Lithium battery cover plate with inverted pole columns

Abstract

The utility model relates to the technical field of lithium battery structures, in particular to a pole inverted type lithium battery cover plate which comprises a pole, an aluminum cover plate, a plastic block, a sealing ring, a pressing block, a plastic bracket and a connecting sheet, the aluminum cover plate is provided with a pole mounting hole, the pole mounting hole is sleeved with a sealing ring, the sealing ring is sleeved at the lower end of the pole, and the plastic block is sleeved at the upper end of the pole; the bottom end of the pole penetrates through the pole mounting hole and then is fixedly connected with the pressing block, and the lower surface of the pressing block is fixedly connected with the connecting piece. According to the utility model, the pole welding area is transferred from the outer surface of the cover plate in the traditional process to the inside of the battery, so that the conditions of stress fatigue and even breakage of the pole in the subsequent processes of machining, assembling, testing, transporting and the like are effectively reduced; and the problems of poor overcurrent of the module, abnormal data acquisition and the like caused by defects generated when the surface of the pole is welded with the busbar and the flexible circuit board are avoided.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery structure technology, and more specifically, it relates to a lithium battery cover plate with inverted electrode post. Background Technology

[0002] Energy shortage and environmental pollution are two major problems facing the world today. To address these issues, energy storage and new energy vehicles have developed rapidly. Lithium-ion batteries, with their high specific energy, low self-discharge, long cycle life, lack of memory effect, and environmental friendliness, have gained widespread market application. Benefiting from the rapid development and updates in lithium-ion battery technology, the demand for lithium-ion battery structural components has also increased rapidly. As battery models are updated, their cover structures often need adjustment. Furthermore, in different fields or environments, the actual assembly process for the same model of batteries requires welding busbars, studs, and threaded holes to the terminals to facilitate series and parallel connections between batteries and sampling by the battery management system.

[0003] Most existing cover plate structures employ riveting of the pole post and pressure block followed by laser welding, with the welding location typically being the upper surface of the pole post (see appendix). Figure 1 As indicated by arrow A, depressions and gaps in the welding process make it difficult to machine the terminal post surface during battery assembly. Subsequent machining processes can also cause stress fatigue at the welded area of ​​the terminal post clamping block, while increasing the risk of failure due to vibration and collision during transportation. In addition, due to the limited welding area between the terminal post and the clamping block, the area of ​​the aluminum busbar or stud needs to be increased to cover the welded area of ​​the terminal post and the clamping block during assembly, indirectly increasing time, material, and labor costs.

[0004] In the other type of integrated cover plate structure for the terminal block, the plastic bracket can only be formed by secondary injection molding of molten plastic. The plastic bracket obtained by this method will shrink in volume as the temperature drops after molding, resulting in poor sealing effect. This will bring certain safety hazards to the battery and increase the analysis cost of cell failure due to poor sealing. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a reverse-clamped lithium battery cover plate, which solves the problem of difficult reprocessing after welding the electrode post and the pressure block of the existing lithium battery cover plate, and effectively avoids structural defects such as poor stability and poor welding of connecting pieces after the surface treatment of the electrode post.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] A reverse-mount lithium battery cover includes a terminal post, an aluminum cover for sealing the lithium battery casing, a plastic block for preventing the upper end of the terminal post from electrically connecting to the aluminum cover, a sealing ring for preventing the lower end of the terminal post from electrically connecting to the aluminum cover, a pressure block for electrically connecting to the terminal post, a plastic bracket for preventing the pressure block from electrically connecting to the aluminum cover, and a connecting piece for electrically connecting the lithium battery tab to the pressure block. The aluminum cover has a terminal post mounting hole, a sealing ring is fitted into the terminal post mounting hole, the sealing ring fits over the lower end of the terminal post, and the plastic block fits over the upper end of the terminal post. The upper surface of the plastic block abuts against the terminal post, and its lower surface abuts against the upper surface of the aluminum cover. The upper surface of the plastic bracket abuts against the lower surface of the aluminum cover, and its lower surface abuts against the upper surface of the pressure block. The bottom end of the terminal post passes through the terminal post mounting hole and is fixedly connected to the pressure block, and the lower surface of the pressure block is fixedly connected to the connecting piece.

[0008] Optionally, the electrode includes a first electrode and a second electrode, the first electrode and the second electrode are integrally formed, the diameter of the first electrode is larger than the diameter of the second electrode; the plastic block has a T-shaped hole for accommodating the first electrode and fitting the second electrode.

[0009] Optionally, the upper surface of the aluminum cover plate is recessed downward to form a plastic groove for accommodating the plastic block, and its lower surface is raised downward to form a boss; the sealing ring includes a thin cylindrical ring and a large cylindrical ring, which are integrally formed, and the diameter of the thin cylindrical ring is smaller than that of the large cylindrical ring; the outer ring of the thin cylindrical ring is fitted into the pole mounting hole, and the inner ring of the thin cylindrical ring is fitted into the second pole; the upper surface of the large cylindrical ring abuts against the boss, and its lower surface abuts against the upper surface of the pressure block.

[0010] Optionally, the upper surface of the plastic bracket is provided with a boss groove for accommodating the boss, and the lower surface is provided with a pressing block groove for accommodating the pressing block; the plastic bracket is provided with a rubber ring hole for accommodating the large cylindrical ring, the upper end of the rubber ring hole is connected to the boss groove, and the lower end of the rubber ring hole is connected to the pressing block groove.

[0011] Optionally, the upper outer edge of the thin cylindrical ring is chamfered to facilitate the installation of the sealing ring on the aluminum cover plate.

[0012] Optionally, the distance between the sidewall of the rubber ring hole and the outer wall of the large cylindrical ring is 0.5-1.5mm.

[0013] Optionally, the connecting piece is a double-layer butterfly connecting piece.

[0014] Optionally, the aluminum cover plate is provided with an explosion-proof valve vent and a liquid injection port.

[0015] In summary, this utility model has the following beneficial effects: by transferring the electrode welding area from the outer surface of the cover plate in the traditional process to the inside of the battery, the stress fatigue or even fracture of the electrode during subsequent machining, assembly, testing, and transportation is effectively reduced, and defects generated when welding the electrode surface to the busbar and flexible circuit board are avoided, which can cause problems such as poor module current and abnormal data acquisition. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of a lithium battery cover in the prior art;

[0017] Figure 2 This is a first structural schematic diagram of the present invention;

[0018] Figure 3 This is a schematic diagram of the second structure of this utility model;

[0019] Figure 4 This is a top view of the present invention;

[0020] Figure 5 yes Figure 4 Sectional view of section BB;

[0021] Figure 6 yes Figure 5 A magnified view of a portion of the image;

[0022] Figure 7 This is the first exploded view of this utility model;

[0023] Figure 8 This is the second exploded view of this utility model. Detailed Implementation

[0024] To make the objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein.

[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] This utility model provides an inverted lithium battery cover plate with a terminal post 1, such as Figure 2-8 As shown, the battery includes a terminal post 1, an aluminum cover plate 2 for sealing the lithium battery casing, a plastic block 3 for preventing the upper end of the terminal post 1 from being electrically connected to the aluminum cover plate 2, a sealing ring 4 for preventing the lower end of the terminal post 1 from being electrically connected to the aluminum cover plate 2, a pressure block 5 for being electrically connected to the terminal post 1, a plastic bracket 6 for preventing the pressure block 5 from being electrically connected to the aluminum cover plate 2, and a connecting piece 7 for electrically connecting the lithium battery tab to the pressure block 5. The aluminum cover plate 2 has a terminal post mounting hole 21, the sealing ring 4 is fitted into the terminal post mounting hole 21, the sealing ring 4 is fitted into the lower end of the terminal post 1, and the plastic block 3 is fitted into the upper end of the terminal post 1. The upper surface of the plastic block 3 abuts against the terminal post 1, and its lower surface abuts against the upper surface of the aluminum cover plate 2. The upper surface of the plastic bracket 6 abuts against the lower surface of the aluminum cover plate 2, and its lower surface abuts against the upper surface of the pressure block 5. The bottom end of the terminal post 1 passes through the terminal post mounting hole 21 and is fixedly connected to the pressure block 5. The lower surface of the pressure block 5 is fixedly connected to the connecting piece 7.

[0028] In this embodiment, the electrode post 1 passes through the plastic block 3, aluminum cover plate 2, sealing ring 4, and plastic bracket 6 sequentially from top to bottom before being riveted to the pressure block 5, achieving initial fixation of the cover plate assembly. Then, laser welding is performed on the riveted ends of the electrode post 1 and pressure block 5, with the welding trajectory along the outer ring of the electrode post 1. Next, the connecting piece 7 is placed on the surface of the pressure block 5, and laser welding is used to weld the connecting piece 7 to the pressure block 5, with the welding trajectory being two parallel lines. The electrode post 1, plastic block 3, sealing ring 4, pressure block 5, and connecting piece 7 installed on the aluminum cover plate 2 are in two sets, corresponding to the positive and negative terminals of the lithium battery, respectively. Furthermore, the aluminum cover plate 2 has a conventional explosion-proof valve vent hole 24 and a liquid injection hole 25. An explosion-proof plate 8 is installed below the explosion-proof valve vent hole 24, and an explosion-proof valve protective patch 9 is installed above the explosion-proof valve vent hole 24.

[0029] This invention effectively reduces stress fatigue and even breakage of the terminal post 1 during subsequent machining, assembly, testing, and transportation by transferring the welding area of ​​the terminal post 1 from the outer surface of the cover plate in traditional processes to the inside of the battery. It also avoids defects caused by welding the terminal post 1 surface to the busbar and flexible circuit board, which can lead to poor module current and abnormal data acquisition. Furthermore, the terminal post 1 uses an inverted mounting method; after being riveted to the clamping block 5, the riveted area is laser-welded, further enhancing the tensile strength of the terminal post 1.

[0030] Furthermore, the electrode 1 includes a first electrode 11 and a second electrode 12. The first electrode 11 and the second electrode 12 are integrally formed. The diameter of the first electrode 11 is larger than the diameter of the second electrode 12. The plastic block 3 has a T-shaped hole 31 for accommodating the first electrode 11 and fitting the second electrode 12.

[0031] like Figure 6-8 As shown, the first pole post 11 is rectangular, and the second pole post 12 is cylindrical. When connected, they form a T-shape. The upper half of the T-shaped hole 31 accommodates the first pole post 11, with its bottom surface abutting and fitting against the bottom surface of the first pole post 11, while a gap exists between its sidewall and the sidewall of the first pole post 11. The lower half of the T-shaped hole 31 is fitted with the upper end of the second pole post 12. The second pole post 12 passes through the T-shaped hole 31, the pole post mounting hole 21, the sealing ring 4, and the through hole on the pressure block 5 before being riveted to the pressure block 5.

[0032] This utility model can also be designed with one-piece molded flat-head poles or stud poles according to assembly requirements and flow conditions. After the cover plate is assembled, there is no need to process the surface of the pole, which reduces the stress caused by mechanical processing after the cover plate is assembled and avoids fatigue and loosening to the greatest extent.

[0033] In this invention, the plastic block 3 can partially cover the outer wall of the first electrode post 11 or a plastic gasket can be used, thereby reducing material costs while ensuring that the electrode post 1 is isolated from the aluminum cover plate 2. In addition, the total height of the aluminum battery cover plate can be controlled by adjusting the thickness of the plastic block 3 and the depth of the plastic groove 22 in the aluminum cover plate 2.

[0034] Furthermore, the upper surface of the aluminum cover plate 2 is recessed downward to form a plastic groove 22 for accommodating the plastic block 3, and its lower surface is raised downward to form a boss 23; the sealing ring 4 includes a thin cylindrical ring 41 and a large cylindrical ring 42, which are integrally formed, and the diameter of the thin cylindrical ring 41 is smaller than the diameter of the large cylindrical ring 42; the outer ring of the thin cylindrical ring 41 is fitted into the pole mounting hole 21, and the inner ring of the thin cylindrical ring 41 is fitted into the second pole 12; the upper surface of the large cylindrical ring 42 abuts against the boss 23, and its lower surface abuts against the upper surface of the pressure block 5.

[0035] Furthermore, the upper surface of the plastic bracket 6 is provided with a boss groove 61 for accommodating the boss 23, and the lower surface is provided with a pressing block groove 62 for accommodating the pressing block 5; the plastic bracket 6 is provided with a rubber ring hole 63 for accommodating the large cylindrical ring 42, the upper end of the rubber ring hole 63 is connected to the boss groove 61, and the lower end of the rubber ring hole 63 is connected to the pressing block groove 62.

[0036] like Figure 6-8 As shown, the bottom surface of the plastic groove 22 abuts against and adheres to the bottom surface of the plastic block 3; the bottom surface of the boss groove 61 abuts against and adheres to the bottom surface of the boss 23; the top surface of the pressure block groove 62 abuts against and adheres to the top surface of the pressure block 5; the inner wall of the thin cylindrical ring 41 adheres to the outer wall of the second pole post 12; the upper surface of the large cylindrical ring 42 adheres to the bottom surface of the boss 23, and its lower surface adheres to the top surface of the pressure block 5. There is a gap between the pole post mounting hole 21 and the second pole post 12 for accommodating the thin cylindrical ring 41. The thickness of the large cylindrical ring 42 is slightly greater than the depth of the rubber ring hole 63, and the distance between the side wall of the rubber ring hole 63 and the outer wall of the large cylindrical ring 42 is 0.5-1.5mm, so as to achieve better sealing performance between the aluminum cover plate 2 and the pressure block 5.

[0037] In this utility model, the sealing ring 4 is T-shaped. The large cylindrical ring 42 can increase the area of ​​force exerted on the pole post 1 and the pressure block 5 when they are riveted together, so that the sealing ring 4 is in a compressed state, which enhances the sealing performance of the cover plate. At the same time, it completely isolates the pole post 1 and the aluminum cover plate 2, preventing them from contacting and conducting electricity.

[0038] Furthermore, the upper outer edge of the thin cylindrical ring 41 is provided with a chamfer to facilitate the installation of the sealing ring 4 on the aluminum cover plate 2.

[0039] like Figure 6 As shown, the chamfer on the upper outer edge of the thin cylindrical ring 41 (not shown in the attached figure) facilitates the insertion of the sealing ring 4 into the terminal mounting hole 21, thereby accelerating the assembly efficiency of the lithium battery cover.

[0040] Furthermore, the connecting piece 7 is a double-layer butterfly connecting piece.

[0041] like Figure 3 As shown, the connecting piece 7 has a double-layer butterfly folding structure (bent at its notch). One half of its area to be welded is placed on the surface of the pressure block 5. Laser welding is used to weld the connecting piece 7 to the pressure block 5, and the welding trajectory is two parallel lines, thereby further stabilizing the pole post 1. In addition, the other half of the connecting piece 7 that is not welded can be folded freely. Whether it is a tab welded separately from the pole sheet or a foil tab cut from the pole sheet, it can be placed between the two foldable halves of the connecting piece 7 for welding, avoiding the defect of the tab being welded through when the tab is placed on a single connecting piece (i.e., a single-layer connecting piece) in traditional welding.

[0042] In summary, the terminal post 1 in the lithium battery cover has a T-shaped stepped structure. The upper part of the first terminal post 11 is a cuboid, and the lower part of the second terminal post 12 is a cylinder. The sealing ring is also T-shaped. During assembly, the sealing ring 4 is inverted T-shaped, covering the outer circumference of the second terminal post 12 with its inner ring. When the second terminal post 12 is riveted to the pressure block 5, the outer ring of the sealing ring 4 is subjected to the squeezing force of the pressure block 5, which can achieve a better sealing effect. After the terminal post 1 and the pressure block 5 are riveted, the riveted surfaces are laser welded, which enhances the tensile strength and fatigue resistance of the terminal post 1 and the pressure block 5. Simultaneously, the welding location of the terminal post 1 is transferred from the outside of the battery in traditional processes to the inside of the battery. Since the upper surface of the first terminal post 11 does not require welding, positioning holes or threaded holes can be pre-drilled according to the module assembly requirements, reducing stress caused by machining after the cover plate is assembled, avoiding fatigue and loosening. This solves the problem of difficult re-processing of the terminal post surface in existing battery cover plates. Finally, during the welding of the connecting piece 7, the terminal post 1 is further stabilized, effectively reducing stress fatigue and even fracture of the terminal post 1 during subsequent machining, assembly, testing, and transportation. This avoids defects on the surface of the terminal post 1 during welding with the busbar and FPC, preventing problems such as poor module current and abnormal data acquisition. Furthermore, the structural components used in the cover plate have advantages such as simple molding, fewer types, and low cost.

[0043] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A type of inverted electrode cover for lithium batteries, characterized in that, The device includes a terminal post, an aluminum cover plate for sealing the lithium battery casing, a plastic block for preventing the upper end of the terminal post from electrically connecting to the aluminum cover plate, a sealing ring for preventing the lower end of the terminal post from electrically connecting to the aluminum cover plate, a pressure block for electrically connecting to the terminal post, a plastic bracket for preventing the pressure block from electrically connecting to the aluminum cover plate, and a connecting piece for electrically connecting the lithium battery tab to the pressure block. The aluminum cover plate has a terminal post mounting hole, a sealing ring is fitted into the terminal post mounting hole, the sealing ring fits onto the lower end of the terminal post, and the plastic block fits onto the upper end of the terminal post. The upper surface of the plastic block abuts against the terminal post, and its lower surface abuts against the upper surface of the aluminum cover plate. The upper surface of the plastic bracket abuts against the lower surface of the aluminum cover plate, and its lower surface abuts against the upper surface of the pressure block. The bottom end of the terminal post passes through the terminal post mounting hole and is fixedly connected to the pressure block, and the lower surface of the pressure block is fixedly connected to the connecting piece.

2. The inverted lithium battery cover plate according to claim 1, characterized in that, The electrode includes a first electrode and a second electrode, which are integrally formed. The diameter of the first electrode is larger than that of the second electrode. The plastic block has a T-shaped hole for housing the first electrode and fitting the second electrode.

3. The inverted lithium battery cover plate according to claim 2, characterized in that, The upper surface of the aluminum cover plate is recessed downward to form a plastic groove for accommodating the plastic block, and its lower surface is raised downward to form a boss; the sealing ring includes a thin cylindrical ring and a large cylindrical ring, which are integrally formed, and the diameter of the thin cylindrical ring is smaller than that of the large cylindrical ring; the outer ring of the thin cylindrical ring is fitted into the pole mounting hole, and the inner ring of the thin cylindrical ring is fitted into the second pole; the upper surface of the large cylindrical ring abuts against the boss, and its lower surface abuts against the upper surface of the pressure block.

4. The inverted lithium battery cover plate according to claim 3, characterized in that, The upper surface of the plastic bracket has a boss groove for accommodating the boss, and the lower surface has a pressing block groove for accommodating the pressing block; the plastic bracket has a rubber ring hole for accommodating the large cylindrical ring, the upper end of the rubber ring hole is connected to the boss groove, and the lower end of the rubber ring hole is connected to the pressing block groove.

5. The inverted lithium battery cover plate according to claim 3, characterized in that, The upper outer edge of the thin cylindrical ring is chamfered to facilitate the installation of the sealing ring on the aluminum cover plate.

6. The inverted lithium battery cover plate according to claim 4, characterized in that, The distance between the side wall of the rubber ring hole and the outer wall of the large cylindrical ring is 0.5-1.5mm.

7. The inverted lithium battery cover plate according to claim 1, characterized in that, The connecting piece is a double-layer butterfly connecting piece.

8. The inverted lithium battery cover plate according to claim 6, characterized in that, The aluminum cover plate has an explosion-proof valve vent and a liquid injection port.

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