce the configuration requirements and energy consumption of the injection equipment, and the effect is more obvious for large-cell and long-cycle square aluminum shell batteries.

[0051] Taking into account the complexity of the process and the fact that the requirements of the complex structure on the pole may be relatively high, as a preferred embodiment, the shape of the cross-section of the terminal through hole 8 in the present application can be set to a circular shape to reduce the complexity of the process. Of course, without considering the complexity of the structure and the processing requirements for the pole, the cross-section of the terminal through hole 8 extending axially along the positive terminal 4 can also be set to an elliptical shape, and the present invention does not make specific limitations on this.

[0052] Another embodiment of the utility model further provides a lithium battery, comprising a housing and an electrode assembly contained in the housing, and the lithium battery pole and cover assembly described in the above embodiment, wherein the cover assembly covers the housing and seals the electrode assembly in the housing. Since the lithium battery has the same advantages as the lithium battery pole and cover assembly in the above embodiment, they will not be described in detail.

[0053] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A lithium battery pole, the pole comprising a terminal arranged outside the pole, characterized in that: The terminal body is provided with a through hole extending along its axial direction, and an explosion-proof plate can be fixed in the through hole to close the through hole.

2. A lithium battery electrode according to claim 1, characterized in that: A step is arranged in the through hole of the terminal, the step surface of the step faces the top end side of the terminal, and the step surface is provided with a welding groove for fixing the explosion-proof disc.

3. A lithium battery cover plate assembly, comprising a cover plate substrate and a pole arranged on the cover plate substrate, characterized in that: The pole comprises a terminal arranged at the top of the pole, and the body of the terminal is provided with a through hole extending along its axial direction, and an explosion-proof plate can be fixed in the through hole to close the through hole.

4. A cover plate assembly according to claim 3, characterized in that: A step is arranged in the through hole of the terminal, the step surface of the step faces the top end side of the terminal, and the step surface is provided with a welding groove for fixing the explosion-proof disc.

5. The cover plate assembly according to claim 3, characterized in that: A sealing ring is arranged between the terminal and the cover substrate, and an upper plastic is arranged on the cover outside the terminal. The upper plastic at least covers a part of the outer peripheral surface of the terminal to seal the covered part of the terminal.

6. A cover plate assembly according to claim 3, characterized in that: The cross section of the terminal is circular, and the cross section of the through hole is circular.

7. A cover plate assembly according to claim 3, characterized in that: The cross-sectional area of ​​the through hole of the terminal is larger than the cross-sectional area of ​​the explosion-proof disk.

8. The cover plate assembly according to claim 3, characterized in that: A boss is provided at the axial top end of the terminal, and the end surface of the boss is used to fix the explosion-proof patch.

9. A cover plate assembly according to claim 3, characterized in that: The substrate is provided with substrate through holes, and the substrate through holes are correspondingly connected with the through holes on the terminals.

10. A lithium battery, characterized in that: It comprises a shell and an electrode assembly contained in the shell, and a lithium battery pole and a cover plate assembly as claimed in any one of claims 1 to 9, wherein the cover plate assembly covers the shell and seals the electrode assembly in the shell.

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