Battery cover plate assembly and battery

Abstract

The utility model relates to the field of batteries, and discloses a battery cover plate assembly and a battery, the battery cover plate assembly comprises a cover plate, an insulation pad and a cover cap which are sequentially stacked from top to bottom, the cover plate is a steel piece, the cover cap is a steel-aluminum composite piece, the cover cap comprises a cover cap body and a leading-out terminal, and the leading-out terminal is arranged on the cover plate body. The cover cap body is in insulated connection with the cover plate through the insulation pad, the cover cap body is a steel part, an aluminum layer is arranged on one surface, far away from the cover plate, of the cover cap body, and the aluminum layer is used for being electrically connected with a battery cell tab. According to the battery cover plate assembly, the sealing performance, the conductivity and the corrosion resistance of the battery can be improved.

Description

Technical Field

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

[0002] Lithium-ion battery technology, with its unique zero memory effect, fast charge and discharge capabilities, high energy density, long cycle life and environmental friendliness, has been widely used in the field of small electronic devices. However, as the market's requirements for the endurance of lithium-ion batteries continue to increase, the development of lithium-ion batteries with higher energy density has become a top priority. Among them, the use of laser welding structure batteries, by compressing the shell volume to release more internal cavity space, thereby improving space utilization and meeting the demand for increased energy density, has become an important direction for future development in this field.

[0003] The existing laser welding structure batteries on the market are mainly composed of caps, winding cores and steel shells, and their caps are usually made of steel sheets, insulating rubber rings and aluminum parts (or steel parts) pressed together through a hot pressing process, but there are still many problems in practical applications. Specifically, the insufficient pressing and peeling force between the aluminum parts and the insulating rubber rings often leads to the failure of the sealing performance of the cap, which in turn causes battery leakage problems. In addition, when aluminum parts are used as positive poles, a dense oxide film is easily formed on their surface, affecting the conductivity, resulting in poor battery contact and inability to use normally. If the cap uses steel parts as the positive pole, although it can meet the sealing requirements, it is prone to corrosion under high voltage systems and poor moisture control, which ultimately leads to battery performance failure.

[0004] In summary, the existing laser welding structure batteries still have many deficiencies in the design and material selection of the cap assembly, which urgently need to be improved through technological innovation. Summary of the invention

[0005] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a battery cover assembly and a battery.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A battery cover plate assembly comprises: a cover plate, an insulating pad and a cap which are stacked in sequence from top to bottom, wherein the cover plate is a steel part, the cap is a steel-aluminum composite part, the cap comprises a cap body and a lead-out terminal, the cap body is insulated and connected to the cover plate via the insulating pad, the cap body is a steel part, and an aluminum layer is provided on a side of the cap body away from the cover plate, and the aluminum layer is used to be electrically connected to a battery cell tab.

[0008] In one embodiment, the aluminum layer is formed on a side of the cap body away from the cover plate by electroplating, and the thickness of the aluminum layer is 0.02-0.05 mm.

[0009] In one embodiment, the cover plate is provided with a first through hole, the lead terminal is arranged on a side of the cap body away from the aluminum layer, and the lead terminal is led out from the first through hole.

[0010] In one embodiment, the lead terminal protrudes from the cover plate, and a height difference between an end surface of the lead terminal and an end surface of the cover plate is 0.5-2 mm.

[0011] In one embodiment, the cover plate and the insulating pad are both annular sheet structures, the insulating pad is provided with a second through hole, the lead terminal is sequentially passed through the second through hole and the first through hole, the cap body is a circular sheet structure, and the lead terminal is a cylindrical structure.

[0012] In one embodiment, the diameter of the lead terminal is smaller than the diameter of the first through hole.

[0013] In one embodiment, the second through hole has a diameter smaller than that of the first through hole, and an outer diameter of the insulating pad is larger than a diameter of the cap body.

[0014] The utility model also provides a battery, comprising: a battery cell assembly, a steel shell and the above-mentioned battery cover assembly, wherein the steel shell is provided with an open end and a receiving cavity, the battery cell assembly is placed in the receiving cavity, and the battery cover assembly is used to block the open end.

[0015] In one embodiment, the cover plate is laser-sealed and welded to the open end of the steel shell.

[0016] In one embodiment, the battery cell assembly includes a battery cell body, a positive electrode ear and a negative electrode ear, the positive electrode ear and the negative electrode ear are respectively led out from two ends of the battery cell body, the negative electrode ear is welded to the steel shell, and the positive electrode ear is welded to the aluminum layer.

[0017] Compared with the prior art, the utility model has at least the following advantages:

[0018] 1. Improve battery sealing performance: When the traditional cap is made of pure aluminum, there is a problem of insufficient peeling force at the joint with the insulating rubber ring. In the utility model, by adopting a steel-aluminum composite structure, the cap body is a high-strength steel part, which ensures a stable connection with the cover plate. At the same time, the durability and rigidity of the steel part significantly enhance the sealing of the overall structure, effectively avoiding leakage caused by sealing failure.

[0019] 2. Improve battery conductivity and reprocessing performance: In order to solve the problem that the surface oxidation of aluminum parts affects the conductivity, the cap provided by the utility model sets the aluminum layer on the side of the cap body away from the cover plate, which is directly connected to the battery cell tab, which not only takes advantage of the excellent conductivity of aluminum material, but also avoids the negative impact of its surface oxidation on the stability of electrical contact. In addition, the steel-aluminum composite design takes into account the advantages of both materials. The addition of the aluminum layer not only improves the conductivity, but also facilitates subsequent welding or other reprocessing, improving the flexibility and efficiency of battery manufacturing.

[0020] 3. Solve the problem of high voltage corrosion: The utility model sets an insulating pad between the cap body and the environment with high electrochemical activity, and designs the part directly in contact with the electrolyte as an aluminum layer with stronger corrosion resistance, which effectively isolates the direct contact between the steel parts and the electrolyte, and greatly inhibits the occurrence of corrosion. This structural optimization makes the battery show better stability and longer service life in the high voltage system, solving the corrosion problem in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic structural diagram of a battery cover assembly according to one embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the structure of a battery according to one embodiment of the utility model;

[0024] Figure 3 This is a schematic diagram of the explosion structure of a battery according to one embodiment of the utility model;

[0025] Figure 4 This is a schematic structural diagram of an unsealed battery according to one embodiment of the utility model.

[0026] The numbers in the figure are: 10, battery; 100, battery cover assembly; 110, cover; 111, first through hole; 120, insulating pad; 121, second through hole; 130, cap; 131, cap body; 132, lead terminal; 133, aluminum layer; 200, steel shell; 210, open end; 300, battery cell assembly; 310, battery cell body; 320, positive electrode ear; 330, negative electrode ear. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant drawings. The drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0028] See also Figure 1 and Figure 2 A battery cover plate assembly (100) comprises: a cover plate (110), an insulating pad (120) and a cap (130) which are stacked in sequence from top to bottom, the cover plate (110) being a steel part, the cap (130) being a steel-aluminum composite part, the cap (130) comprising a cap body (131) and a lead-out terminal (132), the cap body (131) being insulated and connected to the cover plate (110) via the insulating pad (120), the cap body (131) being a steel part, and an aluminum layer (133) being arranged on a side of the cap body (131) away from the cover plate (110), the aluminum layer (133) being used for being electrically connected to a battery cell tab.

[0029] It should be noted that the cover plate (110) in the utility model is partially made of high-strength steel material, which not only enhances the mechanical strength of the overall structure, but also improves the ability to resist external impact and pressure, provides a solid upper closed interface for the battery (10), and effectively protects the internal components. The cap (130) is designed as a steel-aluminum composite. The cap body (131) and the lead terminal (132) are an integrally formed steel structure, which ensures the strength and sealing of the connection with the cover plate (110), and at the same time, an aluminum layer (133) is integrated on the side of the cap body (131) facing the battery cell. This design combines the mechanical strength of steel and the high electrical conductivity of aluminum, achieving complementary material properties. The aluminum layer (133) is arranged on a side of the cap body (131) away from the cover plate (110) and is directly connected to the battery cell tab, making full use of the low resistance characteristics of aluminum, optimizing the current transmission path, and improving the conductivity. At the same time, it also avoids the oxidation problem that may be caused by direct exposure of the aluminum material to the environment, thereby ensuring the electrical contact reliability and stability of the battery (10) performance during long-term use.

[0030] The battery cover assembly (100) provided by the utility model achieves comprehensive improvement of the performance of the battery (10) through a carefully designed multi-level structure, scientific matching of materials, and precise grasp of details, especially significant improvement in sealing, electrical conductivity, and corrosion resistance.

[0031] See also Figure 1 and Figure 2Furthermore, an aluminum layer (133) is formed on the cap body (131) on a side away from the cover plate (110) by electroplating, and the thickness of the aluminum layer (133) is 0.02-0.05 mm.

[0032] It should be noted that the electroplating technology can accurately control the deposition of the aluminum layer (133), ensuring that the aluminum layer (133) is tightly combined with the steel cap body (131) to form a stable composite structure. At the same time, the thickness of the aluminum layer (133) of 0.02-0.05 mm can not only ensure excellent electrical conductivity, reduce resistance loss, and improve the efficiency of charging and discharging of the battery (10), but also maintain good mechanical stability, avoiding the increase in weight due to excessive thickness or insufficient electrical conductivity due to excessive thinness.

[0033] See also Figure 1 and Figure 2 Furthermore, the cover plate (110) is provided with a first through hole (111), the lead terminal (132) is arranged on a side of the cap body (131) away from the aluminum layer (133), and the lead terminal (132) is led out from the first through hole (111).

[0034] It should be noted that, through the first through hole (111), the lead terminal (132) can pass through the cover plate (110) and connect to the external circuit system. The lead terminal (132) is arranged on the side of the cap body (131) away from the aluminum layer (133). Such a layout ensures the effective connection between the lead terminal (132) and the external circuit, and avoids its direct contact with the internal electrochemical reaction, thereby improving safety.

[0035] See also Figure 1 and Figure 2 Furthermore, the lead terminal (132) protrudes from the cover plate (110), and the height difference between the end surface of the lead terminal (132) and the end surface of the cover plate (110) is 0.5~2mm.

[0036] It should be noted that the lead terminal (132) has a certain amount of protrusion relative to the cover plate (110), which can ensure that the lead terminal (132) can form a stable and reliable physical contact when docking with the external connector, reducing the risk of loosening or falling off due to vibration or external force. At the same time, by accurately controlling the height difference between the lead terminal (132) and the cover plate (110), the risk of short circuit that may occur during the use of the battery (10) can be reduced (the lead terminal (132) and the cover plate (110) are respectively connected to the positive and negative poles of the battery (10)), especially in high voltage or high current environments, this design can provide safer operating conditions. Furthermore, on an automated production line, a constant and appropriate height difference is conducive to machine vision positioning and precise grasping, improving the accuracy and efficiency of assembly.

[0037] See also Figure 1 and Figure 2 Furthermore, the cover plate (110) and the insulating pad (120) are both annular sheet structures, the insulating pad (120) is provided with a second through hole (121), the lead terminal (132) is sequentially passed through the second through hole (121) and the first through hole (111), the cap body (131) is a circular sheet structure, and the lead terminal (132) is a cylindrical structure.

[0038] It should be noted that the second through hole (121) specially provided on the insulating pad (120) is precisely aligned with the first through hole (111) on the cover plate (110), and together provide a path for the lead terminal (132) to penetrate the two-layer structure. This design not only ensures the continuity of the electrical connection, but also strengthens the fixation of the position of the lead terminal (132), avoiding potential risks of offset or misalignment. This structure is suitable for cylindrical batteries (10), is conducive to the compact layout of the battery (10), saves space, and also facilitates the assembly and disassembly of the battery (10).

[0039] See also Figure 1 and Figure 2 Furthermore, the diameter of the lead terminal (132) is smaller than the diameter of the first through hole (111).

[0040] It should be noted that by ensuring that there is a certain gap between the diameter of the lead terminal (132) and the diameter of the first through hole (111), even when the battery (10) experiences slight deformation due to vibration, temperature change or long-term use, the lead terminal (132) will not make unnecessary contact with the inner wall of the cover plate (110), thereby effectively avoiding the occurrence of short circuits and improving the safety of the battery (10). At the same time, the appropriate diameter difference also facilitates the insertion and fixation of the lead terminal (132), making it easier to align and pass through the first through hole (111) during assembly, reducing friction resistance during assembly, and after assembly, the existence of the gap can accommodate an appropriate amount of insulating material or coating, further enhancing the effect of electrical isolation.

[0041] See also Figure 1 and Figure 2 Furthermore, the diameter of the second through hole (121) is smaller than the diameter of the first through hole (111), and the outer diameter of the insulating pad (120) is larger than the diameter of the cap body (131).

[0042] It should be noted that the diameter of the second through hole (121) is designed to be smaller than the first through hole (111). This size difference not only ensures that the lead terminal (132) maintains proper positioning and stability when passing through the two through holes, but also further strengthens the insulation protection at the level of the insulating pad (120). Even if the lead terminal (132) is slightly displaced in extreme cases, the insulating pad (120) material around the second through hole (121) can still provide a sufficient barrier to prevent accidental touch, thereby increasing safety redundancy. In addition, the outer diameter of the insulating pad (120) is designed to be larger than the diameter of the cap body (131). This design is intended to provide more comprehensive insulation coverage. When the cap body (131) and the cover plate (110) are assembled, the excess portion of the insulating pad (120) that extends beyond the edge of the cap (130) can form an insulating ring, effectively preventing any possible current conduction path from being formed, especially when the battery (10) is subjected to external pressure or deformation, thereby preventing the risk of short circuit caused by direct contact between the cap (130) and the cover plate (110).

[0043] See also Figure 2 and Figure 3 The utility model also provides a battery (10), comprising: a battery cell assembly (300), a steel shell (200) and the above-mentioned battery cover assembly (100), wherein the steel shell (200) is provided with an open end (210) and a receiving cavity, the battery cell assembly (300) is placed in the receiving cavity, and the battery cover assembly (100) is used to block the open end (210).

[0044] It should be noted that, as the energy source of the battery (10), the battery cell assembly (300) is responsible for storing and releasing electrical energy. It contains positive and negative electrode materials, electrolytes and necessary diaphragms, and is the basis for the performance of the battery (10). The steel shell (200) is the outer shell of the battery (10). Its structure is provided with an open end (210) for assembling and sealing the internal structure of the battery (10). At the same time, a receiving cavity is constructed inside to provide a safe and stable storage space for the battery cell assembly (300). The selection of the material of the steel shell (200) takes into account mechanical strength, cost-effectiveness and environmental protection requirements. As mentioned above, the battery cover assembly (100) includes a cover (110), an insulating pad (120) and a cap (130) of a steel-aluminum composite structure. Through precise stacking and fixing design, the open end (210) of the battery (10) is efficiently blocked. The innovative cover plate (110) component design effectively solves the problems of sealing failure, low conductivity and corrosion under high voltage, and significantly improves the overall performance and service life of the battery (10).

[0045] Furthermore, the cover plate (110) and the opening end (210) of the steel shell (200) are laser sealed and welded.

[0046] It should be noted that laser welding is a non-contact precision welding method that can achieve seamless connection between the cover plate (110) and the open end (210) of the steel shell (200), forming an extremely tight sealed interface. This welding method can effectively prevent electrolyte leakage and external gas and moisture penetration, significantly improve the sealing performance of the battery (10), and extend the service life of the battery (10).

[0047] See also Figures 2 to 4 Furthermore, the battery cell assembly (300) includes a battery cell body (310), a positive electrode ear (320) and a negative electrode ear (330), the positive electrode ear (320) and the negative electrode ear (330) are respectively led out from the two ends of the battery cell body (310), the negative electrode ear (330) is welded to the steel shell (200), and the positive electrode ear (320) is welded to the aluminum layer (133).

[0048] It should be noted that the negative electrode ear (330) is directly welded to the steel shell (200). This design utilizes the steel shell (200) as the negative electrode of the battery (10), simplifies the structure, and also enhances the overall mechanical strength and conductive continuity of the battery (10). The positive electrode ear (320) is welded to the aluminum layer (133) on the cap body (131). The aluminum layer (133) is specifically used to establish a low-resistance electrical connection with the positive electrode ear (320), giving full play to the excellent conductive properties of aluminum material, while avoiding oxidation problems that may be caused by direct contact of aluminum with the external environment. Through such a design, not only is the smooth flow of current inside the battery cell assembly (300) ensured, but also the material properties are effectively utilized, thereby improving the overall electrical performance and reliability of the battery (10).

[0049] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A battery cover assembly, characterized in that: include: The cover plate, insulating pad and cap are stacked in sequence from top to bottom, the cover plate is a steel part, the cap is a steel-aluminum composite part, the cap includes a cap body and a lead-out terminal, the cap body is insulated and connected to the cover plate through the insulating pad, the cap body is a steel part, and an aluminum layer is arranged on a side of the cap body away from the cover plate, and the aluminum layer is used to be electrically connected to the battery cell tab.

2. The battery cover assembly according to claim 1, characterized in that: The aluminum layer is formed on the side of the cap body away from the cover plate by electroplating, and the thickness of the aluminum layer is 0.02-0.05 mm.

3. The battery cover assembly according to claim 1, characterized in that: The cover plate is provided with a first through hole, the lead terminal is arranged on a side of the cap body away from the aluminum layer, and the lead terminal is led out from the first through hole.

4. The battery cover assembly according to claim 3, characterized in that: The lead terminal protrudes from the cover plate, and a height difference between an end surface of the lead terminal and an end surface of the cover plate is 0.5-2 mm.

5. The battery cover assembly according to claim 3, characterized in that: The cover plate and the insulating pad are both annular sheet structures, the insulating pad is provided with a second through hole, the lead terminal is sequentially passed through the second through hole and the first through hole, the cap body is a circular sheet structure, and the lead terminal is a cylindrical structure.

6. The battery cover assembly according to claim 5, characterized in that: A diameter of the lead terminal is smaller than a diameter of the first through hole.

7. The battery cover assembly according to claim 5, characterized in that: The diameter of the second through hole is smaller than that of the first through hole, and the outer diameter of the insulating pad is larger than the diameter of the cap body.

8. A battery, characterized in that: include: A battery cell assembly, a steel shell, and a battery cover assembly as described in any one of claims 1 to 7, wherein the steel shell is provided with an open end and a receiving cavity, the battery cell assembly is placed in the receiving cavity, and the battery cover assembly is used to block the open end.

9. The battery according to claim 8, characterized in that The cover plate is laser sealed and welded to the open end of the steel shell.

10. The battery according to claim 9, characterized in that The battery cell assembly comprises a battery cell body, a positive electrode ear and a negative electrode ear. The positive electrode ear and the negative electrode ear are respectively led out from two ends of the battery cell body. The negative electrode ear is welded to the steel shell, and the positive electrode ear is welded to the aluminum layer.

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