Cover plate assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate assembly, a battery cell and a battery pack. The cover body is provided with an anti-explosion valve and a protrusion arranged on the periphery of the anti-explosion valve in a surrounding mode. The supporting plate is arranged opposite to the anti-explosion valve and is connected with the bulge; the supporting plate is provided with an air hole and an annular reinforcing rib surrounding the air hole, and the length direction and the width direction of the annular reinforcing rib are consistent with the length direction and the width direction of the supporting plate. The length and the width of the supporting plate are L0 and W0 respectively; the length and the width of the annular reinforcing rib are L1 and W1 respectively; the relationship between L0 and L1 meets the following conditions: 85 < = L1 / L0 < = 95, and (L0-L1) > = 5mm; w0 and W1 satisfy the following relations: 85 < = W1 / W0 < = 95, and (W0-W1) > = 4mm. According to the invention, the support plate opposite to the explosion-proof valve is arranged on the cover body, so that the position of the pole group can be limited in the axial direction when the battery cell is subjected to thermal runaway, the pole group is prevented from randomly moving along with high-temperature airflow to shield the explosion-proof valve, and the exhaust smoothness of the exhaust channel is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate assembly, a battery cell and a battery pack. Background Art

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing. In traditional square lithium batteries, the cover plate and the shell are welded and sealed, and the electrode group is encapsulated inside the shell. Among them, the lower surface of the cover plate is installed with a lower plastic (PP material), which is used to press against the top of the electrode group to limit the electrode group. However, when the lithium battery is thermally runaway, high-temperature gas will be generated inside the battery. Since the temperature of the high-temperature gas is much higher than the melting point of the PP material, the lower plastic will completely melt in a high-temperature environment, thereby losing its limiting effect on the electrode group. At this time, the electrode group may be lifted up by the airflow to block the explosion-proof valve above, thereby affecting the exhaust effect of the explosion-proof valve. Summary of the invention

[0003] In view of this, the present invention provides a cover plate assembly, a battery cell and a battery pack to solve the problem that when thermal runaway occurs in the battery cell, the lower plastic will lose its limiting effect on the electrode group due to its own melting, thereby causing the electrode group to block the explosion-proof valve and affect the smoothness of the battery cell exhaust.

[0004] In a first aspect, the present invention provides a cover plate assembly, comprising:

[0005] The cover body is provided with an explosion-proof valve and a protrusion surrounding the explosion-proof valve;

[0006] A support plate is arranged opposite to the explosion-proof valve and connected to the protrusion; the support plate is provided with an air hole and an annular reinforcement rib surrounding the air hole, and the length and width directions of the annular reinforcement rib are consistent with the length and width directions of the support plate; the length and width of the support plate are L0 and W0 respectively; the length and width of the annular reinforcement rib are L1 and W1 respectively; the relationship between L0 and L1 satisfies: 0.85≤L1 / L0≤0.95, (L0-L1)≥5mm; the relationship between W0 and W1 satisfies: 0.85≤W1 / W0≤0.95, (W0-W1)≥4mm.

[0007] Beneficial effects: The present invention, by providing a support plate on the cover body that is arranged opposite to the explosion-proof valve, can limit the position of the pole group in the axial direction when thermal runaway occurs in the battery cell, thereby preventing it from moving arbitrarily with the high-temperature airflow and blocking the explosion-proof valve, thereby ensuring smooth exhaust of the exhaust channel. Secondly, by providing a protrusion between the support plate and the cover body, a channel suitable for airflow can be formed between the explosion-proof valve and the support plate, thereby preventing the support plate from affecting the smooth discharge of gas inside the battery cell. Furthermore, by providing annular reinforcement ribs on the periphery of the air vent, the overall strength of the support plate can be enhanced, and the probability of the support plate being significantly deformed by the impact of high-temperature gas in the case of thermal runaway can be reduced. Furthermore, by providing reinforcement ribs on the support plate according to the above parameters, not only the structural strength of the periphery of the air vent can be guaranteed, but also the overall weight and cost of the support plate can be prevented from excessively increasing.

[0008] In an optional embodiment, the support plate is also provided with a cross reinforcement rib which is offset from the air vent, and the cross reinforcement rib is located inside the annular reinforcement rib, and the rib height h of the cross reinforcement rib and the annular reinforcement rib is 0.2mm≤h≤1.0mm; the rib width w of the cross reinforcement rib and the annular reinforcement rib is 1.0mm≤w≤3.5mm.

[0009] Beneficial effects: The synergistic effect of the cross reinforcement ribs and the annular reinforcement ribs can more effectively disperse the load and improve the overall rigidity and strength of the cover support plate. At the same time, the reasonable rib height and rib width design (0.2mm≤h≤1.0mm, 1.0mm≤w≤3.5mm) can not only effectively improve the structural stability of the support plate in a limited space, but also will not increase unnecessary material costs or affect the layout of other components due to excessive size.

[0010] In an optional embodiment, the cross reinforcement rib includes a first reinforcement rib and a second reinforcement rib arranged vertically, and the annular reinforcement rib is symmetrical about the axis of the first reinforcement rib and the second reinforcement rib.

[0011] Beneficial effects: The vertically arranged cross ribs can effectively enhance the local rigidity of the support plate and improve the overall structure's ability to resist deformation. Secondly, the symmetrical layout of the annular ribs about the cross rib axis further optimizes the stress distribution, making the structure more evenly stressed and avoiding structural failure due to excessive impact force of high-temperature gas. In addition, this symmetrical design also reduces manufacturing difficulty and ensures product reliability and consistency.

[0012] In an optional embodiment, the first reinforcing rib extends along the width direction of the cover body and is connected to the annular reinforcing rib; the second reinforcing rib extends along the length direction of the cover body and is connected to the annular reinforcing rib.

[0013] Beneficial effects: The present invention connects the first reinforcing rib and the second reinforcing rib to the annular reinforcing rib, enabling the cross-shaped reinforcing rib and the annular reinforcing rib to form a stable frame structure, thereby further dispersing stress concentration and reducing the risk of deformation or damage caused by excessive local stress.

[0014] In an alternative embodiment, the distance between the first reinforcing rib and the outer edge in the length direction of the annular reinforcing rib is A, and A satisfies 10 mm ≤ A ≤ 30 mm; the distance between the second reinforcing rib and the outer edge in the width direction of the annular reinforcing rib is B, and B satisfies 5 mm ≤ B ≤ 15 mm.

[0015] Beneficial effects: By setting the first reinforcing rib and the second reinforcing rib according to the above parameters, it is possible to enhance the anti-deformation ability of the support plate in the length and width directions, and at the same time provide sufficient strength and stability to the area around the ventilation holes, ensuring that it will not be damaged due to external forces during use.

[0016] In an alternative embodiment, it further includes a plastic plate, and the plastic plate is provided with a mounting groove adapted to the shape of the support plate, and the support plate is installed between the plastic plate and the cover body by being inserted into the mounting groove.

[0017] Beneficial effects: Since the material of the plastic plate is a non-conductive material, by providing a plastic plate on the side of the support plate away from the cover body, the pole group in the battery cell can be separated from the cover body, avoiding short-circuit between the pole group and the cover body. Secondly, by providing a mounting groove on the plastic plate that is adapted to the shape of the support plate, it can not only avoid interference between the support plate and the plastic plate, but also reduce the overall thickness of the cover assembly, reducing the space occupied inside the battery cell housing. In addition, the mounting groove on the plastic plate enables the operator to determine the installation position of the support plate on the plastic plate in a short time, improving the assembly efficiency.

[0018] In an alternative embodiment, the bottom of the mounting groove is provided with a through-hole communicating with the ventilation hole.

[0019] Beneficial effects: Even when the battery cell does not undergo thermal runaway, a certain amount of gas will be generated inside the battery cell. To ensure the use safety of the battery cell, this part of the gas needs to be discharged to the external environment in a timely manner. Based on this, the present invention provides a through-hole communicating with the ventilation hole of the support plate at the bottom of the mounting groove, which can not only smoothly discharge the gas generated during the normal operation of the battery cell, but also smoothly discharge the gas generated during the thermal runaway of the battery cell, improving the use safety of the battery cell.

[0020] In an alternative embodiment, there are multiple ventilation holes and multiple air passing holes. Along the thickness direction of the cover plate assembly, at least part of the orthographic projections of the multiple ventilation holes and the multiple air passing holes towards the explosion-proof valve fall within the explosion-proof valve.

[0021] Advantages: First, the arrangement of multiple ventilation holes and air passing holes can significantly improve the gas flow efficiency and optimize the air permeability of the cover plate assembly. Second, by setting at least part of the orthographic projections of these holes within the range of the explosion-proof valve, it is ensured that when pressure relief is required, gas can quickly and smoothly discharge through the explosion-proof valve, thereby effectively enhancing the safety and reliability of the cover plate assembly.

[0022] Second, the present invention provides an electric core, including:

[0023] A housing provided with a cavity and an opening communicating with the cavity;

[0024] An electrode group disposed within the cavity;

[0025] The above-mentioned cover plate assembly, where the cover body covers and seals the opening, and the support plate abuts against the electrode group.

[0026] Advantages: Compared with the existing electric cores, the electric core equipped with the above-mentioned cover plate assembly can effectively solve the problem that the lower plastic cannot continuously play a limiting role on the electrode group when the electric core undergoes thermal runaway, resulting in the movement of the electrode group and blocking the explosion-proof valve, affecting the smooth exhaust of the electric core.

[0027] Third, the present invention provides a battery pack, including:

[0028] A protective housing;

[0029] The above-mentioned electric core, arranged in the protective housing in sequence along its thickness direction.

[0030] Advantages: Since the battery pack of the present invention is equipped with the above-mentioned electric core, it has all the advantages of the above-mentioned electric core and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is an exploded view of a cover plate assembly according to an embodiment of the present invention;

[0033] Figure 2 As Figure 1 shown, an exploded view of the cover plate assembly from another perspective;

[0034] Figure 3 A top view schematic diagram of a support plate according to an embodiment of the present invention;

[0035] Figure 4 A structural schematic diagram of an electric core according to an embodiment of the present invention.

[0036] Explanation of reference numerals:

[0037] 1. Cover body; 101. Explosion-proof valve; 102. Protrusion; 2. Support plate; 201. Vent hole; 202. Annular reinforcing rib; 203. Cross reinforcing rib; 2031. First reinforcing rib; 2032. Second reinforcing rib; 3. Plastic plate; 301. Installation groove; 3011. Air passing hole; 4. Housing; 401. Cavity; 402. Opening; 5. Electrode group; 6. Insulating film. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] Next, in conjunction with Figures 1 to 4 , embodiments of the present invention will be described.

[0040] According to an embodiment of the present invention, on the one hand, as Figures 1 to 3 shown, a cover plate assembly is provided, including: a cover body 1 and a support plate 2.

[0041] Specifically, the cover body 1 is provided with an explosion-proof valve 101 and a protrusion 102 surrounding the explosion-proof valve 101; the support plate 2 is disposed opposite to the explosion-proof valve 101 and connected to the protrusion 102; the support plate 2 is provided with a vent hole 201 and an annular reinforcing rib 202 surrounding the vent hole 201, and the length direction and width direction of the annular reinforcing rib 202 are both consistent with the length direction and width direction of the support plate 2; the length and width of the support plate 2 are L0 and W0 respectively; the length and width of the annular reinforcing rib 202 are L1 and W1 respectively; the relationship between L0 and L1 satisfies: 0.85 ≤ L1 / L0 ≤ 0.95, (L0 - L1) ≥ 5 mm; the relationship between W0 and W1 satisfies: 0.85 ≤ W1 / W0 ≤ 0.95, (W0 - W1) ≥ 4 mm.

[0042] In this embodiment, by providing a support plate 2 on the cover body 1 which is disposed opposite to the explosion-proof valve 101, the position of the electrode group 5 can be limited axially when the battery cell undergoes thermal runaway, preventing it from randomly moving with the high-temperature gas flow and blocking the explosion-proof valve 101, thus ensuring the smoothness of the exhaust passage for exhaust gas. Secondly, by providing a protrusion 102 between the support plate 2 and the cover body 1, a channel suitable for air flow can be formed between the explosion-proof valve 101 and the support plate 2, preventing the support plate 2 from affecting the smooth discharge of the gas inside the battery cell. Furthermore, by providing an annular reinforcing rib 202 on the periphery of the ventilation hole 201, the overall strength of the support plate 2 can be enhanced, reducing the probability of the support plate 2 undergoing significant deformation under the impact of high-temperature gas during thermal runaway. Further, by providing the reinforcing rib on the support plate 2 according to the above parameters, not only can the structural strength around the ventilation hole 201 be ensured, but also the overall weight and cost of the support plate 2 can be prevented from increasing excessively.

[0043] It can be understood that for simplifying the manufacturing process, the annular reinforcing rib 202 and the support plate 2 in this embodiment are integrally formed by a stamping process.

[0044] It should be noted that the material of the support plate 2 in this embodiment is a high-temperature resistant material. Exemplarily, the material of the support plate 2 is metal. At the same time, the support plate 2 is welded to the cover body 1.

[0045] According to an embodiment of the present invention, as Figure 3 shown, a cross-shaped reinforcing rib 203 which is misaligned with the ventilation hole 201 is further provided on the support plate 2. The cross-shaped reinforcing rib 203 is located inside the annular reinforcing rib 202. The rib height h of the cross-shaped reinforcing rib 203 and the annular reinforcing rib 202 is 0.2 mm ≤ h ≤ 1.0 mm; the rib width w of the cross-shaped reinforcing rib 203 and the annular reinforcing rib 202 is 1.0 mm ≤ w ≤ 3.5 mm. The synergistic effect of the cross-shaped reinforcing rib 203 and the annular reinforcing rib 202 can more effectively disperse the load, improving the overall stiffness and strength of the cover plate support plate 2. At the same time, the reasonable design of the rib height and rib width (0.2 mm ≤ h ≤ 1.0 mm, 1.0 mm ≤ w ≤ 3.5 mm) can not only effectively improve the structural stability of the support plate 2 in a limited space, but also not increase unnecessary material costs or affect the layout of other components due to excessive dimensions.

[0046] According to an embodiment of the present invention, as Figures 1 to 3As shown, the cross reinforcement rib 203 includes a first reinforcement rib 2031 and a second reinforcement rib 2032 arranged vertically, and the annular reinforcement rib 202 is symmetrical about the first reinforcement rib 2031 and the second reinforcement rib 2032. The vertically arranged cross reinforcement rib 203 can effectively enhance the local rigidity of the support plate 2 and improve the deformation resistance of the overall structure. Secondly, the symmetrical layout of the annular reinforcement rib 202 about the cross reinforcement rib 203 further optimizes the stress distribution, makes the structure more uniformly stressed, and avoids structural failure due to excessive impact force of high-temperature gas. In addition, this symmetrical design also reduces the manufacturing difficulty and ensures the reliability and consistency of the product.

[0047] According to one embodiment of the present invention, Figures 1 to 3 As shown, the first reinforcing rib 2031 extends along the width direction of the cover body 1 and is connected to the annular reinforcing rib 202; the second reinforcing rib 2032 extends along the length direction of the cover body 1 and is connected to the annular reinforcing rib 202. In this embodiment, the first reinforcing rib 2031 and the second reinforcing rib 2032 are connected to the annular reinforcing rib 202, so that the cross reinforcing rib 203 and the annular reinforcing rib 202 can form a stable frame structure, thereby further dispersing stress concentration and reducing the risk of deformation or damage caused by excessive local force.

[0048] According to one embodiment of the present invention, Figure 3 As shown, the distance between the first reinforcing rib 2031 and the outer edge of the annular reinforcing rib 202 in the length direction is A, and A satisfies 10mm≤A≤30mm; the distance between the second reinforcing rib 2032 and the outer edge of the annular reinforcing rib 202 in the width direction is B, and B satisfies 5mm≤B≤15mm. In this embodiment, by setting the first reinforcing rib 2031 and the second reinforcing rib 2032 according to the above parameters, the deformation resistance of the support plate 2 in the length and width directions can be enhanced, and sufficient strength and stability can be provided for the area around the air vent 201 to ensure that it will not be damaged by external forces during use.

[0049] According to one embodiment of the present invention, Figure 1 and Figure 2 As shown, a plastic plate 3 is also included. A mounting groove 301 matching the shape of the support plate 2 is provided on the plastic plate 3. The support plate 2 is installed between the plastic plate 3 and the cover body 1 by being inserted into the mounting groove 301 .

[0050] Since the material of the plastic plate 3 is a non-conductive material, by providing the plastic plate 3 on the side of the support plate 2 away from the cover body 1, the pole group 5 inside the battery cell can be separated from the cover body 1, avoiding a short circuit between the pole group 5 and the cover body 1. Secondly, by providing the installation groove 301 on the plastic plate 3 that is adapted to the shape of the support plate 2, not only can the interference between the support plate 2 and the plastic plate 3 be avoided, but also the overall thickness of the cover plate assembly can be reduced, reducing the space occupied inside the battery cell housing 4. In addition, the installation groove 301 on the plastic plate 3 enables the operator to determine the installation position of the support plate 2 on the plastic plate 3 in a short time, improving the assembly efficiency.

[0051] According to an embodiment of the present invention, as Figure 1 and Figure 2 shown, a through hole 3011 communicating with the ventilation hole 201 is provided at the bottom of the installation groove 301. Even when the battery cell does not undergo thermal runaway, a certain amount of gas is generated inside the battery cell. To ensure the use safety of the battery cell, this part of the gas needs to be discharged to the external environment in a timely manner. Based on this, in the embodiment of the present invention, by providing the through hole 3011 communicating with the ventilation hole 201 of the support plate 2 at the bottom of the installation groove 301, not only can the gas generated during the normal operation of the battery cell be smoothly discharged, but also the gas generated during the thermal runaway of the battery cell can be smoothly discharged, improving the use safety of the battery cell.

[0052] According to an embodiment of the present invention, as Figure 1 and Figure 2 shown, both the ventilation holes 201 and the through holes 3011 are multiple. Along the thickness direction of the cover plate assembly, at least part of the orthographic projections of the multiple ventilation holes 201 and the multiple through holes 3011 towards the explosion-proof valve 101 fall within the explosion-proof valve 101. First, the provision of the multiple ventilation holes 201 and through holes 3011 can significantly improve the gas flow efficiency and optimize the ventilation performance of the cover plate assembly. Secondly, by arranging at least part of the orthographic projections of these holes within the range of the explosion-proof valve 101, it is ensured that when pressure relief is required, the gas can be quickly and smoothly discharged through the explosion-proof valve 101, thereby effectively improving the safety and reliability of the cover plate assembly.

[0053] According to an embodiment of the present invention, on the other hand, as Figure 4 shown, a battery cell is also provided, including: a housing 4, a pole group 5, and the above-mentioned cover plate assembly.

[0054] Specifically, the housing 4 is provided with a cavity 401 and an opening 402 communicating with the cavity 401; the pole group 5 is disposed inside the cavity 401; the cover body 1 of the above-mentioned cover plate assembly covers and seals the opening 402, and the support plate 2 abuts against the pole group 5.

[0055] Compared with the existing battery cells, the battery cell equipped with the above cover plate assembly can effectively solve the problem that the lower plastic cannot continuously play a role in limiting the electrode group 5 when the battery cell undergoes thermal runaway, resulting in the movement of the electrode group 5 and blocking the explosion-proof valve 101, which affects the smooth exhaust of the battery cell.

[0056] It should be noted that, to prevent the electrode group 5 from coming into direct contact with the housing 4 and causing a short circuit, an insulating film 6 can be wrapped around the outside of the electrode group 5.

[0057] According to an embodiment of the present invention, on the other hand, a battery pack is also provided, including: a protective housing and the above battery cell. Specifically, the above battery cell is arranged in the protective housing in sequence along its thickness direction. Since the battery pack of the embodiment of the present invention is equipped with the above battery cell, it has all the advantages of the above battery cell, which will not be elaborated here.

[0058] Next, the technical effects of the technical solution of the present invention will be described in conjunction with specific embodiments and comparative examples.

[0059] Embodiment 1: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 35 mm, A is 27.5 mm, B is 11.5 mm;

[0060] Embodiment 2: L0 is 75 mm, W0 is 40 mm, L1 is 68 mm, W1 is 35 mm, A is 26.5 mm, B is 11.5 mm;

[0061] Embodiment 3: L0 is 75 mm, W0 is 40 mm, L1 is 65 mm, W1 is 35 mm, A is 25 mm, B is 11.5 mm;

[0062] Comparative Example 1: L0 is 75 mm, W0 is 40 mm, L1 is 71 mm, W1 is 36 mm, A is 28 mm, B is 12 mm;

[0063] Comparative Example 2: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 37 mm, A is 28 mm, B is 12.5 mm;

[0064] Comparative Example 3: L0 is 75 mm, W0 is 40 mm, L1 is 63 mm, W1 is 35 mm, A is 24 mm, B is 11.5 mm;

[0065] Comparative Example 4: L0 is 75 mm, W0 is 40 mm, L1 is 65 mm, W1 is 33 mm, A is 25 mm, B is 10.5 mm;

[0066] Comparative Example 5: L0 is 75 mm, W0 is 40 mm, L1 is 65 mm, W1 is 32 mm, A is 25 mm, B is 10 mm.

[0067] Table 1

[0068]

[0069]

[0070] It can be seen that the strength of the support plate 2 is directly related to the size and position of the annular reinforcing rib 202. When (L0 - L1) ≥ 5 mm and (W0 - W1) ≥ 4 mm are satisfied, the forming process requirements of the annular reinforcing rib 202 are met; when 85 ≤ L1 / L0 ≤ 95 and 85 ≤ W1 / W0 ≤ 95 are satisfied, the self-effect of the annular reinforcing rib 202 can be ensured, the overall strength of the support plate 2 can be significantly improved, and the passing rate of the cell safety test can be increased.

[0071] Example 4: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 35 mm, A is 30 mm, and B is 14 mm;

[0072] Example 5: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 35 mm, A is 29 mm, and B is 13 mm;

[0073] Example 6: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 35 mm, A is 28 mm, and B is 12 mm;

[0074] Comparative Example 6: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 36 mm, A is 33 mm, and B is 16.5 mm;

[0075] Comparative Example 7: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 36 mm, A is 32.5 mm, and B is 16 mm;

[0076] Comparative Example 8: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 36 mm, A is 32 mm, and B is 15.5 mm;

[0077] Comparative Example 9: L0 is 75 mm, W0 is 40 mm, L1 is 70 mm, W1 is 36 mm, A is 31 mm, and B is 15 mm.

[0078] Table 2

[0079]

[0080]

[0081] It can be seen that the strength of the support plate 2 is directly related to the spacing between the annular reinforcing rib 202 and the first reinforcing rib 2031 and the second reinforcing rib 2032. Only when 10mm ≤ A ≤ 30mm and 5mm ≤ B ≤ 15mm can the structural strength be ensured and the safety performance of the battery cell be improved.

[0082] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: The cover body is provided with an explosion-proof valve and a protrusion surrounding the explosion-proof valve; A support plate is arranged opposite to the explosion-proof valve and connected to the protrusion; the support plate is provided with an air hole and an annular reinforcing rib surrounding the air hole, and the length direction and width direction of the annular reinforcing rib are consistent with the length direction and width direction of the support plate; the length and width of the support plate are L0 and W0 respectively; the length and width of the annular reinforcing rib are L1 and W1 respectively; The relationship between L0 and L1 satisfies: 0.85≤L1 / L0≤0.95, (L0-L1)≥5mm; the relationship between W0 and W1 satisfies: 0.85≤W1 / W0≤0.95, (W0-W1)≥4mm.

2. The cover plate assembly according to claim 1, characterized in that: The support plate is also provided with a cross reinforcement rib staggered with the air vent, the cross reinforcement rib is located inside the annular reinforcement rib, the rib height h of the cross reinforcement rib and the annular reinforcement rib is 0.2mm≤h≤1.0mm; the rib width w of the cross reinforcement rib and the annular reinforcement rib is 1.0mm≤w≤3.5mm.

3. The cover plate assembly according to claim 2, characterized in that: The cross reinforcement ribs include a first reinforcement rib and a second reinforcement rib that are vertically arranged, and the annular reinforcement ribs are symmetrical about the first reinforcement rib and the second reinforcement rib.

4. The cover plate assembly according to claim 3, characterized in that: The first reinforcing rib extends along the width direction of the cover body and is connected to the annular reinforcing rib; the second reinforcing rib extends along the length direction of the cover body and is connected to the annular reinforcing rib.

5. The cover plate assembly according to claim 4, characterized in that: The distance between the first reinforcing rib and the outer edge of the annular reinforcing rib in the length direction is A, and A satisfies 10mm≤A≤30mm; the distance between the second reinforcing rib and the outer edge of the annular reinforcing rib in the width direction is B, and B satisfies 5mm≤B≤15mm.

6. The cover plate assembly according to any one of claims 1 to 5, characterized in that: It also includes a plastic plate, on which a mounting groove matching the shape of the support plate is provided, and the support plate is installed between the plastic plate and the cover body by being inserted into the mounting groove.

7. The cover plate assembly according to claim 6, characterized in that: The bottom of the installation groove is provided with an air hole connected with the air hole.

8. The cover plate assembly according to claim 7, characterized in that: There are multiple air holes and multiple air holes. Along the thickness direction of the cover plate assembly, at least part of the positive projections of the multiple air holes and multiple air holes toward the explosion-proof valve fall into the explosion-proof valve.

9. A battery cell, characterized in that: include: A shell having a cavity and an opening communicating with the cavity; A pole group is disposed in the cavity; The cover plate assembly according to any one of claims 1 to 8, wherein the cover body covers and seals the opening, and the support plate abuts against the pole group.

10. A battery pack, characterized in that: include: Protective housing; The battery cells described in claim 9 are arranged in sequence in the protective shell along the thickness direction thereof.

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