Battery cell cover plate and battery cell

Abstract

The present application relates to the technical field of batteries, and in particular to a battery cell cover plate and a battery cell. The battery cell cover plate comprises: a cover plate body provided with a mounting hole, the mounting hole being provided with a first mounting part and a second mounting part; a pressure relief member provided on the first mounting part; and a support member provided on the second mounting part, wherein the pressure relief member abuts against the support member, the support force provided by the support member to the pressure relief member is F, in units of N, the weight of the battery cell is G, in units of N, and G / F≤0.12. In the present application, the mounting hole on the cover plate body is divided into two parts, i.e., the first mounting part and the second mounting part. The first mounting part is used for mounting the pressure relief member, and the second mounting part is used for mounting the support member. By providing the support member, the structural strength of the area of the cover plate body where the pressure relief member is mounted can be effectively improved, and the pressure relief member abuts against the support member, so that the support member can also serve as a support platform for the pressure relief member, thereby ensuring that the pressure relief member is reliably and firmly mounted, and improving the safety of the battery cell.

Description

Battery cell cover plate and battery cell

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. CN202411230825.2, filed on September 4, 2024, entitled "Battery cell cover plate and battery cell", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery cell cover plate and a battery cell. BACKGROUND

[0004] With the increasing maturity of lithium ion battery technology, lithium ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the use performance and safety of lithium ion batteries are increasingly required.

[0005] The lithium battery cover plate is a key accessory in the lithium ion battery, which functions to be welded with the shell to form a sealed cavity, lead out the positive and negative poles of the pole group, and serve as an assembly carrier. The traditional cover plate includes a riveting block, an upper plastic, a pole, a top cover sheet, a lower plastic, a sealing ring, and a pressure relief valve, and the top cover sheet is provided with a sink structure for assembling the pressure relief valve, so that the top cover sheet is welded with the pressure relief valve. Because the installation space for the pressure relief valve needs to be reserved on the cover plate, especially for the cover plate of the blade battery or the square battery, the length-width ratio is large, which makes the area of the cover plate where the pressure relief valve is arranged relatively weak. When the battery is impacted or dropped, the cover plate is easily bent and deformed at the position where the pressure relief valve is arranged, which causes the pressure relief valve to crack, thereby increasing the safety risks such as battery liquid leakage and fire.

[0006] SUMMARY

[0007] Therefore, the purpose of the present application is to provide a battery cell cover plate and a battery cell to solve the problem that the area of the existing cover plate where the pressure relief valve is installed is structurally weak, the cover plate is easily bent and deformed at the position where the pressure relief valve is arranged when the battery cell is impacted, which causes the pressure relief valve to crack, thereby increasing the safety risks such as battery liquid leakage and fire.

[0008] The first purpose of the present application is to provide a battery cell cover plate, comprising:

[0009] A cover plate body is provided with a mounting hole, and the mounting hole is formed with a first mounting part and a second mounting part;

[0010] A pressure relief part is arranged in the first mounting part;

[0011] A support part is arranged in the second mounting part, and the pressure relief part abuts against the support part; the support force provided by the support part for the pressure relief part is F, the weight of the battery cell is G, and G / F≤0.12.

[0012] Beneficial effects: The installation hole is arranged on the cover plate body, the installation hole is divided into two parts of the first installation part and the second installation part, the first installation part is used for installing the pressure relief piece, and the second installation part is used for installing the support piece. The support piece can effectively improve the structural strength of the area of the cover plate body for installing the pressure relief piece. The pressure relief piece abuts against the support piece, so that the support piece can also serve as a support platform of the pressure relief piece. In addition, by limiting the ratio between the support force F provided by the support piece for the pressure relief piece and the weight G of the battery cell as G / F≤0.12, the support of the support piece on the pressure relief piece is further ensured to be reliable, so that the installation of the pressure relief piece is reliable and firm, and the safety of the battery cell is improved.

[0013] In an optional embodiment, the support piece is connected with the second installation part in interference fit, and the interference amount between the support piece and the second installation part is 0.03mm to 0.08mm.

[0014] In an optional embodiment, the pressure relief piece is connected with the first installation part in welding, and the pressure relief piece and the first installation part are connected in clearance fit before welding. The fitting clearance between the pressure relief piece and the first installation part is 0.04mm to 0.1mm.

[0015] In an optional embodiment, a boss part protruding towards the support piece is formed on the side of the pressure relief piece, and the width dimension of the boss part in the second direction is n.

[0016] The pressure relief piece is formed with a recessed notch part, and the distance between the notch part and the edge of the pressure relief piece in the second direction is k.

[0017] In an optional embodiment, the support piece is formed in an annular structure, the distance between the inner ring and the outer ring of the support piece is s, and n

[0018] In an optional embodiment, the mechanical structural strength of the support piece is greater than the mechanical structural strength of the cover plate body.

[0019] In an optional embodiment, the thickness dimension of the cover plate body in the first direction is M, the thickness dimension of the support piece in the first direction is t, and the maximum thickness dimension of the pressure relief piece in the first direction is m, and M=t+m.

[0020] In an optional embodiment, along the axial direction of the installation hole, the first installation part is arranged on the side of the cover plate body facing the inside of the battery cell, and the second installation part is arranged on the side of the cover plate body facing the outside of the battery cell.

[0021] In an optional embodiment, the battery cell cover further comprises:

[0022] A protection member is arranged on the side of the support member away from the pressure relief member.

[0023] A second object of the present application is to provide an electric core comprising the electric core cover plate according to any one of the preceding technical solutions. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0025] Fig. 1 is an exploded view of the structure of the electric core cover plate provided by the embodiments of the present application;

[0026] Fig. 2 is a structural schematic view of the electric core cover plate provided by the embodiments of the present application;

[0027] Fig. 3 is a sectional view along A-A in Fig. 2;

[0028] Fig. 4 is an enlarged structural schematic view of P in Fig. 3;

[0029] Fig. 5 is a structural schematic view of the support member in the electric core cover plate provided by the embodiments of the present application;

[0030] Fig. 6 is a structural schematic view of the support member in the electric core cover plate provided by the embodiments of the present application under another application;

[0031] Fig. 7 is a sectional view along B-B in Fig. 6;

[0032] Fig. 8 is a structural schematic view of the cover plate main body in the electric core cover plate provided by the embodiments of the present application;

[0033] Fig. 9 is a structural schematic view of the pressure relief member in the electric core cover plate provided by the embodiments of the present application;

[0034] Fig. 10 is a sectional view along C-C in Fig. 9.

[0035] Legend of reference signs: 10-cover plate main body; 11-mounting hole; 111-first mounting part; 112-second mounting part; 20-pressure relief member; 21- boss part; 22-scored part; 30-support member; 40-protection member; 50-pole; 60-sealing member; 71-first insulation member; 72-second insulation member; 80-riveting member; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0036] In order to make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] According to a first aspect of the present application, an electric cell cover plate is provided, which specifically comprises a cover plate body 10, a pressure relief member 20, and a support member 30.

[0038] In the following, the specific structure of the electric cell cover plate according to the present embodiment will be described.

[0039] In the present embodiment, as shown in FIGS. 1-3, the cover plate body 10 is formed in a plate structure, the cover plate body 10 can be made of aluminum material, the cover plate body 10 can be formed in a rectangular or circular shape, and a mounting hole 11 is formed on the cover plate body 10, which is formed in a through hole structure penetrating through the cover plate body 10 in a first direction D1.

[0040] Specifically, as shown in FIGS. 4 and 8, the mounting hole 11 is formed with a first mounting portion 111 and a second mounting portion 112, the first mounting portion 111 and the second mounting portion 112 are arranged along the axis of the mounting hole 11, the pressure relief member 20 is arranged on the first mounting portion 111, and the support member 30 is arranged on the second mounting portion 112. The support member 30 can play a role of a support strengthening structure for the cover plate body 10, so as to effectively improve the structural strength of the region of the cover plate body 10 where the pressure relief member 20 is mounted. The pressure relief member 20 abuts against the support member 30, so that the support member 30 can also serve as a support platform for the pressure relief member 20, ensuring reliable and firm installation of the pressure relief member 20 and improving the safety of the electric cell.

[0041] Preferably, in the present embodiment, as shown in FIGS. 3 and 4, along the axial direction of the mounting hole 11, the first mounting portion 111 is arranged on the side of the cover plate body 10 facing the inside of the electric cell, and the second mounting portion 112 is arranged on the side of the cover plate body 10 facing the outside of the electric cell. In this way, the support member 30 is mounted on the side of the cover plate body 10 facing the outside of the electric cell, and the pressure relief member 20 is mounted on the side of the cover plate body 10 facing the inside of the electric cell, thereby forming protection for the pressure relief member 20.

[0042] Further, in the present embodiment, the support member 30 is connected to the second mounting portion 112 in an interference fit, so as to ensure that the support member 30 can effectively improve the structural strength of the region of the cover plate body 10 where the pressure relief member 20 is mounted. Preferably, the interference amount between the support member 30 and the second mounting portion 112 is 0.03-0.08 mm, so as to ensure the connection strength between the support member 30 and the cover plate body 10 and reduce the assembly difficulty.

[0043] Preferably, the mechanical structural strength of the support 30 is greater than that of the cover plate body 10. The mechanical structural strength refers to the maximum load per unit area that a material can withstand when subjected to external force, including bending strength, tensile strength, compressive strength and impact strength. The material of the support 30 can be alloy steel, carbon steel or other materials with higher mechanical properties than the cover plate body 10. In an optional embodiment, the material of the support 30 is 45 steel, and the material of the cover plate body 10 is aluminum, so that the mechanical structural strength of the support 30 is much greater than that of the cover plate body 10.

[0044] Preferably, the support force provided by the support 30 is F, F = P x S, where P is the yield strength of the material of the support 30, and S is the cross-sectional area of the support 30 in the direction perpendicular to the axis, that is, the cross-sectional area of the support 30. The weight of the battery cell is G, and G / F ≤ 0.12, so that the support 30 can effectively and reliably support the pressure relief member 20.

[0045] Further, in the present embodiment, as shown in FIGS. 3 and 4, the pressure relief member 20 is welded to the first mounting portion 111, and the pressure relief member 20 and the first mounting portion 111 are in clearance fit before welding, so that the welding strength between the pressure relief member 20 and the cover plate body 10 is reliable. Preferably, the fitting clearance between the pressure relief member 20 and the first mounting portion 111 is 0.04 mm to 0.1 mm.

[0046] In the present embodiment, as shown in FIGS. 4, 9 and 10, the pressure relief member 20 is formed in a sheet structure, and the side portion of the pressure relief member 20 is formed with a boss portion 21 protruding towards the support 30. The boss portion 21 can be formed in a ring structure, so as to increase the size of the welding area of the pressure relief member 20 and the first mounting portion 111 in the first direction D1, so as to ensure the welding strength between the pressure relief member 20 and the first mounting portion 111. The boss portion 21 abuts against the support 30, and the width dimension of the boss portion 21 in the second direction D2 is n, in mm, so that the support 30 can effectively support the pressure relief member 20. A recessed score portion 22 is formed on the surface of the side of the pressure relief member 20 facing the outside of the battery cell. The score portion 22 can be formed in a ring structure with an opening, so that when the pressure relief member 20 is opened, the area inside the ring structure is only in an opened state and will not completely fall off, so as to avoid the short circuit caused by metal lapping. The score portion 22 thins the thickness of the local position of the pressure relief member 20 in the first direction D1. When the battery cell fails and gas is generated inside, the gas pressure in the battery cell causes the pressure relief member 20 to crack along the shape of the score portion 22, so as to break the pressure relief member 20. The distance between the score portion 22 and the edge of the pressure relief member 20 in the second direction D2 is k, in mm, and n < k.

[0047] In the embodiment, as shown in FIGS. 5-7, the support 30 is formed into a ring structure, so that the gas in the battery cell can be discharged from the ring of the support 30 when the pressure relief member 20 is opened. Preferably, the support 30 is formed into a ring structure with equal distance between the inner ring and the outer ring, i.e., the entire width of the support 30 is equal, and the distance between the inner ring and the outer ring of the support 30 is s, in mm, n < s < k, so that in the second direction D2, the inner ring of the support 30 protrudes from the inner wall of the boss portion 21, so that the support 30 can effectively and reliably support the cover body 10 and the pressure relief member 20.

[0048] In the preferred embodiment, as shown in FIGS. 7, 8 and 10, the thickness of the cover body 10 in the first direction D1 is M, in mm, the thickness of the support 30 in the first direction D1 is t, in mm, and the maximum thickness of the pressure relief member 20 in the first direction D1 is m (i.e., the thickness of the boss portion 21 in the first direction D1 is m, as described above), in mm, M = t + m, so that the support 30 can fill the mounting hole 11 except the position where the pressure relief member 20 is arranged, so that the support 30 can reliably support the cover body 10, effectively improve the mechanical structural strength of the area of the cover body 10 where the pressure relief member 20 is arranged, and avoid the area of the cover body 10 where the pressure relief member 20 is arranged from being bent and deformed under impact, causing the pressure relief member 20 to crack, thereby reducing the risk of battery leakage, fire, and the like.

[0049] In the embodiment, the first direction D1 is perpendicular to the second direction D2, and the first direction D1 can be the thickness direction of the battery cover plate. When the cover body 10 is formed into a rectangular structure, the second direction D2 can be the length direction of the cover body 10.

[0050] In the embodiment, as shown in FIGS. 1-4, the battery cover plate further comprises a protection member 40, which can be formed into a sheet structure. The protection member 40 is arranged on the side of the support 30 away from the pressure relief member 20, so as to avoid the components outside the battery from damaging the pressure relief member 20, causing the pressure relief member 20 to open prematurely. Preferably, the protection member 40 has an opening between the support 30, so that the gas in the battery cell can be discharged in time when the pressure relief member 20 is opened.

[0051] In addition, in the embodiment, as shown in FIGS. 1-3, the battery cover plate further comprises a pole 50, a sealing member 60, a first insulating member 71, a second insulating member 72, and a riveting member 80, wherein the pole 50 passes through the through hole on the cover body 10 and is connected to the tab on the pole group inside the battery cell.

[0052] The first insulating member 71 and the second insulating member 72 can both be made of plastic material to play the role of insulation protection, wherein the first insulating member 71 is arranged around the circumferential sidewall of the pole 50 and is arranged on the side of the cover plate body 10 facing the outside of the battery cell, and the second insulating member 72 is arranged on the side of the cover plate body 10 facing the inside of the battery cell to separate the cover plate body 10 and the pole 50, so as to avoid short circuit.

[0053] The riveting member 80 is riveted to the pole 50, so as to realize the positioning of the pole 50 and the cover plate body 10. Part of the first insulating member 71 is arranged around part of the circumferential sidewall of the riveting member 80, so as to also play the role of insulation protection for the riveting member 80. The riveting member 80 can be formed as a block structure with a stepped hole.

[0054] The sealing member 60 is embedded between the first insulating member 71 and the bottom plate of the pole 50 in the first direction D1, and is embedded between the cover plate body 10 and the sidewall of the pole 50 in the second direction D2, so as to ensure the assembly sealing of the pole 50 and the cover plate body 10, avoid liquid leakage of the battery cell, and ensure the safety of the battery cell. The sealing member 60 can be a sealing ring with elasticity.

[0055] Next, the battery cell drop test is conducted on battery cell covers of different sizes to verify whether the support member 30 can reliably support the pressure relief member 20. The material of the cover plate body 10 is aluminum, and the specific test is shown in the following table.

[0056] Test one: the weight G of the battery cell is 60N, the thickness dimension t of the support member 30 in the first direction is 1.5mm, the thickness dimension M of the cover plate body 10 in the first direction D1 is 2mm, the distance k between the notch part 22 and the edge of the pressure relief member 20 in the second direction D2 is 1.3mm, the material of the support member 30 is 45# steel, the yield strength P of which is 355Mpa, the cross-sectional area S of the support member 30 is changed by adjusting the distance s between the inner ring and the outer ring of the support member 30 to conduct multiple tests, and the support force F is P×S. The test results are shown in Table 1.

[0057] Table 1

[0058] Test two: the weight G of the battery cell is 95N, the thickness dimension t of the support member 30 in the first direction is 2mm, the thickness dimension M of the cover plate body 10 in the first direction D1 is 2.5mm, the distance k between the notch part 22 and the edge of the pressure relief member 20 in the second direction D2 is 1.5mm, the material of the support member 30 is 45# steel, the yield strength P of which is 355Mpa, the cross-sectional area S of the support member is changed by adjusting the distance s between the inner ring and the outer ring of the support member 30 to conduct multiple tests, and the support force F is P×S. The test results are shown in Table 2.

[0059] Table 2

[0060] Test three: the weight of the battery cell G = 80 N, the thickness dimension t of the support 30 in the first direction is 2 mm, the thickness dimension M of the cover plate body 10 in the first direction D1 is 2.5 mm, the distance k between the notched part 22 and the edge of the pressure relief part 20 in the second direction D2 is 2 mm, the material of the support 30 is Q235 steel, the yield strength P of which is 235 MP, the cross-sectional area S of the support is changed by adjusting the distance s between the inner ring and the outer ring of the support 30 to conduct multiple tests, the support force F = P x S, and the test results are shown in Table 3.

[0061] Table 3

[0062] As can be seen from the above Tables 1 to 3, in the embodiments 1-3 to 1-10, the embodiments 2-3 to 2-10 and the embodiments 3-3 to 3-10, the pressure relief part 20 is normal in the drop test, which is mainly because the support 30 can provide sufficient support to the pressure relief part 20. According to the tests one to three, when the weight G of the battery cell and the support force provided by the support 30 to the pressure relief part 20 satisfy G / F≤0.12, the problem that the pressure relief part 20 is deformed or even cracked under the impact of the battery cell can be avoided, thereby ensuring the safety of the battery cell.

[0063] According to the battery cell cover provided in the present application, the mounting hole is divided into two parts, i.e., the first mounting part and the second mounting part, the first mounting part is used for mounting the pressure relief part, and the second mounting part is used for mounting the support. The support can effectively improve the structural strength of the region of the cover plate body where the pressure relief part is mounted. The pressure relief part and the support are in abutment, so that the support can also serve as a support platform for the pressure relief part. In addition, by limiting the ratio between the support force F provided by the support to the pressure relief part and the weight G of the battery cell to be G / F≤0.12, the support of the pressure relief part by the support is further ensured to be reliable, thereby ensuring the reliable and firm installation of the pressure relief part and improving the safety of the battery cell.

[0064] According to the battery cell provided in the present application, the battery cell cover is as described above. The structural strength of the battery cell cover is effectively improved under the action of the support, so that the cracking of the pressure relief part under the impact of external force is avoided, and the safety of the battery cell is ensured.

[0065] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims. Industrial applicability

[0066] The electric cell cover plate of the present application, the mounting hole is set on the cover plate body, the mounting hole is divided into two parts of the first mounting part and the second mounting part, the first mounting part is used for mounting the pressure relief part, and the second mounting part is used for mounting the supporting part. The supporting part can effectively improve the structural strength of the area of the cover plate body mounting the pressure relief part. The pressure relief part abuts against the supporting part, so that the supporting part can also serve as a supporting platform for the pressure relief part. In addition, by limiting the ratio between the supporting force F provided by the supporting part for the pressure relief part and the weight G of the electric cell to be G / F≤0.12, the supporting of the supporting part on the pressure relief part is further ensured to be reliable, so as to ensure the reliable and firm installation of the pressure relief part and improve the safety of the electric cell.

Claims

1. An electrode cover plate, characterized by, The battery cell cover plate comprises: a cover plate body provided with a mounting hole, the mounting hole being formed with a first mounting portion and a second mounting portion; a pressure relief member arranged at the first mounting portion; a support member arranged at the second mounting portion, the pressure relief member abutting against the support member; the support force provided by the support member for the pressure relief member is F, in N, the weight of the battery cell is G, in N, and G / F≤0.

12.

2. The cell cover plate of claim 1, wherein, The support member is connected to the second mounting portion in interference fit, and the interference amount between the support member and the second mounting portion is 0.03mm to 0.08mm.

3. The cell cover plate of claim 1, wherein, The pressure relief member is connected to the first mounting portion in welding, and the pressure relief member and the first mounting portion are connected in clearance fit before welding, and the fitting clearance between the pressure relief member and the first mounting portion is 0.04mm to 0.1mm.

4. The cell cover plate of claim 1, wherein, The side portion of the pressure relief member is formed with a boss portion protruding towards the support member, and the width dimension of the boss portion in the second direction is n. The pressure relief member is formed with a recessed notch portion, and the distance between the notch portion and the edge of the pressure relief member in the second direction is k.

5. The cell cover plate of claim 4, wherein, The support member is formed in an annular structure, and the distance between the inner ring and the outer ring of the support member is s, and n 6. The cell cover plate of claim 1, wherein, The mechanical structural strength of the support member is greater than that of the cover plate body.

7. The cell cover plate of claim 1, wherein, The thickness dimension of the cover plate body in the first direction is M, the thickness dimension of the support member in the first direction is t, and the maximum thickness dimension of the pressure relief member in the first direction is m, and M=t+m.

8. The cell cover plate of claim 1, wherein, In the axial direction of the mounting hole, the first mounting portion is arranged on the side of the cover plate body facing the inside of the battery cell, and the second mounting portion is arranged on the side of the cover plate body facing the outside of the battery cell.

9. The cell cover plate of claim 1, wherein, The battery cell cover plate further comprises: a protection member arranged on the side of the support member away from the pressure relief member.

10. An electric cell characterized by The battery cell cover plate comprises the battery cell cover plate according to any one of claims 1 to 9.

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