Battery cells, batteries and power consuming devices

Abstract

This application provides a battery cell, a battery, and a power consuming device. The battery cell includes a housing, the housing including a pressure release member, the pressure release member having a first groove formed therein, the pressure release member rupturing along the first groove to release internal pressure of the battery cell. The first groove includes a first groove segment, a second groove segment, and a third groove segment, the first groove segment facing the third groove segment, the second groove segment connecting the first groove segment and the third groove segment, and the remaining thicknesses of the first groove segment and the third groove segment are both smaller than the remaining thickness of the second groove segment. This corresponds to increasing the remaining thickness of the second groove segment, improving the fatigue strength of the pressure release member in the area where the second groove segment is located, further reducing the possibility of the pressure release member rupturing at the second groove segment during normal use of the battery cell, improving the long-term reliability of the pressure release member, and extending the service life of the battery cell.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to Chinese patent application No. 2023106370020, entitled "Battery Cell, Battery and Power Consumption Device," filed on May 31, 2023, the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of battery technology, and more particularly to battery cells, batteries, and power consuming devices. [Background technology]

[0003] BACKGROUND ART With the development of new energy technology, batteries are increasingly being applied in mobile phones, notebook computers, electric motorcycles, electric cars, electric airplanes, electric boats, electric car toys, electric boat toys, electric airplane toys, power tools, etc.

[0004] In the case of a typical battery cell, a pressure release member is installed in the battery cell. In the event of thermal runaway, the pressure release member releases the internal pressure of the battery cell to improve the reliability of the battery cell. In addition to improving the reliability of the battery cell, the service life of the battery cell is also an issue that needs to be considered. Therefore, how to extend the service life of the battery cell is an issue that needs to be resolved as soon as possible in battery technology. Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, and a power consuming device that can effectively extend the service life of the battery cell.

[0006] According to a first aspect, an embodiment of the present application provides a battery cell, the battery cell comprising a housing, the housing including a pressure release member, the pressure release member having a first groove formed therein, the pressure release member being configured to be ruptured along the first groove to release internal pressure of the battery cell, the first groove including a first groove segment, a second groove segment and a third groove segment, the first groove segment being disposed opposite the third groove segment, the second groove segment connecting the first groove segment and the third groove segment, and both of the remaining thickness of the first groove segment and the remaining thickness of the third groove segment being smaller than the remaining thickness of the second groove segment.

[0007] In the above technical solution, the remaining thickness of both the first groove segment and the third groove segment is smaller than the remaining thickness of the second groove segment, which is equivalent to increasing the remaining thickness of the second groove segment. This improves the fatigue strength of the pressure release member in the area where the second groove segment is installed, further reducing the possibility of the pressure release member rupturing at the position of the second groove segment during normal use of the battery cell, improving the long-term reliability of the pressure release member, and extending the service life of the battery cell.

[0008] In some embodiments, the depth of the first groove segment is greater than the depth of the second groove segment, so that the remaining thickness of the first groove segment is less than the remaining thickness of the second groove segment. By forming the first groove segment deeper than the second groove segment in the pressure release member during molding, the remaining thickness of the first groove segment can be made less than the remaining thickness of the second groove segment, which is simple to achieve.

[0009] In some embodiments, the depth of the third groove segment is greater than the depth of the second groove segment, so that the remaining thickness of the third groove segment is less than the remaining thickness of the second groove segment. By forming the third groove segment deeper than the second groove segment in the pressure release member during molding, the remaining thickness of the third groove segment can be made less than the remaining thickness of the second groove segment, which is easy to achieve.

[0010] In some embodiments, the remaining thickness of the first groove segment is equal to the remaining thickness of the third groove segment, and when the pressure of the battery cell is released, the synchronization of the pressure release member rupturing along the first groove segment and the third groove segment is better, so that the time for the pressure release member to rupture along the first groove is further shortened, and the timeliness of the pressure release is improved.

[0011] In some embodiments, both ends of the second groove segment are connected to the first groove segment and the third groove segment, respectively, along the extension direction of the second groove segment. In this way, both ends of the second groove segment do not extend beyond the first groove segment and the third groove segment, respectively. Therefore, during the pressure release process, pressure can be released precisely through the area defined by the first groove segment, the second groove segment, and the third groove segment. The pressure release member is not likely to burst and release pressure in other areas, making it easier to achieve directional pressure release.

[0012] In some embodiments, the first groove segment and the second groove segment are connected at a first position, and the first position is located away from both ends of the first groove segment along the extension direction of the first groove segment. During the pressure release process, after the pressure release member ruptures at the first position, the crack can spread from the first position to both ends along the first groove segment, thereby shortening the time it takes for the pressure release member to rupture along the first groove segment.

[0013] In some embodiments, the first position is located at the midpoint of the first groove segment along the extension direction of the first groove segment, and during the pressure release process, the cracks propagate an equal distance from the first position to both ends along the first groove segment, further shortening the time it takes for the pressure release member to rupture along the first groove segment.

[0014] In some embodiments, the third groove segment and the second groove segment are connected at a second position, and the second position is located away from both ends of the third groove segment along the extension direction of the third groove segment. During the pressure release process, after the pressure release member ruptures at the second position, the crack can spread from the second position to both ends along the third groove segment, thereby shortening the time it takes for the pressure release member to rupture along the third groove segment.

[0015] In some embodiments, the second position is located at the midpoint of the third groove segment along the extension direction of the third groove segment, and the cracks propagate from the second position to both ends along the third groove segment over an equal distance during the pressure release process, further shortening the time it takes for the pressure release member to rupture along the third groove segment.

[0016] In some embodiments, the first groove segment, the second groove segment, and the third groove segment are all grooves that extend along a straight line, which can reduce the difficulty of forming the first groove segment, the second groove segment, and the third groove segment.

[0017] In some embodiments, the first groove segment is perpendicular to the second groove segment and / or the third groove segment is perpendicular to the second groove segment. When the first groove segment is perpendicular to the second groove segment, stress is more concentrated near the connection position between the first groove segment and the second groove segment, and the processing depth of the first groove segment can be reduced and the processing difficulty of the first groove segment can be reduced when the explosion pressure of the battery cell is constant. When the third groove segment is perpendicular to the second groove segment, stress is more concentrated near the connection position between the third groove segment and the second groove segment, and the processing depth of the third groove segment can be reduced and the processing difficulty of the third groove segment can be reduced when the explosion pressure of the battery cell is constant.

[0018] In some embodiments, the first groove further includes at least one fourth groove segment, the fourth groove segment being located between the first groove segment and the third groove segment and connected to the second groove segment. Because the second groove segment has a greater residual thickness than the first groove segment, the second groove segment is less susceptible to rupture than the first and third groove segments. After the fourth groove segment is installed, stress is more concentrated at the connection position between the second groove segment and the fourth groove segment, forming a stress concentration point, weakening the strength of the second groove segment at this position and making it more susceptible to breakage, thereby reducing the likelihood of the pressure release member rupturing along the second groove segment.

[0019] In some embodiments, the remaining thickness of the first groove segment and the remaining thickness of the third groove segment are both smaller than the remaining thickness of the fourth groove segment, making the connection between the fourth groove segment and the second groove segment less susceptible to rupture than the connection between the first groove segment and the second groove segment and the connection between the third groove segment and the second groove segment, reducing the possibility that the pressure release member will be deformed by an external force during normal use of the battery cell and rupture at the connection between the fourth groove segment and the second groove segment, thereby extending the service life of the battery cell.

[0020] In some embodiments, there is only one fourth groove segment, which simplifies the structure of the first groove and reduces manufacturing costs.

[0021] In some embodiments, the second groove segment and the fourth groove segment are connected at a third position, and the distance between the third position and the first groove segment along the extension direction of the second groove segment is L1, and the distance between the third position and the third groove segment is L2, satisfying |L1-L2|≦1 mm. The third position can be as central as possible in the extension direction of the second groove segment, thereby reducing the difficulty of the pressure release member rupturing along the second groove segment.

[0022] In some embodiments, |L1-L2|≦0.5 mm, further reducing the difficulty of the pressure release member rupturing along the second groove segment.

[0023] In some embodiments, the fourth groove segment is plural, and the plural fourth groove segments are spaced apart along the extension direction of the second groove segment. A plurality of stress concentrators can be formed at the connection positions between the second groove segment and the plural fourth groove segments, which can further reduce the difficulty of the pressure release member rupturing along the second groove segment.

[0024] In some embodiments, the plurality of fourth groove segments are uniformly distributed in the second groove segment along the extension direction of the second groove segment, the length of the portion of the second groove segment located between the first groove segment and the third groove segment is L3, the number of fourth groove segments is N, and L3 / N≦25 mm is satisfied. This prevents the distance between two adjacent stress concentration areas on the second groove segment from being too large, so that a crack occurring in the pressure release member in the second groove segment can more easily spread from one stress concentration area to another, thereby reducing the likelihood of the pressure release member rupturing along the second groove segment.

[0025] In some embodiments, 8 mm≦L3 / N≦20 mm. This further reduces the distance between two adjacent stress concentrations on the second groove segment, so that any cracks that occur in the pressure release member along the second groove segment can more easily spread from one stress concentration to another. Naturally, the distance between two adjacent stress concentrations on the second groove segment is not too small, reducing the possibility that the two stress concentrations will be too close together and cause the pressure release member to rupture along the second groove segment during normal use of the battery cell.

[0026] In some embodiments, 20 mm≦L3≦150 mm. When L3<20 mm, the distance between the first groove segment and the third groove segment is small, the pressure relief area of ​​the pressure relief member is small, and the pressure relief efficiency of the pressure relief member is low. When L3>150 mm, the length of the second groove segment is too long, and the fatigue strength of the pressure relief member in the middle region of the second groove segment is low. When 20 mm≦L3≦150 mm, not only can the pressure relief area of ​​the pressure relief member be increased, but the fatigue strength of the pressure relief member at the position of the second groove segment can also be improved.

[0027] In some embodiments, 10 mm≦L3≦100 mm.

[0028] In some embodiments, the length of the fourth groove segment is L4, and the length of the first groove segment is L5, satisfying L4 / L5≦1 / 4. If L4 / L5>1 / 4, the length of the fourth groove segment is too long, reducing the fatigue strength of the pressure release member at the fourth groove segment. This increases the likelihood of the pressure release member being broken during normal use of the battery cell, thereby affecting the service life of the battery cell. Furthermore, if a crack propagates along the second groove segment during pressure release, the crack will likely propagate along the fourth groove segment rather than continuing along the second groove segment. This prevents the pressure release member from rupturing completely along the second groove segment, thereby reducing the pressure release area of ​​the pressure release member. In contrast, if L4 / L5≦1 / 4, the service life of the battery cell can be effectively extended. When the pressure in the battery cell is released, the pressure release member can rupture completely along the second groove segment, thereby increasing the pressure release area of ​​the pressure release member.

[0029] In some embodiments, L4 / L5≦1 / 6, which further reduces the impact of the fourth groove segment on the service life of the battery cell and the pressure relief area of ​​the pressure relief member.

[0030] In some embodiments, the first groove segment, the second groove segment, and the third groove segment define a pressure relief area, and the pressure relief member has a guide groove disposed at a distance from the second groove segment, configured to guide the pressure relief area to reverse and open. The guide groove contributes to the reversal and opening of the pressure relief area, reduces the difficulty of reversing the pressure relief area, and effectively improves the timeliness of pressure release.

[0031] In some embodiments, the first groove segment, the second groove segment, and the third groove segment define two pressure relief areas, each located on either side of the second groove segment, and the pressure relief member has two guide grooves, the second groove segment is located between the two guide grooves, and the two guide grooves are configured to guide the two pressure relief areas so that they open in reverse. During the pressure release process, the two guide grooves respectively guide the two pressure relief areas, improving the opening speed of the two pressure relief areas and allowing for more timely pressure release.

[0032] In some embodiments, neither the first groove segment nor the third groove segment contacts the guide groove. The guide groove is less likely to affect the first groove segment and the third groove segment, improving the fatigue strength of the pressure release member at the first groove segment and the third groove segment. This reduces the likelihood of the pressure release member rupturing at the connection point during normal use of the battery cell due to stress concentration between the guide groove and the first groove segment and the third groove segment. Furthermore, after the pressure release member ruptures along the first groove segment and the third groove segment during the pressure release process, the crack is less likely to spread to the guide groove, reducing the likelihood of the pressure release member detaching and scattering after the pressure release area opens.

[0033] In some embodiments, the guide groove and the first groove are respectively disposed on both sides of the pressure relief member along the thickness direction of the pressure relief member, so that the influence of the guide groove on the first groove during molding is reduced, and on the other hand, the guide groove can provide a better guiding effect for the pressure relief area, making it easier for the pressure relief area to invert and open.

[0034] In some embodiments, the guide groove extends along the extension direction of the second groove segment.

[0035] In some embodiments, the first and third groove segments are located on opposite sides of the guide groove along the extension direction of the second groove segment. The length of the second groove segment between the first and third groove segments is L3, and the length of the guide groove is L6, satisfying 1 mm≦L3−L6≦10 mm. When L3−L6<1 mm, the distance between at least one of the first and third groove segments and the guide groove is small, and the influence of the guide groove on the first and third groove segments is large. This increases the possibility of the pressure release member prematurely rupturing at a position close to the guide groove of the first or third groove segment, potentially releasing pressure prematurely. When L3−L6>10 mm, the length of the guide groove is short, reducing the ability of the guide groove to contribute to the reversal of the pressure release region. In contrast, when 1 mm≦L3−L6≦10 mm, not only is the possibility of the pressure release member prematurely releasing pressure reduced, but the guide groove's ability to contribute to the reversal and release of the pressure release region is also improved.

[0036] In some embodiments, 2 mm≦L3−L6≦6 mm, which further reduces the likelihood that the pressure release member will prematurely release pressure and further improves the guiding ability of the pressure release area of ​​the guide groove to contribute to reverse opening.

[0037] In some embodiments, along the extending direction of the first groove segment, the distance between the guide groove and the second groove segment is L7, and the length of the portion of the first groove segment that extends in the direction approaching the guide groove from the second groove segment is L8, and 0.5 mm ≤ |L7 - L8| ≤ 15 mm. When |L7 - L8| < 0.5 mm, since the distance between the end of the first groove segment and the guide groove is small, when a crack in the pressure relief member diffuses along the first groove segment to the end of the first groove segment, the crack can easily diffuse into the guide groove. As a result, the pressure relief region detaches. When |L7 - L8| > 15 m and L7 > L8, the distance between the guide groove and the second groove segment is large, and the ability to contribute to the inversion of the pressure relief region of the guide groove is low. When L7 < L8, the distance between the guide groove and the second groove segment is small, the area of the inversion opening of the pressure relief region is small, and the pressure relief area of the pressure relief region decreases. In contrast, when 0.5 mm ≤ |L7 - L8| ≤ 15 mm, not only can the possibility of detachment and scattering of the pressure relief region be reduced, but the difficulty of the inversion opening of the pressure relief region can also be lowered, and the opening area of the pressure relief region can be increased.

[0038] In some embodiments, 1 mm ≤ |L7 - L8| ≤ 10 mm.

[0039] In some embodiments, a second groove is provided in the pressure relief member, and the first groove is provided on the groove bottom surface of the second groove. By providing the second groove, the forming depth of the first groove can be reduced, the forming force received by the pressure relief member during the forming of the first groove can be reduced, and the possibility of cracks occurring in the pressure relief member during the forming of the first groove can be reduced.

[0040] In some embodiments, the second groove includes a fifth groove segment, a sixth groove segment, and a seventh groove segment, the fifth groove segment and the seventh groove segment are oppositely disposed, the sixth groove segment connects the fifth groove segment and the seventh groove segment, the first groove segment is disposed on the groove bottom surface of the fifth groove segment, the second groove segment is disposed on the groove bottom surface of the sixth groove segment, and the third groove segment is disposed on the groove bottom surface of the seventh groove segment. Because the first groove segment, the second groove segment, and the third groove segment are disposed on the groove bottom surfaces of the fifth groove segment, the sixth groove segment, and the seventh groove segment, respectively, each groove segment in the second groove corresponds to each groove segment in the first groove, which effectively reduces the space occupied by the second groove in the pressure release member and improves the strength of the pressure release member.

[0041] In some embodiments, the pressure release member includes a third groove, the third groove including an eighth groove segment, a ninth groove segment, and a tenth groove segment, the eighth groove segment and the tenth groove segment being opposite each other, the ninth groove segment connecting the eighth groove segment and the tenth groove segment, the fifth groove segment being located at the groove bottom surface of the eighth groove segment, the sixth groove segment being located at the groove bottom surface of the ninth groove segment, and the seventh groove segment being located at the groove bottom surface of the tenth groove segment. Because the fifth groove segment, the sixth groove segment, and the seventh groove segment are located at the groove bottom surfaces of the eighth groove segment, the ninth groove segment, and the tenth groove segment, respectively, each groove segment in the third groove corresponds to each groove segment in the second groove, thereby effectively reducing the space occupied by the third groove in the pressure release member and improving the strength of the pressure release member.

[0042] In some embodiments, the pressure release member has a third groove formed therein, and the second groove is formed on the bottom surface of the third groove. By forming the third groove, the molding depth of the second groove can be reduced, which reduces the molding force that the pressure release member receives when the second groove is molded, and reduces the possibility of cracks occurring in the pressure release member when the second groove is molded.

[0043] In some embodiments, the pressure release member includes a first surface and a second surface disposed opposite each other along the thickness direction of the pressure release member. The third groove, the second groove, and the first groove are sequentially disposed in a direction from the first surface to the second surface. The distance between the first surface and the second surface is H0, the remaining thickness of the second groove is H1, and the remaining thickness of the third groove is H2, and these satisfy 0.1≦H1 / H0≦0.5 and / or 0.2≦H2 / H0≦0.8. When H1 / H0<0.1, the remaining thickness of the second groove is small and the depth of the second groove is large, making it difficult to form the second groove. When H1 / H0>0.5, the remaining thickness of the second groove is large and the depth of the first groove is large, making it difficult to form the first groove. When 0.1≦H1 / H0≦0.5, the difficulty of forming the first and second grooves can be reduced. When H2 / H0<0.2, the remaining thickness of the third groove is small and the depth of the third groove is large, making it difficult to form the third groove. When H2 / H0>0.8, the remaining thickness of the third groove is large and the depth of the second groove is large, making it difficult to form the second groove. On the other hand, when 0.2≦H2 / H0≦0.8, the difficulty of forming the third groove and the second groove can be reduced.

[0044] In some embodiments, 0.1≦H1 / H0≦0.3.

[0045] In some embodiments, 0.2≦H2 / H0≦0.6.

[0046] In some embodiments, the remaining thickness of the first groove segment is D1, and the remaining thickness of the second groove segment is D2, where 0.15≦D1 / D2≦0.95 is satisfied. If D1 / D2<0.15, the remaining thickness of the second groove segment is too large, which increases the risk that the pressure release member will not rupture along the second groove segment when pressure is released, reducing the timeliness of pressure release. If D1 / D2>0.95, the remaining thickness of the second groove segment is too small, which increases the risk that the pressure release member will rupture along the second groove segment during normal use of the battery cell, affecting the service life of the battery cell. In contrast, if 0.15≦D1 / D2≦0.95, the timeliness of pressure release of the battery cell can be improved and the service life of the battery cell can be extended.

[0047] In some embodiments, 0.3≦D1 / D2≦0.9, which can provide better performance of the battery cell, improve the timeliness of pressure relief of the battery cell, and extend the service life of the battery cell.

[0048] In some embodiments, 0.5≦D1 / D2≦0.85, which not only further improves the overall performance of the battery cell and reduces the probability of the pressure release member rupturing along the second groove segment during normal use of the battery cell, but also reduces the probability of the battery cell exploding during thermal runaway.

[0049] In some embodiments, the remaining thickness of the third groove segment is D3, and satisfies 0.15≦D3 / D2≦0.95. If D3 / D2<0.15, the remaining thickness of the second groove segment is too large, which may result in the pressure release element failing to rupture along the second groove segment during pressure release, resulting in poor timeliness of pressure release. If D3 / D2>0.95, the remaining thickness of the second groove segment is too small, which may result in the pressure release element rupturing along the second groove segment during normal use of the battery cell, resulting in poor service life. In contrast, if 0.15≦D3 / D2≦0.95, the timeliness of pressure release of the battery cell can be improved and the service life of the battery cell can be extended.

[0050] In some embodiments, 0.3≦D3 / D2≦0.9, which results in better performance of the battery cell and improves the timeliness of pressure relief of the battery cell while extending the service life of the battery cell.

[0051] In some embodiments, 0.5≦D3 / D2≦0.85, which not only further improves the overall performance of the battery cell and reduces the probability of the pressure release member rupturing along the second groove segment during normal use of the battery cell, but also reduces the probability of the battery cell exploding during thermal runaway.

[0052] In some implementations, 0.03 mm≦D3≦0.5 mm.

[0053] In some embodiments, 0.15 mm≦D3≦0.4 mm.

[0054] In some embodiments, 0.03 mm≦D1≦0.5 mm and / or 0.05 mm≦D2≦0.65 mm.

[0055] In some embodiments, 0.15 mm≦D1≦0.4 mm.

[0056] In some embodiments, 0.25 mm≦D2≦0.5 mm.

[0057] In some embodiments, the housing includes a first wall portion, and the pressure release member is the first wall portion; alternatively, the pressure release member is installed separately from the first wall portion, and the pressure release member is attached to the first wall portion. When the first wall portion is used as the pressure release member, the first groove can be molded directly into the first wall portion to form an integrated pressure release structure, which is more reliable, eliminates the pressure release member attachment process, and reduces the manufacturing cost of the battery cell. When the pressure release member is attached to the first wall portion, the pressure release member is a member independent of the housing, and the pressure release member and the housing can be manufactured and assembled separately, which reduces manufacturing difficulty and improves efficiency.

[0058] In some embodiments, the housing includes a case and an end cover, the case having an opening, the end cover sealing the opening, and the end cover being the first wall portion, whereby the end cover has a pressure release function and molding the first groove into the end cover is less difficult.

[0059] In some embodiments, the housing includes a case and an end cover, the case has an opening, the end cover seals the opening, and at least one wall of the case is a first wall, whereby the case has a pressure release function, and when pressure is released, waste matter discharged from inside the battery cells is less likely to affect an external member outside the end cover, reducing the possibility of damage to the external member due to the waste matter.

[0060] In some embodiments, the case includes a bottom wall and a plurality of side walls, the side walls are disposed around the bottom wall, the case has an opening at an end opposite the bottom wall, and the bottom wall is a first wall portion. The bottom wall has a pressure release function, and when a battery cell experiences thermal runaway, pressure can be released through the bottom wall. In the battery, the pressure release member is not easily blocked by other battery cells.

[0061] In some embodiments, the first wall is a rectangular wall, the second groove segment extends along the length of the first wall, and both the first and third groove segments extend along the width of the first wall. In this manner, the first wall can provide more space for the second groove segment, making it longer and increasing the pressure relief area of ​​the pressure relief member.

[0062] In some embodiments, along the thickness direction of the pressure relief member, the first wall portion has an outer surface, the outer surface faces away from the interior of the housing, the first groove segment has a first intermediate surface extending along its extending direction, the second groove segment has a second intermediate surface extending along its extending direction, the third groove segment has a third intermediate surface extending along its extending direction, the minimum distance from the center point of the outer surface to the first intermediate surface is M1, the minimum distance from the center point of the outer surface to the second intermediate surface is M2, the minimum distance from the center point of the outer surface to the third intermediate surface is M3, and M2 < M1 and M2 < M3 are satisfied. When the internal pressure of the battery cell changes, the first wall portion is more likely to deform the closer it is to the center point. If M2 < M1 and M2 < M3, the first groove segment and the third groove segment are farther from the center point, and the fatigue strength of the pressure relief member at the first groove segment and the third groove segment is improved.

[0063] In some embodiments, along the thickness direction of the pressure relief member, the projection of the center point of the outer surface is located within the second groove segment, and / or |M3 - M1| ≤ 5 mm is satisfied. When the projection of the center point of the outer surface is located within the second groove segment and the second groove segment is closer to the center point of the outer surface, when the pressure relief member releases pressure, it can rupture more timely along the second groove segment, and the timeliness of pressure release of the pressure relief member is improved. When |M3 - M1| ≤ 5 mm, both the first groove segment and the third groove segment are far from the center point, and the influence on the first groove segment and the third groove segment due to the deformation near the center point of the pressure relief member is reduced.

[0064] In some embodiments, the outer surface is rectangular or circular or regular polygon.

[0065] According to the second aspect, the embodiments of the present application provide a battery, and the battery includes a battery cell according to any one of the embodiments of the first aspect.

[0066] According to the third aspect, the embodiments of the present application provide an electric power consuming device, and the electric power consuming device includes a battery cell according to any one of the embodiments of the first aspect for providing electrical energy to the electric power consuming device.

[0067] In order to more clearly explain the technical solutions of the embodiments of the present application, the following will briefly describe the drawings that need to be used in the embodiments. It should be understood that the following drawings only illustrate some embodiments of the present application, and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without exerting creative efforts. [Brief explanation of the drawings]

[0068] [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] FIG. 1 is an exploded view of a battery according to some embodiments of the present application. [Figure 3] FIG. 1 is an exploded view of a battery cell according to some embodiments of the present application. [Figure 4] 1 is a structural schematic diagram of a battery cell according to some embodiments of the present application; [Figure 5] FIG. 5 is a partial view of the pressure release member shown in FIG. 4. [Figure 6] 6 is a cross-sectional view of the pressure release member shown in FIG. 5 along the line AA. [Figure 7] FIG. 7 is a partial enlarged view of a portion B in FIG. 6. [Figure 8] FIG. 7 is a partial enlarged view of a portion C in FIG. 6. [Figure 9] 10A-10C are partial views of a pressure relief member according to some alternative embodiments of the present application. [Figure 10] FIG. 10 is a cross-sectional view of the pressure release member shown in FIG. 9 . [Figure 11] FIG. 11 is a partial enlarged view of a portion E in FIG. [Figure 12] 10A-10C are partial views of a pressure relief member according to still other embodiments of the present application. [Figure 13] 10A-10C are partial views of a pressure relief member according to still other embodiments of the present application. [Figure 14] 14 is a cross-sectional view of the pressure release member shown in FIG. 13, taken along line F-F. [Figure 15]1 is a structural schematic diagram of a battery cell according to some other embodiments of the present application. [Figure 16] FIG. 16 is a partial enlarged view of a portion F in FIG. [Figure 17] FIG. 17 is a partial view of the pressure release member shown in FIG. 16. [Figure 18] 10 is a partial view of a housing according to still other embodiments of the present application. [Figure 19] FIG. 19 is a partial view of the pressure release member shown in FIG. 18. [Figure 20] 20 is a cross-sectional view of the pressure release member shown in FIG. 19 . [Figure 21] FIG. 20 is a cross-sectional view of the pressure release member shown in FIG. 19 . [Figure 22] FIG. 22 is a partial enlarged view of a portion J in FIG. 21. [Figure 23] FIG. 22 is a partial enlarged view of a portion K in FIG. 21. [Figure 24] FIG. 2 is an exploded view of a housing according to some embodiments of the present application. [Figure 25] FIG. 10 is an exploded view of a housing according to some alternative embodiments of the present application. [Figure 26] FIG. 10 is an exploded view of a housing according to still other embodiments of the present application. [Figure 27] FIG. 10 is an exploded view of a housing according to still other embodiments of the present application. [Figure 28] 1 is a partial view of a first wall according to some embodiments of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0069] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative efforts fall within the scope of protection of the present application.

[0070] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the brief description of the drawings above are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the drawings above are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0071] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0072] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0073] In the embodiments of the present application, the same reference numerals represent the same elements, and for the sake of brevity, detailed descriptions of the same elements will be omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various elements in the embodiments of the present application shown in the drawings, and the overall thickness, length, width, and other dimensions of the integrated device, are illustrative examples and should not be construed as any limitation on the present application.

[0074] The term "plurality" as used herein refers to two or more (including two).

[0075] In the embodiments of the present application, the battery cell may be a secondary battery, and a secondary battery refers to a battery cell that can be continuously used after being discharged by activating the active material through charging.

[0076] Battery cells include, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead acid batteries, and the like.

[0077] A battery cell generally comprises an electrode assembly, which includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (e.g., lithium ions) shuttle between the positive electrode and the negative electrode, undergoing intercalation and deintercalation. The separator, located between the positive electrode and the negative electrode, serves to reduce the risk of short-circuiting between the positive electrode and the negative electrode while allowing the active ions to pass through.

[0078] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0079] For example, the positive electrode current collector has two surfaces that face each other in the thickness direction thereof, and the positive electrode active material is disposed on one or both of the two facing surfaces of the positive electrode current collector.

[0080] For example, the positive electrode current collector can be a metal foil sheet or a composite current collector. For example, the metal foil sheet can be silver-plated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector can include a polymeric material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0081] For example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO), lithium nickel oxide (e.g., LiNiO), lithium manganese oxide (e.g., LiMnO, LiMnO), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523(may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05 O2) and modifying compounds thereof, and the like.

[0082] In some embodiments, the positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the positive electrode, a positive electrode active material may or may not be provided on the surface of the metal foam. For example, a lithium source material, such as potassium metal or sodium metal, may be filled and / or deposited in the metal foam, and the lithium source material may be lithium metal and / or a lithium-rich material.

[0083] In some examples, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0084] For example, the negative electrode current collector can be a metal foil sheet, a metal foam, or a composite current collector. For example, the metal foil sheet can be made of silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymeric material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0085] For example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0086] For example, the negative electrode current collector has two surfaces that face each other in the thickness direction of the negative electrode current collector, and the negative electrode active material is disposed on either one or both of the two facing surfaces of the negative electrode current collector.

[0087] For example, the negative electrode active material may be any negative electrode active material for battery cells well known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may be selected from at least one of silicon elemental, silicon oxide, silicon carbon composite, silicon nitrogen composite, and silicon alloy. The tin-based material may be selected from at least one of tin elemental, tin oxide, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination.

[0088] In some examples, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

[0089] In some embodiments, the separator is a separator membrane, which can be selected from any well-known separator membrane with a porous structure that has excellent chemical and mechanical stability.

[0090] For example, the separator may be made of at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, and when the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be located between the positive electrode and the negative electrode as a separate component, or may be attached to the surfaces of the positive electrode and the negative electrode.

[0091] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive and negative electrodes and simultaneously serves to transport ions and separate the positive and negative electrodes.

[0092] In some embodiments, the battery cell further includes an electrolyte, which serves as ionic conductor between the positive electrode and the negative electrode. The electrolyte may be in a liquid, gel, or solid state. Here, the liquid electrolyte includes an electrolyte salt and a solvent.

[0093] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0094] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may optionally be an ether-based solvent. The ether-based solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0095] Here, the gel electrolyte comprises a polymer-based electrolyte skeletal network combined with an ionic liquid-lithium salt.

[0096] Here, the solid electrolyte includes polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0097] By way of example, the polymer solid electrolyte may be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0098] By way of example, the inorganic solid electrolyte may include one or more of oxide solid electrolytes (crystalline perovskites, sodium superionic conductors, garnets, amorphous LiPON thin films), sulfide solid electrolytes (crystalline lithium superionic conductors (lithium germanium phosphate sulfur, sulfur silver germanite), amorphous sulfides), and halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0099] For example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0100] In some embodiments, the electrode assembly is a wound structure, in which the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0101] In some embodiments, the electrode assembly is a laminate structure.

[0102] For example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be provided by alternately stacking them.

[0103] For example, multiple positive electrode sheets may be installed, and the negative electrode sheet may be folded to form multiple folded segments that are stacked and installed, with one positive electrode sheet sandwiched between adjacent folded segments.

[0104] By way of example, both the positive and negative electrode sheets are folded to form a plurality of folded segments arranged in a stack.

[0105] For example, a plurality of separators may be provided, and each may be provided between any adjacent positive electrode sheets or negative electrode sheets.

[0106] For example, the separator may be disposed continuously, or may be disposed by folding or winding between any adjacent positive or negative electrode sheets.

[0107] In some embodiments, the electrode assembly may have a cylindrical, flat, or polygonal prism shape.

[0108] In some embodiments, the electrode assembly is provided with tabs that allow current to be conducted from the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab.

[0109] In some embodiments, the battery cell may include a housing for packaging components such as an electrode assembly and an electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0110] For example, the battery cells may be cylindrical battery cells, prismatic battery cells, soft-pack battery cells, or battery cells of other shapes, where the prismatic battery cells include square-housing battery cells, blade-shaped battery cells, and polygonal prism battery cells, and the polygonal prism battery cells are, for example, hexagonal prism battery cells, etc., and are not particularly limited in this application.

[0111] The battery referred to in the examples of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity.

[0112] In some embodiments, the battery may be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0113] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or modules are housed in the housing.

[0114] In some embodiments, the housing may be used as part of a chassis structure of a vehicle, for example, a portion of the housing may form at least a portion of the floor of the vehicle, or a portion of the housing may form at least a portion of the transverse and longitudinal beams of the vehicle.

[0115] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage electrical cabinet, or the like.

[0116] The development of battery technology requires simultaneous consideration of multiple design factors, such as performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge ratio, as well as the safety of the battery cell.

[0117] In order to improve the safety of the battery cell, a pressure release member can be installed on the battery cell, so that if the battery cell experiences thermal runaway, the pressure release member can release the internal pressure of the battery cell. In order to ensure timely pressure release by the pressure release member, a groove can be installed on the pressure release member, so that the pressure release member is thinner at the position where the groove is installed, and when the internal pressure of the battery cell reaches a threshold, the pressure release member will burst at the position of the groove, thereby achieving the purpose of releasing the internal pressure of the battery cell.

[0118] To further improve the timeliness of the pressure release member, the groove of the pressure release member may be divided into multiple segments, such as a first groove segment, a second groove segment, and a third groove segment, where the first groove segment and the third groove segment are arranged opposite each other and the second groove segment connects the first groove segment and the third groove segment. In this way, after the pressure release member bursts along the first groove segment, the second groove segment, and the third groove segment, it has a large pressure release area, thereby achieving rapid pressure release.

[0119] During normal use of the battery cell, the internal pressure of the battery cell may change, and during long-term use, the pressure release member may be deformed due to the pressure change of the battery cell, which may cause the pressure release member to rupture at the position of the second groove segment, especially since the fatigue strength of the middle region of the second groove segment is lower, which may cause the pressure release member to rupture at the position of the second groove segment during normal use of the battery cell, affecting the service life of the battery cell.

[0120] In view of this, an embodiment of the present application provides a battery cell, in which a pressure release member in the battery cell is provided with a first groove. The first groove includes a first groove segment, a second groove segment, and a third groove segment. The first groove segment is provided opposite the third groove segment, and the second groove segment connects the first groove segment and the third groove segment. Both the remaining thickness of the first groove segment and the remaining thickness of the third groove segment are smaller than the remaining thickness of the second groove segment.

[0121] In such a battery cell, the remaining thickness of both the first groove segment and the third groove segment is smaller than the remaining thickness of the second groove segment, which is equivalent to increasing the remaining thickness of the second groove segment. This improves the fatigue strength of the pressure release member in the area where the second groove segment is installed, further reducing the possibility of the pressure release member rupturing at the position of the second groove segment during normal use of the battery cell, improving the long-term reliability of the pressure release member and extending the service life of the battery cell.

[0122] The battery cells described in the embodiments of the present application are applied to batteries and power consuming devices that use the battery cells.

[0123] The power consuming devices may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, etc. The vehicles may be fuel oil vehicles, gas vehicles, or new energy vehicles, and the new energy vehicles may be pure electric vehicles, hybrid vehicles, or range extender vehicles, etc. The spacecraft may include airplanes, rockets, space shuttles, spaceships, etc. The electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric plane toys, etc. The power tools may include metal cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, hammer drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not particularly limit the above power consuming devices.

[0124] In the following embodiment, for ease of explanation, the power consuming device is a vehicle.

[0125] Referring to Fig. 1, Fig. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. A battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, front, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 can function as an operating power source for the vehicle 1000.

[0126] The vehicle 1000 may also include a controller 200 and a motor 300, where the controller 200 is used to control the battery 100 to power the motor 300, for example, for the operating power consumption needs of the vehicle 1000 during startup, navigation, and driving.

[0127] In some embodiments of the present application, the battery 100 can provide not only the operating power source for the vehicle 1000, but also the driving power for the vehicle 1000, in place of, or in place of, fuel oil or natural gas.

[0128] 2, which is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20, and the battery cell 10 is housed within the housing 20.

[0129] Here, the housing 20 is a member that houses the battery cells 10 and provides an accommodation space for the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 may include a first portion 201 and a second portion 202, which cover each other to define an accommodation space for accommodating the battery cells 10. The first portion 201 and the second portion 202 may have various shapes, such as a rectangular parallelepiped or a cylindrical body. The first portion 201 may have a hollow structure with one side open, and the second portion 202 may also have a hollow structure with one side open. When the open side of the second portion 202 is covered by the open side of the first portion 201, the housing 20 having an accommodation space is formed. Alternatively, the first part 201 may have a hollow structure with one side open, and the second part 202 may have a plate-like structure, and when the second part 202 covers the open side of the first part 201, a housing 20 having an accommodation space is formed. The first part 201 and the second part 202 may be sealed by a sealing element, which may be a sealing ring, a sealant, or the like.

[0130] The battery 100 may have one or more battery cells 10. When there are multiple battery cells 10, the multiple battery cells 10 may be connected in series, parallel, or series-parallel, where series-parallel connection means that the multiple battery cells 10 are connected in both series and parallel. First, multiple battery cells 10 may be connected in series, parallel, or series-parallel to form a battery module, and then multiple battery modules may be connected in series, parallel, or series-parallel to form an entire battery module, which is then housed in the housing 20. Alternatively, all of the battery cells 10 may be directly connected in series, parallel, or series-parallel, and then all of the battery cells 10 may be housed in the housing 20 as a whole.

[0131] 3, which is an exploded view of a battery cell 10 according to some embodiments of the present application. The battery cell 10 may include a housing 1 and an electrode assembly 2, and the electrode assembly 2 is housed within the housing 1.

[0132] In some embodiments, the housing 1 may include a case 11 and an end cover 12, where the case 11 has an opening and the end cover 12 seals the opening of the case 11.

[0133] The case 11 is a member for housing the electrode assembly 2, and may have a hollow structure with an opening at one end, or may have openings at opposite ends. The case 11 may have various shapes, such as a cylindrical shape or a rectangular parallelepiped shape. The case 11 may be made of a variety of materials, such as copper, iron, aluminum, steel, and aluminum alloy.

[0134] The end cover 12 is a component that seals the opening of the case 11 and isolates the internal environment of the battery cell 10 from the external environment. The end cover 12 and the case 11 collectively define an accommodation space for accommodating the electrode assembly 2, electrolyte, and other components. The end cover 12 may be connected to the case 11 by welding or seaming to seal the opening of the case 11. The shape of the end cover 12 may match the shape of the housing 1. For example, if the case 11 has a rectangular parallelepiped structure, the end cover 12 may have a rectangular plate-like structure that fits the housing 1. Alternatively, for example, if the case 11 has a cylindrical structure, the end cover 12 may have a circular plate-like structure that fits the case 11. The end cover 12 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic. The end cover 12 and the case 11 may be made of the same or different materials.

[0135] In an embodiment in which the case 11 is a hollow structure with an opening formed at one end, one end cover 12 may be provided correspondingly. In an embodiment in which the case 11 is a hollow structure with openings formed at opposite ends, two end covers 12 may be provided correspondingly, with the two end covers 12 sealing the two openings of the case 11, respectively, and the two end covers 12 and the case 11 jointly defining an accommodating space.

[0136] In some embodiments, the battery cell 10 may further include an electrode terminal 3. The electrode terminal 3 is installed in the housing 1 and electrically connected to a tab 21 of the electrode assembly 2 for outputting electrical energy from the battery cell 10. The electrode terminal 3 may be installed in the case 11 of the housing 1 or in the end cover 12 of the housing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, by direct welding. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, by a current collecting member 4. The current collecting member 4 may be a metal conductor such as copper, iron, aluminum, steel, or an aluminum alloy.

[0137] For example, as shown in FIG. 3 , an opening is formed at one end of the case 11, and there is one end cover 12 in the housing 1, with one end bar 12 sealing one opening of the case 11. Two electrode terminals 3 are installed on the end cover 12, and the two electrode terminals 3 are a positive terminal and a negative terminal, respectively. A positive electrode tab and a negative electrode tab are formed on the end of the electrode assembly 2 facing the end cover 12, and the positive electrode terminal is connected to the positive electrode tab via one current collecting member 4, and the negative electrode terminal is connected to the negative electrode tab via another current collecting member 4.

[0138] 3 , in some embodiments, the battery cell 10 may further include an insulating member 5. The insulating member 5 is a member that separates the case 11 from the electrode assembly 2, and the insulating member 5 provides insulation and separation between the case 11 and the electrode assembly 2. The insulating member 5 is made of an insulating material, and examples of the material of the insulating member 5 include, but are not limited to, plastic, rubber, etc.

[0139] For example, the insulating member 5 is wrapped around the outside of the electrode assembly 2 along the circumferential direction of the opening of the case 11. The number of electrode assemblies 2 in the housing 1 may be one or more. When there is one electrode assembly 2, the insulating member 5 wraps around this electrode assembly 2. When there are multiple electrode assemblies 2, one insulating member 5 may be provided for each electrode assembly 2, and each insulating member 5 may wrap around one electrode assembly 2. Alternatively, multiple electrode assemblies 2 may function as an integrated member, and the insulating member 5 may wrap around this integrated member.

[0140] 4 to 8, Fig. 4 is a structural schematic diagram of a battery cell 10 according to some embodiments of the present application, Fig. 5 is a partial view of the pressure release member 13 shown in Fig. 4, Fig. 6 is a cross-sectional view taken along line AA of the pressure release member 13 shown in Fig. 5, Fig. 7 is a partial enlarged view of part B in Fig. 6, and Fig. 8 is a partial enlarged view of part C in Fig. 6. The embodiments of the present application provide a battery cell 10, which includes a housing 1, which includes a pressure release member 13, which has a first groove 131 formed in the pressure release member 13, and which is configured to be able to rupture along the first groove 131 to release the internal pressure of the battery cell 10. The first groove 131 includes a first groove segment 1311, a second groove segment 1312, and a third groove segment 1313, the first groove segment 1311 is located opposite the third groove segment 1313, the second groove segment 1312 connects the first groove segment 1311 and the third groove segment 1313, and both the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are smaller than the remaining thickness of the second groove segment 1312.

[0141] The pressure release member 13 is a member inside the battery cell 10 for releasing internal pressure of the battery cell 10. The end cover 12 of the housing 1 may be used as the pressure release member 13, or at least a portion of the case 11 of the housing 1 may be used as the pressure release member 13. For example, the housing 1 includes multiple walls that collectively define an internal space of the housing 1, and at least one wall of the housing 1 is used as the pressure release member 13. The pressure release member 13 may be a member independent of the case 11 and the end cover 12. For example, the pressure release member 13 is a member attached to the end cover 12, or for example, the pressure release member 13 is a member attached to the case 11. As can be understood, when the end cover 12 is used as the pressure release member 13, the first groove 131 is provided in the end cover 12, and when at least a portion of the case 11 is used as the pressure release member 13, the first groove 131 is provided in the case 11.

[0142] The first groove 131 may be formed by various methods, such as stamping, milling, or etching. The first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 may be linear grooves extending along a straight line, or may be non-linear grooves extending along a non-linear line, such as arcuate grooves extending along an arcuate line. When the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are linear grooves, the first groove segment 1311 and the third groove segment 1313 may be arranged parallel to each other or at a small angle therebetween, for example, an angle of 10 degrees or less between the first groove segment 1311 and the third groove segment 1313. The first groove segment 1311 and the second groove segment 1312 may be disposed perpendicularly or at an acute or obtuse angle, and the third groove segment 1313 and the second groove segment 1312 may be disposed perpendicularly or at an acute or obtuse angle.

[0143] The second groove segment 1312 may be connected to the first groove segment 1311 and the third groove segment 1313, with both ends of the second groove segment 1312 connected to the first groove segment 1311 and the third groove segment 1313, respectively, or at least one of the first groove segment 1311 and the third groove segment 1313 may be connected at a position away from the end of the second groove segment 1312, with at least one of the first groove segment 1311 and the third groove segment 1313 being located between both ends of the second groove segment 1312. The first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 may be formed in various shapes, such as U-shaped, N-shaped, or H-shaped.

[0144] The first groove segment 1311 and the second groove segment 1312 are connected at a first location 1314, which may be located at one end of the first groove segment 1311 or may be offset from both ends of the first groove segment 1311. The third groove segment 1313 and the second groove segment 1312 are connected at a second location 1315, which may be located at one end of the third groove segment 1313 or may be offset from both ends of the third groove segment 1313. The first groove segment 1311 may be formed with its thinnest point near the first location 1314, and the third groove segment 1313 may be formed with its weakest point near the second location 1315. When the pressure of the battery cell 10 is released, the pressure release member 13 ruptures at the weakest position of the first groove segment 1311 and the weakest position of the third groove segment 1313. Then, the crack spreads along the second groove segment 1312 as it spreads along the first groove segment 1311 and the third groove segment 1313. This shortens the time it takes for the pressure release member 13 to rupture along the first groove 131, improving the timeliness of the pressure release. Here, at least one of the weakest position of the first groove segment 1311 and the weakest position of the third groove segment 1313 may be used as an explosion position that will rupture first when the pressure release member 13 releases pressure. When the internal pressure of the battery cell 10 reaches the explosion pressure, the pressure release member 13 ruptures first from the explosion position.

[0145] The remaining thickness of the first groove segment 1311 refers to the thickness of the remaining part after the first groove segment 1311 of the pressure relief member 13 is installed, and this remaining part may be the groove bottom wall of the first groove segment 1311. The thickness of the groove bottom wall of the first groove segment 1311 may be uniform or non-uniform. When the thickness of the groove bottom wall of the first groove segment 1311 is non-uniform, the thickness at the thinnest position of the groove bottom wall of the first groove segment 1311 is the remaining thickness of the first groove segment 1311. The remaining thickness of the second groove segment 1312 refers to the thickness of the remaining part after the second groove segment 1312 of the pressure relief member 13 is installed, and this remaining part may be the groove bottom wall of the second groove segment 1312. The thickness of the groove bottom wall of the second groove segment 1312 may be uniform or non-uniform. When the thickness of the groove bottom wall of the second groove segment 1312 is non-uniform, the thickness at the thinnest position of the groove bottom wall of the second groove segment 1312 is the remaining thickness of the second groove segment 1312. The remaining thickness of the third groove segment 1​​​​​​​In the embodiment of the present application, the remaining thickness of both the first groove segment 1311 and the third groove segment 1313 is smaller than the remaining thickness of the second groove segment 1312, which is equivalent to increasing the remaining thickness of the second groove segment 1312. This improves the fatigue strength of the pressure release member 13 in the area where the second groove segment 1312 is installed, further reducing the possibility of the pressure release member 13 rupturing at the position of the second groove segment 1312 during normal use of the battery cell 10, improving the long-term reliability of the pressure release member 13, and extending the service life of the battery cell 10.

[0148] In some embodiments, with continued reference to FIG. 7, the depth of the first groove segment 1311 is greater than the depth of the second groove segment 1312, such that the remaining thickness of the first groove segment 1311 is less than the remaining thickness of the second groove segment 1312.

[0149] For example, the pressure release member 13 includes a first surface 132 and a second surface 133 disposed opposite each other along the thickness direction X of the pressure release member, a first groove segment 1311 and a second groove segment 1312 disposed on the first surface 132, the distance between the first surface 132 and the second surface 133 is H0, the distance between the groove bottom surface (first groove bottom surface 1311a) of the first groove segment 1311 and the second surface 133 is D1, the distance between the groove bottom surface (second groove bottom surface 1312a) of the second groove segment 1312 and the second surface 133 is D2, the depth of the first groove segment 1311 is H0-D1, and the depth of the second groove segment 1312 is H0-D2, where H0-D1 > H0-D2. Here, H0 may be the thickness of the pressure release member 13.

[0150] The first groove segment 1311 may include a first groove bottom surface 1311a and two first groove side surfaces 1311b, which are arranged opposite each other along the width direction of the first groove segment 1311 and connected via the first groove bottom surface 1311a. The two first groove side surfaces 1311b may be arranged parallel to each other or at an acute angle. For example, the distance between the two first groove side surfaces 1311b in the width direction of the first groove segment 1311 gradually decreases along the depth direction of the first groove segment 1311, so that the two first groove side surfaces 1311b form inclined slopes. Here, the first groove bottom surface 1311a may be a flat surface or a circular arc surface.

[0151] The second groove segment 1312 may include a second groove bottom surface 1312a and two second groove side surfaces (not shown in FIG. 7 ), which are arranged opposite each other along the width direction of the second groove segment 1312 and connected via the second groove bottom surface 1312a. The two second groove side surfaces may be arranged parallel to each other or at an acute angle. For example, the distance between the two second groove side surfaces in the width direction of the second groove segment 1312 gradually decreases along the depth direction of the second groove segment 1312, resulting in the two second groove side surfaces forming inclined slopes. Here, the second groove bottom surface 1312a may be a flat surface or a circular arc surface.

[0152] During molding, the first groove segment 1311 is machined deeper than the second groove segment 1312 in the pressure release member 13, so that the remaining thickness of the first groove segment 1311 can be made smaller than the remaining thickness of the second groove segment 1312, which is a simple method of implementation.

[0153] In some embodiments, with continued reference to FIG. 8, the depth of the third groove segment 1313 is greater than the depth of the second groove segment 1312, such that the remaining thickness of the third groove segment 1313 is less than the remaining thickness of the second groove segment 1312.

[0154] Here, the thickness of the first groove segment 1311 and the thickness of the third groove segment 1313 may or may not be equal.

[0155] For example, along the thickness direction X of the pressure release member, the pressure release member 13 includes a first surface 132 and a second surface 133 arranged opposite each other, a first groove segment 1311 and a second groove segment 133 arranged on the first surface 132, the distance between the first surface 132 and the second surface 133 is H0, the distance between the groove bottom surface (third groove bottom surface 1313a) of the third groove segment 1313 and the second surface 133 is D3, the distance between the groove bottom surface (second groove bottom surface 1312a) of the second groove segment 1312 and the second surface 133 is D2, the depth of the third groove segment 1313 is H0-D3, and the depth of the second groove segment 1312 is H0-D2, where H0-D3>H0-D2.

[0156] The third groove segment 1313 may include a third groove bottom surface 1313a and two third groove side surfaces 1313b, which are arranged opposite each other along the width direction of the third groove segment 1313 and connected via the third groove bottom surface 1313a. The two third groove side surfaces 1313b may be arranged parallel to each other or at an acute angle. For example, the distance between the two third groove side surfaces 1313b along the width direction of the third groove segment 1313 gradually decreases along the depth direction of the third groove segment 1313, so that the two third groove side surfaces 1313b form inclined slopes. Here, the third groove bottom surface 1313a may be a flat surface or a circular arc surface.

[0157] During molding, the third groove segment 1313 is machined deeper than the second groove segment 1312 in the pressure release member 13, so that the remaining thickness of the third groove segment 1313 can be made smaller than the remaining thickness of the second groove segment 1312, which is a simple method of implementation.

[0158] In some embodiments, the remaining thickness of the first groove segment 1311 is equal to the remaining thickness of the third groove segment 1313 .

[0159] As can be seen, D1 = D3. For example, the depth of the first groove segment 1311 is equal to the depth of the third groove segment 1313, so that the remaining thickness of the first groove segment 1311 is equal to the remaining thickness of the third groove segment 1313.

[0160] When the pressure of the battery cell 10 is released, the synchronization of the pressure release member 13 rupturing along the first groove segment 1311 and the third groove segment 1313 is better, so the time for the pressure release member 13 to rupture along the first groove 131 is further shortened, and the timeliness of pressure release is improved.

[0161] In some embodiments, still referring to FIG. 5, along the extension direction of the second groove segment 1312, both ends of the second groove segment 1312 are connected to the first groove segment 1311 and the third groove segment 1313, respectively.

[0162] Here, one end of the second groove segment 1312 is connected to the first groove segment 1311 at a first location 1314 , and the other end of the second groove segment 1312 is connected to the third groove segment 1313 at a second location 1315 .

[0163] In this embodiment, the two ends of the second groove segment 1312 are connected to the first groove segment 1311 and the third groove segment 1313, respectively, so that the two ends of the second groove segment 1312 do not extend beyond the first groove segment 1311 and the third groove segment 1313, respectively. During the pressure release process, the pressure can be released precisely through the area defined by the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313. This makes it difficult for the pressure release member 13 to burst and release pressure in other areas, making it easier to achieve directional pressure release.

[0164] In some embodiments, the first groove segment 1311 and the second groove segment 1312 are connected at a first position 1314, and along the extension direction of the first groove segment 1311, the first position 1314 is spaced from both ends of the first groove segment 1311.

[0165] The first position 1314 is offset from both ends of the first groove segment 1311, i.e., the first position 1314 is not located at either end of the first groove segment 1311, but is located between both ends of the first groove segment 1311 along the extension direction of the first groove segment 1311. The first position 1314 may be at the midpoint of the first groove segment 1311 or may be offset from the midpoint of the first groove segment 1311.

[0166] During the pressure release process, after the pressure release member 13 ruptures at the first position 1314, the crack can spread from the first position 1314 to both ends along the first groove segment 1311, thereby shortening the time it takes for the pressure release member 13 to rupture along the first groove segment 1311.

[0167] In some embodiments, with continued reference to FIG. 5, the first position 1314 is located at the midpoint of the first groove segment 1311 along the extension direction of the first groove segment 1311 .

[0168] Along the extension direction of the first groove segment 1311, the first position 1314 can divide the first groove segment 1311 into two parts of equal length.

[0169] During the pressure release process, the cracks spread the same distance along the first groove segment 1311 from the first position 1314 to both ends, further reducing the time it takes for the pressure release member 13 to burst along the first groove segment 1311.

[0170] In some embodiments, still referring to FIG. 5 , the third groove segment 1313 and the second groove segment 1312 are connected at a second position 1315, and along the extension direction of the third groove segment 1313, the second position 1315 is offset from both ends of the third groove segment 1313.

[0171] The second position 1315 is offset from both ends of the third groove segment 1313, i.e., the second position 1315 is not located at either end of the third groove segment 1313, but is located between both ends of the third groove segment 1313 along the extension direction of the third groove segment 1313. The second position 1315 may be at the midpoint of the third groove segment 1313 or may be offset from the midpoint of the third groove segment 1313.

[0172] When the first position 1314 is off both ends of the first groove segment 1311 and the second position 1315 is off both ends of the third groove segment 1313, the first groove segment 1311, the second groove segment 1312 and the third groove segment 1313 jointly define two pressure release areas 134, which are located on both sides of the second groove segment 1312. During the pressure release process, both pressure release areas 134 can be opened, which effectively improves the timeliness of the pressure release.

[0173] In this embodiment, the second position 1315 is off both ends of the third groove segment 1313, and during the pressure release process, after the pressure release member 13 ruptures at the second position 1315, the crack can spread from the second position 1315 to both ends along the third groove segment 1313, thereby shortening the time it takes for the pressure release member 13 to rupture along the third groove segment 1313.

[0174] In some embodiments, with continued reference to FIG. 5, the second position 1315 is located at the midpoint of the third groove segment 1313 along the extension direction of the third groove segment 1313 .

[0175] Along the extension direction of the third groove segment 1313, the second position 1315 can divide the third groove segment 1313 into two parts of equal length.

[0176] During the pressure release process, the cracks spread the same distance along the third groove segment 1313 from the second position 1315 to both ends, further reducing the time it takes for the pressure release member 13 to burst along the third groove segment 1313.

[0177] In some embodiments, and with continued reference to FIG. 5, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are all grooves that extend along a linear locus.

[0178] The first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are all straight grooves. The first groove segment 1311 and the second groove segment 1312 may be perpendicular or may be disposed at an acute or obtuse angle. The third groove segment 1313 and the second groove segment 1312 may be perpendicular or may be disposed at an acute or obtuse angle. The lengths of the first groove segment 1311 and the third groove segment 1313 may or may not be equal.

[0179] In this embodiment, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are all linear grooves, which reduces the difficulty of forming the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313.

[0180] In some embodiments, with continued reference to FIG. 5, the first groove segment 1311 is perpendicular to the second groove segment 1312 and / or the third groove segment 1313 is perpendicular to the second groove segment 1312.

[0181] As can be appreciated, if the first groove segment 1311 is perpendicular to the second groove segment 1312, the third groove segment 1313 can be perpendicular to the second groove segment 1312, and the third groove segment 1313 and the second groove segment 1312 can be disposed at an acute or obtuse angle. If the third groove segment 1313 is perpendicular to the second groove segment 1312, the first groove segment 1311 can be perpendicular to the second groove segment 1312, and the first groove segment 1311 and the second groove segment 1312 can be disposed at an acute or obtuse angle.

[0182] When the first groove segment 1311 is perpendicular to the second groove segment 1312, stress is more concentrated near the connection position (first position 1314) between the first groove segment 1311 and the second groove segment 1312. Therefore, for a given explosion pressure of the battery cell 10, the processing depth of the first groove segment 1311 can be reduced, making it easier to process the first groove segment 1311. That is, because stress is more concentrated near the connection position between the first groove segment 1311 and the second groove segment 1312, even if the remaining thickness of the first groove 1311 is increased, the pressure release member 13 can still rupture near the connection position between the first groove segment 1311 and the second groove segment 1312 when the internal pressure of the battery cell 10 reaches the explosion pressure. When the third groove segment 1313 is perpendicular to the second groove segment 1312, stress is more concentrated near the connection position (second position 1315) between the third groove segment 1313 and the second groove segment 1312. Therefore, for a given explosion pressure of the battery cell 10, the processing depth of the third groove segment 1313 can be reduced, reducing the difficulty of processing the third groove segment 1313. That is, because stress is more concentrated near the connection position between the third groove segment 1313 and the second groove segment 1312, even if the remaining thickness of the third groove segment 1313 is increased, the pressure release member 13 can still rupture near the connection position between the third groove segment 1313 and the second groove segment 1312 when the internal pressure of the battery cell 10 reaches the explosion pressure.

[0183] In some embodiments, referring to Figure 9, Figure 9 is a partial view of a pressure release member 13 according to some other embodiments of the present application. The first groove 131 further includes at least one fourth groove segment 1316, which is located between the first groove segment 1311 and the third groove segment 1313 and is connected to the second groove segment 1312.

[0184] The first groove 131 may have one or more fourth groove segments 1316. The fourth groove segment 1316 may be formed by various methods, such as stamping, milling, and etching. The fourth groove segment 1316 may be a linear groove extending along a straight line, or a non-linear groove extending along a non-linear line, such as an arcuate groove extending along a circular line. When the fourth groove segment 1316 is a linear groove, the fourth groove segment 1316 and the second groove segment 1312 may be perpendicular or may form an acute or obtuse angle. The connection point between the fourth groove segment 1316 and the second groove segment 1312 may be located at one end of the fourth groove segment 1316; for example, the fourth groove segment 1316 and the second groove segment 1312 form a "T"-shaped structure. The connection points between the fourth groove segment 1316 and the second groove segment 1312 may be offset from both ends of the fourth groove segment 1316, for example, the fourth groove segment 1316 and the second groove segment 1312 form a "cross" shaped structure.

[0185] For example, in FIG. 9, the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the fourth groove segment 1316 are all linear grooves, and the first groove segment 1311, the third groove segment 1313, and the fourth groove segment 1316 are all perpendicular to the second groove segment 1312.

[0186] Since the remaining thickness of the second groove segment 1312 is greater than the remaining thicknesses of the first groove segment 1311 and the third groove segment 1313, the second groove segment 1312 is less likely to rupture than the first groove segment 1311 and the third groove segment 1313. If the second groove segment 1312 is too long, the pressure relief member 13 may not be able to rupture completely along the second groove segment 1312. After installing the fourth groove segment 1316, the stress at the connection position between the second groove segment 1312 and the fourth groove segment 1316 becomes more concentrated, forming a stress concentration area. The strength of the second groove segment 1312 at this position becomes weaker and it is more likely to be damaged, reducing the difficulty for the pressure relief member 13 to rupture along the second groove segment 1312.

[0187] In some embodiments, referring to FIGS. 9 to 11, FIG. 10 is a cross-sectional view of the D-D position of the pressure relief member 13 shown in FIG. 9, and FIG. 11 is a partial enlarged view of the E position in FIG. 10. Both the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are smaller than the remaining thickness of the fourth groove segment 1316.

[0188] The remaining thickness of the fourth groove segment 1316 is the thickness of the remaining part after installing the fourth groove segment 1316 of the pressure relief member 13, and this remaining part may be the groove bottom wall of the fourth groove segment 1316. The thickness of the groove bottom wall of the fourth groove segment 1316 may be uniform or non-uniform. When the thickness of the groove bottom wall of the fourth groove segment 1316 is non-uniform, the thickness at the thinnest position of the groove bottom wall of the fourth groove segment 1316 is the remaining thickness of the fourth groove segment 1316.

[0189] Here, the remaining thickness of the fourth groove segment 1316 is D4. As can be understood, D1 < D4 and D3 < D4. D4 may be greater than or equal to D2 or less than D2.

[0190] In this embodiment, since both the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are smaller than the remaining thickness of the fourth groove segment 1316, the connection position between the fourth groove segment 1316 and the second groove segment 1312 is less likely to rupture than the connection position between the first groove segment 1311 and the second groove segment 1312 and the connection position between the third groove segment 1313 and the second groove segment 1312. The pressure relief member 13 reduces the possibility of deformation due to external force during the normal use process of the battery cell 10 and rupturing from the connection position between the fourth groove segment 1316 and the second groove segment 1312, thereby extending the service life of the battery cell 10.

[0191] In some embodiments, continuing to refer to FIG. 9, the fourth groove segment 1316 is one.

[0192] As can be understood, in the first groove, there is only one fourth groove segment 1316 connected to the second groove segment 1312. In this way, the structure of the first groove 131 is simplified and the manufacturing cost is reduced. The fourth groove segment 1316 may be installed at the midpoint position of the second groove segment 1312 or may be offset from the midpoint position of the second groove segment 1312.

[0193] In some embodiments, the second groove segment 1312 and the fourth groove segment 1316 are connected at the third position 1317. Along the extending direction of the second groove segment 1312, the distance between the third position 1317 and the first groove segment 1311 is L1, and the distance between the third position 1317 and the third groove segment 1313 is L2, satisfying |L1 - L2| ≤ 1 mm.

[0194] Here, L1 > L2 may be true, whereby the third groove segment 1313 is closer to the fourth groove segment 1316 than the first groove segment 1311. L1 < L2 may also be true, whereby the first groove segment 1311 is closer to the fourth groove segment 1316 than the third groove segment 1313. Of course, L1 = L2 may also be true.

[0195] |L1-L2| may be any one point value of 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc. or a range value between any two.

[0196] In this embodiment, when |L1-L2|≦1 mm, the third position 1317 can be located as centrally as possible in the extension direction of the second groove segment 1312, thereby reducing the difficulty of the pressure release member 13 rupturing along the second groove segment 1312. For example, when pressure is released, an explosion position of the pressure release member 13 is formed near only one of the first position 1314 and the second position 1315, and the pressure release member 13 ruptures along the second groove segment 1312 from the previously opened position to the other. Regardless of whether the explosion position is near the first position 1314 or the second position 1315, locating the third position 1317 as centrally as possible in the second groove segment 1312 contributes to the pressure release member 13 rupturing along the second groove segment 1312.

[0197] In some embodiments, |L1-L2|≦0.5 mm.

[0198] |L1-L2| may be any one point value or a range value between any two of 0.1 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.35 mm, 0.38 mm, 0.4 mm, 0.45 mm, 0.48 mm, 0.5 mm, etc.

[0199] In this embodiment, if |L1-L2|≦0.5 mm, the difficulty of the pressure release member 13 rupturing along the second groove segment 1312 is further reduced.

[0200] In some embodiments, there are multiple fourth groove segments 1316, and the multiple fourth groove segments 1316 are spaced apart along the extension direction of the second groove segment 1312. Multiple stress concentration portions can be formed at the connection positions between the second groove segment 1312 and the multiple fourth groove segments 1316, which can further reduce the difficulty of the pressure release member 13 rupturing along the second groove segment 1312.

[0201] 12, which is a partial view of a pressure release member 13 according to some embodiments of the present application. A plurality of fourth groove segments 1316 are uniformly distributed in the second groove segment 1312 along the extension direction of the second groove segment 1312, the length of the portion of the second groove segment 1312 located between the first groove segment 1311 and the third groove segment 1313 is L3, the number of fourth groove segments 1316 is N, and L3 / N≦25 mm is satisfied.

[0202] In an embodiment in which both ends of the second groove segment 1312 are connected to the first groove segment 1311 and the third groove segment 1313, respectively, the entire second groove segment 1312 is located between the first groove segment 1311 and the third groove segment 1313, and the length of the portion of the second groove segment 1312 located between the first groove segment 1311 and the third groove segment 1313 is the length of the second groove segment 1312.

[0203] The N fourth groove segments 1316 can divide the second groove segment 1312 into N+1 segments, and because the N fourth groove segments 1316 are uniformly distributed in the second groove segment 1312, the lengths of the N+1 segments in the second groove segment 1312 are substantially equal. For example, in FIG. 12 , there are three fourth groove segments 1316, and the three fourth groove segments 1316 divide the second groove segment 1312 into four segments, and the lengths of the four segments in the second groove segment 1312 are substantially equal.

[0204] L3 / N may be any one point value of 1 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm, 23 mm, 25 mm, etc. or a range value between any two of them.

[0205] In this embodiment, when L3 / N≦25 mm, the distance between two adjacent stress concentration points on the second groove segment 1312 is not too large, so that a crack that occurs in the pressure release member 13 on the second groove segment 1312 can more easily spread from one stress concentration point to another, thereby reducing the difficulty of the pressure release member 13 rupturing along the second groove segment 1312.

[0206] In some embodiments, 8 mm≦L3 / N≦20 mm.

[0207] L3 / N may be any one point value of 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc. or a range value between any two of them.

[0208] In this embodiment, when 8 mm≦L3 / N≦20 mm, the distance between two adjacent stress concentrations on the second groove segment 1312 is further reduced, so that a crack occurring in the pressure release member 13 on the second groove segment 1312 can more easily spread from one stress concentration to another. Naturally, the distance between two adjacent stress concentrations on the second groove segment 1312 is not too small, which reduces the possibility of the pressure release member 13 rupturing along the second groove segment 1312 during normal use of the battery cell 10, which would be caused by two stress concentrations being too close to each other.

[0209] In some embodiments, 20 mm≦L3≦150 mm.

[0210] L3 may be any one point value such as 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, etc., or a range value between any two.

[0211] When L3<20mm, the distance between the first groove segment 1311 and the third groove segment 1313 is small, the pressure release area of ​​the pressure release member 13 is small, and the pressure release efficiency of the pressure release member 13 is low. When L3>150mm, the length of the second groove segment 1312 is too long, and the fatigue strength of the pressure release member 13 in the middle region of the second groove segment 1312 is low. In contrast, when 20mm≦L3≦150mm, not only can the pressure release area of ​​the pressure release member 13 be increased, but the fatigue strength of the pressure release member 13 at the position of the second groove segment 1312 can also be improved.

[0212] In some embodiments, 10 mm≦L3≦100 mm.

[0213] L3 may be any one point value such as 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, etc., or a range value between any two.

[0214] In some embodiments, the length of the fourth groove segment 1316 is L4 and the length of the first groove segment 1311 is L5, where L4 / L5≦1 / 4.

[0215] L4 / L5 may be any one point value such as 1 / 15, 1 / 14, 1 / 13, 1 / 12, 1 / 11, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, etc., or a range value between any two of them.

[0216] If L4 / L5 > 1 / 4, the length of the fourth groove segment 1316 is too long, reducing the fatigue strength of the pressure release member 13 at the position of the fourth groove segment 1316. This makes it more likely that the pressure release member 13 will be easily damaged during normal use of the battery cell 10, affecting the service life of the battery cell 10. Furthermore, if a crack propagates along the second groove segment 1312 during the pressure release process, when the crack propagates to the connection position between the second groove segment 1312 and the fourth groove segment 1316, it will tend to propagate along the fourth groove segment 1316 rather than continuing to propagate along the second groove segment 1312. As a result, the pressure release member 13 will not be able to completely rupture along the second groove segment 1312, and the pressure release area of ​​the pressure release member 13 will be reduced. In contrast, when L4 / L5≦1 / 4, the service life of the battery cell 10 can be effectively extended, and the pressure release member 13 can completely burst along the second groove segment 1312 when the pressure of the battery cell 10 is released, thereby increasing the pressure release area of ​​the pressure release member 13.

[0217] In some embodiments, L4 / L5≦1 / 6.

[0218] In this embodiment, L4 / L5 may be any one of point values ​​such as 1 / 15, 1 / 14, 1 / 13, 1 / 12, 1 / 11, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, etc., or a range value between any two of them.

[0219] In this embodiment, when L4 / L5≦1 / 6, the influence of the fourth groove segment 1316 on the service life of the battery cell 10 and the pressure release area of ​​the pressure release member 13 is further reduced.

[0220] 13, which is a partial view of a pressure release member 13 according to some embodiments of the present application. A first groove segment 1311, a second groove segment 1312, and a third groove segment 1313 define a pressure release region 134. A guide groove 135 is provided in the pressure release member 13 and is spaced apart from the second groove segment 1312. The guide groove 135 is configured to guide the pressure release region 134 to reverse and open.

[0221] The pressure release area 134 is an area defined by the first groove segment 1311, the second groove segment 1312 and the third groove segment 1313 of the pressure release member 13, and the first groove segment 1311, the second groove segment 1312 and the third groove segment 1313 are located at the edge positions of the pressure release area 134, and when the pressure release member 13 ruptures along the first groove segment 1311, the second groove segment 1312 and the third groove segment 1313, the pressure release area 134 can be inverted outward and opened. The first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 can define one pressure release area 134, for example, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are sequentially connected to form a U-shaped structure, or the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 can also define two pressure release areas 134, for example, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 form an H-shaped structure.

[0222] In an embodiment in which the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are sequentially connected to form a U-shaped structure, the connecting line between the end of the first groove segment 1311 remote from the second groove segment 1312 and the end of the third groove segment 1313 remote from the second groove segment 1312 is the first connecting line, and the area jointly surrounded by the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the first connecting line is the pressure release area 134. In an embodiment in which the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 form an H-shaped structure, the connecting line between one end of the first groove segment 1311 and one end of the third groove segment 1313 is the second connecting line, the connecting line between the other end of the first groove segment 1311 and the other end of the third groove segment 1313 is the third connecting line, the area surrounded by the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the second connecting line is one pressure release region 134, and the area surrounded by the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the third connecting line is the other pressure release region 134.

[0223] The guide groove 135 is a groove provided in the pressure release member 13 that contributes to the reversal and opening of the pressure release area 134. The guide groove 135 may be a linear groove or a non-linear groove such as an arc-shaped groove. For example, the guide groove 135 is a linear groove parallel to the second groove segment 1312.

[0224] For example, the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are both smaller than the remaining thickness of the guide groove 135 .

[0225] In this embodiment, the installation of the guide groove 135 contributes to the reversal and opening of the pressure release area 134, reduces the difficulty of reversing the pressure release area 134, and effectively improves the timeliness of pressure release.

[0226] 13, in some embodiments, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 define two pressure relief areas 134, each located on either side of the second groove segment 1312. The pressure relief member 13 is provided with two guide grooves 135, and the second groove segment 1312 is located between the two guide grooves 135, which are configured to guide the two pressure relief areas 134 to reverse and open.

[0227] The areas of the two pressure relief regions 134 may or may not be equal. For example, the two pressure relief regions 134 are symmetrically distributed on both sides of the second groove segment 1312. In FIG. 13 , the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are all linear grooves. The first groove segment 1311 is parallel to the third groove segment 1313, the first groove segment 1311 is perpendicular to the second groove segment 1312, the length of the first groove segment 1311 is equal to the length of the third groove segment 1313, and the second groove segment 1312 is connected to the midpoint of the first groove segment 1311 and the midpoint of the third groove segment 1313, thereby realizing the two pressure relief regions 134 being symmetrically distributed on both sides of the second groove segment 1312.

[0228] For example, the two guide grooves 135 are parallel to the second groove segment 1312, the distances between the two guide grooves 135 and the second groove segment 1312 are equal, and the two guide grooves 135 are symmetrically distributed on both sides of the second groove segment 1312.

[0229] During the pressure release process, the two guide grooves 135 respectively play a guiding role for the two pressure release areas 134, thereby improving the release speed of the two pressure release areas 134 and enabling the pressure to be released in a more timely manner.

[0230] In some embodiments, both the first groove segment 1311 and the third groove segment 1313 do not contact the guide groove 135 .

[0231] The first groove segment 1311 does not contact the guide groove 135, i.e., the first groove segment 1311 is not connected to the guide groove 135. The first groove segment 1311 and the guide groove 135 may be spaced apart so as to be non-contacting, for example, the first groove segment 1311 and the guide groove 135 may be spaced apart along the extension direction of the first groove segment 1311 and / or the first groove segment 1311 and the guide groove 135 may be spaced apart along the extension direction of the guide groove 135 and / or the first groove segment 1311 and the guide groove 135 may be spaced apart along the thickness direction X of the pressure release member. The third groove segment 1313 does not contact the guide groove 135, i.e., the third groove segment 1313 is not connected to the guide groove 135. The third groove segment 1313 and the guide groove 135 may be spaced apart so as to be out of contact with each other, for example, the third groove segment 1313 and the guide groove 135 may be spaced apart along the extension direction of the third groove segment 1313, and / or the third groove segment 1313 and the guide groove 135 may be spaced apart along the extension direction of the guide groove 135, and / or the third groove segment 1313 and the guide groove 135 may be spaced apart along the thickness direction X of the pressure release member.

[0232] In this embodiment, neither the first groove segment 1311 nor the third groove segment 1313 contacts the guide groove 135, and the guide groove 135 is less likely to affect the first groove segment 1311 and the third groove segment 1313. This improves the fatigue strength of the pressure release member 13 at the first groove segment 1311 and the third groove segment 1313, and reduces the possibility of the pressure release member 13 rupturing at the connection position during normal use of the battery cell 10 due to stress concentration caused by the connection between the guide groove 135 and the first groove segment 1311 and the third groove segment 1313. Furthermore, after the pressure release member 13 ruptures along the first groove segment 1311 and the third groove segment 1313 during the pressure release process, the crack is less likely to spread to the guide groove 135, reducing the possibility of the pressure release member 13 rupturing and scattering after the pressure release area 134 opens.

[0233] In some embodiments, referring to Figure 14, Figure 14 is an FF cross-sectional view of the pressure release member 13 shown in Figure 13. Along the thickness direction X of the pressure release member, a guide groove 135 and a first groove 131 are respectively installed on both sides of the pressure release member 13.

[0234] During molding, the guide groove 135 can be molded on one side of the pressure release member 13 along the thickness direction X of the pressure release member, and then the first groove 131 can be molded on the other side of the pressure release member 13. In some embodiments, the first groove 131 faces the outside of the housing 1, and the guide groove 135 faces the inside of the housing 1. In other embodiments, the first groove 131 faces the inside of the housing 1, and the guide groove 135 faces the outside of the housing 1.

[0235] For example, along the thickness direction X of the pressure release member, the pressure release member 13 may include a first surface 132 and a second surface 133 disposed opposite to each other, and the first groove 131 may be disposed on the first surface 132, and the guide groove 135 may be disposed on the second surface 133. As can be seen, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are all disposed on the first surface 132, and in an embodiment in which the first groove 131 includes a fourth groove segment 1316, the fourth groove segment 1316 is also disposed on the first surface 132.

[0236] In this embodiment, the guide groove 135 and the first groove 131 are respectively installed on both sides of the thickness direction of the pressure release member 13, so that the influence of the guide groove 135 on the first groove 131 during molding is reduced; on the other hand, the guide groove 135 can exert a better guiding effect on the pressure release area 134, so that the pressure release area 134 can be more easily inverted and released.

[0237] In some embodiments, with continued reference to FIG. 13, the guide groove 135 extends along the extension direction of the second groove segment 1312.

[0238] As can be seen, the extension direction of the guide groove 135 coincides with the extension direction of the second groove segment 1312. In some embodiments, both the guide groove 135 and the second groove segment 1312 are grooves extending along arcuate loci, and when observed along the thickness direction X of the pressure release member, the center of the arcuate locus of the guide groove 135 overlaps with the center of the arcuate locus of the second groove segment 1312. In other embodiments, as shown in FIG. 13 , both the guide groove 135 and the second groove segment 1312 are grooves extending along linear loci, and the guide groove 135 is parallel to the second groove segment 1312.

[0239] In this embodiment, since the guide groove 135 extends along the extending direction of the second groove segment 1312, the pressure release area 134 can reverse and open more regularly.

[0240] In some embodiments, still referring to FIG. 13 , along the extension direction of the second groove segment 1312, the first groove segment 1311 and the third groove segment 1313 are located on either side of the guide groove 135, respectively, the length of the portion of the second groove segment 1312 located between the first groove segment 1311 and the third groove segment 1313 is L3, and the length of the guide groove 135 is L6, satisfying 1 mm≦L3−L6≦10 mm.

[0241] Along the extension direction of the second groove segment 1312, one end of the guide groove 135 and the first groove segment 1311 are spaced apart, and the other end of the guide groove 135 and the third groove segment 1313 are spaced apart, and there is a distance between them. For example, along the extension direction of the second groove segment 1312, the distance between one end of the guide groove 135 and the first groove segment 1311 is equal to the distance between the other end of the guide groove 135 and the third groove segment 1313.

[0242] L3-L6 may be any one point value of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc. or a range value between any two.

[0243] When L3-L6<1 mm, the distance between at least one of the first groove segment 1311 and the third groove segment 1313 and the guide groove 135 is small, and the influence of the guide groove 135 on at least one of the first groove segment 1311 and the third groove segment 1313 is large. This increases the possibility of the pressure release member 13 prematurely bursting at a position close to the guide groove 135 of the first groove segment 1311 or the third groove segment 1313, increasing the possibility of premature pressure release. When L3-L6>10 mm, the length of the guide groove 135 is short, and the guide groove 135's ability to contribute to the reversal of the pressure release region 134 is low. In contrast, when 1 mm≦L3-L6≦10 mm, not only is the possibility of the pressure release member 13 prematurely releasing pressure reduced, but the guide groove 135's ability to contribute to the reversal and release of the pressure release region 134 is also improved.

[0244] In some embodiments, 2 mm≦L3−L6≦6 mm.

[0245] In this embodiment, L3-L6 may be any one of the following point values ​​or a range value between any two of 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.3mm, 5.5mm, 5.8mm, 6mm, etc.

[0246] In this embodiment, when 2 mm≦L3-L6≦6 mm, the possibility that the pressure release member 13 will release the pressure prematurely is further reduced, and the guiding ability of the guide groove 135 to contribute to the reversal and opening of the pressure release area 134 is further improved.

[0247] In some embodiments, still referring to FIG. 13, the distance between the guide groove 135 and the second groove segment 1312 along the extension direction of the first groove segment 1311 is L7, and the length of the portion of the first groove segment 1311 extending from the second groove segment 1312 toward the guide groove 135 is L8, where 0.5 mm|≦L7-L8|≦15 mm.

[0248] The distance between the guide groove 135 and the second groove segment 1312 is equal to the length of the shortest connecting line between the guide groove 135 and the second groove segment 1312, and the shortest connecting line coincides with the extension direction of the first groove segment 1311.

[0249] In the embodiment where L7>L8, the guide groove 135 contributes more to the reversal and opening of the pressure release area 134.

[0250] |L7-L8| may be any one point value of 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc. or a range value between any two of them.

[0251] When |L7 - L8| < 0.5 mm, since the distance between the end of the first groove segment 1311 and the guide groove 135 is small, when a crack in the pressure relief member 13 diffuses along the first groove segment 1311 to the end of the first groove segment 1311, the crack easily diffuses into the guide groove 135. As a result, the pressure relief area 134 detaches. When |L7 - L8| > 15 mm and L7 > L8, the distance between the guide groove 135 and the second groove segment 1312 is large, and the ability to contribute to the inversion of the pressure relief area 134 of the guide groove 135 is low. When L7 < L8, the distance between the guide groove 135 and the second groove segment 1312 is small, the area of the inverted opening of the pressure relief area 134 is small, and the pressure relief area of the pressure relief area 134 decreases. In contrast, when 0.5 mm ≤ |L7 - L8| ≤ 15 mm, not only can the possibility of detachment and scattering of the pressure relief area 134 be reduced, but also the difficulty of the inverted opening of the pressure relief area 134 can be lowered, and the opening area of the pressure relief area 134 can be increased.

[0252] In some embodiments, 1 mm ≤ |L7 - L8| ≤ 10 mm.

[0253] In this embodiment, |L7 - L8| may be any one of the point values such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm or a range value between any two of them.

[0254] In some embodiments, referring to FIGS. 15 and 16, FIG. 15 is a schematic structural view of the battery cell 10 according to some other embodiments of the present application, and FIG. 16 is a partial enlarged view of the F portion of FIG. 15. A second groove 136 is provided in the pressure relief member 13, and the first groove 131 is provided on the groove bottom surface of the second groove 136.

[0255] The first groove 131 is located on the groove bottom surface of the second groove 136, and as can be seen, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 of the first groove 131 are all located on the groove bottom surface of the second groove 136. In an embodiment in which the first groove 131 further includes a fourth groove segment 1316, the fourth groove segment 1316 is also located on the groove bottom surface of the second groove 136. The first groove 131 and the second groove 136 may be aligned along the thickness direction X (not shown in FIGS. 15 and 16 ) of the pressure release member. During molding, the second groove 136 can be molded in the pressure release member 13, and then the first groove 131 can be molded on the groove bottom surface of the second groove 136.

[0256] 16 , the second groove 136 may have the same shape as the first groove 131. For example, the first groove 131 may be an H-shaped groove, and the second groove 136 may also be an H-shaped groove. In other examples, the second groove 136 may have a different shape from the first groove 131. For example, the first groove 131 may be an H-shaped groove, and the second groove 136 may be a circular groove or a rectangular groove. A circular groove is a groove with a circular cross section, and a rectangular groove is a groove with a rectangular cross section. The cross section of the circular groove is perpendicular to the depth direction of the circular groove, and the cross section of the rectangular groove is perpendicular to the depth direction of the rectangular groove. The second groove 136 may be formed by various methods, such as stamping, milling, and etching. For example, if the second groove 136 is a rectangular groove and both the first groove 131 and the second groove 136 are formed in the pressure release member 13 by stamping, during molding, the rectangular second groove 136 can be stamped into the pressure release member 13, and then the first groove 131 can be stamped into the bottom surface of the second groove 136.

[0257] In this embodiment, by installing the second groove 136, the molding depth of the first groove 131 is reduced, the molding force received by the pressure release member 13 when the first groove 131 is molded is reduced, and the possibility of cracks occurring in the pressure release member 13 when the first groove 131 is molded is reduced.

[0258] 17, in some embodiments, Figure 17 is a partial view of the pressure release member 13 shown in Figure 16. The second groove 136 includes a fifth groove segment 1361, a sixth groove segment 1362, and a seventh groove segment 1363, where the fifth groove segment 1361 and the seventh groove segment 1363 are disposed opposite each other, and the sixth groove segment 1362 connects the fifth groove segment 1361 and the seventh groove segment 1363. The first groove segment 1311 is disposed on the groove bottom surface of the fifth groove segment 1361, the second groove segment 1312 is disposed on the groove bottom surface of the sixth groove segment 1362, and the third groove segment 1313 is disposed on the groove bottom surface of the seventh groove segment 1363.

[0259] The fifth groove segment 1361 can coincide with the extension direction of the first groove segment 1311, the sixth groove segment 1362 can coincide with the extension direction of the second groove segment 1312, and the seventh groove segment 1363 can coincide with the extension direction of the third groove segment 1313, so that the shape of the second groove 136 substantially coincides with the shape of the first groove 131. The groove width of the fifth groove segment 1361 is larger than the groove width of the first groove segment 1311, the groove width of the sixth groove segment 1362 is larger than the groove width of the second groove segment 1312, and the groove width of the seventh groove segment 1363 is larger than the groove width of the third groove segment 1313. For example, the groove bottom surfaces of the fifth groove segment 1361, the sixth groove segment 1362, and the seventh groove segment 1363 are located on the same plane.

[0260] 17, in an embodiment in which the first groove 131 further includes a fourth groove segment 1316, the groove side of the sixth groove segment 1362 may be recessed at a position corresponding to the fourth groove segment 1316 to form a first recess 1364 to provide a molding space for the fourth groove segment 1316. The first recess 1364 may be arc-shaped, and the radius of the first recess 1364 may be 0.5 mm to 2 mm.

[0261] In this embodiment, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 are respectively installed on the groove bottom surfaces of the fifth groove segment 1361, the sixth groove segment 1362, and the seventh groove segment 1363, so that each groove segment in the second groove 136 corresponds to each groove segment in the first groove 131, thereby effectively reducing the space occupied by the second groove 136 in the pressure release member 13 and improving the strength of the pressure release member 13.

[0262] 18 and 19, in some embodiments, Fig. 18 is a partial view of a housing 1 according to further some embodiments of the present application, and Fig. 19 is a partial view of a pressure release member 13 shown in Fig. 18. The pressure release member 13 is provided with a third groove 137, which includes an eighth groove segment 1371, a ninth groove segment 1372, and a tenth groove segment 1373, the eighth groove segment 1371 and the tenth groove segment 1373 being disposed opposite each other, and the ninth groove segment 1372 connecting the eighth groove segment 1371 and the tenth groove segment 1373. The fifth groove segment 1361 is disposed on the groove bottom surface of the eighth groove segment 1371, the sixth groove segment 1362 is disposed on the groove bottom surface of the ninth groove segment 1372, and the seventh groove segment 1363 is disposed on the groove bottom surface of the tenth groove segment 1373.

[0263] The eighth groove segment 1371 can coincide with the extension direction of the fifth groove segment 1361, the ninth groove segment 1372 can coincide with the extension direction of the sixth groove segment 1362, and the tenth groove segment 1373 can coincide with the extension direction of the seventh groove segment 1363, so that the shape of the third groove 137 substantially coincides with the shape of the second groove 136. The groove width of the eighth groove segment 1371 is larger than the groove width of the fifth groove segment 1361, the groove width of the ninth groove segment 1372 is larger than the groove width of the sixth groove segment 1362, and the groove width of the tenth groove segment 1373 is larger than the groove width of the seventh groove segment 1363. For example, the groove bottom surfaces of the eighth groove segment 1371, the ninth groove segment 1372, and the tenth groove segment 1373 are located on the same plane.

[0264] 19 , a position of the groove side of the ninth groove segment 1372 corresponding to the first recess 1364 can be recessed to form a second recess 1374 to provide a molding space for the first recess 1364. Both the second recess 1374 and the first recess 1364 can be arc-shaped, with the radius of the second recess 1374 being larger than the radius of the first recess 1364.

[0265] In this embodiment, the fifth groove segment 1361, the sixth groove segment 1362, and the seventh groove segment 1363 are respectively installed on the groove bottom surfaces of the eighth groove segment 1371, the ninth groove segment 1372, and the tenth groove segment 1373, so that each groove segment in the third groove 137 corresponds to each groove segment in the second groove 136, thereby effectively reducing the space occupied by the third groove 137 in the pressure release member 13 and improving the strength of the pressure release member 13.

[0266] In some embodiments, the pressure release member 13 has a third groove 137 formed therein, and the second groove 136 is formed at the bottom of the third groove 137 .

[0267] The first groove 131, the second groove 136, and the third groove 137 may be arranged in the thickness direction X of the pressure release member. When the first groove 131, the second groove 136, and the third groove 137 are formed in the pressure release member 13, the third groove 137 can be formed in the pressure release member 13, then the second groove 136 can be formed on the bottom surface of the third groove 137, and finally the first groove 131 can be formed on the bottom surface of the second groove 136.

[0268] 19 , the third groove 137 may have the same shape as the second groove 136, for example, the second groove 136 is an H-shaped groove and the third groove 137 is also an H-shaped groove. In other examples, the third groove 137 may have a different shape from the second groove 136, for example, the second groove 136 is an H-shaped groove and the third groove 137 is a circular groove or a rectangular groove. The third groove 137 may be formed by various methods, such as stamping, milling, and etching. For example, if both the second groove 136 and the third groove 137 are rectangular grooves and the first groove 131, the second groove 136 and the third groove 137 are all formed in the pressure release member 13 by stamping, during molding, the rectangular third groove 137 can be stamped into the pressure release member 13, then the rectangular second groove 136 can be stamped on the bottom surface of the third groove 137, and then the first groove 131 can be stamped on the bottom surface of the second groove 136.

[0269] In this embodiment, by installing the third groove 137, the molding depth of the second groove 136 is reduced, the molding force received by the pressure release member 13 when the second groove 136 is molded is reduced, and the possibility of cracks occurring in the pressure release member 13 when the second groove 136 is molded is reduced.

[0270] In some embodiments, referring to Figure 20, Figure 20 is a cross-sectional view taken along line G-G of the pressure release member 13 shown in Figure 19. Along the thickness direction X of the pressure release member, the pressure release member 13 includes a first surface 132 and a second surface 133 facing each other, and the third groove 137, the second groove 136, and the first groove 131 are sequentially disposed in a direction from the first surface 132 to the second surface 133. The distance between the first surface 132 and the second surface 133 is H0, the remaining thickness of the second groove 136 is H1, and the remaining thickness of the third groove 137 is H2, satisfying 0.1 ≤ H1 / H0 ≤ 0.5 and / or 0.2 ≤ H2 / H0 ≤ 0.8.

[0271] Both the first surface 132 and the second surface 133 may be flat, and the first surface 132 may be parallel to the second surface 133. The distance between the first surface 132 and the second surface 133 may be the thickness of the pressure release member 13. The remaining thickness of the third groove 137 is the thickness of the remaining part of the pressure release member 13 after the third groove 137 is installed. This remaining part may be the groove bottom wall of the third groove 137, and the groove bottom wall of the third groove 137 is the part between the groove bottom surface of the third groove 137 and the second surface 133. The remaining thickness of the third groove 137 is equal to the minimum distance between the groove bottom surface of the third groove 137 and the second surface 133. The remaining thickness of the second groove 136 is the thickness of the remaining portion after the second groove 136 of the pressure release member 13 is installed, and this remaining portion may be the groove bottom wall of the second groove 136, and the groove bottom wall of the second groove 136 is the portion between the groove bottom surface of the second groove 136 and the second surface 133. The remaining thickness of the second groove 136 is equal to the minimum distance between the groove bottom surface of the second groove 136 and the second surface 133.

[0272] H1 / H0 may be any one of the following point values: 0.1, 0.2, 0.3, 0.4, 0.5, etc., or a range value between any two of them. H2 / H0 may be any one of the following point values: 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc., or a range value between any two of them.

[0273] When H1 / H0<0.1, the remaining thickness of the second groove 136 is small, the depth of the second groove 136 is large, the difficulty of forming the second groove 136 is high, and molding is difficult; when H1 / H0>0.5, the remaining thickness of the second groove 136 is large, the depth of the second groove 136 is small, the molding depth of the first groove 131 is large, and the difficulty of forming the first groove 131 is high. On the other hand, when 0.1≦H1 / H0≦0.5, the difficulty of forming the first groove 131 and the second groove 136 can be reduced.

[0274] When H2 / H0<0.2, the remaining thickness of the third groove 137 is small, the depth of the third groove 137 is large, the difficulty of forming the third groove 137 is high, and molding is difficult; when H2 / H0>0.8, the remaining thickness of the third groove 137 is large, the depth of the third groove 137 is small, the molding depth of the second groove 136 is large, and the difficulty of forming the second groove 136 is high. On the other hand, when 0.2≦H2 / H0≦0.8, the difficulty of forming the third groove 137 and the second groove 136 can be reduced.

[0275] In some embodiments, 0.1≦H1 / H0≦0.3.

[0276] H1 / H0 may be any one point value of 0.1, 0.13, 0.15, 0.18, 0.2, 0.23, 0.25, 0.28, etc. or a range value between any two.

[0277] In some embodiments, 0.2≦H2 / H0≦0.6.

[0278] H2 / H0 may be any one point value of 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, etc. or a range value between any two.

[0279] 21 to 23, in some embodiments, Fig. 21 is a cross-sectional view of the pressure release member 13 shown in Fig. 19 taken along line II, Fig. 22 is a partially enlarged view of a portion J in Fig. 21, and Fig. 23 is a partially enlarged view of a portion K in Fig. 21. The remaining thickness of the first groove segment 1311 is D1, and the remaining thickness of the second groove segment 1312 is D2, satisfying 0.15≦D1 / D2≦0.95.

[0280] D1 / D2 may be any one point value or a range value between any two of 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc.

[0281] The inventors conducted tests on multiple groups, with different D2 values ​​for the battery cells 10 in different groups, and measured the explosion rate of the battery cells 10 in each group during thermal runaway and the rupture rate at which the pressure release member 13 ruptures along the second groove segment 1312 under normal use conditions of the battery cells 10. The test results are shown in Table 1.

[0282] The method for measuring the remaining thickness of the first groove segment 1311 and the third groove segment 1313 is as follows: the pressure release member 13 is cut into three segments, the cutting direction is perpendicular to the extension direction of the first groove segment 1311, the cross section of the middle segment is polished to thoroughly remove burrs, and then placed in a three-dimensional coordinate measuring machine, and the remaining thickness of the first groove segment 1311 and the third groove segment 1313 at the cross section are measured using the three-dimensional coordinate measuring machine.

[0283] The method for measuring the remaining thickness of the second groove segment 1312 is as follows: the above-mentioned intermediate segment is cut into three segments, and the cutting direction is perpendicular to the extension direction of the second groove segment 1312. The cross section of the intermediate segment of these three segments is polished to thoroughly remove burrs, and then it is placed in a three-dimensional coordinate measuring machine, and the remaining thickness of the second groove segment 1312 at the cross section is measured using the three-dimensional coordinate measuring machine.

[0284] The method for measuring the explosion rate of a battery cell 10 during thermal runaway is as follows: a small heating film is built into the battery cell 10, and electricity is passed through the heating film to heat the battery cell 10 until it experiences thermal runaway, and it is observed whether the battery cell 10 explodes. For each group of tests, 1,000 battery cells 10 are used, and the explosion rate of the battery cells 10 is calculated, where explosion rate Q1 = number of exploded battery cells 10 / total number of battery cells 10 × 100%.

[0285] The method for measuring the rupture rate of the pressure release member 13 along the second groove segment 1312 under normal use conditions of the battery cell 10 is as follows: the battery cell 10 is left at 25±2°C and cycled charged and discharged in the charge / discharge range of 5% to 97% SOC, and 1,000 groups of tests are simultaneously performed to observe whether the pressure release member 13 ruptures along the second groove segment 1312 when the service life of the battery cell 10 drops to 80% SOH. The rupture rate of the pressure release member 13 along the second groove segment 1312 is calculated, where the rupture rate Q2 = number of ruptured battery cells 10 / total number of battery cells 10 × 100%.

[0286] [Table 1]

[0287] As can be seen from Table 1 above, when D1 / D2<0.15, the timeliness of pressure release is low and the probability of explosion during thermal runaway of the battery cell 10 is high, and when D1 / D2>0.95, the probability of rupture of the pressure release member 13 along the second groove segment 1312 during normal use of the battery cell 10 is high, affecting the service life of the battery cell 10. In contrast, when 0.15≦D1 / D2≦0.95, not only is the timeliness of pressure release of the battery cell 10 improved, but the service life of the battery cell 10 can also be extended.

[0288] In some embodiments, 0.3≦D1 / D2≦0.9.

[0289] In this embodiment, D1 / D2 may be any one of the following point values ​​or a range value between any two of 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, etc.

[0290] From Table 1 above, it can be seen that when 0.3≦D1 / D2≦0.9, the performance of the battery cell 10 is better, and the timeliness of pressure release of the battery cell 10 can be improved while the service life of the battery cell 10 can be extended.

[0291] In some embodiments, 0.5≦D1 / D2≦0.85.

[0292] In this embodiment, D1 / D2 may be any one of the following point values ​​or a range value between any two of 0.5, 0.52, 0.53, 0.55, 0.57, 0.58, 0.59, 0.6, 0.62, 0.63, 0.65, 0.67, 0.68, 0.69, 0.7, 0.72, 0.73, 0.75, 0.77, 0.78, 0.79, 0.8, 0.82, 0.83, 0.85, etc.

[0293] It can be seen from Table 1 above that when 0.5≦D1 / D2≦0.85, the overall performance of the battery cell 10 is further improved, and not only is the probability of the pressure release member 13 rupturing along the second groove segment 1312 during normal use of the battery cell 10 reduced, but the probability of the battery cell 10 exploding during thermal runaway can also be reduced.

[0294] In some embodiments, the remaining thickness of the third groove segment 1313 is D3, and satisfies 0.15≦D3 / D2≦0.95.

[0295] D3 / D2 may be any one point value or a range value between any two of 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc.

[0296] As can be seen from Table 1 above, when D3 / D2<0.15, the timeliness of pressure release is low and the probability of explosion during thermal runaway of the battery cell 10 is high, and when D3 / D2>0.95, the probability of rupture of the pressure release member 13 along the second groove segment 1312 during normal use of the battery cell 10 is high, affecting the service life of the battery cell 10. In contrast, when 0.15≦D3 / D2≦0.95, not only is the timeliness of pressure release of the battery cell 10 improved, but the service life of the battery cell 10 can also be extended.

[0297] In some embodiments, 0.3≦D3 / D2≦0.9.

[0298] In this embodiment, D3 / D2 may be any one of the following point values ​​or a range value between any two of 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, etc.

[0299] From Table 1 above, it can be seen that when 0.3≦D3 / D2≦0.9, the performance of the battery cell 10 is better, and the timeliness of pressure release of the battery cell 10 can be improved, while the service life of the battery cell 10 can be extended.

[0300] In some embodiments, 0.5≦D3 / D2≦0.85.

[0301] In this embodiment, D3 / D2 may be any one of the following point values ​​or a range value between any two of 0.5, 0.52, 0.53, 0.55, 0.57, 0.58, 0.59, 0.6, 0.62, 0.63, 0.65, 0.67, 0.68, 0.69, 0.7, 0.72, 0.73, 0.75, 0.77, 0.78, 0.79, 0.8, 0.82, 0.83, 0.85, etc.

[0302] It can be seen from Table 1 above that when 0.5≦D3 / D2≦0.85, the overall performance of the battery cell 10 is further improved, and not only is the probability of the pressure release member 13 rupturing along the second groove segment 1312 during normal use of the battery cell 10 reduced, but the probability of the battery cell 10 exploding during thermal runaway can also be reduced.

[0303] In some embodiments, 0.03 mm≦D3≦0.5 mm.

[0304] In this embodiment, D3 may be any one of the point values ​​of 0.03 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc., or a range value between any two of them.

[0305] In some embodiments, 0.15 mm≦D3≦0.4 mm.

[0306] In this embodiment, D3 may be any one of the point values ​​of 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, etc., or a range value between any two of them.

[0307] In some embodiments, 0.03 mm≦D1≦0.5 mm and / or 0.05 mm≦D2≦0.65 mm.

[0308] In this embodiment, D1 may be any one of the following point values ​​or a range value between any two of 0.03 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc. D2 may be any one of the following point values ​​or a range value between any two of 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, etc.

[0309] In some embodiments, 0.15 mm≦D1≦0.4 mm.

[0310] D1 may be any one point value or a range value between any two of 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, etc.

[0311] In some embodiments, 0.25 mm≦D2≦0.5 mm.

[0312] In this embodiment, D2 may be any one of the point values ​​of 0.25 mm, 0.27 mm, 0.3 mm, 0.32 mm, 0.35 mm, 0.37 mm, 0.4 mm, 0.42 mm, 0.45 mm, 0.47 mm, 0.5 mm, etc., or a range value between any two of them.

[0313] In some embodiments, referring to Figure 24, Figure 24 is an exploded view of a housing 1 according to some embodiments of the present application. The housing 1 includes a first wall 14, and a pressure release member 13 (not shown in Figure 24) is the first wall 14.

[0314] The housing 1 may include multiple walls, which collectively define an internal space of the housing 1. For example, if the housing 1 has a rectangular parallelepiped shape, the housing 1 has six walls, including two opposing walls in the longitudinal direction, two opposing walls in the width direction, and two opposing walls in the height direction.

[0315] In the housing 1, at least one wall is the first wall 14, i.e., at least one wall is provided with a first groove 131. For example, in the case where the housing 1 includes a case 11 and an end cover 12, if the end cover 12 is used as one wall of the housing 1, the end cover 12 may be the first wall 14, or at least one wall of the case 11 may be the first wall 14.

[0316] As can be seen, the first groove 131 is located in the first wall portion 14. The first groove 131 may face the inside of the housing 1 or the outside of the housing 1.

[0317] In an embodiment, when the first wall portion 14 is used as the pressure release member 13, the first groove 131 can be molded directly into the first wall portion 14 to form an integrated pressure release structure, which is more reliable, eliminates the installation process of the pressure release member 13, and reduces the manufacturing cost of the battery cell 10.

[0318] In some embodiments, referring to Figure 25, Figure 25 is an exploded view of a housing 1 according to some other embodiments of the present application. The housing 1 includes a first wall 14, and the pressure release member 13 is installed separately from the first wall 14, and the pressure release member 13 is attached to the first wall 14.

[0319] The pressure release member 13 and the housing 1 are two separate components that are molded separately and then attached together. The pressure release member 13 may be attached to the first wall 14 by welding, adhesive, etc. For example, a pressure release hole 141 is provided in the first wall 14, and the pressure release member 13 covers the pressure release hole 141.

[0320] In this embodiment, when the pressure release member 13 is attached to the first wall portion 14, the pressure release member 13 is a member independent of the housing 1, and the pressure release member 13 and the housing 1 may be manufactured and assembled separately, which reduces the manufacturing difficulty and increases the efficiency.

[0321] 24 and 25, in some embodiments of the present application, the housing 1 includes a case 11 and an end cover 12. The case 11 has an opening, and the end cover 12 seals the opening. At least one wall of the case 11 is a first wall 14.

[0322] Case 11 may include multiple walls, and the multiple walls define the interior space of case 11. In case 11, one wall may be first wall 14, or multiple walls may be first wall 14. For example, in Figures 24 and 25, only one wall in case 11 is first wall 14.

[0323] In this embodiment, the case 11 has a pressure release function, and when pressure is released, waste materials discharged from inside the battery cell 10 are less likely to affect the external components on the outside of the end cover 12, reducing the possibility of damage to the external components due to the waste materials. The external components here may be components that are located outside the battery cell 10 and connected to the electrode terminals 3 on the end cover 12.

[0324] 24 and 25, in some embodiments, the case 11 includes a bottom wall 111 and a plurality of side walls 112, the side walls 112 being disposed around the periphery of the bottom wall 111, and the case 11 has an opening formed at an end opposite the bottom wall 111. The bottom wall 111 is the first wall portion 14.

[0325] The bottom wall 111 is a wall portion facing the opening of the case 11, and the side walls 112 are walls portion installed around the bottom wall 111 of the case 11, and the bottom wall 111 and the side walls 112 are integrally formed. The number of side walls 112 of the case 11 may be three, four, five, six or more. For example, in Figures 24 and 25, the case 11 has a rectangular parallelepiped shape, and the number of side walls 112 of the case 11 is four.

[0326] In this embodiment, the bottom wall 111 has a pressure release function, and if the battery cell 10 experiences thermal runaway, the pressure can be released through the bottom wall 111, and in the battery 100, the pressure release member 13 is not easily blocked by other battery cells 10.

[0327] 26 and 27, in some embodiments, Fig. 26 is an exploded view of a housing 1 according to some embodiments of the present application, and Fig. 27 is an exploded view of a housing 1 according to still other embodiments of the present application. The housing 1 includes a case 11 and an end cover 12, the case 11 has an opening, the end cover 12 seals the opening, and the end cover 12 is a first wall portion 14.

[0328] In the embodiment shown in FIG. 26, the end cover 12 is the pressure relief member 13 .

[0329] In the embodiment shown in FIG. 27, the pressure release member 13 and the end cover 12 are two separate components, and the pressure release member 13 is attached to the end cover 12.

[0330] In this embodiment, the end cover 12 has a pressure release function, and the difficulty of forming the first groove 131 in the end cover 12 is lower.

[0331] In some embodiments, the first wall 14 is a rectangular wall, the second groove segment 1312 extends along the longitudinal direction Y of the first wall, and both the first groove segment 1311 and the third groove segment 1313 extend along the width direction Z of the first wall.

[0332] As can be seen, the length of the first wall 14 is greater than the width of the first wall 14 , and both the first groove segment 1311 and the third groove segment 1313 are perpendicular to the second groove segment 1312 .

[0333] In this embodiment, the second groove segment 1312 extends along the longitudinal direction Y of the first wall portion, and the first wall portion can provide more space for the second groove segment 1312, making the second groove segment 1312 longer and increasing the pressure release area of ​​the pressure release member 13.

[0334] In some other embodiments, the second groove segment 1312 may extend along the width direction Z of the first wall portion, and both the first groove segment 1311 and the third groove segment 1313 may extend along the width direction Y of the first wall portion.

[0335] In some embodiments, referring to FIG. 28, FIG. 28 is a partial view of the first wall portion according to some embodiments of the present application. Along the thickness direction X (not shown in FIG. 28) of the pressure relief member, the first wall portion 14 has an outer surface 142, and the outer surface 142 faces away from the inside of the housing 1. The first groove segment 1311 has a first intermediate plane 1311c extending along its extending direction, the second groove segment 1312 has a second intermediate plane 1312c extending along its extending direction, and the third groove segment 1313 has a third intermediate plane 1313c extending along its extending direction. The minimum distance from the center point 1421 of the outer surface 142 to the first intermediate plane 1311c is M1, the minimum distance from the center point 1421 of the outer surface 142 to the second intermediate plane 1312c is M2, and the minimum distance from the center point 1421 of the outer surface 142 to the third intermediate plane 1313c is M3, satisfying M2 < M1 and M2 < M3.

[0336] Here, M1 may be equal to M3, M1 may be less than M3, or M1 may be greater than M3.

[0337] In an embodiment where the first wall portion 14 is used as the pressure relief member 13, the thickness direction X of the pressure relief member is the thickness direction of the first wall portion 14. In an embodiment where the pressure relief member 13 is attached to the first wall portion 14, the thickness direction X of the pressure relief member coincides with the thickness direction of the first wall portion 14.

[0338] The outer surface 142 is the surface of the first wall portion 14 facing away from the interior of the housing 1, i.e., the outer surface 142 faces the exterior of the housing 1. Along the thickness direction X of the pressure release member, the first wall portion 14 also has an inner surface facing the interior of the housing 1, and the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 may all be recessed along a direction from the outer surface 142 of the first wall portion 14 toward the inner surface, or along a direction from the inner surface of the first wall portion 14 toward the outer surface 142. In an embodiment in which the first wall portion 14 is used as the pressure release member 13, one of the inner surface and the outer surface 142 of the first wall portion 14 is the first surface 132 of the pressure release member 13, and the other is the second surface 133 of the pressure release member 13.

[0339] The center point 1421 of the outer surface 142 is the geometric center of the outer surface 142. The outer surface 142 may be circular, polygonal, etc. The polygon may be triangular, quadrilateral, pentagonal, hexagonal, etc.

[0340] The first intermediate surface 1311c coincides with the extension direction of the first groove segment 1311, and in the width direction of the first groove segment 1311, the first intermediate surface 1311c is located at the center of the first groove segment 1311 and is perpendicular to the width direction of the first groove segment 1311. The second intermediate surface 1312c coincides with the extension direction of the second groove segment 1312, and in the width direction of the second groove segment 1312, the second intermediate surface 1312c is located at the center of the second groove segment 1312 and is perpendicular to the width direction of the second groove segment 1312. The third intermediate surface 1313c coincides with the extension direction of the third groove segment 1313, and in the width direction of the third groove segment 1313, the third intermediate surface 1313c is located at the center of the third groove segment 1313, and the third intermediate surface 1313c is perpendicular to the width direction of the third groove segment 1313.

[0341] The minimum distance from the center point 1421 of the outer surface 142 to the first intermediate plane 1311c can be measured on the perpendicular line of the first intermediate surface 1311c passing through the center point 1421 of the outer surface 142. The minimum distance from the center point 1421 of the outer surface 142 to the second intermediate surface 1312c can be measured on the perpendicular line of the second intermediate surface 1312c passing through the center point 1421 of the outer surface 142. The minimum distance from the center point 1421 of the outer surface 142 to the third intermediate surface 1313c can be measured on the perpendicular line of the third intermediate surface 1313c passing through the center point 1421 of the outer surface 142.

[0342] When the internal pressure of the battery cell changes, the first wall portion 14 is more likely to deform as it is closer to the center point 1421. Since M2 < M1 and M2 < M3, the first groove segment 1311 and the third groove segment 1313 are farther from the center point 1421, and the fatigue strength of the pressure relief member 13 at the first groove segment 1311 and the third groove segment 1313 is improved.

[0343] In some embodiments, along the thickness direction X of the pressure relief member, the projection of the center point 1421 of the outer surface 142 is located within the second groove segment 1312, and / or |M3 - M1| ≤ 5 mm.

[0344] Along the thickness direction of the pressure relief member 13, the projection of the center point 1421 is located within the second groove segment 1312, that is, the perpendicular line passing through the center point 1421 of the outer surface 142 passes through the second groove segment 1312. As an example, the center point 1421 of the outer surface 142 is located within the second intermediate surface 1312c.

[0345] |M3 - M1| may be any one of the point values such as 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm or the range value between any two of them.

[0346] In this embodiment, the projection of the center point 1421 of the outer surface 142 is located within the second groove segment 1312, and the second groove segment 1312 is closer to the center point 1421 of the outer surface 142, so that the pressure release member 13 can burst along the second groove segment 1312 in a more timely manner when releasing pressure, thereby improving the timeliness of pressure release of the pressure release member 13. When |M3-M1|≦5 mm, both the first groove segment 1311 and the third groove segment 1313 are farther from the center point 1421, so that the impact on the first groove segment 1311 and the third groove segment 1313 caused by deformation near the center point 1421 of the pressure release member 13 is reduced.

[0347] In some embodiments, the outer surface 142 is rectangular, circular, or a regular polygon.

[0348] In an embodiment in which the outer surface 142 is rectangular, the intersection of the two diagonals of the rectangle is the center point 1421 of the outer surface 142. The first wall 14 is a rectangular wall, and the longitudinal direction of the outer surface 142 coincides with the longitudinal direction Y of the first wall, and the width direction of the outer surface 142 coincides with the width direction Z of the first wall. The outer surface 142 may be a regular rectangle or an irregular rectangle, and for example, two adjacent sides of the rectangle may be connected by a chamfer, which may be a circular arc chamfer.

[0349] In an embodiment where the outer surface 142 is circular, the center of the circle is the center point 1421 of the outer surface 142. The first wall 14 may be a circular wall since the outer surface 142 is circular.

[0350] In an embodiment in which the outer surface 142 is a regular polygon, the center of the inscribed circle of the regular polygon is the center point 1421 of the outer surface 142. The regular polygon may be an equilateral triangle, a regular quadrilateral, a regular pentagon, a regular hexagon, or the like. The outer surface 142 may be a regular regular polygon or an irregular regular polygon, for example, two adjacent sides of a regular polygon may be connected by a chamfer, and the chamfer may be an arc chamfer. Since the outer surface 142 is a regular polygon, the first wall portion 14 may be a regular polygon wall portion.

[0351] An embodiment of the present application provides a battery 100 including a battery cell 10 according to any one of the above embodiments.

[0352] An embodiment of the present application provides a power consuming device comprising a battery cell 10 according to any one of the above embodiments for supplying electrical energy to the power consuming device.

[0353] An embodiment of the present application further provides a battery cell 10, which includes a housing 1 and an electrode assembly 2. The electrode assembly 2 has a positive electrode tab and a negative electrode tab, and the electrode assembly 2 is housed within the housing 1. The housing 1 has a rectangular parallelepiped shape and includes a case 11 and an end cover 12. The case 11 has an opening, and the end cover 12 seals the opening. A positive electrode terminal and a negative electrode terminal are installed on the end cover 12. The positive electrode terminal is electrically connected to the positive electrode tab via one current collecting member 4, and the negative electrode terminal is electrically connected to the negative electrode tab via the other current collecting member 4. A wall of the case 11 facing the end cover 12 is a pressure release member 13. The pressure release member 13 is provided with a first groove 131. The pressure release member 13 is configured to rupture along the first groove 131 to release internal pressure in the battery cell 10.The first groove 131 includes a first groove segment 1311, a second groove segment 1312, a third groove segment 1313, and a fourth groove segment. The first groove segment 1311 is located opposite the third groove segment 1313. The second groove segment 1312 connects the first groove segment 1311 and the third groove segment 1313. The first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the fourth groove segment 1316 are all grooves extending along a straight line. Both the first groove segment 1311 and the third groove segment 1313 are perpendicular to the second groove segment 1312. One end of the second groove segment 1312 is connected to the midpoint of the first groove segment 1311, and the other end of the second groove segment 1312 is perpendicular to the midpoint of the first groove segment 1311. is connected to the midpoint of the third groove segment 1313, and both the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are smaller than the remaining thickness of the second groove segment 1312, and the remaining thickness of the first groove segment 1311 is equal to the remaining thickness of the third groove segment 1313; the fourth groove segment 1316 is located between the first groove segment 1311 and the third groove segment 1313, and the fourth groove segment 1316 is connected to the second groove segment 1312 and is perpendicular to the second groove segment 1312; the midpoint of the fourth groove segment 1316 is connected to the midpoint of the second groove segment 1312, and both the remaining thickness of the first groove segment 1311 and the remaining thickness of the third groove segment 1313 are smaller than the remaining thickness of the fourth groove segment 1316.

[0354] Here, the first groove segment 1311, the second groove segment 1312, and the third groove segment 1313 define two pressure relief areas 134, which are located on either side of the second groove segment 1312. The pressure relief member 13 is provided with two guide grooves 135, with the second groove segment 1312 located between the two guide grooves 135, which respectively guide the two pressure relief areas 134 to open in an inverted manner. Neither the first groove segment 1311 nor the third groove segment 1313 contacts the guide grooves 135, which extend along the thickness direction X of the pressure relief member, in the direction in which the second groove segment 1312 extends. The guide grooves 135 and the first groove 131 are located on either side of the pressure relief member 13.

[0355] The pressure release member 13 has a second groove 136 and a third groove 137. The second groove 136 includes a fifth groove segment 1361, a sixth groove segment 1362, and a seventh groove segment 1363. The fifth groove segment 1361 and the seventh groove segment 1363 are arranged opposite each other, and the sixth groove segment 1362 connects the fifth groove segment 1361 and the seventh groove segment 1363. The first groove segment 1311 is arranged on the groove bottom surface of the fifth groove segment 1361, the second groove segment 1312 is arranged on the groove bottom surface of the sixth groove segment 1362, and the third groove segment 1313 is arranged on the groove bottom surface of the seventh groove segment 1363. The third groove 137 includes an eighth groove segment 1371, a ninth groove segment 1372, and a tenth groove segment 1373, the eighth groove segment 1371 and the tenth groove segment 1373 being disposed opposite each other, and the ninth groove segment 1372 connecting the eighth groove segment 1371 and the tenth groove segment 1373. The fifth groove segment 1361 is disposed on the groove bottom surface of the eighth groove segment 1371, the sixth groove segment 1362 is disposed on the groove bottom surface of the ninth groove segment 1372, and the seventh groove segment 1363 is disposed on the groove bottom surface of the tenth groove segment 1373.

[0356] The second groove segment 1312 and the fourth groove segment 1316 are connected at a third position 1317. Along the extension direction of the second groove segment 1312, the distance between the third position 1317 and the first groove segment 1311 is L1, and the distance between the third position 1317 and the third groove segment 1313 is L2, satisfying |L1-L2|≦1 mm. The length of the fourth groove segment 1316 is L4, and the length of the first groove segment 1311 is L5, satisfying L4 / L5≦1 / 4. Along the extension direction of the second groove segment 1312, the first groove segment 1311 and the third groove segment 1313 are located on either side of the guide groove 135, and the length of the portion of the second groove segment 1312 located between the first groove segment 1311 and the third groove segment 1313 is L3, and the length of the guide groove 135 is L6, which satisfies 1 mm≦L3−L6≦10 mm. Along the extension direction of the first groove segment 1311, the distance between the guide groove 135 and the second groove segment 1312 is L7, and the length of the portion of the first groove segment 1311 extending from the second groove segment 1312 toward the guide groove 135 is L8, which satisfies 0.5 mm≦|L7−L8|≦15 mm. The remaining thickness of the first groove segment 1311 is D1, and the remaining thickness of the second groove segment 1312 is D2, which satisfy 0.15≦D1 / D2≦0.95, 0.03 mm≦D1≦0.5 mm, and 0.05 mm≦D2≦0.65 mm.

[0357] It should be noted that, unless contradictory, the embodiments and features of the embodiments in the present application can be combined with each other.

[0358] The above examples are only intended to illustrate the technical solution of the present application and are not intended to limit the present application, and those skilled in the art may make various modifications and variations to the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. [Explanation of symbols]

[0359] 1 - housing, 11 - case, 111 - bottom wall, 112 - side wall, 12 - end cover, 13 - pressure release member, 131 - first groove, 1311 - first groove segment, 1311a - first groove bottom surface, 1311b - first groove side surface, 1311c - first intermediate surface, 1312 - second groove segment, 1312a - second groove bottom surface, 1312c - second intermediate surface, 1313 - third groove segment, 1313a - third groove bottom surface, 1313b - third groove side surface, 1313c - third intermediate surface, 1314 - first position, 1315 - second position, 1316 - fourth groove segment, 1317 - third position, 132 - first surface, 133 - second surface, 134 - pressure release area, 135 - guide groove, 136 - second groove, 13 61—fifth groove segment, 1362—sixth groove segment, 1363—seventh groove segment, 1364—first recess, 137—third groove, 1371—eighth groove segment, 1372—ninth groove segment, 1373—tenth groove segment, 1374—second recess, 14—first wall portion, 141—pressure relief hole, 142—outer surface, 1421—center point, 2—electrode assembly, 21—tab, 3—electrode terminal, 4—current collecting member, 5—insulating member, 10—battery cell, 20—casing, 201—first part, 202—second part, 100—battery, 200—controller, 300—motor, 1000—vehicle, X—thickness direction of pressure relief member, Y—longitudinal direction of first wall, Z—width direction of first wall portion.

Claims

1. A battery cell, a housing including a pressure release member, the pressure release member having a first groove formed therein, the pressure release member configured to rupture along the first groove to release internal pressure of the battery cell; wherein the first groove includes a first groove segment, a second groove segment, and a third groove segment, the first groove segment is disposed opposite the third groove segment, the second groove segment connects the first groove segment and the third groove segment, and both the remaining thickness of the first groove segment and the remaining thickness of the third groove segment are smaller than the remaining thickness of the second groove segment.

2. The battery cell of claim 1 , wherein a depth of the first groove segment is greater than a depth of the second groove segment, such that a remaining thickness of the first groove segment is less than a remaining thickness of the second groove segment.

3. The battery cell of claim 2 , wherein a depth of the third groove segment is greater than a depth of the second groove segment, such that a remaining thickness of the third groove segment is less than a remaining thickness of the second groove segment.

4. The battery cell according to any one of claims 1 to 3, wherein a remaining thickness of the first groove segment is equal to a remaining thickness of the third groove segment.

5. The battery cell according to any one of claims 1 to 4, wherein both ends of the second groove segment are connected to the first groove segment and the third groove segment, respectively, along the extension direction of the second groove segment.

6. The battery cell according to any one of claims 1 to 5, wherein the first groove segment and the second groove segment are connected at a first position, and the first position is spaced apart from both ends of the first groove segment along the extension direction of the first segment.

7. The battery cell according to claim 6 , wherein the first position is located at a midpoint of the first groove segment along an extension direction of the first groove segment.

8. The battery cell according to any one of claims 1 to 6, wherein the third groove segment and the second groove segment are connected at a second position, and the second position is spaced apart from both ends of the third groove segment along the extension direction of the third groove segment.

9. The battery cell according to claim 8 , wherein the second position is located at a midpoint of the third groove segment along the extension direction of the third groove segment.

10. The battery cell according to any one of claims 1 to 9, wherein the first groove segment, the second groove segment, and the third groove segment are grooves that extend along linear loci.

11. The battery cell of claim 10 , wherein the first groove segment is perpendicular to the second groove segment and / or the third groove segment is perpendicular to the second groove segment.

12. 12. The battery cell of claim 1, wherein the first groove further includes at least one fourth groove segment, the fourth groove segment being located between the first groove segment and the third groove segment and connected to the second groove segment.

13. The battery cell of claim 12 , wherein the remaining thickness of the first groove segment and the remaining thickness of the third groove segment are both less than the remaining thickness of the fourth groove segment.

14. The battery cell according to claim 12 or 13, wherein the number of the fourth groove segments is one.

15. The second groove segment and the fourth groove segment are connected at a third position, and the distance between the third position and the first groove segment along the extension direction of the second groove segment is L 1 and the distance between the third position and the third groove segment is L 2 and |L 1 -L 2 |≦1 mm, optionally |L 1 -L 2 The battery cell according to claim 14 , wherein |≦0.5 mm is satisfied.

16. The battery cell according to claim 12 or 13, wherein the fourth groove segments are plural, and the plural fourth groove segments are spaced apart along the extension direction of the second groove segments.

17. The fourth groove segments are uniformly distributed in the second groove segment along the extending direction of the second groove segment, and the length of the portion of the second groove segment located between the first groove segment and the third groove segment is L 3 the number of the fourth groove segments is N, and L 3 / N≦25 mm, optionally, 8 mm≦L 3 The battery cell according to claim 16 , wherein / N≦20 mm.

18. 20mm≦L 3 ≦150 mm, optionally, 10 mm≦L 3 18. The battery cell of claim 17, wherein the thickness is ≦100 mm.

19. The length of the fourth groove segment is L 4 and the length of the first groove segment is L 5 and L 4 / L 5 ≦1 / 4, optionally, L 4 / L 5 The battery cell according to any one of claims 12 to 18, wherein the battery cell satisfies the following:

20. the first groove segment, the second groove segment, and the third groove segment define a pressure relief region; The battery cell of any one of claims 1 to 19, wherein the pressure release member has a guide groove, the guide groove is spaced apart from the second groove segment, and the guide groove is configured to guide the pressure release area to invert and open.

21. the first groove segment, the second groove segment, and the third groove segment define two pressure relief regions, the two pressure relief regions being located on either side of the second groove segment, respectively; 21. The battery cell of claim 20, wherein the pressure release member has two guide grooves, the second groove segment is located between the two guide grooves, and the two guide grooves are configured to respectively guide the two pressure release areas to invert and open.

22. 22. The battery cell according to claim 20 or 21, wherein both the first groove segment and the third groove segment are out of contact with the guide groove.

23. 23. The battery cell of claim 20, wherein the guide groove and the first groove are respectively disposed on both sides of the pressure release member along the thickness direction of the pressure release member.

24. The battery cell according to any one of claims 20 to 23, wherein the guide groove extends along the extending direction of the second groove segment.

25. The first groove segment and the third groove segment are located on both sides of the guide groove along the extending direction of the second groove segment, and the length of the portion of the second groove segment located between the first groove segment and the third groove segment is L 3 and the length of the guide groove is L 6 and 1 mm≦L 3 -L 6 ≦10 mm, optionally 2 mm≦L 3 -L 6 The battery cell according to any one of claims 20 to 24, wherein the thickness satisfies ≦6 mm.

26. The distance between the guide groove and the second groove segment along the extension direction of the first groove segment is L 7 and the length of the portion of the first groove segment extending from the second groove segment in a direction approaching the guide groove is L 8 and 0.5 mm≦|L 7 -L 8 |≦15 mm, optionally, 1 mm≦|L 7 -L 8 The battery cell according to any one of claims 20 to 25, wherein |≦10 mm.

27. The battery cell according to any one of claims 1 to 26, wherein the pressure release member has a second groove formed therein, and the first groove is formed on a groove bottom surface of the second groove.

28. the second groove includes a fifth groove segment, a sixth groove segment, and a seventh groove segment, the fifth groove segment and the seventh groove segment being disposed opposite to each other, and the sixth groove segment connecting the fifth groove segment and the seventh groove segment; 28. The battery cell of claim 27, wherein the first groove segment is located on the groove bottom surface of the fifth groove segment, the second groove segment is located on the groove bottom surface of the sixth groove segment, and the third groove segment is located on the groove bottom surface of the seventh groove segment.

29. The pressure release member has a third groove, the third groove including an eighth groove segment, a ninth groove segment, and a tenth groove segment, the eighth groove segment and the tenth groove segment being disposed opposite each other, and the ninth groove segment connecting the eighth groove segment and the tenth groove segment; 29. The battery cell of claim 28, wherein the fifth groove segment is located on the groove bottom surface of the eighth groove segment, the sixth groove segment is located on the groove bottom surface of the ninth groove segment, and the seventh groove segment is located on the groove bottom surface of the tenth groove segment.

30. 30. The battery cell according to claim 27, wherein the pressure release member has a third groove formed therein, and the second groove is formed on a bottom surface of the third groove.

31. The pressure release member includes a first surface and a second surface that are disposed opposite to each other along a thickness direction of the pressure release member, and the third groove, the second groove, and the first groove are sequentially disposed along a direction from the first surface toward the second surface, Here, the distance between the first surface and the second surface is H 0 and the remaining thickness of the second groove is H 1 and the remaining thickness of the third groove is H 2 and 0.1≦H 1 / H 0 ≦0.5, optionally 0.1≦H 1 / H 0 ≦0.3 and / or 0.2≦H 2 / H 0 ≦0.8, optionally 0.2≦H 2 / H 0 31. The battery cell of claim 30, wherein the σ is less than or equal to 0.

6.

32. The remaining thickness of the first groove segment is D 1 and the remaining thickness of the second groove segment is D 2 and 0.15≦D 1 / D 2 ≦0.95, optionally 0.3≦D 1 / D 2 ≦0.9, optionally 0.5≦D 1 / D 2 The battery cell according to any one of claims 1 to 31, wherein the battery cell satisfies ≦0.

85.

33. The remaining thickness of the third groove segment is D 3 and 0.15≦D 3 / D 2 ≦0.95, optionally 0.3≦D 3 / D 2 ≦0.9, optionally 0.5≦D 3 / D 2 33. The battery cell of claim 32, wherein the ratio satisfies ≦0.

85.

34. 0.03 mm≦D 3 ≦0.5 mm, optionally 0.15 mm≦D 3 34. The battery cell of claim 33, wherein the thickness is ≦0.4 mm.

35. 0.03 mm≦D 1 ≦0.5 mm, optionally 0.15 mm≦D 1 ≦0.4 mm, and / or 0.05 mm≦D 2 ≦0.65 mm, optionally 0.25 mm≦D 2 33. The battery cell of claim 32, wherein the thickness is ≦0.5 mm.

36. the housing includes a first wall; The battery cell of any one of claims 1 to 35, wherein the pressure release member is the first wall portion, or the pressure release member is installed separately from the first wall portion and attached to the first wall portion.

37. The housing includes: a case having an opening; 37. The battery cell of claim 36, further comprising an end cover that seals the opening, the end cover being the first wall portion.

38. The housing includes: a case having an opening; an end cover that seals the opening, 37. The battery cell of claim 36, wherein at least one wall portion of the case is the first wall portion.

39. the case includes a bottom wall and a plurality of side walls, the plurality of side walls are disposed around the periphery of the bottom wall, and the opening is formed at an end of the case facing the bottom wall; 39. The battery cell of claim 38, wherein the bottom wall is the first wall portion.

40. 40. The battery cell of claim 36, wherein the first wall is a rectangular wall, the second groove segment extends along a longitudinal direction of the first wall, and both the first groove segment and the third groove segment extend along a width direction of the first wall.

41. Along a thickness of the pressure relief member, the first wall portion has an outer surface, the outer surface being spaced away from an interior of the housing; The first groove segment has a first intermediate surface extending along its extension direction, the second groove segment has a second intermediate surface extending along its extension direction, and the third groove segment has a third intermediate surface extending along its extension direction, and the minimum distance from a center point of the outer surface to the first intermediate surface is M 1 and the minimum distance from the center point of the outer surface to the second intermediate surface is M 2 and the minimum distance from the center point of the outer surface to the third intermediate surface is M 3 and M 2 <M 1 , M 2 <M 3 The battery cell according to any one of claims 36 to 40, which satisfies the above.

42. a projection of the center point of the outer surface along the thickness direction of the pressure release member lies within the second groove segment; and / or |M 3 -M 1 42. The battery cell of claim 41, wherein |≦5 mm.

43. 43. The battery cell of claim 41 or 42, wherein the outer surface is rectangular, circular, or a regular polygon.

44. A battery comprising the battery cell according to any one of claims 1 to 43.

45. A power consuming device comprising the battery cell of any one of claims 1 to 43 for supplying electrical energy to the power consuming device.

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