Battery cell

Abstract

Disclosed in the present application is a battery cell, comprising a cover plate, a sealing member, an explosion-proof valve, and a crimping member. The cover plate is provided with an explosion-proof hole and a limiting groove in communication with the explosion-proof hole. The sealing member is disposed in the limiting groove. The explosion-proof valve is disposed in the limiting groove and located on the side of the sealing member away from the cover plate in the direction of thickness, and covers the explosion-proof hole. The crimping member is disposed in the limiting groove and connected to the cover plate, the explosion-proof valve and the sealing member are clamped between the crimping member and the cover plate, and the sealing member is compressed between the cover plate and the explosion-proof valve, so that the explosion-proof valve is sealingly connected to the cover plate by means of the sealing member. The present application meets, by means of controlling the compression amount of the sealing member, the requirement for sealing the cover plate, and solves the safety problem of battery cell leakage caused by nicks, deformation and cracking of the explosion-proof valve resulting from welding.

Description

A single battery

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. CN202410804483.4, filed on June 21, 2024, entitled "A single battery", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application belongs to the technical field of battery, in particular relates to a single battery. 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. The cover plate is welded with the shell to form a sealed cavity, the positive and negative electrodes of the lead-out pole group are led out, and the cover plate serves as an assembly carrier. When the explosion-proof valve and the cover plate are welded, thermal expansion and contraction occurs, which easily causes the explosion-proof valve to stretch and deform, the notch to thin, the valve opening pressure to decrease, and even the explosion-proof valve to crack. In addition, defects such as welding flash exist when the explosion-proof valve and the cover plate are welded, which easily causes the cover plate to leak, resulting in a high single battery failure rate.

[0005] SUMMARY

[0006] Therefore, the purpose of the present application is to provide a single battery, which aims to solve the technical problem that the welding of the explosion-proof valve and the cover plate easily causes the explosion-proof valve to stretch and deform, resulting in a high single battery failure rate.

[0007] The single battery provided by the present application comprises:

[0008] The cover plate is provided with an explosion-proof hole and a limiting groove communicating with the explosion-proof hole;

[0009] The sealing element is arranged in the limiting groove;

[0010] The explosion-proof valve is arranged in the limiting groove and located on the side of the sealing element away from the cover plate in the thickness direction, and covers the explosion-proof hole;

[0011] The pressure connecting element is arranged in the limiting groove and connected with the cover plate, the explosion-proof valve and the sealing element are clamped between the pressure connecting element and the cover plate, and the sealing element is compressed between the cover plate and the explosion-proof valve, so that the explosion-proof valve is sealed and connected with the cover plate through the sealing element;

[0012] The maximum size of the sealing element in the thickness direction in the uncompressed state is d, the maximum size of the explosion-proof valve in the thickness direction is t, and the maximum size of the pressure connecting element arranged in the limiting groove in the thickness direction is m, which satisfies: 0.25≤(d+t-m) / d≤0.45.

[0013] Beneficial effects: the application adopts a crimping piece to limit the position of the explosion-proof valve and the sealing piece, by controlling the maximum size m of the crimping piece arranged in the limiting groove in the thickness direction, the compression amount of the sealing piece can be controlled between 25% and 45%, so as to meet the requirements of the sealing cover plate, and the application optimizes the assembly mode of the explosion-proof valve, solves the safety problem that the welding causes the explosion-proof valve to be cracked and deformed due to the notch, and causes the single battery to leak.

[0014] In an optional embodiment, the crimping piece comprises a body and a plurality of limiting bosses connected with the body, the explosion-proof valve and the sealing piece are clamped between the body and the cover plate, the plurality of limiting bosses are located on the side of the body facing the cover plate, and the limiting bosses are in interference fit with the limiting grooves.

[0015] In an optional embodiment, the limiting grooves comprise a first limiting groove and a plurality of second limiting grooves in communication with the first limiting groove, the plurality of limiting grooves are arranged on the outer periphery of the first limiting groove, the explosion-proof valve and the sealing piece are arranged in the first limiting groove, each limiting boss is arranged in a second limiting groove in correspondence, and the limiting boss is in interference fit with the second limiting groove.

[0016] In an optional embodiment, the maximum size of the cover plate in the thickness direction is M, and the single battery satisfies 0.4≤m / M≤0.7.

[0017] In an optional embodiment, the explosion-proof valve comprises a bearing part and a weak part connected with each other, the bearing part is arranged around the weak part, the bearing part is located between the sealing piece and the crimping piece and connected with the sealing piece and the crimping piece respectively, and the weak part is configured to be damaged when subjected to a preset pressure impact.

[0018] In an optional embodiment, along the length direction of the limiting boss, the limiting boss is in interference fit with the second limiting groove.

[0019] In an optional embodiment, the maximum size of the second limiting groove in the length direction is E, the maximum size of the limiting boss in the length direction in the uncompressed state is e, and 0.015mm≤e-E≤0.03mm is satisfied.

[0020] In an optional embodiment, along the width direction of the limiting boss, the limiting boss is in clearance fit with the second limiting groove.

[0021] In an optional embodiment, the maximum size of the second limiting groove in the width direction is A, the maximum size of the limiting boss in the width direction in the uncompressed state is a, and 0mm<a-A≤0.1mm is satisfied.

[0022] In an optional embodiment, the maximum size d of the sealing piece in the thickness direction in the uncompressed state satisfies 0.6mm≤d≤1mm.

[0023] In an alternative embodiment, the maximum dimension t of the explosion-proof valve in the thickness direction satisfies: 0.5mm≤t≤0.8mm.

[0024] In an alternative embodiment, the maximum dimension m of the crimping piece arranged in the limiting groove in the thickness direction satisfies: 0.8mm≤m≤1.4mm. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the description of the specific embodiments or prior art will be briefly introduced below. 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.

[0026] FIG. 1 is a structural schematic view of a cover plate assembly according to an embodiment of the present application;

[0027] FIG. 2 is a structural schematic view of a cover plate according to an embodiment of the present application;

[0028] FIG. 3 is a bottom view of a cover plate according to an embodiment of the present application;

[0029] FIG. 4 is a top view of a cover plate according to an embodiment of the present application;

[0030] FIG. 5 is a sectional view of a cover plate assembly according to an embodiment of the present application;

[0031] FIG. 6 is a sectional view of a sealing piece according to an embodiment of the present application;

[0032] FIG. 7 is a structural schematic view of a crimping piece according to an embodiment of the present application;

[0033] FIG. 8 is a front view of a crimping piece according to an embodiment of the present application;

[0034] FIG. 9 is a top view of a crimping piece according to an embodiment of the present application.

[0035] Legend: 1-cover plate; 2-sealing piece; 3-explosion-proof valve; 4-crimping piece; 5-first insulating piece; 6-second insulating piece; 7-pole; 8-pole sealing ring; 9-riveting piece; 10-explosion-proof hole; 11-limiting groove; 12-first surface; 13-second surface; 14-pole hole; 30-bearing part; 31-weak part; 40-body; 41-limiting boss; 70-pole body; 71-flange; 100-cover plate assembly; 110-first limiting groove; 111-second limiting groove; X-thickness direction; Y-length direction; Z-width 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] 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. The cover plate is welded with the shell to form a sealed cavity, leads the positive and negative poles of the pole group, and serves as an assembly carrier. When the explosion-proof valve and the cover plate are welded, thermal expansion and cold shrinkage easily cause the explosion-proof valve to stretch and deform, the notch to thin, the opening valve pressure to decrease, and even the explosion-proof valve to crack. In addition, defects such as welding flash exist when the explosion-proof valve and the cover plate are welded, which easily causes the cover plate to leak, resulting in a high single battery failure rate.

[0038] Therefore, the single battery in the embodiments of the present application includes a cover plate, a sealing element, an explosion-proof valve, and a crimping element. The cover plate is provided with an explosion-proof hole and a limiting groove communicating with the explosion-proof hole. The sealing element is arranged in the limiting groove. The explosion-proof valve is arranged in the limiting groove and located on the side of the sealing element away from the cover plate in the thickness direction, and covers the explosion-proof hole. The crimping element is arranged in the limiting groove and connected with the cover plate. The explosion-proof valve and the sealing element are clamped between the crimping element and the cover plate, and the sealing element is compressed between the cover plate and the explosion-proof valve to seal and connect the explosion-proof valve and the cover plate through the sealing element. The maximum size of the sealing element in the thickness direction in the uncompressed state is d, the maximum size of the explosion-proof valve in the thickness direction is t, and the maximum size of the crimping element arranged in the limiting groove in the thickness direction is m, which satisfies 0.25≤(d+t-m) / d≤0.45. The crimping element is used to limit the explosion-proof valve and the sealing element in the embodiments of the present application. By controlling the maximum size m of the crimping element arranged in the limiting groove in the thickness direction, the compression amount of the sealing element can be controlled to be between 25% and 45%, so as to meet the sealing requirement of the cover plate. The assembly mode of the explosion-proof valve is optimized in the present application to solve the safety problem of the explosion-proof valve notch deformation and cracking caused by welding, and the leakage of the single battery.

[0039] The single battery of the present application will be described in detail below with reference to the drawings. The features in the following embodiments and implementation manners can be combined with each other without conflict.

[0040] Fig. 1 is a structural schematic diagram of a cover plate assembly 100 according to an embodiment of the present application; Fig. 2 is a structural schematic diagram of a cover plate 1 according to an embodiment of the present application; Fig. 3 is a bottom view of the cover plate 1 according to an embodiment of the present application; Fig. 4 is a top view of the cover plate 1 according to an embodiment of the present application; Fig. 5 is a sectional view of the cover plate assembly 100 according to an embodiment of the present application; Fig. 6 is a sectional view of a sealing member 2 according to an embodiment of the present application; Fig. 7 is a structural schematic diagram of a crimping member 4 according to an embodiment of the present application; Fig. 8 is a front view of the crimping member 4 according to an embodiment of the present application; Fig. 9 is a top view of the crimping member 4 according to an embodiment of the present application.

[0041] In the embodiment shown in Figs. 1-9, the battery cell comprises a cover plate assembly 100, which comprises a cover plate 1, a first insulating member 5, a second insulating member 6, a pole 7, and a pole sealing ring 8. The cover plate 1 comprises a first face 12 and a second face 13 oppositely arranged along a thickness direction X, the first insulating member 5 is connected to the first face 12, and the second insulating member 6 is connected to the second face 13. A riveting member 9 is arranged on a side of the first insulating member 5 away from the cover plate 1. The cover plate 1 has a pole hole 14 extending through the cover plate 1 along the thickness direction X. The pole 7 comprises a pole body 70 and a flange 71 connected to each other, the flange 71 is arranged in the pole hole 14 and connected to the cover plate 1, the pole body 70 is arranged on a side of the second insulating member 6 away from the cover plate 1, and the pole sealing ring 8 is sleeved on the flange 71 and clamped between the second insulating member 6 and the pole body 70.

[0042] Referring to FIGS. 1-9, the embodiments of the present application provide a single battery including a cover plate 1, a sealing member 2, an explosion-proof valve 3, and a pressure contact member 4. The cover plate 1 is provided with an explosion-proof hole 10 and a limiting groove 11 communicating with the explosion-proof hole 10. The sealing member 2 is arranged in the limiting groove 11. The explosion-proof valve 3 is arranged in the limiting groove 11 and located on the side of the sealing member 2 away from the cover plate 1 in the thickness direction X, and covers the explosion-proof hole 10. The pressure contact member 4 is arranged in the limiting groove 11 and connected with the cover plate 1. The explosion-proof valve 3 and the sealing member 2 are clamped between the pressure contact member 4 and the cover plate 1. The sealing member 2 is compressed between the cover plate 1 and the explosion-proof valve 3, so that the explosion-proof valve 3 is sealingly connected with the cover plate 1 through the sealing member 2. The maximum size of the sealing member 2 in the thickness direction X in the uncompressed state is d, the maximum size of the explosion-proof valve 3 in the thickness direction X is t, and the maximum size of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X is m, which satisfies: 0.25≤(d+t-m) / d≤0.45. The pressure contact member 4 is used to limit the explosion-proof valve 3 and the sealing member 2 in the embodiments of the present application. By controlling the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X, the compression amount of the sealing member 2 can be controlled to be between 25% and 45%, so as to meet the requirement of sealing the cover plate 1. In this way, the sealing effect can be avoided due to the small compression amount, and the risk of damage to the sealing member 2 and the accelerated aging of the sealing member 2 due to the large compression amount can be avoided, thereby avoiding the safety problem of single battery leakage. The assembly mode of the explosion-proof valve 3 is optimized in the embodiments of the present application, so as to solve the safety problem of single battery leakage caused by the indentation deformation and cracking of the explosion-proof valve 3 due to welding.

[0043] In the embodiments shown in FIGS. 1, 5, 7-9, the pressure contact member 4 includes a body 40 and a plurality of limiting bosses 41 connected with the body 40. The explosion-proof valve 3 and the sealing member 2 are clamped between the body 40 and the cover plate 1. The plurality of limiting bosses 41 are located on the side of the body 40 facing the cover plate 1 and are in interference fit with the limiting groove 11. The body 40 has a ring structure, and the plurality of limiting bosses 41 are arranged at intervals on the side of the body 40 facing the cover plate 1. The limiting bosses 41 are embedded in the limiting groove 11 to connect the pressure contact member 4 and the cover plate 1, and limit the sealing member 2 and the explosion-proof valve 3 between the body 40 and the cover plate 1, so that the sealing member 2 is compressed and deformed in the thickness direction X, thereby meeting the requirement of compressing the sealing member 2 to seal the cover plate 1. In the embodiments of the present application, the maximum size of the limiting boss 41 in the thickness direction X is the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X, and the maximum size of the limiting boss 41 in the thickness direction X is the same as the maximum size of the limiting groove 11 in the thickness direction X. By limiting the maximum size of the limiting boss 41 in the thickness direction X, the compression amount of the sealing member 2 can be controlled, thereby meeting the requirement of sealing the cover plate 1.

[0044] In the embodiments shown in FIGS. 2 and 3, the limiting groove 11 has a first limiting groove 110 and a plurality of second limiting grooves 111 in communication with the first limiting groove 110, the plurality of limiting grooves 11 are arranged at the outer periphery of the first limiting groove 110, the explosion-proof valve 3 and the sealing member 2 are arranged in the first limiting groove 110, each limiting boss 41 is arranged in a second limiting groove 111 corresponding to it and is in interference fit with the second limiting groove 111. The explosion-proof valve 3 and the first limiting groove 110 are in clearance fit, which avoids the explosion-proof valve 3 from being extruded and deformed during assembly, thereby ensuring the safety and reliability of the single battery.

[0045] In the embodiments shown in FIG. 5, the explosion-proof valve 3 includes a bearing part 30 and a weak part 31 connected with each other, the bearing part 30 is arranged around the weak part 31, the bearing part 30 is located between and connected with the sealing member 2 and the crimping member 4, and the weak part 31 is configured to be damaged when subjected to a preset pressure impact.

[0046] FIG. 6 is a cross-sectional view of the sealing member 2 in an uncompressed state in the embodiments of the present application. In the embodiments shown in FIG. 6, the maximum dimension d of the sealing member 2 in the uncompressed state along the thickness direction X satisfies: 0.6mm≤d≤1mm. Specifically, the maximum dimension d of the sealing member 2 in the uncompressed state along the thickness direction X can be any value or a range value between any two values selected from 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm and 1mm.

[0047] In the embodiments shown in FIG. 5, the maximum dimension t of the explosion-proof valve 3 along the thickness direction X satisfies: 0.5mm≤t≤0.8mm. Specifically, the maximum dimension t of the explosion-proof valve 3 along the thickness direction X can be any value or a range value between any two values selected from 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm and 0.8mm.

[0048] In the embodiments shown in FIGS. 5 and 8, the maximum dimension m of the crimping member 4 arranged in the limiting groove 11 along the thickness direction X satisfies: 0.8mm≤m≤1.4mm. Specifically, the maximum dimension m of the crimping member 4 arranged in the limiting groove 11 along the thickness direction X can be any value or a range value between any two values selected from 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm and 1.4mm.

[0049] In the embodiments of the present application, the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X is adjusted to control the compression amount of the sealing member 2, and the reasonable sealing ring compression amount range is confirmed by helium detection data. For specific data, refer to Tables 1 to 3.

[0050] Table 1:

[0051] As can be seen from the embodiments and comparative examples in Table 1, in this case, the maximum size d of the sealing member 2 in the thickness direction X in the uncompressed state is 0.6 mm, and the maximum size t of the explosion-proof valve 3 in the thickness direction X is 0.5 mm. By adjusting the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X and using a helium mass spectrometer to detect the helium leak rate, when the helium leak rate is less than 1 × 10 -7 / Pa.m 3 / s, the sealing requirement of the explosion-proof valve 3 and the cover plate 1 is met. According to Examples 1 to 6, by adjusting the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X to be between 0.83 mm and 0.95 mm, 0.25 ≤ (d + t - m) / d ≤ 0.45 is met, that is, the compression amount of the sealing member 2 is between 25% and 45%, which meets the requirement that the helium leak rate is less than 1 × 10 -7 / Pa.m 3 / s. According to Comparative Examples 1 to 5, when the compression amount of the sealing member 2 is less than 25% or greater than 45%, the requirement that the helium leak rate is less than 1 × 10 -7 / Pa.m 3 / s cannot be met, and the sealing requirement of the explosion-proof valve 3 and the cover plate 1 cannot be met.

[0052] Table 2:

[0053] As can be seen from the embodiments and comparative examples in Table 2, in this case, the maximum size d of the sealing member 2 in the thickness direction X in the uncompressed state is 0.8 mm, and the maximum size t of the explosion-proof valve 3 in the thickness direction X is 0.5 mm. By adjusting the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X and using a helium mass spectrometer to detect the helium leak rate, when the helium leak rate is less than 1 × 10 -7 / Pa.m 3 / s, the sealing requirement of the explosion-proof valve 3 and the cover plate 1 is met. According to Examples 1 to 5, by adjusting the maximum size m of the pressure contact member 4 arranged in the limiting groove 11 in the thickness direction X to be between 0.94 mm and 1.1 mm, 0.25 ≤ (d + t - m) / d ≤ 0.45 is met, that is, the compression amount of the sealing member 2 is between 25% and 45%, which meets the requirement that the helium leak rate is less than 1 × 10 -7 / Pa.m 3The requirement of / s is not met. Referring to Comparative Examples 1 to 6, when the compression of seal 2 is less than 25% or greater than 45%, the helium leak detection rate of less than 1×10⁻⁶ cannot be achieved. -7 / Pa.m 3 The / s requirement also fails to meet the sealing requirements between the explosion-proof valve 3 and the cover plate 1.

[0054] Table 3:

[0055] As shown in Table 3, in this case, the maximum dimension d of the sealing element 2 along the thickness direction X in the uncompressed state is 0.8 mm, and the maximum dimension t of the explosion-proof valve 3 along the thickness direction X is 0.6 mm. By adjusting the maximum dimension m of the pressing element 4 set in the limiting groove 11 along the thickness direction X and using a helium mass spectrometer to detect the helium leak rate, when the helium leak rate is less than 1×10 -7 / Pa.m 3 At a speed of / s, the sealing requirements between the explosion-proof valve 3 and the cover plate 1 are met. Referring to Examples 1 to 5, by adjusting the maximum dimension m of the pressing component 4 set in the limiting groove 11 along the thickness direction X to be between 1.04mm and 1.2mm, the requirement of 0.25≤(d+tm) / d≤0.45 is met, that is, the compression of the sealing component 2 is between 25% and 45%, which satisfies the requirement that the helium leak detection rate is less than 1×10 -7 / Pa.m 3 The requirement of / s is not met. Referring to Comparative Examples 1 to 6, when the compression of seal 2 is less than 25% or greater than 45%, the helium leak detection rate of less than 1×10⁻⁶ cannot be achieved. -7 / Pa.m 3 The / s requirement also fails to meet the sealing requirements between the explosion-proof valve 3 and the cover plate 1.

[0056] In the embodiment shown in Figure 5, the maximum dimension of the cover plate 1 along the thickness direction X is M, and the single cell satisfies: 0.4 ≤ m / M ≤ 0.7. In the embodiment of this application, the cover plate 1 has a limiting groove 11, and the maximum dimension m of the pressing member 4 disposed in the limiting groove 11 along the thickness direction X is equal to the maximum dimension of the limiting groove 11 in the thickness direction X. By limiting the ratio of the maximum dimension of the limiting groove 11 in the thickness direction X to the maximum dimension M of the cover plate 1 along the thickness direction X, it can be ensured that the setting of the limiting groove 11 to connect the pressing member 4 does not affect the strength of the cover plate 1, thereby improving the safety and stability of the single cell.

[0057] In the embodiment shown in FIG. 3 and FIG. 9, the length direction Y of the limiting boss 41 shown is the length direction Y of the limiting boss 41 provided on the straight section of the body 40. The length direction Y of the limiting boss 41 provided on the bent section of the body 40 is not shown. Along the length direction Y of the limiting boss 41, the limiting boss 41 is interference fit with the second limiting groove 111. In this way, the connection stability of the limiting boss 41 and the second limiting groove 111 can be improved, and the compression seal 2 can be compressed to seal the cover plate 1. The maximum dimension of the second limiting groove 111 in the length direction Y is E, and the maximum dimension of the limiting boss 41 in the length direction Y in the uncompressed state is e, and it is satisfied that 0.015 mm≤e-E≤0.03 mm. The difference between the maximum dimension e of the limiting boss 41 in the length direction Y in the uncompressed state and the maximum dimension E of the second limiting groove 111 in the length direction Y is the interference amount of the limiting boss 41 and the second limiting groove 111 in the length direction Y. By controlling the interference amount to be between 0.015 mm and 0.03 mm, the connection stability of the limiting boss 41 and the second limiting groove 111 can be improved, and the compression seal 2 can be compressed to seal the cover plate 1.

[0058] In the embodiment shown in FIG. 3 and FIG. 9, the width direction Z of the limiting boss 41 shown is the width direction Z of the limiting boss 41 provided on the straight section of the body 40. The width direction Z of the limiting boss 41 provided on the bent section of the body 40 is not shown. Along the width direction Z of the limiting boss 41, the limiting boss 41 is clearance fit with the second limiting groove 111. In this way, the limiting boss 41 can be prevented from being extruded and deformed in the width direction Z by the side wall of the second limiting groove 111. The limiting boss 41 is deformed inwardly when extruded in the width direction Z, which causes the explosion-proof valve 3 to be extruded into the first limiting groove 110. By clearance fit between the limiting boss 41 and the second limiting groove 111 in the width direction Z, the limiting boss 41 can be prevented from being extruded into the explosion-proof valve 3, and thus the safety and reliability of the single battery can be ensured.

[0059] In the embodiment shown in FIG. 3 and FIG. 9, the maximum dimension of the second limiting groove 111 in the width direction Z is A, and the maximum dimension of the limiting boss 41 in the width direction Z in the uncompressed state is a, and it is satisfied that 0 mm

[0060] In some embodiments, the crimping piece 4 is made of a metal material. Specifically, the material of the crimping piece 4 can be at least one of copper, aluminum, etc. In this way, the connection reliability of the crimping piece 4 and the cover plate 1 can be ensured.

[0061] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0062] 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

[0063] The single battery of the embodiment of the present application comprises a cover plate, a sealing piece, an explosion-proof valve and a crimping piece. The crimping piece is used to limit the position of the explosion-proof valve and the sealing piece. By controlling the maximum size m of the crimping piece arranged in the limiting groove along the thickness direction, the compression amount of the sealing piece can be controlled to be between 25% and 45%, so as to meet the requirement of sealing the cover plate. The present application solves the safety problem of single battery leakage caused by the deformation and cracking of the explosion-proof valve due to welding by optimizing the assembly method of the explosion-proof valve.

Claims

1. A single cell, characterized by, The utility model relates to a battery safety valve structure, including: Cover plate is equipped with explosion -proof hole and the limit slot that communicates explosion -proof hole; Sealing element is arranged in the limit slot; Explosion -proof valve is arranged in the limit slot and is located the side of sealing element away from cover plate along the thickness direction, and is covered and is equipped with explosion -proof hole; Pressure -welding piece is arranged in the limit slot and is connected with cover plate, and explosion -proof valve and sealing element are clamped between pressure -welding piece and cover plate, and sealing element is compressed between cover plate and explosion -proof valve to make explosion -proof valve pass through sealing element and cover plate sealed connection; Wherein, the maximum size of the sealing element along the thickness direction in the uncompressed state is d, the maximum size of the explosion -proof valve along the thickness direction is t, and the maximum size of the pressure -welding piece arranged in the limit slot along the thickness direction is m, satisfying: 0.25≤(d+t-m) / d≤0.

45.

2. The cell according to claim 1, wherein The pressure -welding piece includes a body and a plurality of limiting bosses connected to the body, the explosion -proof valve and the sealing element are clamped between the body and the cover plate, a plurality of the limiting bosses are located on the side of the body facing the cover plate, and are in interference fit with the limit slot.

3. The cell according to claim 2, wherein The limit slot has a first limit slot and a plurality of second limit slots in communication with the first limit slot, a plurality of limit slots are arranged on the outer periphery of the first limit slot, the explosion -proof valve and the sealing element are arranged in the first limit slot, and each of the limiting bosses is arranged in one of the second limit slots and is in interference fit with the second limit slot.

4. The cell according to claim 1, wherein The maximum size of the cover plate along the thickness direction is M, and the single battery satisfies: 0.4≤m / M≤0.

7.

5. The cell according to claim 1, wherein The explosion -proof valve includes a load bearing portion and a weak portion connected to each other, the load bearing portion is arranged around the weak portion, the load bearing portion is located between the sealing element and the pressure -welding piece and connected to the sealing element and the pressure -welding piece respectively, and the weak portion is configured to be damaged when subjected to a predetermined pressure impact.

6. The cell according to claim 3, wherein Along the length direction of the limiting boss, the limiting boss is in interference fit with the second limit slot.

7. The cell according to claim 6, wherein The maximum size of the second limit slot in the length direction is E, and the maximum size of the limiting boss in the length direction in the uncompressed state is e, satisfying: 0.015mm≤e-E≤0.03mm.

8. The cell according to claim 3, wherein Along the width direction of the limiting boss, the limiting boss is in clearance fit with the second limit slot.

9. The cell according to claim 8, wherein The maximum size of the second limit slot in the width direction is A, and the maximum size of the limiting boss in the width direction in the uncompressed state is a, satisfying: 0mm<a-A≤0.1mm.

10. The cell according to claim 1, wherein The maximum size d of the sealing element along the thickness direction in the uncompressed state satisfies: 0.6mm≤d≤1mm; and / or The maximum size t of the explosion -proof valve along the thickness direction satisfies: 0.5mm≤t≤0.8mm; and / or The maximum size m of the pressure -welding piece arranged in the limit slot along the thickness direction satisfies: 0.8mm≤m≤1.4mm.

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