Power battery top cover structure and power battery

Abstract

A power battery top cover structure and a power battery. The power battery top cover structure comprises a top cover sheet (1), poles (2), and upper plastic parts (3), wherein two pole holes (11) are formed at an interval in the top cover sheet (1), two poles (2) are provided and respectively pass through the two pole holes (11), a pole groove (21) is circumferentially formed in the outer wall of each pole (2), knurling (210) is pressed at the bottoms of the pole grooves (21), two upper plastic parts (3) are provided and are respectively sleeved on the two poles (2), the upper plastic parts (3) extend into the corresponding pole grooves (21), the inner walls of the upper plastic parts (3) abut against the knurling (210), and the bottoms of the upper plastic parts (3) abut against the top cover sheet (1).

Description

Power battery top cover structure and power battery

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 22, 2023, with application number 202323521236.3, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of power batteries, for example, to a power battery top cover structure and a power battery. Background Art

[0003] With the continuous development of society and the increasing awareness of environmental protection, more and more devices are choosing lithium batteries as their working power source, such as mobile phones, laptops, power tools, and electric vehicles, which provides a broad space for the development of lithium batteries. The lithium batteries used in power tools and electric vehicles are usually called power batteries. The power battery includes multiple battery cells, which are connected in parallel to form a bus assembly. The bus assembly is electrically connected to a pair of poles to transmit electrical energy. However, during the casting and welding production process, the poles are demolded in a cylindrical shape. The poles with this structure cannot guarantee the acid creep distance of the battery. Over time, it is easy to cause corrosion and leakage of the poles, thereby affecting the battery life. For this reason, grooves are machined on the poles and filled with special materials to delay acid creep. In addition, since liquid substances such as electrolyte are injected into the power battery, in order to ensure the sealing of the power battery, the power battery also includes an outer shell and a top cover sheet closed with the outer shell. Two pole through-holes are provided on the top cover sheet, and the poles pass through the pole through-holes of the top cover sheet, and a plastic part is injection-molded in the pole groove. The inner wall of the plastic part is sealed against the hole wall of the pole through-hole, and the bottom of the plastic part is against the top cover sheet to insulate the pole and the top cover sheet.

[0004] However, during the assembly process, the pole passes through the pole hole, the plastic part is installed in the pole groove, the inner wall of the plastic part circumferentially abuts the groove wall of the pole groove, and the bottom of the plastic part abuts the top cover. When the power battery is subjected to severe vibration, the plastic part and the pole will become loose, which will cause the top cover to loosen and rotate easily, resulting in pressure relief at the pole, and the electrolyte inside the battery will overflow from the pole and explode, posing a huge safety hazard.

[0005] Summary of the Invention

[0006] The present application provides a power battery top cover structure, which has a stable structure and can prevent the pole from depressurizing.

[0007] The present application provides a power battery top cover structure, comprising:

[0008] A top cover plate, wherein two pole holes are provided at intervals on the top cover plate;

[0009] There are two poles, and the two poles are respectively inserted into the two pole holes. The outer wall of the pole is circumferentially provided with a pole groove, and the bottom of the pole groove is pressed with knurling;

[0010] The upper plastic part is provided with two upper plastic parts, and the two upper plastic parts are respectively sleeved on the two poles. The upper plastic part extends into the pole slot and the inner wall of the upper plastic part abuts against the knurling, and the bottom of the upper plastic part abuts against the top cover.

[0011] In some embodiments, the knurling is straight or oblique, and the knurling forms an angle with the horizontal direction.

[0012] In some embodiments, the lower end surface of the pole extends circumferentially to form a limiting protrusion, and the limiting protrusion and the upper plastic part are respectively provided on opposite sides of the top cover sheet.

[0013] In some embodiments, the top cover plate is provided with two installation grooves spaced apart from each other, the two installation grooves are coaxial with the two pole holes respectively, and the two upper plastic parts are both circumferentially provided with an annular groove, the groove wall of the annular groove circumferentially abuts against the groove wall of the installation groove.

[0014] In some embodiments, the pole is separated from the top cover sheet, and the power battery top cover structure further includes a seal, which is sleeved on the pole, and the bottom of the seal abuts against the limiting protrusion, and the seal is configured to block the gap between the pole and the top cover sheet.

[0015] In some embodiments, the sealing member is made of an elastic material, and at least a portion of the top cover sheet is sandwiched between the upper plastic member and the sealing member.

[0016] In some embodiments, the top cover piece is further provided with a mounting hole, the mounting hole passes through the top cover piece, and a fixing groove is provided on the lower end surface of the top cover piece, the fixing groove is coaxial with the mounting hole, and an explosion-proof valve is fixed in the fixing groove.

[0017] In some embodiments, a baffle is fixed to the top cover piece, and the baffle covers the mounting hole.

[0018] In some embodiments, the top cover sheet is provided with a liquid injection hole, and the liquid injection hole passes through the top cover sheet.

[0019] The present application provides a power battery with a high pass rate.

[0020] The present application also provides a power battery, comprising a battery housing and the power battery top cover structure as described above assembled on the battery housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a partial cross-sectional view of a power battery top cover structure provided in an embodiment of the present application;

[0022] FIG2 is a partial cross-sectional view of a top cover sheet provided in an embodiment of the present application;

[0023] FIG3 is a first structural diagram of a pole provided in an embodiment of the present application;

[0024] FIG4 is a second structural diagram of a pole provided in an embodiment of the present application;

[0025] FIG5 is a partial cross-sectional view of a power battery provided in an embodiment of the present application.

[0026] In the picture:

[0027] 1. Top cover; 11. Pole hole; 12. Mounting slot; 13. Mounting hole; 14. Fixing slot; 15. Filling hole; 2. Pole; 21. Pole slot; 210. Knurling; 22. Limiting protrusion; 3. Upper plastic part; 31. Annular groove; 4. Seal; 5. Explosion-proof valve; 6. Baffle; 7. Battery case. DETAILED DESCRIPTION

[0028] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application as appropriate.

[0029] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., regarding orientations or positions, are based on the orientations or positions shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0031] This embodiment provides a power battery top cover structure that is stable and can prevent pole pressure release.

[0032] Optionally, as shown in Figure 1, the power battery top cover structure includes a top cover sheet 1, a pole 2 and an upper plastic part 3, wherein, as shown in Figure 2, two pole holes 11 are spaced apart on the top cover sheet 1, two poles 2 are provided, and two upper plastic parts 3 are provided. The two poles 2 are respectively correspondingly penetrated through the two pole holes 11. To ensure the acid creep distance between the pole 2 and the top cover sheet 1, as shown in Figure 3 or Figure 4, a pole groove 21 is circumferentially opened on the outer wall of the pole 2, and the two upper plastic parts 3 are respectively sleeved on the two poles 2, and the upper plastic parts 3 extend into the pole groove 21. The bottom of the upper plastic part 3 abuts against the top cover sheet 1 to improve the insulation effect between the pole 2 and the top cover sheet 1.

[0033] In some embodiments, to prevent loosening between the upper plastic member 3 and the pole 2, which could cause the top cover 1 to loosen and rotate, a knurling pattern 210 is formed on the bottom of the pole slot 21. The upper plastic member 3 extends into the pole slot 21, and the inner wall of the upper plastic member 3 abuts the knurling pattern 210, thereby increasing friction between the upper plastic member 3 and the pole 2. Optionally, as shown in Figures 3 and 4, the knurling pattern 210 can be straight or oblique, and the knurling pattern 210 can be angled with the horizontal. This prevents the upper plastic member 3 from rotating about the pole 2, preventing pressure relief at the pole 2 and improving safety.

[0034] Optionally, the lower end surface of the pole 2 extends circumferentially to form a limiting protrusion 22, and the limiting protrusion 22 and the upper plastic part 3 are arranged on opposite sides of the top cover sheet 1. By providing the limiting protrusion 22, the pole 2 can be stably inserted into the pole hole 11 and will not pass through the pole hole 11.

[0035] Optionally, as shown in Figures 1 and 2, two mounting grooves 12 are spaced apart on the top cover sheet 1, and the two mounting grooves 12 are coaxial with the two pole holes 11 respectively. The two upper plastic parts 3 are both circumferentially provided with an annular groove 31, and the groove wall of the annular groove 31 circumferentially abuts against the groove wall of the mounting groove 12, thereby fixing the upper plastic part 3 and the top cover sheet 1, thereby improving the structural stability of the power battery top cover structure.

[0036] Optionally, the pole 2 is spaced from the top cover sheet 1. To improve the sealing performance of the power battery top cover structure and prevent pressure release from the pole 2, the power battery top cover structure is further provided with a seal 4. The seal 4 is sleeved on the pole 2, and the bottom of the seal 4 abuts against the limiting protrusion 22. The seal 4 is configured to block the gap between the pole 2 and the top cover sheet 1. It is understood that two seals 4 are provided, one for each of the two poles 2.

[0037] Optionally, the seal 4 is made of elastic material, and can be interference fitted to improve the structural stability of the power battery top cover structure. That is, at least part of the top cover sheet 1 is sandwiched between the upper plastic part 3 and the seal 4, and the top cover sheet 1 squeezes the seal 4 to deform, thereby being able to apply downward pressure to the pole 2 and upward force to the top cover sheet 1. The force is transmitted to the upper plastic part 3. Since the upper plastic part 3 is inserted in the pole slot 21, it has the effect of enhancing the structural stability.

[0038] The top cover sheet 1 also has a mounting hole 13 extending through the top cover sheet 1. An explosion-proof valve 5 is mounted at the mounting hole 13 to enhance safety. Optionally, a fixing groove 14 is provided on the lower end surface of the top cover sheet 1. The fixing groove 14 is coaxial with the mounting hole 13. The explosion-proof valve 5 is fixedly mounted in the fixing groove 14 and circumferentially welded to the wall of the fixing groove 14. By circumferentially welding the explosion-proof valve 5 to the wall of the fixing groove 14, when the internal pressure of the power battery reaches a certain value, the explosion-proof valve 5 explodes from the middle region. The edge region of the explosion-proof valve 5 remains connected to the wall of the fixing groove 14, preventing the explosion-proof valve 5 from bursting and injuring anyone.

[0039] Optionally, a baffle 6 is fixedly provided on the upper end surface of the mounting hole 13 , and the mounting hole 13 and the explosion-proof valve 5 are covered by the baffle 6 to prevent dust from falling.

[0040] Optionally, as shown in FIG2 , a liquid injection hole 15 is provided on the top cover sheet 1 , and the liquid injection hole 15 passes through the top cover sheet 1 . During the assembly process, electrolyte can be injected into the power battery through the liquid injection hole 15 .

[0041] When assembling the power battery top cover structure provided in the present application, a pole groove 21 is processed on the pole 2, and then a knurling 210 is pressed in the pole groove 21. A seal 4 is sleeved on the pole 2. The two poles 2 are respectively sleeved in the two pole holes 11 from bottom to top, and the limiting protrusion 22 is pressed upward to inject the upper plastic part 3. By pressing the knurling 210 in the pole groove 21, the upper plastic part 3 is prevented from rotating around the pole 2 as the axis, which can prevent pressure relief at the pole 2 and improve the safety performance of the power battery top cover structure.

[0042] In addition, Figure 5 is a partial cross-sectional view of a power battery provided in an embodiment of the present application. As shown in Figure 5, the present application also provides a power battery comprising a battery housing 7 and the power battery top cover structure described above, assembled on the battery housing 7. By applying the power battery top cover structure described above, the qualified rate of the power battery is improved.

[0043] The present application provides a power battery top cover structure, the power battery top cover structure includes a top cover sheet, a pole and an upper plastic part, wherein the top cover sheet is provided with two pole holes at intervals, the pole is provided with two poles, the two poles are respectively inserted into the two pole holes, the outer wall of the pole is circumferentially provided with a pole groove, the bottom of the pole groove is pressed with knurling, the upper plastic part is provided, the two upper plastic parts are respectively sleeved on the two poles, the upper plastic part extends into the pole groove and the inner wall of the upper plastic part abuts the knurling, and the bottom of the upper plastic part abuts the top cover sheet; the upper plastic part extends into the pole groove and the inner wall of the upper plastic part abuts the knurling, so as to increase the friction between the upper plastic part and the pole, avoid the upper plastic part rotating around the pole as the axis, prevent pressure relief at the pole, and improve safety performance; the power battery includes a battery housing and the above-mentioned power battery top cover structure assembled on the battery housing, with a high pass rate.

Claims

1. A power battery top cover structure, comprising: A top cover sheet (1), wherein the top cover sheet (1) is provided with two pole holes (11) at intervals; A pole (2), wherein two poles (2) are provided, and the two poles (2) are respectively inserted into the two pole holes (11), and a pole groove (21) is circumferentially opened on the outer wall of the pole (2), and a knurling (210) is pressed on the bottom of the pole groove (21); An upper plastic part (3), wherein two upper plastic parts (3) are provided, and the two upper plastic parts (3) are respectively sleeved on the two poles (2), the upper plastic part (3) extends into the pole slot (21) and the inner wall of the upper plastic part (3) abuts against the knurling (210), and the bottom of the upper plastic part (3) abuts against the top cover sheet (1).

2. The power battery top cover structure according to claim 1, wherein: The knurling (210) is a straight knurling or an oblique knurling, and the knurling (210) forms an angle with the horizontal direction.

3. The power battery top cover structure according to claim 1, wherein: The lower end surface of the pole (2) extends circumferentially to form a limiting protrusion (22), and the limiting protrusion (22) and the upper plastic part (3) are arranged on opposite sides of the top cover sheet (1).

4. The power battery top cover structure according to claim 1, wherein: The top cover sheet (1) is provided with two installation grooves (12) at intervals, the two installation grooves (12) are coaxial with the two pole holes (11) respectively, and the two upper plastic parts (3) are both provided with an annular groove (31) in the circumferential direction, and the groove wall of the annular groove (31) is circumferentially abutted against the groove wall of the installation groove (12).

5. The power battery top cover structure according to claim 3, wherein: The pole (2) is spaced apart from the top cover sheet (1); the power battery top cover structure further comprises a sealing member (4); the sealing member (4) is sleeved on the pole (2); the bottom of the sealing member (4) abuts against the limiting protrusion (22); and the sealing member (4) is configured to seal the space between the pole (2) and the top cover sheet (1).

6. The power battery top cover structure according to claim 5, wherein: The sealing member (4) is made of elastic material, and at least a portion of the top cover sheet (1) is sandwiched between the upper plastic member (3) and the sealing member (4).

7. The power battery top cover structure according to claim 1, wherein: The top cover sheet (1) is also provided with a mounting hole (13), the mounting hole (13) passing through the top cover sheet (1), and a fixing groove (14) is provided on the lower end surface of the top cover sheet (1), the fixing groove (14) is coaxial with the mounting hole (13), and an explosion-proof valve (5) is fixedly arranged in the fixing groove (14).

8. The power battery top cover structure according to claim 7, wherein: The top cover sheet (1) is fixedly provided with a baffle (6), and the baffle (6) covers the mounting hole (13).

9. The power battery top cover structure according to any one of claims 1 to 8, wherein: The top cover sheet (1) is provided with a liquid injection hole (15), and the liquid injection hole (15) passes through the top cover sheet (1).

10. A power battery, comprising a battery housing (7) and the power battery top cover structure according to any one of claims 1 to 9 assembled on the battery housing (7).

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