Lithium battery cover plate

Abstract

The utility model discloses a lithium battery cover plate which is characterized in that a top cover sheet is provided with a through hole and an inner sinking table; one end of a pole of the pole assembly penetrates through the through hole and is exposed out of the through hole; the pole assembly comprises a pole, a coating piece and a connecting substrate, the pole is arranged in a stepped manner and is provided with a first stepped part and a second stepped part; the cross section of the wrapping piece is in a C shape, the wrapping piece wraps the periphery of the second step part, a plurality of fixing parts are further arranged on the lower surface of the wrapping piece in a protruding mode, and the length of the fixing parts is larger than the sum of the thickness of the connecting base plate and the thickness of the bottom cover plate. The bottom cover plate is arranged below the wrapping piece and located on the inner sinking table of the top cover piece, and the bottom cover plate is fixed to the top cover piece through welding; one end of the fixing part sequentially penetrates out of the assembly holes of the connecting substrate and the bottom cover plate, and forms a fixing inverted buckle in a hot melting manner; the utility model provides a lithium battery cover plate, which solves the problems that the sealing performance of the existing battery cover plate is insufficient, the deformation quantity of a sealing element is difficult to determine and a bottom cover plate is easy to fall off.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery cover plates, specifically to a lithium battery cover plate. Background Technology

[0002] The rapid development of the new energy vehicle and energy storage industries has driven a rapid increase in demand for lithium-ion batteries in my country, leading to a significant increase in demand for lithium-ion battery structural components. With the rapid development of the battery structural component industry and the increasing demands of OEMs, battery structural component companies are engaged in fierce competition to gain a larger market share. This has resulted in an increasing number and variety of battery structures, while product quality has improved and prices have decreased. Against this backdrop, many battery structural component suppliers, in order to maintain the competitiveness of their supplied battery structural components and maintain or even increase product profits, must seek more optimized structural designs in all aspects of product design, development, production, and supply, reducing costs while ensuring product quality.

[0003] At present, the battery cover structure of most battery structural component manufacturers is too complicated and costly. More importantly, in terms of sealing performance and conductivity, the overall volume of the pole is large and requires secondary injection molding to complete its axial loosening. Therefore, it is necessary to improve it to reduce the volume of the pole, such as the publication number: CN117134049A, named a lithium battery cover structure with low resistance. This method can reduce the axial height of the pole and does not require secondary injection molding on the front of the cover. However, this method still has certain defects: (1) The sealing performance is difficult to determine. In this method, the axial limit of the pole is achieved by the cooperation of the cover and the mounting ring to clamp the pole and the seal. However, since the outer ring of the mounting ring needs to form a step for the bottom pressure plate to be snapped on, there is an installation position between the mounting ring and the cover. This means that the welding position of the connection between the mounting ring and the cover needs to be avoided. Welding is performed around the perimeter. This method can only be achieved by through welding. However, this through welding method is difficult to guarantee the uniformity and firmness of the welding, and it is even more difficult to guarantee the tightness of the welding. If the welding is too thick, it will cause the seal between the mounting ring and the cover plate to be compressed too much, which will greatly reduce the service life of the seal and cause rapid wear. If the welding position is insufficient or there is a missed weld, the compression of the seal is not enough and it will not achieve the sealing effect. (2) The bottom cover is easy to fall off. When installed on the vehicle, it is affected by external bumps and external forces. The snap-fit ​​method cannot guarantee the overall firmness. If the connection point falls off, it will easily lead to risks such as battery leakage. (3) The position of the mounting ring is not precisely limited before welding. It is easy to deviate during the welding process and misalignment will occur. It is impossible to guarantee the alignment effect of the pole and the sealing ring. If there is a lifting or other situation, the sealing performance of the sealing ring will be greatly reduced.

[0004] In summary, existing lithium battery covers need further improvement. Utility Model Content

[0005] The purpose of this utility model is to overcome the above-mentioned defects or problems in the background technology and provide a lithium battery cover plate that is simple in structure, easy to manufacture, easy to implement and low in cost, and solves the problems of insufficient sealing performance, difficulty in determining the deformation of the sealing element and easy detachment of the bottom cover plate in the existing battery cover plate.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A lithium battery cover plate is used to seal and cover a battery housing; the battery cover plate includes: a top cover plate, an electrode post assembly, a sealing element, and a bottom cover plate.

[0008] A top cover sheet is used to seal and weld to the battery box body, and the top cover sheet has a through hole and an inner recessed platform; the through hole allows one end of the terminal post of the terminal post assembly to pass through and be exposed; the inner recessed platform is used for the terminal post assembly to be limited and installed.

[0009] An electrode assembly is disposed between a top cover plate and a bottom cover plate; the electrode assembly includes an electrode, a covering component, and a connecting base plate; the electrode is stepped and is configured as a first stepped portion and a second stepped portion; the covering component has a C-shaped cross-section and covers the second stepped portion, and restricts the circumferential movement of the electrode by a limiting structure; the lower surface of the covering component is also provided with several fixing portions, and the length of the fixing portions is greater than the sum of the thicknesses of the connecting base plate and the bottom cover plate; the bottom cover plate is disposed below the covering component and is located in the inner recess of the top cover plate, and is fixed to the top cover plate by welding;

[0010] A sealing element is fitted around the outer periphery of the first stepped portion of the pole post and falls between the covering element and the outer periphery of the first stepped portion.

[0011] The bottom cover plate is located below the connecting base plate and has mounting holes for the fixing part to pass through;

[0012] One end of the fixing part passes through the assembly holes connecting the base plate and the bottom cover plate in sequence, and forms a fixing buckle by hot melting to prevent the bottom cover plate from falling off.

[0013] Furthermore, an inward groove is formed on the outer periphery of the covering for the insertion of an annular connecting substrate, so that the covering and the connecting substrate are fixed together, thereby defining the height of the covering and the connecting substrate.

[0014] Furthermore, the upper edge of the covering member inwardly covers a portion of the peripheral wall and upper surface of the second step portion of the pole post, so that the upper surface of the second step portion forms an installation annular groove for the sealing member limiting device; the installation annular groove is used to limit the outward transition deformation of the sealing member.

[0015] Furthermore, the limiting structure includes a protrusion formed on the inner peripheral wall of the cover and an interlocking portion located on the outer periphery of the second step portion; the cover is plastically molded to correspond to the second step portion of the pole post, and the protrusion and the interlocking portion are correspondingly engaged to make the cover, the pole post, and the connecting substrate integrated as one.

[0016] Furthermore, the inner recessed platform of the top cover plate is arranged in a stepped manner, and a first recessed platform and a second recessed platform are continuously arranged from the lower surface inward. The first recessed platform is used for the sealing element and the covering element limiting device; the second recessed platform is used for the connection base plate and is welded to the periphery and / or the surface of the second recessed platform.

[0017] Furthermore, the sealing element has a convex cross-sectional shape; the portion of the sealing element fitted onto the first stepped portion is interference-fitted with the inner wall of the through hole of the top cover plate, and the portion placed on the second stepped portion is clamped with the inner surface of the top cover plate to form a secondary seal.

[0018] Furthermore, a raised ring is formed downward at the edge of the through hole corresponding to the top cover plate. This raised ring is used to press against the sealing element to form a triple seal.

[0019] Furthermore, it also includes an explosion-proof valve assembly, which is welded or riveted to a through hole in the middle of the top cover plate for tearing and releasing pressure when the internal pressure is too high; the explosion-proof valve assembly includes an explosion-proof sheet and an explosion-proof membrane, the explosion-proof sheet being fixedly mounted on the top cover plate and sealed by the explosion-proof membrane.

[0020] Furthermore, the top cover plate is also provided with a liquid injection hole, the edge of which is inclined inward, and a counter-pushing groove is punched on the inner surface of the top cover plate at the position corresponding to the edge of the hole, so as to make the edge of the hole and the hole position flat.

[0021] As can be seen from the above description of this utility model, compared with the prior art, this utility model has the following beneficial effects:

[0022] (1) This utility model provides a lithium battery cover plate, which has a simple structure, is easy to manufacture, is easy to implement, and has low cost. First, this utility model significantly reduces the thickness of the electrode post, making it thinner to achieve a low-resistance conductivity effect. The overall thickness of the battery cover plate is greatly reduced, resulting in good conductivity, high heat dissipation, and lower cost. On this basis, this utility model uses a covering component to cover the electrode post around its perimeter, while simultaneously fixing the connecting substrate together to form an electrode post assembly. This ensures that the dimensions of the electrode post, covering component, and connecting substrate in the entire assembly are more accurate, thus ensuring that the sealing component held by the connecting substrate after welding to the top cover plate is secure. The deformation is guaranteed, and most importantly, the connecting substrate and the top cover plate can be laser welded around the perimeter to ensure overall flatness. There is no need to use through welding, avoiding excessive deformation and the influence of high temperature on the pole deformation. In addition, the fixing part extending from the lower surface of the cover penetrates the connecting substrate and the bottom cover plate. However, the mushroom-shaped fixing buckle formed by hot melting ensures the stable connection of the bottom cover plate. This ingenious interlocking design achieves the advantages of determining the deformation of the sealing component, reducing the impact of welding thermal conductivity on the deformation of the thin pole, ensuring a flat welding trajectory that is less prone to welding defects, and ensuring a stable fixed connection of the bottom cover plate.

[0023] (2) The covering part of this utility model is also provided with an installation ring groove, which enables easy assembly when installing the sealing part and prevents it from swaying; at the same time, it restricts the sealing part from deforming outward along the radial direction, thus playing a double limiting role.

[0024] (3) The inner recessed platform on the top cover of this utility model is set as a stepped structure. The stepped structure forms a limit to ensure the accuracy of the dimensions. Combined with the accurate dimensions of the electrode assembly, it ensures the deformation of the sealing component after assembly (i.e., controls the deformation of the sealing component so that it does not deform to the point of not sealing, nor does it deform excessively and reduce its lifespan). At the same time, it provides a good welding position for the connecting substrate, and the heat generated during the welding process will not be quickly conducted to the electrode post, causing the electrode post to deform.

[0025] (4) The present invention sets the sealing element to be convex, so that the top cover plate and the periphery of the pole form a secondary seal and protection, which plays the role of dustproof, waterproof and insulating; and under the action of the convex ring, a third seal is formed, which further enhances the sealing performance and prevents the internal electrolyte from leaking.

[0026] (5) The present invention provides a reverse push groove at the injection hole to prevent irregular opening of the injection hole, which would result in the hole corners not being able to be sealed when plugging. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a three-dimensional exploded view of the lithium battery cover plate of this utility model;

[0029] Figure 2 This is a three-dimensional structural diagram of the lithium battery cover plate of this utility model;

[0030] Figure 3 This is a cross-sectional view of the lithium battery cover plate described in this utility model;

[0031] Figure 4 This is a three-dimensional exploded view of the electrode assembly described in this utility model;

[0032] Figure 5 This is a three-dimensional structural diagram of the electrode assembly described in this utility model;

[0033] Figure 6 This is a bottom view of the top cover plate described in this utility model;

[0034] Figure 7 The present utility model Figure 6 Sectional view of section A. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are preferred embodiments of the present utility model and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0036] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and drawings of this utility model is for distinguishing different objects and not for describing a specific order.

[0037] Unless otherwise expressly defined, in the claims, description, and accompanying drawings of this utility model, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," and "counterclockwise" to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing this utility model and simplifying the description. It does 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 should not be construed as limiting the specific protection scope of this utility model.

[0038] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims, description and drawings of this utility model shall be interpreted broadly, that is, any connection in which there is no displacement relationship or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection and fixed connection through other devices or components.

[0039] In the claims, description and drawings of this utility model, the terms "comprising", "having" and variations thereof are used to mean "including but not limited to".

[0040] See Figure 1-4 The present invention provides a lithium battery cover plate, which is used to seal the opening of the battery box to form a complete lithium battery shell, and then inject battery fluid to form a lithium battery.

[0041] The battery cover plate described in this embodiment includes: a top cover plate 1, an electrode post 2, a covering component 3, a connecting substrate 4, a sealing component 5, a bottom cover plate 6, an explosion-proof sheet 7, and an explosion-proof film 8.

[0042] The top cover 1 is made of aluminum and is used to seal and weld to the battery box. The top cover 1 has a through hole 11, an inner recessed platform 12, an injection hole 13, and a through hole 14 for welding the explosion-proof sheet 7. The through hole 11 allows one end of the terminal post 2 of the terminal post 2 assembly to pass through and be exposed. The inner recessed platform 12 is used for limiting the terminal post 2 assembly. The injection hole 13 is used to inject battery fluid into the battery box and then seal it.

[0043] In this embodiment, as shown in Figures 6 and 7, the inner recessed platform 12 of the top cover plate 1 is arranged in a stepped manner, and a first recessed platform 121 and a second recessed platform 122 are continuously arranged from the lower surface inward. The first recessed platform 121 is used for the sealing member 5 and the covering member 3 to limit the installation; the second recessed platform 122 is used for the connection base plate 4 and is welded to the periphery and / or the platform surface of the second recessed platform 122.

[0044] The pole post 2 assembly is disposed between the top cover plate 1 and the bottom cover plate 6;

[0045] The pole post 2 assembly in this embodiment includes pole post 2, cover 3 and connecting substrate 4;

[0046] The pole post 2 is arranged in a stepped manner and is divided into a first stepped part 21 and a second stepped part 22. It should be noted that the pole post 2 in this embodiment has a thin overall thickness and is made of copper material or copper-aluminum composite material.

[0047] The cover 3 has a C-shaped cross section and covers the second step portion 22, and restricts the circumferential movement of the pole post 2 by the limiting structure 9. It should be noted that the cover 3 is an insulating material, such as plastic, and the second step portion 22 of the pole post 2 is wrapped by secondary injection molding.

[0048] The outer periphery of the covering 3 forms an inward groove 31, into which the annular connecting base plate 4 is inserted, so that the covering 3 and the connecting base plate 4 are fixed together, thereby limiting the height of the covering 3 and the connecting base plate 4. This ensures the height dimension of the covering 3 and the pole post 2. By controlling this dimension, the deformation and compression of the sealing element 5 can be more accurately controlled during subsequent assembly.

[0049] The limiting structure 9 here includes a protrusion 91 formed on the inner peripheral wall of the cover 3 and an insert 92 located on the outer periphery of the second step portion 22; the cover 3 is plastically molded to correspond to the second step portion 22 of the pole post 2, and the protrusion 91 and the insert 92 are correspondingly engaged to make the cover 3, the pole post 2, and the connecting substrate 4 integrated into one, so that the size of the entire pole post 2 assembly is precisely controllable.

[0050] In addition, the upper edge of the covering 3 covers the peripheral wall and a portion of the upper surface of the second step portion 22 of the pole post 2 inward, so that the upper surface of the second step portion 22 forms an installation ring groove A for limiting the sealing element 5; the installation ring groove A is used to limit the transition deformation of the sealing element 5, that is, to achieve precise positioning when installing the sealing element 5, while preventing the sealing element 5 from deforming outward excessively. In other words, the deformation of the sealing element 5 can be precisely controlled by the installation ring groove A.

[0051] Furthermore, several fixing parts 32 are protruding on the lower surface of the covering 3, and the length of the fixing part 32 is greater than the sum of the thicknesses of the connecting substrate 4 and the bottom cover plate 6; wherein, one end of the fixing part 32 passes through the assembly hole 61 of the connecting substrate 4 and the bottom cover plate 6 in sequence, and forms a fixing buckle by hot melting to prevent the bottom cover plate 6 from falling off.

[0052] The connecting substrate 4 is located below the covering 3 and within the inner recess 12 of the top cover plate 1. The bottom cover plate 6 is fixed to the top cover plate 1 by welding. Laser welding is preferred here because it has a small weld seam and high precision. The connecting substrate 4 is almost flush with the lower surface of the top cover plate 1. This welding of the perimeter of the connecting substrate 4 results in high stability after welding and is less prone to leakage.

[0053] The sealing element 5 is sleeved on the outer periphery of the first stepped portion 21 of the pole post 2 and falls between the covering element 3 and the outer periphery of the first stepped portion 21. It should be noted that the sealing element 5 in this embodiment adopts a "convex" cross-sectional shape. The part of the sealing element 5 sleeved on the first stepped portion 21 is press-fitted with the inner wall of the through hole 11 of the top cover plate 1, and the part placed on the second stepped portion 22 is clamped with the inner surface of the top cover plate 1 to form a secondary seal.

[0054] The bottom cover plate 6 is located below the connecting base plate 4 and has mounting holes for the fixing part 32 to pass through.

[0055] It also includes an explosion-proof valve assembly, which is welded or riveted to the through hole 14 in the middle of the top cover plate 1 for tearing and releasing pressure when the internal pressure is too high; the explosion-proof valve assembly includes an explosion-proof plate 7 and an explosion-proof membrane 8, the explosion-proof plate 7 is fixedly installed on the top cover plate 1 and sealed by the explosion-proof membrane 8.

[0056] The top cover plate 1 is also provided with a liquid injection hole 13, which is inclined inward at the edge of its outer surface, and a push groove 15 is punched on the inner surface of the top cover plate 1 at the position corresponding to the edge of the hole, so that the edge and hole are flat.

[0057] More specifically, a raised ring 16 is formed downward at the edge of the top cover plate corresponding to the through hole 11. The raised ring 16 is used to press against the sealing element 5 to form a triple seal.

[0058] In actual preparation: such as Figure 1-7 As shown;

[0059] (1) The top cover plate 1 is made of aluminum material and the through hole 11, the first countersunk plate 121, the second countersunk plate 122, the injection hole 13 and the through hole 14 are formed by stretching and punching die; Among them, when preparing the injection hole 13, since the hole diameter of the injection hole 13 is small and the aluminum material is flexible, after punching the injection hole 13 from the front of the top cover plate 1, a reverse push groove 15 is punched from the lower surface of the top cover plate 1 at the position corresponding to the edge and hole position. In this way, the edge of the entire injection hole 13 is flat, and the edge will not form a gap when the plunger is inserted later, thus improving the sealing performance;

[0060] (2) A thin pole piece 2 is prepared by using copper or copper-aluminum composite material, and after cutting, the outer dimensions are refined to form a pole piece 2 with a first step portion 21, a second step portion 22 and an interlocking portion 92. The pole piece is then prepared for use.

[0061] (3) Prepare the connecting substrate 4, which is formed into an annular sheet by stamping. After forming, it is placed into the injection mold along with the pole 2. The covering part 3 is prepared by secondary injection molding, so that the three are formed into one. At this time, the outer periphery of the covering part 3 is formed for the connecting substrate 4 to fit into, while the upper part covers the outer periphery and upper surface of the second step 22. The height dimension between the three is more accurate by injection molding, which makes it easier to accurately control the deformation of the sealing part 5 when assembling with the top cover 1 later.

[0062] It should also be noted that the lower surface of the cover 3 extends out with several fixing parts 32. The length of the fixing parts 32 is greater than the sum of the thicknesses of the connecting substrate 4 and the bottom cover plate 6, so as to allow the bottom cover plate 6 to be heat-fused and fixed after installation.

[0063] (4) The convex-shaped sealing element 5 is fitted around the outer periphery of the first step 21 of the pole post 2 and rests on the second step 22. Then it is integrally installed into the inner recess 12 of the top cover plate 1. At this time, the outer periphery of the sealing element 5 and the inner wall of the through hole 11 are press-fitted to form the first seal, that is, the primary seal (for dust prevention, waterproofing and leakage prevention). The through hole 11 forms a convex ring 16 at the edge of the lower surface, which forms the second seal with the sealing element 5, that is, the secondary seal. The upper and lower surfaces of the sealing element 5 are clamped by the top cover plate and the covering 3 to form a tertiary seal to prevent battery fluid leakage.

[0064] (5) The connecting substrate 4 is placed in the second recess of the top cover plate 1 and the two are fixed by laser welding. After this part is fixed, since the dimensions of each part of the inner recess 12 and pole post 2 are accurate, the position is determined and the pressure is calculated accurately before welding, so the deformation of the sealing element 5 can be accurately determined, thereby controlling the sealing to ensure good sealing while not being over-compressed, which has multiple excellent effects such as good sealing performance, long service life, and no need for dissection testing.

[0065] (6) After the bottom cover plate 6 is injection molded, it is fitted onto the fixing part 32, so that the free end of the fixing part 32 is exposed on the bottom cover plate 6. After the fixing part 32 is heat-melted by high temperature, a mushroom-shaped fixing buckle is formed by pressing, thus fixing the top cover plate to the lower surface of the top cover plate 1.

[0066] (7) Weld the explosion-proof sheet 7 to the through hole 14 of the top cover sheet 1. After forming, attach the explosion-proof film 8 to the explosion-proof sheet 7 to play the role of dustproof and waterproof.

[0067] (8) Weld the entire battery cover plate to the battery box body and connect them into one piece. Then inject the liquid into the injection hole 13, that is, inject battery liquid, and then seal the injection hole 13 to complete the preparation of the entire lithium battery.

[0068] This invention provides a lithium battery cover plate with a simple structure, easy manufacturing, and low cost. Firstly, it significantly reduces the thickness of the electrode post, making it thinner to achieve low-resistance conductivity. The overall thickness of the battery cover plate is greatly reduced, resulting in good conductivity, high heat dissipation, and lower cost. Furthermore, the electrode post is surrounded by a covering component, and a connecting substrate is simultaneously fixed together to form an electrode post assembly. This ensures more precise dimensions of the electrode post, covering component, and connecting substrate in the entire assembly, and ensures that the sealing component held by the connecting substrate after welding to the top cover plate is properly formed. The variable deformation is ensured, and most importantly, the connecting substrate and top cover plate can be laser-welded around the perimeter, ensuring overall flatness without the need for through-welding. This avoids excessive deformation and the influence of high temperatures on the electrode deformation. Furthermore, the fixing part extending from the lower surface of the cover plate penetrates the connecting substrate and bottom cover plate, and a mushroom-shaped fixing buckle formed by heat fusion ensures a stable connection of the bottom cover plate. This ingenious interlocking design simultaneously achieves advantages such as determining the deformation of the seal, reducing the impact of welding thermal conductivity on the deformation of the thin electrode plate, ensuring a smooth welding trajectory that reduces the risk of weak welds, and providing a stable and fixed connection of the bottom cover plate. The cover plate of this invention also features an installation ring groove, which allows for easy assembly and prevents misalignment when installing the seal; it also limits the radial outward deformation of the seal, providing a dual limiting function. The inner recessed platform on the top cover of this invention is designed with a stepped structure. This stepped structure forms a limiting position, ensuring dimensional accuracy. Combined with the precise dimensions of the electrode assembly, this ensures the deformation of the sealing component after assembly (i.e., controlling the deformation of the sealing component to prevent it from deforming into a non-sealing state, while also preventing excessive deformation that would reduce its lifespan). It also provides a good welding position for the connecting substrate, and the heat generated during welding is not rapidly conducted to the electrode post, causing deformation. This invention also features a convex sealing component, creating a secondary seal and protection between the top cover and the periphery of the electrode post, providing dustproof, waterproof, and insulating functions. Furthermore, the convex ring creates a tertiary seal, further enhancing the sealing performance and preventing internal electrolyte leakage. Finally, this invention incorporates a reverse thrust groove at the injection hole to prevent irregular opening of the injection hole from causing the corners of the hole to fail to seal during plugging.

[0069] The description of the above specification and embodiments is used to explain the scope of protection of this utility model, but does not constitute a limitation on the scope of protection of this utility model.

Claims

1. A lithium battery cover for sealing a battery housing; characterized in that: The battery cover includes: a top cover plate, a terminal post assembly, a sealing element, and a bottom cover plate; A top cover sheet is used to seal and weld to the battery box body, and the top cover sheet has a through hole and an inner recessed platform; the through hole allows one end of the terminal post of the terminal post assembly to pass through and be exposed; the inner recessed platform is used for the terminal post assembly to be limited and installed. An electrode assembly is disposed between a top cover plate and a bottom cover plate; the electrode assembly includes an electrode, a covering component, and a connecting base plate; the electrode is stepped and is configured as a first stepped portion and a second stepped portion; the covering component has a C-shaped cross-section and covers the second stepped portion, and restricts the circumferential movement of the electrode by a limiting structure; the lower surface of the covering component is also provided with several fixing portions, and the length of the fixing portions is greater than the sum of the thicknesses of the connecting base plate and the bottom cover plate; the bottom cover plate is disposed below the covering component and is located in the inner recess of the top cover plate, and is fixed to the top cover plate by welding; A sealing element is fitted around the outer periphery of the first stepped portion of the pole post and falls between the covering element and the outer periphery of the first stepped portion. The bottom cover plate is located below the connecting base plate and has mounting holes for the fixing part to pass through; One end of the fixing part passes through the assembly holes connecting the base plate and the bottom cover plate in sequence, and forms a fixing buckle by hot melting to prevent the bottom cover plate from falling off.

2. A lithium battery cover plate as described in claim 1, characterized in that: The outer periphery of the covering has an inwardly formed groove for the insertion of a ring-shaped connecting substrate, so that the covering and the connecting substrate are fixed together, and the height of the covering and the connecting substrate is defined.

3. A lithium battery cover plate as described in claim 2, characterized in that: The upper edge of the covering member covers the peripheral wall and a portion of the upper surface of the second step portion of the pole post inward, so that the upper surface of the second step portion forms an installation annular groove for the sealing member limiting device; the installation annular groove is used to limit the outward transition deformation of the sealing member.

4. A lithium battery cover plate as described in claim 3, characterized in that: The limiting structure includes a protrusion formed on the inner peripheral wall of the cover and an insert located on the outer periphery of the second step portion; the cover is plastically molded to correspond to the second step portion of the pole post, and the protrusion and the insert are matched to make the cover, pole post and connecting substrate integrated.

5. A lithium battery cover plate as described in claim 4, characterized in that: The inner recessed platform of the top cover plate is arranged in a stepped manner, and a first recessed platform and a second recessed platform are continuously arranged from the lower surface inward. The first recessed platform is used for the sealing element and the covering element limiting device; the second recessed platform is used for the connection base plate and is welded to the periphery and / or the surface of the second recessed platform.

6. A lithium battery cover plate as described in claim 5, characterized in that: The sealing element has a convex cross-sectional shape; the portion of the sealing element fitted onto the first stepped portion is interference-fitted with the inner wall of the through hole of the top cover plate, and the portion placed on the second stepped portion is clamped with the inner surface of the top cover plate to form a secondary seal.

7. A lithium battery cover plate as described in claim 6, characterized in that... The top cover plate forms a downward-facing protruding ring at the edge of the through hole, which is used to press against the sealing element to form a triple seal.

8. A lithium battery cover plate as described in claim 1, characterized in that: It also includes an explosion-proof valve assembly, which is welded or riveted to a through hole in the middle of the top cover plate for tearing and releasing pressure when the internal pressure is too high; the explosion-proof valve assembly includes an explosion-proof plate and an explosion-proof membrane, the explosion-proof plate being fixedly installed on the top cover plate and sealed by the explosion-proof membrane.

9. A lithium battery cover plate as described in claim 1, characterized in that: The top cover plate is also provided with a liquid injection hole, which is inclined inward at the edge of its outer surface, and a counter-pushing groove is punched on the inner surface of the top cover plate at the position corresponding to the edge of the hole, so that the edge and hole position are flat.

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