Cylindrical battery monomer, battery device and power utilization device

Abstract

The utility model provides a cylindrical battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. The cylindrical battery cell comprises a shell, an electrode assembly and a first current collecting component. The first wall of the shell is provided with a pressure relief component, and the pressure relief component is provided with a pressure relief groove. The first current collecting component comprises a body part, a supporting part and a butt joint part, the body part is connected with the electrode assembly, the butt joint part is connected with the shell, and the supporting part is connected with the body part and the butt joint part and is configured to be capable of deforming. In a projection plane perpendicular to the first direction, the orthographic projection of the butt joint part extends in the circumferential direction of the shell and is located on the peripheral side of the orthographic projection of the body part, and the orthographic projection of the butt joint part and the orthographic projection of the body part are arranged at intervals in the radial direction of the cylindrical battery monomer, so that an exhaust gap is formed between the orthographic projection of the butt joint part and the orthographic projection of the body part; therefore, the pressure relief rate of the cylindrical battery monomer can be improved, and the use reliability of the cylindrical battery monomer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a cylindrical battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. Among them, the battery device usually includes a box body and a plurality of cylindrical battery monomers accommodated in the box body.

[0003] In the battery technology, in order to ensure the safety of the cylindrical battery monomer, a pressure relief structure for relieving the internal pressure of the cylindrical battery monomer is generally arranged on the shell of the cylindrical battery monomer, so that when the cylindrical battery monomer occurs thermal runaway, the pressure relief structure can relieve the internal pressure of the cylindrical battery monomer. However, the existing cylindrical battery monomer has a low pressure relief rate when thermal runaway occurs, so that the cylindrical battery monomer has a risk of fire and explosion due to untimely pressure relief, thereby resulting in low use reliability of the cylindrical battery monomer. UTILITY MODEL CONTENT

[0004] The present application provides a cylindrical battery monomer, a battery device and a power utilization device, which can effectively improve the use reliability of the cylindrical battery monomer.

[0005] In a first aspect, the present application provides a cylindrical battery monomer, the axial direction of the cylindrical battery monomer is a first direction, the cylindrical battery monomer includes a shell, an electrode assembly and a first current collecting member; the shell has a first wall, a pressure relief component is arranged on the first wall, and the pressure relief component is provided with a pressure relief groove; the electrode assembly is accommodated in the shell; the first current collecting member includes a body portion, a support portion and a butt joint portion, along the first direction, the body portion is located on the side of the electrode assembly facing the first wall and connected with the electrode assembly, the butt joint portion is located on the side of the body portion facing the first wall and connected with the shell, and the support portion connects the body portion and the butt joint portion, and the support portion is configured to be capable of deforming; wherein, in a projection plane perpendicular to the first direction, the orthographic projection of the butt joint portion extends along the circumferential direction of the shell and is located on the outer circumferential side of the orthographic projection of the body portion, and the orthographic projection of the butt joint portion and the orthographic projection of the body portion are arranged in the radial direction of the cylindrical battery monomer, so as to form an exhaust gap between the orthographic projection of the butt joint portion and the orthographic projection of the body portion.

[0006] In the technical scheme, the first current collecting component is provided with a body part, a supporting part and a connecting part, the body part and the connecting part are connected with the electrode assembly and the shell respectively, and the supporting part is connected between the body part and the connecting part to realize the electrical connection between the electrode assembly and the shell through the first current collecting component. The supporting part can play a certain buffering role between the body part and the connecting part, the body part and the electrode assembly and the connecting part and the shell during the shaking or displacement of the electrode assembly, which can alleviate the rigid pulling between the body part and the connecting part, the body part and the electrode assembly and the connecting part and the shell, and is beneficial to further reducing the risk of connection failure between the body part and the electrode assembly and between the connecting part and the shell, and reducing the damage of the first current collecting component. In addition, in the projection plane perpendicular to the first direction, the orthogonal projection of the connecting part and the orthogonal projection of the body part are provided with an exhaust gap in the radial direction of the cylindrical battery monomer, so that the thermal runaway gas in the cylindrical battery monomer enters the area of the first wall through the exhaust gap between the connecting part and the body part, and then passes through the pressure relief groove of the pressure relief part on the first wall to be discharged, thereby reducing the obstruction of the first current collecting component to the exhaust path in the cylindrical battery monomer, improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer, and reducing the risk of explosion of the cylindrical battery monomer due to untimely pressure relief, thereby improving the use reliability of the cylindrical battery monomer.

[0007] In some embodiments, along the first direction, at least part of the projection of the pressure relief groove is located in the exhaust gap.

[0008] In the technical scheme, the pressure relief groove is provided with a structure in which at least part of the projection in the first direction is located in the exhaust gap, so that the pressure relief groove is provided with a structure corresponding to the exhaust gap between the connecting part and the body part in at least part of the first direction, thereby further improving the internal exhaust smoothness and pressure relief smoothness of the cylindrical battery monomer, and further improving the pressure relief rate of the cylindrical battery monomer.

[0009] In some embodiments, in the projection plane perpendicular to the first direction, the diameter of the orthogonal projection of the outer edge of the connecting part is D1, the orthogonal projection of the supporting part extends in the radial direction of the cylindrical battery monomer and has a length L1, and 1 / 15≤L1 / D1≤1 / 3 is satisfied.

[0010] In the above technical solution, in the projection plane perpendicular to the first direction, by setting the orthographic projection of the butt joint portion and the orthographic projection of the body portion as a structure arranged at intervals in the radial direction of the cylindrical battery monomer, and setting the ratio of the length of the support portion of the first current collecting member in the radial direction of the cylindrical battery monomer to the diameter of the orthographic projection of the outer edge of the butt joint portion as 1 / 15 to 1 / 3, on the one hand, it can alleviate the phenomenon that the size occupied by the support portion in the radial direction of the cylindrical battery monomer is too small, and is beneficial to expand the exhaust space between the butt joint portion and the body portion, so that the thermal runaway gas inside the cylindrical battery monomer can be discharged through the area provided with the pressure relief groove of the pressure relief component on the first wall after passing through the exhaust space between the butt joint portion and the body portion, thereby improving the internal exhaust smoothness of the cylindrical battery monomer, to improve the pressure relief rate of the cylindrical battery monomer, and thus can reduce the risk of bursting or explosion of the cylindrical battery monomer due to untimely pressure relief. On the other hand, it can alleviate the phenomenon that the size occupied by the support portion in the radial direction of the cylindrical battery monomer is too large, causing insufficient support strength of the support portion between the body portion and the butt joint portion, thereby effectively improving the support effect of the first current collecting member on the electrode assembly and the effect of resisting the expansion of the electrode assembly during use, to alleviate the phenomenon of excessive expansion or displacement of the electrode assembly, and thus is beneficial to improve the use stability and reliability of the cylindrical battery monomer.

[0011] In some embodiments, 1 / 7≤L1 / D1≤1 / 4.

[0012] In the above technical solution, in the projection plane perpendicular to the first direction, by further setting the ratio of the length of the support portion of the first current collecting member in the radial direction of the cylindrical battery monomer to the diameter of the orthographic projection of the outer edge of the butt joint portion as 1 / 7 to 1 / 4, on the one hand, it can further alleviate the phenomenon that the size occupied by the support portion in the radial direction of the cylindrical battery monomer is too small, and is beneficial to further expand the exhaust space between the butt joint portion and the body portion, so that the thermal runaway gas inside the cylindrical battery monomer can be discharged through the area provided with the pressure relief groove of the pressure relief component on the first wall after passing through the exhaust space between the butt joint portion and the body portion, thereby further improving the internal exhaust smoothness of the cylindrical battery monomer, to further improve the pressure relief rate of the cylindrical battery monomer, and thus can further reduce the risk of bursting or explosion of the cylindrical battery monomer due to untimely pressure relief. On the other hand, it can further alleviate the phenomenon that the size occupied by the support portion in the radial direction of the cylindrical battery monomer is too large, causing insufficient support strength of the support portion between the butt joint portion and the body portion, thereby further improving the support effect of the first current collecting member on the electrode assembly and the effect of resisting the expansion of the electrode assembly during use, to further alleviate the phenomenon of excessive expansion or displacement of the electrode assembly, and thus is beneficial to further improve the use stability and reliability of the cylindrical battery monomer.

[0013] In some embodiments, 3mm≤L1≤15mm.

[0014] In the above technical solution, in the projection plane perpendicular to the first direction, by setting the length of the support portion of the first current collecting member in the radial direction of the cylindrical battery monomer to 3-15 mm, on the one hand, setting the length of the support portion in the radial direction of the cylindrical battery monomer to be greater than or equal to 3 mm can increase the exhaust space between the butt joint portion and the body portion, so that the thermal runaway gas inside the cylindrical battery monomer passes through the exhaust space between the butt joint portion and the body portion, and then is discharged through the area where the pressure relief component on the first wall is provided with a pressure relief groove, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery monomer. On the other hand, setting the length of the support portion in the radial direction of the cylindrical battery monomer to be less than or equal to 15 mm can alleviate the phenomenon that the support portion is too long to cause insufficient support strength between the butt joint portion and the body portion, which is beneficial to improve the support effect of the first current collecting member on the electrode assembly and the effect of resisting the expansion of the electrode assembly during use, so as to further alleviate the phenomenon of excessive expansion or displacement of the electrode assembly.

[0015] In some embodiments, the thickness of the support portion is T1, and in the projection plane perpendicular to the first direction, the width of the orthogonal projection of the support portion in the direction perpendicular to the extension direction thereof is W, and satisfies 0.3mm 2 ≤W×T1≤8mm 2 .

[0016] In the above technical solution, by setting the product of W and T1 to 0.3mm 2 to 8mm 2 , on the one hand, setting the product of W and T1 to be less than or equal to 8mm 2 can alleviate the phenomenon that W and T1 are too large to cause excessive deformation of the support portion, so as to improve the deformation capability of the support portion when the body portion and the butt joint portion approach or move away from each other in the first direction, so that the support portion can play a better buffering role between the body portion and the butt joint portion, thereby reducing the rigid pulling phenomenon between the butt joint portion and the body portion, between the body portion and the electrode assembly, and between the butt joint portion and the shell during the process of the electrode assembly shaking or shifting. On the other hand, setting the product of W and T1 to be greater than or equal to 0.3mm 2 can improve the structural strength of the support portion, which is beneficial to alleviate the phenomenon of insufficient support strength of the support portion between the body portion and the butt joint portion, so as to improve the support effect of the first current collecting member on the electrode assembly and the effect of resisting the expansion of the electrode assembly during use, and can improve the flow capacity of the support portion, which is beneficial to improve the flow guiding effect and flow guiding demand of the first current collecting member.

[0017] In some embodiments, 2mm≤W≤10mm.

[0018] In the technical scheme, the width of the projection of the supporting part of the first current collecting member in the first direction is set to 2-10 mm. On one hand, the width of the projection of the supporting part in the first direction is set to be greater than or equal to 2 mm, which can improve the flow capacity of the supporting part, improve the flow guiding effect of the first current collecting member, and improve the structural strength of the supporting part, which is beneficial to alleviate the insufficient supporting strength of the supporting part between the butt joint part and the body part, improve the supporting effect of the first current collecting member on the electrode assembly, and resist the expansion of the electrode assembly during use. On the other hand, the width of the projection of the supporting part in the first direction is set to be less than or equal to 10 mm, which can effectively improve the deformation capacity of the supporting part when the butt joint part and the body part move close to or away from each other in the first direction, so that the supporting part can play a better buffering role between the butt joint part and the body part, thereby reducing the rigid pulling phenomenon between the butt joint part and the body part, between the body part and the electrode assembly, and between the butt joint part and the shell during the shaking or displacement of the electrode assembly.

[0019] In some embodiments, 3mm≤W≤5mm.

[0020] In the technical scheme, the width of the projection of the supporting part of the first current collecting member in the first direction is set to 2-10 mm. On one hand, the width of the projection of the supporting part in the first direction is set to be greater than or equal to 2 mm, which can improve the flow capacity of the supporting part, improve the flow guiding effect of the first current collecting member, and improve the structural strength of the supporting part, which is beneficial to alleviate the insufficient supporting strength of the supporting part between the butt joint part and the body part, improve the supporting effect of the first current collecting member on the electrode assembly, and resist the expansion of the electrode assembly during use. On the other hand, the width of the projection of the supporting part in the first direction is set to be less than or equal to 10 mm, which can effectively improve the deformation capacity of the supporting part when the butt joint part and the body part move close to or away from each other in the first direction, so that the supporting part can play a better buffering role between the butt joint part and the body part, thereby reducing the rigid pulling phenomenon between the butt joint part and the body part, between the body part and the electrode assembly, and between the butt joint part and the shell during the shaking or displacement of the electrode assembly.

[0021] In some embodiments, 3mm≤W≤5mm.

[0022] In the technical scheme, the thickness of the support part is set to 0.15mm to 0.8mm, on one hand, setting the thickness of the support part to be greater than or equal to 0.15mm can improve the flow capacity of the support part, improve the flow guiding effect of the first current collecting member, and improve the structural strength of the support part, which is conducive to relieving the insufficient support strength of the support part between the butt joint part and the body part, improving the support effect of the first current collecting member on the electrode assembly, and resisting the expansion of the electrode assembly during use, on the other hand, setting the thickness of the support part to be less than or equal to 0.8mm can effectively improve the deformation capacity of the support part when the butt joint part and the body part move close to or away from each other in the first direction, so that the support part can play a better buffering role between the butt joint part and the body part, between the body part and the electrode assembly, and between the butt joint part and the shell, thereby reducing the rigid pulling phenomenon between the butt joint part and the body part, between the body part and the electrode assembly, and between the butt joint part and the shell during the shaking or displacement of the electrode assembly, and saving the space occupied by the support part in the first direction, which is conducive to improving the internal space utilization of the cylindrical battery monomer.

[0023] In some embodiments, 0.3mm≤T1≤0.5mm.

[0024] In the technical scheme, the thickness of the support part is further set to 0.3mm to 0.5mm, on one hand, setting the thickness of the support part to be greater than or equal to 0.3mm can further improve the flow capacity of the support part, further improve the flow guiding effect of the first current collecting member, and further improve the structural strength of the support part, which is conducive to further relieving the insufficient support strength of the support part between the butt joint part and the body part, further improving the support effect of the first current collecting member on the electrode assembly, and resisting the expansion of the electrode assembly during use, on the other hand, setting the thickness of the support part to be less than or equal to 0.5mm can further improve the deformation capacity of the support part when the butt joint part and the body part move close to or away from each other in the first direction, further improve the buffering effect of the support part between the butt joint part and the body part, thereby further reducing the rigid pulling phenomenon between the butt joint part and the body part, between the body part and the electrode assembly, and between the butt joint part and the shell during the shaking or displacement of the electrode assembly, and further saving the space occupied by the support part in the first direction, which is conducive to further improving the internal space utilization of the cylindrical battery monomer.

[0025] In some embodiments, the thickness of the support part is less than the thickness of the body part; and / or, the thickness of the support part is less than the thickness of the butt joint part.

[0026] In the technical solution, the thickness of the supporting part is set to be less than the thickness of the body part, so that the manufacturing cost and difficulty of the first current collecting member are reduced, and the deformation ability of the supporting part when the body part and the butt joint part are close to or away from each other in the first direction is improved, so that the supporting part can play a better buffering effect between the body part and the butt joint part. Similarly, the thickness of the supporting part is set to be less than the thickness of the butt joint part, so that the manufacturing cost and difficulty of the first current collecting member are reduced, and the deformation ability of the supporting part when the body part and the butt joint part are close to or away from each other in the first direction is improved, so that the supporting part can play a better buffering effect between the body part and the butt joint part.

[0027] In some embodiments, the thickness of the body part is T2, and 0.1mm≤T2≤0.6mm.

[0028] In the technical solution, on the one hand, the thickness of the body part is set to be greater than or equal to 0.1mm, which can effectively improve the structural strength of the body part, improve the supporting effect of the body part on the electrode assembly in the first direction, and improve the effect of the body part of the first current collecting member on resisting the expansion of the electrode assembly in the first direction during the use of the cylindrical battery cell. On the other hand, the thickness of the body part is set to be less than or equal to 0.6mm, which can reduce the manufacturing difficulty and cost of the body part of the first current collecting member, and effectively reduce the space occupied by the body part in the first direction, which is beneficial to improving the internal space utilization rate of the cylindrical battery cell.

[0029] In some embodiments, the supporting part is bent to form a plurality of bending segments, the plurality of bending segments are connected in sequence, and the bending segments at both ends of the plurality of bending segments are connected to the body part and the butt joint part, respectively.

[0030] In the technical solution, the supporting part is set to be bent to form a plurality of bending segments connected in sequence, and the bending segments at both ends of the plurality of bending segments are connected to the body part and the butt joint part, respectively, so that the deformation ability of the supporting part when the body part and the butt joint part are close to or away from each other in the first direction is increased, the buffering effect of the supporting part between the body part and the butt joint part is further improved, and the phenomenon of rigid pulling between the body part and the butt joint part, between the body part and the electrode assembly, and between the butt joint part and the shell is further reduced.

[0031] In some embodiments, the shell further includes a side wall surrounding the first wall, and one end of the side wall in the first direction is connected to the first wall, and a protrusion is provided on the inner circumferential surface of the side wall; wherein, in the first direction, the body part is arranged between the protrusion and the electrode assembly, and the butt joint part is connected to the protrusion.

[0032] In the above technical solution, the protrusion is arranged on the inner circumferential surface of the side wall, the body part is arranged between the protrusion and the electrode assembly in the first direction, and the butt joint part of the first current collecting member is connected with the protrusion, so as to realize the electrical connection between the electrode assembly and the shell. The cylindrical battery cell with the structure can support and limit the electrode assembly through the protrusion, which is beneficial to improve the support effect of the body part of the first current collecting member on the electrode assembly in the first direction. On the other hand, the connection position of the butt joint part and the pressure relief part are arranged on different regions of the shell, so as to alleviate the stress of the first current collecting member acting on the protrusion and being transmitted to the region of the first wall where the pressure relief part is arranged, and reduce the risk of cracking or structural strength reduction of the region of the first wall where the pressure relief groove of the pressure relief part is arranged, so as to improve the service life and use reliability of the battery cell.

[0033] In some embodiments, the body part includes a main body region and a plurality of support regions connected to the outer circumferential surface of the main body region, the plurality of support regions are arranged at intervals along the circumference of the main body region, and at least part of the support regions is located between the electrode assembly and the protrusion in the first direction.

[0034] In the above technical solution, the body part includes a main body region and a plurality of support regions connected to the outer circumferential surface of the main body region, the plurality of support regions are arranged at intervals along the circumference of the main body region, and at least part of the support regions is located between the electrode assembly and the protrusion in the first direction. The body part of the first current collecting member can support the electrode assembly between the protrusion and the electrode assembly, and at the same time, the thermal runaway gas in the cylindrical battery cell can be exhausted through the gaps between the plurality of support regions, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery cell.

[0035] In some embodiments, the protrusion and the pressure relief groove extend along the circumference of the side wall; wherein, in the radial direction of the cylindrical battery cell, the inner diameter of the protrusion is D2, the outer diameter of the main body region is D3, and the inner diameter of the pressure relief groove is D4, and D2≥D3 and D4≥0.75D3 are satisfied.

[0036] In the technical solution, the inner diameter of the protrusion is greater than or equal to the outer diameter of the main body region of the body part, and the inner diameter of the pressure relief groove is greater than or equal to 0.75 times the outer diameter of the main body region of the body part, so that the main body region of the body part is a structure whose projection in the first direction is located inside the protrusion, and the pressure relief groove is a structure whose projection in the first direction is close to the outer edge of the main body region or located outside the main body region, thereby reducing the obstruction of the protrusion and the main body region to the exhaust path inside the cylindrical battery cell, so that the thermal runaway gas inside the cylindrical battery cell can more smoothly pass through the gap between the plurality of support regions, enter the side of the body part facing the first wall, and then directly pass through the area of the pressure relief component on the first wall provided with the pressure relief groove for pressure relief, thereby effectively improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, and reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, thereby improving the use stability and reliability of the cylindrical battery cell.

[0037] In some embodiments, D2 is greater than or equal to D4.

[0038] In the technical solution, the inner diameter of the protrusion is greater than or equal to the inner diameter of the pressure relief groove, so that the pressure relief groove is a structure provided in the gap between the protrusion and the main body region of the body part in the first direction, thereby further reducing the obstruction and obstruction of the protrusion and the main body region to the area of the first wall for pressure relief, thereby further improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, and further reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, thereby further improving the use stability and reliability of the cylindrical battery cell.

[0039] In some embodiments, along the radial direction of the cylindrical battery cell, the outer diameter of the body part is D5, and D2 is less than or equal to 0.95D5.

[0040] In the technical solution, the inner diameter of the protrusion is less than 0.95 times the outer diameter of the body part, so that the inner circumferential surface of the protrusion is a structure whose projection in the first direction is located inside the body part, so that the plurality of support regions connected on the outer circumferential surface of the main body region of the body part can better extend between the electrode assembly and the protrusion, thereby improving the lap joint effect of the plurality of support regions and the protrusion, further improving the support effect of the body part of the first current collecting member on the electrode assembly, and improving the effect of the body part of the first current collecting member on resisting the expansion of the electrode assembly during use of the cylindrical battery cell, thereby improving the use stability of the cylindrical battery cell.

[0041] In some embodiments, the maximum proportion of the plurality of support regions in the circumferential direction of the main body region is P, and 40%≤P≤90%.

[0042] In the above technical solution, on the one hand, by setting the maximum proportion of the plurality of support regions in the circumferential direction of the main body region to be greater than or equal to 40%, the maximum space occupied by the plurality of support regions in the circumferential direction is greater than or equal to 40%, thereby improving the effect of the body portion being overlapped with the protrusions through the plurality of support regions, improving the support effect of the body portion of the first current collecting member on the electrode assembly, and improving the effect of the body portion of the first current collecting member resisting the expansion of the electrode assembly during use of the cylindrical battery monomer. On the other hand, by setting the maximum proportion of the plurality of support regions in the circumferential direction of the main body region to be less than or equal to 90%, the maximum space occupied by the plurality of support regions in the circumferential direction is less than or equal to 90%, thereby alleviating the phenomenon that the plurality of support regions are close in distance in the circumferential direction of the main body region, improving the size of the gap between the plurality of support regions, allowing the thermal runaway gas inside the cylindrical battery monomer to more smoothly enter the side of the body portion facing the first wall through the gap between the plurality of support regions, thereby improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer, and being beneficial to reducing the risk of bursting or explosion of the cylindrical battery monomer due to untimely pressure relief.

[0043] In some embodiments, 50%≤P≤80%.

[0044] In the above technical solution, on the one hand, by further setting the maximum proportion of the plurality of support regions in the circumferential direction of the main body region to be greater than or equal to 50%, the maximum space occupied by the plurality of support regions in the circumferential direction is greater than or equal to 50%, thereby further improving the effect of the body portion being overlapped with the protrusions through the plurality of support regions, further improving the support effect of the body portion of the first current collecting member on the electrode assembly, and further improving the effect of the body portion of the first current collecting member resisting the expansion of the electrode assembly during use of the cylindrical battery monomer. On the other hand, by further setting the maximum proportion of the plurality of support regions in the circumferential direction of the main body region to be less than or equal to 80%, the maximum space occupied by the plurality of support regions in the circumferential direction is less than or equal to 80%, thereby further alleviating the phenomenon that the plurality of support regions are close in distance in the circumferential direction of the main body region, further improving the size of the gap between the plurality of support regions, allowing the thermal runaway gas inside the cylindrical battery monomer to more smoothly enter the side of the body portion facing the first wall through the gap between the plurality of support regions, thereby further improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer, and being beneficial to further reducing the risk of bursting or explosion of the cylindrical battery monomer due to untimely pressure relief.

[0045] In some embodiments, the dimension of the protrusion protruding from the inner circumferential surface of the side wall in the radial direction of the cylindrical battery cell is L2, the dimension of the portion of the positive projection of the support region overlapping with the positive projection of the protrusion in the radial direction of the cylindrical battery cell is L3, and 0.2L2≤L3≤0.9L2 is satisfied.

[0046] In the above technical solution, by setting the dimension of the portion of the projection of the support region overlapping with the protrusion in the radial direction of the cylindrical battery cell to be 0.2 to 0.9 times the dimension of the protrusion protruding from the inner circumferential surface of the side wall, the length of the support region extending in the radial direction of the cylindrical battery cell between the protrusion and the electrode assembly is set to be 0.2 to 0.9 times the dimension of the protrusion protruding from the inner circumferential surface of the side wall, on the one hand, setting the length of the support region extending in the radial direction of the cylindrical battery cell between the protrusion and the electrode assembly to be greater than or equal to 0.2 times the dimension of the protrusion protruding from the inner circumferential surface of the side wall can further improve the mutual lapping effect of the support region and the protrusion, to further improve the support effect of the body portion of the first current collecting member on the electrode assembly, and can further improve the effect of the body portion of the first current collecting member resisting the expansion of the electrode assembly during the use of the cylindrical battery cell. On the other hand, setting the length of the support region extending in the radial direction of the cylindrical battery cell between the protrusion and the electrode assembly to be less than or equal to 0.9 times the dimension of the protrusion protruding from the inner circumferential surface of the side wall can alleviate the phenomenon of the support region lapping too much with the protrusion, thereby reducing the difficulty of assembling the first current collecting member into the shell, and facilitating the body portion of the first current collecting member to be separated from between the protrusion and the electrode assembly under the impact of the thermal runaway gas when the cylindrical battery cell is depressurized, which is beneficial to improving the internal exhaust smoothness and the depressurization rate of the cylindrical battery cell, to further reduce the risk of bursting or explosion of the cylindrical battery cell due to untimely depressurization.

[0047] In some embodiments, 1mm≤L2≤8mm.

[0048] In the technical solution, the size of the protrusion protruding from the inner circumferential surface of the side wall is set to 1mm to 8mm, so that the size of the protrusion in the radial direction of the cylindrical battery cell is 1mm to 8mm. On the one hand, setting the size of the protrusion protruding from the inner circumferential surface of the side wall to be greater than or equal to 1mm can reduce the difficulty of overlapping the protrusion and the support area, reduce the difficulty of setting the body part of the first current collecting member between the protrusion and the electrode assembly, and improve the support effect of the protrusion on the electrode assembly. On the other hand, setting the size of the protrusion protruding from the inner circumferential surface of the side wall to be less than or equal to 8mm can reduce the space occupied by the protrusion in the radial direction of the cylindrical battery cell, which is beneficial to reducing the obstruction of the protrusion to the exhaust path inside the cylindrical battery cell, thereby effectively improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, and reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, thereby improving the use stability and reliability of the cylindrical battery cell.

[0049] In some embodiments, L3≥1mm.

[0050] In the technical solution, the size of the part of the support area overlapping with the protrusion in the radial direction of the cylindrical battery cell is set to be greater than or equal to 1mm, so that the length of the support area extending to the space between the protrusion and the electrode assembly in the radial direction of the cylindrical battery cell is greater than or equal to 1mm, thereby improving the mutual overlapping effect of the support area and the protrusion, and improving the support effect of the body part of the first current collecting member on the electrode assembly. In addition, the effect of the body part of the first current collecting member resisting the expansion of the electrode assembly can be further improved during use of the cylindrical battery cell.

[0051] In some embodiments, the electrode assembly includes a body part and a first tab, the first tab being connected to one end of the body part facing the first wall in the first direction; wherein the body area and the first tab are welded and connected to form a plurality of first connection parts, and a plurality of support areas and the first tab are welded and connected to form a plurality of second connection parts, and the sum of the lengths of the plurality of second connection parts is greater than or equal to the sum of the lengths of the plurality of first connection parts.

[0052] In the technical scheme, the plurality of first connecting portions are formed by welding the plurality of support regions of the body portion to the first tab, and the plurality of second connecting portions are formed by welding the plurality of support regions of the body portion to the first tab, so that the body region and the support region are both structures welded to the first tab, thereby improving the flow area between the first tab and the body portion and improving the connection stability and reliability between the body portion of the first current collecting member and the first tab of the electrode assembly. Since the outer ring length of the first tab is greater than the inner ring length of the first tab, the flow requirement of the outer ring of the first tab is greater than the flow requirement of the inner ring of the first tab. The total length of the plurality of second connecting portions formed by welding the plurality of support regions to the first tab is greater than the total length of the plurality of first connecting portions formed by welding the body region to the first tab, so that the flow area between the outer ring of the first tab and the body portion is greater than the flow area between the inner ring of the first tab and the body portion, thereby improving the flow balance of the inner ring and the outer ring of the first tab and reducing the risk of local lithium precipitation or increased internal resistance of the electrode assembly during use.

[0053] In some embodiments, the plurality of first connecting portions are arranged along the circumferential direction of the side wall, and the first connecting portions extend along the radial direction of the cylindrical battery cell.

[0054] In the technical scheme, the plurality of first connecting portions are arranged along the circumferential direction of the side wall, and the first connecting portions extend along the radial direction of the cylindrical battery cell. On the one hand, this can reduce the welding difficulty between the body region and the first tab and optimize the layout of the plurality of first connecting portions, thereby reducing the interference between the plurality of first connecting portions. On the other hand, this can connect the first tab to the body region at multiple positions along the circumferential direction of the side wall and along the radial direction of the cylindrical battery cell, so that the multiple ring structures of the first tab can be connected to the body region. This can improve the flow area between the first tab and the body region and improve the flow balance between the electrode assembly and the body region, thereby reducing the risk of local lithium precipitation of the electrode assembly during use.

[0055] In some embodiments, the plurality of second connecting portions are arranged along the circumferential direction of the side wall, and the second connecting portions extend along the radial direction of the cylindrical battery cell.

[0056] In the technical solution, the plurality of second connecting parts formed by welding the plurality of support areas and the first tab are arranged in a structure spaced along the circumference of the side wall, and each second connecting part extends in the radial direction of the cylindrical battery monomer. On the one hand, the welding difficulty between the plurality of support areas and the first tab can be reduced, and the layout between the plurality of second connecting parts can be optimized, which is conducive to relieving the interference between the plurality of second connecting parts. On the other hand, the first tab can be connected to the support area at multiple positions in the circumferential direction of the side wall, and the first tab can be connected to the support area at multiple positions in the radial direction of the cylindrical battery monomer. The multiple turns of the first tab can be connected to the support area, thereby improving the flow area between the first tab and the support area and the flow balance between the electrode assembly and the support area, and reducing the risk of local lithium precipitation of the electrode assembly during use.

[0057] In some embodiments, each support area is welded to the first tab to form the second connecting part.

[0058] In the technical solution, each support area of the body part is welded to the first tab, so that the plurality of support areas spaced in the circumferential direction of the main body area are welded to the first tab and correspondingly form the second connecting part. On the one hand, the connection stability and firmness between the first tab and the body part can be further improved. On the other hand, the first tab can be connected to the support area at multiple positions in the circumferential direction of the side wall, which is conducive to improving the flow balance between the electrode assembly and the first current collecting member, thereby reducing the risk of local lithium precipitation of the electrode assembly during use.

[0059] In some embodiments, in the radial direction of the cylindrical battery monomer, the outer diameter of the main body area is D3, and the length of the support area is L4, satisfying 0.5D3≥L4.

[0060] In the technical solution, the radius of the main body area of the body part is greater than or equal to the length of the support area of the body part protruding from the outer circumferential surface of the main body area in the radial direction of the cylindrical battery monomer, thereby relieving the phenomenon that the support area occupies too much space in the body part and causes insufficient structural strength of the body part. This can further improve the phenomenon that the support effect of the body part on the electrode assembly in the first direction is not good, and further improve the effect of the body part resisting the expansion of the electrode assembly during use of the cylindrical battery monomer.

[0061] In some embodiments, the protrusion extends in the circumferential direction of the side wall, the first current collecting member includes a plurality of support parts and a plurality of abutting parts, the plurality of abutting parts are spaced along the circumferential direction of the side wall, each abutting part is connected to the body part through a support part, and the plurality of abutting parts are connected to the protrusion.

[0062] In the technical solution, the protrusion is arranged as a structure extending along the circumference of the side wall, and the first current collecting member is arranged as a structure including a plurality of support portions and a plurality of butt joint portions, the support portions and the butt joint portions correspond to each other, and the plurality of butt joint portions are arranged at intervals along the circumference of the side wall and are connected to the protrusion, so that the protrusion is connected to the butt joint portions at a plurality of positions along the circumference of the side wall. On the one hand, the connection stability and firmness between the first current collecting member and the protrusion can be further improved, and on the other hand, the flow area between the first current collecting member and the protrusion can be further improved, and the flow balance between the first current collecting member and the protrusion can be further improved, so as to reduce the risk of local temperature rise of the protrusion.

[0063] In some embodiments, the plurality of butt joint portions are each welded to the protrusion and correspondingly form a plurality of third connecting portions, the third connecting portions correspond to the butt joint portions one by one, and the third connecting portions extend along the circumference of the side wall; wherein in a projection plane perpendicular to the first direction, the outer edges of the projections of the plurality of third connecting portions are each located on a first circle, and the sum of the arc lengths of the outer edges of the projections of the plurality of third connecting portions is L5, the circumference of the first circle is L6, and L5≥0.5L6 is satisfied.

[0064] In the technical solution, the sum of the arc lengths of the outer edges of the projections of the plurality of third connecting portions in the first direction is greater than or equal to 0.5 times the circumference of the first circle, so that the proportion of the plurality of third connecting portions on the first circle is greater than or equal to 50%, thereby increasing the flow area between the first current collecting member and the protrusion, improving the flow effect between the first current collecting member and the shell, and further reducing the phenomenon of increased internal resistance of the cylindrical battery cell during use.

[0065] In some embodiments, L5≥0.8L6.

[0066] In the technical solution, the sum of the arc lengths of the outer edges of the projections of the plurality of third connecting portions in the first direction is further greater than or equal to 0.8 times the circumference of the first circle, so that the proportion of the plurality of third connecting portions on the first circle is greater than or equal to 80%, thereby further increasing the flow area between the first current collecting member and the protrusion, further improving the flow effect between the first current collecting member and the shell, and further reducing the phenomenon of increased internal resistance of the cylindrical battery cell during use.

[0067] In some embodiments, the butt joint portion is an arc-shaped structure extending along the circumference of the side wall.

[0068] In the technical solution, the abutment part is arranged as an arc-shaped structure extending along the circumference of the side wall, so as to match with the protrusion. On one hand, the abutment part and the protrusion are welded to form a third connecting part extending along the circumference of the side wall, which is beneficial to reduce the welding difficulty between the abutment part and the protrusion. On the other hand, the abutment part can be welded to the protrusion at multiple positions along the circumference of the side wall, so that the first current collecting member can be assembled into the shell without rotating and adjusting the position, which is beneficial to further reduce the welding difficulty between the first current collecting member and the protrusion, thereby effectively improving the assembly efficiency of the cylindrical battery cell.

[0069] In some embodiments, an accommodating cavity is formed in the shell, the body part is configured to divide the accommodating cavity into a first cavity and a second cavity in communication with each other, the electrode assembly is accommodated in the first cavity, the second cavity is located between the body part and the first wall in the first direction, and the pressure relief component is configured to be broken along at least part of the pressure relief groove to release the internal pressure of the second cavity when the cylindrical battery cell is relieved.

[0070] In the above technical solution, the body part separates the accommodating cavity inside the shell into a first cavity and a second cavity arranged along the first direction, the electrode assembly is arranged in the first cavity, and the second cavity is located between the first wall and the body part. By arranging the pressure relief component to be able to break along at least part of the pressure relief groove and release the internal pressure of the second cavity when the cylindrical battery monomer is pressure relieved, the region of the pressure relief component on the first wall where the pressure relief groove is arranged is a structure corresponding to the second cavity. The cylindrical battery monomer with this structure can separate the electrode assembly and the pressure relief component through the second cavity, so that the blocking and shielding of the electrode assembly to the pressure relief component can be relieved when the cylindrical battery monomer is pressure relieved, so that the second cavity inside the shell can be used to buffer and discharge the thermal runaway gas, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery monomer. The maximum size of the second cavity in the first direction is 0.003 to 0.06 times the maximum size of the shell in the first direction. On the one hand, by arranging the maximum size of the second cavity in the first direction to be greater than or equal to 0.003 times the maximum size of the shell in the first direction, the body part and the first wall have enough space to buffer and discharge the thermal runaway gas, which is beneficial to improve the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer, so as to reduce the risk of explosion or explosion of the cylindrical battery monomer due to untimely pressure relief. On the other hand, by arranging the maximum size of the second cavity in the first direction to be less than or equal to 0.06 times the maximum size of the shell in the first direction, the phenomenon that the second cavity occupies too much space for arranging the electrode assembly in the accommodating cavity is alleviated, so as to improve the internal space utilization of the cylindrical battery monomer, and the energy density of the cylindrical battery monomer is improved.

[0071] In some embodiments, 0.01≤H1 / H2≤0.03.

[0072] In the above technical solution, on the one hand, the maximum size of the second cavity in the first direction is further arranged to be greater than or equal to 0.01 times the maximum size of the shell in the first direction, so that the body part and the first wall have more space to buffer and discharge the thermal runaway gas, which is beneficial to further improve the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer, so as to further reduce the risk of explosion or explosion of the cylindrical battery monomer due to untimely pressure relief. On the other hand, the maximum size of the second cavity in the first direction is further arranged to be less than or equal to 0.03 times the maximum size of the shell in the first direction, so as to further alleviate the phenomenon that the second cavity occupies too much space for arranging the electrode assembly in the accommodating cavity, so as to further improve the internal space utilization of the cylindrical battery monomer, and the energy density of the cylindrical battery monomer is further improved.

[0073] In some embodiments, 0.4mm≤H1≤4mm.

[0074] In the technical solution, by setting the maximum size of the second cavity in the first direction to 0.4mm to 4mm, on the one hand, more space between the body part and the first wall can be provided for buffering and discharging the thermal runaway gas, so that the blocking of the electrode assembly and the body part to the exhaust path inside the cylindrical battery cell can be reduced when the cylindrical battery cell is depressurized, thereby further improving the internal exhaust smoothness and the depressurization rate of the cylindrical battery cell, and reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely depressurization. On the other hand, the phenomenon that the second cavity occupies too much space for setting the electrode assembly in the accommodation cavity can be alleviated, thereby further improving the internal space utilization of the cylindrical battery cell, and further improving the energy density of the cylindrical battery cell.

[0075] In some embodiments, the capacity of the cylindrical battery cell is C, and satisfies 0.005mm / Ah≤H1 / C≤0.2mm / Ah.

[0076] In the technical solution, on the one hand, by setting the ratio of the maximum size of the second cavity in the first direction to the capacity of the cylindrical battery cell to be greater than or equal to 0.005mm / Ah, the second cavity has enough space to buffer and discharge the thermal runaway gas when the cylindrical battery cell is depressurized, which is beneficial to match the space for exhaust in the shell with the gas production rate of the cylindrical battery cell in thermal runaway, so as to improve the internal exhaust smoothness of the cylindrical battery cell, thereby effectively reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely depressurization. On the other hand, by setting the ratio of the maximum size of the second cavity in the first direction to the capacity of the cylindrical battery cell to be less than or equal to 0.2mm / Ah, the phenomenon of excessive waste of space for exhaust in the shell can be alleviated, thereby improving the internal space utilization of the cylindrical battery cell, and improving the energy density of the cylindrical battery cell.

[0077] In some embodiments, the positive electrode material of the cylindrical battery cell includes lithium transition metal oxide, and the H1 and C further satisfy 0.01mm / Ah≤H1 / C≤0.2mm / Ah; or, the positive electrode material of the cylindrical battery cell includes lithium-containing phosphate, and the H1 and C further satisfy 0.005mm / Ah≤H1 / C≤0.1mm / Ah.

[0078] In the above technical solution, when the positive electrode material of the cylindrical battery cell includes lithium transition metal oxide, by further setting the ratio of the maximum size of the second cavity in the first direction to the capacity of the cylindrical battery cell to 0.01 mm / Ah to 0.2 mm / Ah, the space for exhaust in the shell can be further matched with the gas production rate of the cylindrical battery cell in thermal runaway, on the one hand, the internal exhaust smoothness of the cylindrical battery cell can be further improved, to further reduce the risk of bursting or explosion of the cylindrical battery cell due to untimely pressure relief, on the other hand, the phenomenon of excessive waste of space for exhaust in the shell can be further alleviated, to further improve the internal space utilization rate of the cylindrical battery cell, which is conducive to further improving the energy density of the cylindrical battery cell. Similarly, when the positive electrode material of the cylindrical battery cell includes lithium-containing phosphate, by further setting the ratio of the maximum size of the second cavity in the first direction to the capacity of the cylindrical battery cell to 0.005 mm / Ah to 0.1 mm / Ah, the space for exhaust in the shell can be further matched with the gas production rate of the cylindrical battery cell in thermal runaway, on the one hand, the internal exhaust smoothness of the cylindrical battery cell can be further improved, to further reduce the risk of bursting or explosion of the cylindrical battery cell due to untimely pressure relief, on the other hand, the phenomenon of excessive waste of space for exhaust in the shell can be further alleviated, to further improve the internal space utilization rate of the cylindrical battery cell, which is conducive to further improving the energy density of the cylindrical battery cell.

[0079] In some embodiments, along the radial direction of the cylindrical battery cell, the inner diameter of the protrusion is D2, and the outer diameter of the electrode assembly is D6, satisfying 0.7≤D2 / D6≤0.95.

[0080] In the above technical solution, by setting the ratio of the inner diameter of the protrusion to the outer diameter of the electrode assembly to 0.7 to 0.95, on the one hand, the inner diameter of the protrusion is set to be greater than or equal to 0.7 times the outer diameter of the electrode assembly, so that most of the area of the electrode assembly is a structure arranged on the inner side of the protrusion in the first direction, thereby reducing the obstruction of the protrusion to the exhaust path inside the cylindrical battery cell, which is conducive to improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, thereby effectively reducing the risk of bursting or explosion of the cylindrical battery cell due to untimely pressure relief. On the other hand, the inner diameter of the protrusion is set to be less than or equal to 0.95 times the outer diameter of the electrode assembly, so that the electrode assembly and the protrusion are a structure in which the projected parts in the first direction overlap, thereby improving the support effect of the protrusion on the electrode assembly through the body part, and also improving the effect of the body part of the first current collecting member against the expansion of the electrode assembly during use of the cylindrical battery cell.

[0081] In some embodiments, 0.75≤D2 / D6≤0.9.

[0082] In the above technical solution, on the one hand, the inner diameter of the protrusion is set to be greater than or equal to 0.75 times the outer diameter of the electrode assembly, so as to further increase the area of the region corresponding to the inner side of the protrusion in the first direction, thereby further reducing the obstruction of the protrusion to the exhaust path inside the cylindrical battery cell, and facilitating further improvement of the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, and further reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief. On the other hand, the inner diameter of the protrusion is set to be less than or equal to 0.9 times the outer diameter of the electrode assembly, so as to further increase the area of the region where the electrode assembly and the protrusion overlap in the first direction, thereby further improving the support effect of the protrusion on the electrode assembly through the body part, and further improving the effect of the body part of the first current collecting member against the expansion of the electrode assembly during use of the cylindrical battery cell.

[0083] In some embodiments, along the first direction, the projection of the pressure relief groove is located in the second cavity.

[0084] In the above technical solution, by setting the pressure relief groove to have a projection in the first direction located in the second cavity, the region of the pressure relief component on the first wall where the pressure relief groove is arranged is arranged corresponding to the second cavity in the first direction, so that when the cylindrical battery cell undergoes thermal runaway and the pressure relief component is at least partially split along the pressure relief groove to relieve pressure, the thermal runaway gas in the second cavity can be more easily discharged, which facilitates further improvement of the discharge rate of the thermal runaway gas in the second cavity, and further improves the pressure relief rate of the cylindrical battery cell, thereby further reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief.

[0085] In some embodiments, along the first direction, the butt joint portion is arranged on the side of the protrusion away from the electrode assembly and connected to the protrusion.

[0086] In the above technical solution, by arranging the butt joint portion of the first current collecting member on the side of the protrusion away from the electrode assembly in the first direction, the butt joint portion and the body part are arranged on the two sides of the protrusion in the first direction, and the butt joint portion and the side of the protrusion away from the electrode assembly are connected to each other. The cylindrical battery cell with this structure can on the one hand share part of the space in the first direction by the first current collecting member and the protrusion, which facilitates improvement of the internal space utilization of the cylindrical battery cell, and on the other hand, the assembly connection between the butt joint portion and the protrusion is not affected by the electrode assembly, which facilitates reduction of the assembly difficulty of the butt joint portion and the protrusion, and facilitates optimization of the production process of the cylindrical battery cell.

[0087] In some embodiments, a groove is formed on the side of the side wall away from the electrode assembly and corresponding to the position of the protrusion along the radial direction of the cylindrical battery cell.

[0088] In the above technical solution, by forming a groove on the side of the side wall away from the electrode assembly and corresponding to the position of the protrusion, the protrusion formed on the side of the side wall facing the electrode assembly is a structure that can be formed by stamping processing, so as to form a protrusion on the side of the side wall facing the electrode assembly and form a groove on the other side and corresponding to the position of the protrusion. The cylindrical battery cell adopting such a structure can reduce the difficulty of forming a protrusion on the side of the side wall facing the electrode assembly, thereby improving the production efficiency of the cylindrical battery cell. On the other hand, the inside of the protrusion can be a hollow structure, so that the protrusion can have the ability of elastic deformation, thereby relieving the rigid pulling between the butt joint part and the protrusion, and reducing the risk of connection failure between the butt joint part and the protrusion.

[0089] In some embodiments, the shell further comprises a second wall disposed opposite to the first wall in the first direction, the second wall is integrally formed with the side wall, one end of the side wall is connected to the second wall in the first direction, and the other end of the side wall encloses an opening, the side wall and the second wall jointly define a receiving cavity, and the electrode assembly is received in the receiving cavity; wherein the first wall closes the opening.

[0090] In the above technical solution, by setting the side wall of the shell to enclose an opening at one end away from the second wall in the first direction, and setting the first wall to close the opening, the first current collecting member is set to be disposed on the side of the electrode assembly facing the opening in the first direction, thereby reducing the difficulty of assembling the body part of the first current collecting member between the electrode assembly and the protrusion, and reducing the connection difficulty between the butt joint part and the protrusion, thereby reducing the assembly difficulty of the cylindrical battery cell, and optimizing the production process of the cylindrical battery cell, thereby improving the production efficiency of the cylindrical battery cell.

[0091] In some embodiments, the side wall is bent to form a flange part at one end away from the second wall in the first direction, and the flange part encloses the opening; wherein, along the first direction, part of the first wall is located between the flange part and the protrusion, and the flange part and the protrusion are configured to cooperate to clamp the first wall.

[0092] In the technical solution, the side wall is bent to form a flange part at one end thereof away from the second wall in the first direction, and part of the first wall is arranged between the protrusion and the flange part in the first direction, so that the protrusion and the flange part can also play a role in assembling and fixing the first wall, thereby achieving the assembly between the first wall and the side wall. The cylindrical battery cell with the structure can reduce the assembly difficulty between the first wall and the side wall, thereby improving the production efficiency of the cylindrical battery cell.

[0093] In some embodiments, the cylindrical battery cell further comprises a sealing member, the sealing member is arranged at least partially between the side wall and the first wall in the radial direction of the cylindrical battery cell, and the sealing member is configured to seal the gap between the first wall and the side wall.

[0094] In the technical solution, the cylindrical battery cell further comprises a sealing member, the sealing member is arranged at least partially between the side wall and the first wall in the radial direction of the cylindrical battery cell, and the sealing member is configured to seal the gap between the first wall and the side wall.

[0095] In some embodiments, the housing further comprises a second wall, the second wall is arranged opposite to the first wall in the first direction; wherein the side wall is integrally formed with the first wall, one end of the side wall is connected to the first wall in the first direction, and the other end of the side wall encloses an opening, the side wall and the first wall jointly define a containing cavity, the electrode assembly is contained in the containing cavity, and the second wall closes the opening.

[0096] In the technical solution, the first wall and the side wall are integrally formed, and one end of the side wall away from the first wall in the first direction encloses an opening for assembling the electrode assembly, and the second wall closes the opening. The cylindrical battery cell with the structure can first form the protrusion on the inner circumferential surface of the side wall, and then assemble the electrode assembly into the containing cavity formed by the side wall and the first wall, thereby reducing the damage of the protrusion to the electrode assembly during the forming process, and improving the production quality of the cylindrical battery cell.

[0097] In some embodiments, the protrusion is an annular structure extending in the circumferential direction of the side wall.

[0098] In the technical solution, the protrusion is arranged in an annular structure with the first end connected to the second end, which can improve the support effect of the protrusion on the electrode assembly through the first current collecting member, and can also realize that the protrusion can be connected to the butt joint part at any position in the circumferential direction of the protrusion, thereby reducing the positioning difficulty and assembly difficulty between the butt joint part and the protrusion.

[0099] In some embodiments, the pressure relief groove is an annular structure extending along the circumference of the sidewall.

[0100] In the above technical solution, by setting the pressure relief groove as an annular structure connected head to tail, the cylindrical battery cell can knock open the area where the pressure relief component is located in the pressure relief groove as a whole when pressure relief, which is conducive to improving the pressure relief area of the cylindrical battery cell to improve the pressure relief rate of the cylindrical battery cell.

[0101] In some embodiments, the electrode assembly is provided with a center through hole penetrating through both ends of the electrode assembly along the first direction, the body part is provided with an exhaust hole penetrating through both sides of the body part along the first direction, and the exhaust hole is in communication with the center through hole; wherein, along the first direction, the projection of the hole wall surface of the center through hole is located in the exhaust hole.

[0102] In the above technical solution, by setting the exhaust hole penetrating through the body part along the first direction on the body part of the first current collecting member, the exhaust hole and the center through hole of the electrode assembly are connected with each other, and the projection of the hole wall surface of the center through hole in the first direction is set to be located in the exhaust hole, so that the hole diameter of the exhaust hole is greater than or equal to the hole diameter of the center through hole, thereby facilitating the hot runaway gas in the center through hole to enter the side of the body part facing the first wall through the exhaust hole and then directly pass through the area where the pressure relief groove of the pressure relief component on the first wall is located for discharge when the cylindrical battery cell appears thermal runaway, which is conducive to improving the smoothness of internal exhaust of the cylindrical battery cell, and thus can effectively reduce the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, to improve the use stability and reliability of the cylindrical battery cell.

[0103] In some embodiments, the hole diameter of the center through hole is D7, and the hole diameter of the exhaust hole is D8, satisfying D8≥1.5D7.

[0104] In the above technical solution, by further setting the hole diameter of the exhaust hole to be greater than or equal to 1.5 times the hole diameter of the center through hole, the smoothness of the hot runaway gas in the center through hole entering the side of the body part facing the first wall through the exhaust hole can be further improved when the cylindrical battery cell appears thermal runaway, which is conducive to further improving the smoothness of internal exhaust of the cylindrical battery cell, so as to further reduce the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, to further improve the use stability and reliability of the cylindrical battery cell.

[0105] In some embodiments, the pressure relief component is integrally formed with the first wall.

[0106] In the technical solution, the pressure relief component is integrally formed with the first wall, so that the pressure relief component is part of the first wall, and the pressure relief groove is directly arranged on the first wall, thereby eliminating the process of assembling the pressure relief component and the first wall, optimizing the processing technology of the cylindrical battery cell, and improving the production efficiency of the cylindrical battery cell.

[0107] In some embodiments, the pressure relief component is arranged separately from the first wall and connected to the first wall.

[0108] In the technical solution, the pressure relief component is arranged separately from the first wall, thereby reducing the difficulty of machining the pressure relief groove directly on the first wall and reducing the influence on the structural strength of the first wall.

[0109] In a second aspect, the embodiments of the present application further provide a battery device comprising the cylindrical battery cell.

[0110] In a third aspect, the embodiments of the present application further provide a power utilization device comprising the cylindrical battery cell, and the cylindrical battery cell is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0111] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0112] Figure 1 The structural diagram of the vehicle is provided for some embodiments of the present application;

[0113] Figure 2 The structural explosion diagram of the battery device is provided for some embodiments of the present application;

[0114] Figure 3 The structural diagram of the cylindrical battery cell is provided for some embodiments of the present application;

[0115] Figure 4 The structural explosion diagram of the cylindrical battery cell is provided for some embodiments of the present application;

[0116] Figure 5 The sectional view of the cylindrical battery cell is provided for some embodiments of the present application;

[0117] Figure 6 The sectional view of the cylindrical battery cell is provided for some embodiments of the present application; Figure 5 The partial enlarged view of the cylindrical battery cell at A is shown;

[0118] Figure 7 Structure diagram of a first current collecting member provided for some embodiments of the present application;

[0119] Figure 8 Front view of a first current collecting member provided for some embodiments of the present application in a first direction;

[0120] Figure 9 Partial sectional view of a housing provided for some embodiments of the present application;

[0121] Figure 10 Structure diagram of a first connecting portion, a second connecting portion and a third connecting portion on a first current collecting member provided for some embodiments of the present application.

[0122] Icon: 1000-vehicle; 100-battery device; 10-box body; 11-first box body; 12-second box body; 20-cylindrical battery cell; 21-housing; 211-first wall; 2111-pressure relief groove; 212-second wall; 213-side wall; 2131-opening; 2132-protrusion; 2133-groove; 2134-flange portion; 214-accommodation cavity; 2141-first cavity; 2142-second cavity; 22-electrode assembly; 221-body portion; 222-first tab; 223-second tab; 224-central through hole; 23-first current collecting member; 231-body portion; 2311-body region; 2312-support region; 2313-exhaust hole; 232-support portion; 2321-bent segment; 233-butting portion; 234-exhaust gap; 24-electrode terminal; 25-second current collecting member; 26-first connecting portion; 27-second connecting portion; 28-third connecting portion; 29-sealing member; 200-controller; 300-motor; X-first direction. DETAILED DESCRIPTION

[0123] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0124] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The articles 'a', 'an', and 'the' each followed by'some or more' or 'one or more' of an element are intended to include one or more articles of the described element and do not exclude other additional elements. The terms "comprises", "comprising", "includes", "including", "has", "having" and the like are inclusive and are used as equivalents of the term "consisting of".

[0125] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another.

[0126] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection", "attaching" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0127] In the application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the character " / " in the application generally represents an "or" relationship between the front and rear associated objects.

[0128] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0129] "Multiple" appearing in the application means two or more (including two).

[0130] In the embodiments of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to use.

[0131] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto.

[0132] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can function to prevent short circuiting of the positive and negative electrodes while allowing the active ions to pass through.

[0133] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0134] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0135] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0136] As an example, the positive electrode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material of a battery can also be used. These positive electrode active materials can be used alone or in combination of two or more. Examples of the lithium-containing phosphates can include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also referred to 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 the lithium transition metal oxides can include, but are not limited to, at least one of lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2(also can be referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), and modified compounds thereof.

[0137] In some embodiments, the positive electrode can employ a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or the like. When the foam metal is used as the positive electrode, the surface of the foam metal can not be provided with a positive electrode active material, or of course can be provided with a positive electrode active material. As an example, the foam metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0138] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0139] As an example, the negative electrode current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, or the like can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or the like. The composite current collector can include a high polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a high polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0140] As an example, the negative electrode sheet can include a negative electrode current collector and a negative electrode active material provided on at least one surface of the negative electrode current collector.

[0141] As an example, the negative current collector has two surfaces opposite in the thickness direction thereof, and the negative active material is disposed on either one or both of the two surfaces of the negative current collector.

[0142] As an example, the negative active material can employ a negative active material for a battery cell known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative active material can also be used. These negative active materials can be used alone or in combination of two or more.

[0143] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0144] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0145] In some embodiments, the separator is a separator film. The separator film can be of various types, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0146] As an example, the material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0147] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes, and functions to transport ions and separate the positive and negative electrodes.

[0148] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0149] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium boric oxalate, lithium difluorophosphoric oxalate, and lithium tetrafluorophosphoric oxalate.

[0150] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl 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, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from ether solvents. The ether solvents can 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.

[0151] In some embodiments, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0152] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0153] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0154] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0155] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0156] In some embodiments, the electrode assembly has a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into the jelly-roll structure.

[0157] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, or the like.

[0158] In some embodiments, the electrode assembly is provided with a positive electrode tab and a negative electrode tab.

[0159] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, or the like.

[0160] As an example, the battery cell can be cylindrical, i.e., a cylindrical battery cell.

[0161] The battery apparatus mentioned in embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0162] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0163] In some embodiments, the battery apparatus can be a battery pack including a box and one or more battery cell assemblies accommodated in the box.

[0164] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box by fixing the battery module in the box.

[0165] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of battery cells in the box.

[0166] As an example, the box can include a first box body and a second box body. The first box body and the second box body are fastened so that an enclosed space is formed inside the box to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first box body can be a top cover or a bottom plate.

[0167] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that an enclosed space is formed inside the box to accommodate the battery cell assembly.

[0168] As an example, the box can be part of the chassis structure of a vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0169] In some embodiments, the battery apparatus refers to an energy storage device, and the energy storage device includes a box with a door on at least one side. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0170] Battery devices have high energy density, low environmental pollution, high power density, long service life, wide application range, and small self-discharge coefficient, and have other outstanding advantages, and are an important part of the development of new energy today. The development of battery technology needs to consider many design factors, such as energy density, cycle life, discharge capacity, and charge-discharge rate, and in addition, the safety of the battery device also needs to be considered.

[0171] For a general cylindrical battery cell, the cylindrical battery cell includes a shell and an electrode assembly contained in the shell, and one tab of the electrode assembly is electrically connected to the shell to serve as an output pole of the cylindrical battery cell through the shell. Correspondingly, a pressure relief structure is usually provided on the shell of the cylindrical battery cell, so that the pressure relief structure can be broken when the cylindrical battery cell is in thermal runaway, to release the internal pressure of the cylindrical battery cell, thereby facilitating the safety of the cylindrical battery cell. In the related art, in order to reduce the difficulty of electrical connection between the electrode assembly and the shell, a current collecting member is usually provided in the shell, and the current collecting member includes a body portion connected to the electrode assembly and used to support the electrode assembly, and a butt joint portion connected to the shell. However, the current collecting member in the related art has poor effects of supporting the electrode assembly and resisting the expansion of the electrode assembly, which causes the electrode assembly to easily move or the tab to be misaligned during use, which is not conducive to improving the use stability of the cylindrical battery cell. In addition, the current collecting member inside the shell hinders and blocks the internal exhaust path or pressure relief structure of the cylindrical battery cell, and is not conducive to the active material of the electrode assembly being ejected outside the shell through the pressure relief structure, thereby causing the cylindrical battery cell to have a low pressure relief rate when thermal runaway occurs, which causes the cylindrical battery cell to have a risk of fire explosion or connection failure due to untimely pressure relief, thereby resulting in low use reliability of the cylindrical battery cell.

[0172] Based on the above considerations, in order to solve the problems of low use stability and low use reliability of the cylindrical battery cell, the embodiments of the present application provide a cylindrical battery cell, the axial direction of the cylindrical battery cell is a first direction, and the cylindrical battery cell includes a shell, an electrode assembly, and a first current collecting member. The shell has a first wall, and a pressure relief component is provided on the first wall, and the pressure relief component is provided with a pressure relief groove. The electrode assembly is contained in the shell. The first current collecting member includes a body portion, a support portion, and a butt joint portion. In the first direction, the body portion is located on the side of the electrode assembly facing the first wall and is connected to the electrode assembly, the butt joint portion is located on the side of the body portion facing the first wall and is connected to the shell, and the support portion connects the body portion and the butt joint portion and is configured to be deformable. In a projection plane perpendicular to the first direction, the orthographic projection of the butt joint portion extends along the circumferential direction of the shell and is located on the outer circumferential side of the orthographic projection of the body portion, and the orthographic projection of the butt joint portion and the orthographic projection of the body portion are arranged in the radial direction of the cylindrical battery cell to form an exhaust gap therebetween.

[0173] In the cylindrical battery cell with the structure, the first current collecting member is provided with a body part, a support part and a butt joint part, the body part and the butt joint part are connected with the electrode assembly and the shell respectively, and the support part is connected between the body part and the butt joint part to realize the electrical connection of the electrode assembly with the shell through the first current collecting member. By arranging the support part to be deformable when the body part and the butt joint part move towards or away from each other in the first direction, the support part can play a certain buffering role between the body part and the butt joint part, so that the rigid pulling between the body part and the butt joint part, between the body part and the electrode assembly, and between the butt joint part and the shell can be alleviated during the movement or displacement of the electrode assembly, which is conducive to further reducing the risk of connection failure between the body part and the electrode assembly and between the butt joint part and the shell, and reducing the damage of the first current collecting member caused by pulling. In addition, in the projection plane perpendicular to the first direction, by arranging the butt joint part and the body part to form an exhaust gap in the radial direction of the cylindrical battery cell, the thermal runaway gas inside the cylindrical battery cell can pass through the exhaust gap between the butt joint part and the body part, enter the side of the first current collecting member facing the first wall, and then pass through the pressure relief groove of the pressure relief part on the first wall to be discharged, so that the first current collecting member can reduce the obstruction of the exhaust path inside the cylindrical battery cell, which is conducive to improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell, thereby reducing the risk of explosion or explosion of the cylindrical battery cell due to untimely pressure relief, and improving the use reliability of the cylindrical battery cell.

[0174] The cylindrical battery cell disclosed in the embodiments of the present application can be used in an electric device such as a vehicle, a ship or an aircraft, but is not limited thereto. The power supply system of the electric device can be composed of the cylindrical battery cell and the battery device disclosed in the present application, so that the movement or displacement of the electrode assembly of the cylindrical battery cell during use can be alleviated, and the problem of easy ignition and explosion of the cylindrical battery cell due to untimely pressure relief can be alleviated, thereby improving the use stability and use reliability of the cylindrical battery cell.

[0175] The embodiments of the present application provide an electric device using a cylindrical battery cell or a battery device as a power supply. The electric device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric plane toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft, etc.

[0176] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0177] Referring to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 1000 is provided for some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, which can be a pure electric automobile, a hybrid automobile, or a range extended automobile, etc. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery device 100 can be used to supply power for the vehicle 1000, for example, the battery device 100 can be used as an operating power source or a use power source of the vehicle 1000, etc. The vehicle 1000 can further include a controller 200 and a motor 300, the controller 200 is used to control the battery device 100 to supply power for the motor 300, for example, to meet the power demand of the vehicle 1000 during starting, navigation, and driving.

[0178] In some embodiments of the present application, the battery device 100 can not only be used as an operating power source or a use power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0179] Referring to Figure 2 and Figure 3 , Figure 2 A structural exploded view of the battery device 100 is provided for some embodiments of the present application, Figure 3 A structural schematic diagram of a cylindrical battery cell 20 is provided for some embodiments of the present application. The battery device 100 includes a box body 10 and the cylindrical battery cell 20, and the cylindrical battery cell 20 is used to be accommodated in the box body 10.

[0180] Among them, the box body 10 is used to provide an assembly space for the cylindrical battery cell 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 are overlapped with each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the cylindrical battery cell 20. The second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-shaped structure, which is overlapped with the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 is overlapped with the open side of the second box body 12.

[0181] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can have various shapes, such as a cylinder, a cuboid, or a square, etc. Exemplarily, in some embodiments, the box body 10 can be a cuboid, and the first box body 11 and the second box body 12 can be arranged in a manner of being overlapped with each other.Figure 2 In the middle, the shape of box 10 is a cuboid.

[0182] In the battery device 100, there can be one or more cylindrical battery cells 20 disposed within the housing 10. When there are multiple cylindrical battery cells 20 disposed within the housing 10, the multiple cylindrical battery cells 20 can be connected in series, in parallel, or in a mixed manner. A mixed connection means that the multiple cylindrical battery cells 20 are connected in both series and parallel. The multiple cylindrical battery cells 20 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of the multiple cylindrical battery cells 20 is housed within the housing 10. Of course, the battery device 100 can also be in the form of multiple cylindrical battery cells 20 first connected in series, in parallel, or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed within the housing 10.

[0183] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting a plurality of cylindrical battery cells 20 to achieve electrical connection between the plurality of cylindrical battery cells 20.

[0184] Each cylindrical battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0185] According to some embodiments of this application, refer to Figure 3 Please refer to further details. Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , Figure 4 This is an exploded view of the structure of a cylindrical battery cell 20 provided in some embodiments of this application. Figure 5 This is a cross-sectional view of a cylindrical battery cell 20 provided in some embodiments of this application. Figure 6 for Figure 5 A magnified view of part A of the cylindrical battery cell 20 shown. Figure 7 This is a schematic diagram of the structure of the first current collection member 23 provided in some embodiments of this application. Figure 8A front view of the first current collecting member 23 in the first direction X is provided for some embodiments of the present application. The present application provides a cylindrical battery cell 20, the axial direction of the cylindrical battery cell 20 is the first direction X, and the cylindrical battery cell 20 includes a shell 21, an electrode assembly 22, and a first current collecting member 23. The shell 21 has a first wall 211, and the first wall 211 is provided with a pressure relief component, and the pressure relief component is provided with a pressure relief groove 2111. The electrode assembly 22 is contained in the shell 21. The first current collecting member 23 includes a body part 231, a support part 232, and a butt joint part 233. In the first direction X, the body part 231 is located on the side of the electrode assembly 22 facing the first wall 211 and connected to the electrode assembly 22, the butt joint part 233 is located on the side of the body part 231 facing the first wall 211 and connected to the shell 21, and the support part 232 connects the body part 231 and the butt joint part 233. The support part 232 is configured to be deformed when the body part 231 and the butt joint part 233 move closer to or away from each other in the first direction X. In the projection plane perpendicular to the first direction X, the front projection of the butt joint part 233 extends along the circumference of the shell 21 and is located on the outer circumferential side of the front projection of the body part 231. The front projection of the butt joint part 233 and the front projection of the body part 231 are arranged in the radial direction of the cylindrical battery cell 20 to form an exhaust gap 234 between the front projection of the butt joint part 233 and the front projection of the body part 231.

[0186] The shell 21 can also be used to contain an electrolyte, such as an electrolyte solution. The shell 21 can have various structural forms. The material of the shell 21 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0187] In the embodiments of the present application, the shell 21 includes a first wall 211, a second wall 212, and a side wall 213. The side wall 213 is a structure surrounding the first wall 211 and the second wall 212. The two ends of the side wall 213 in the first direction X are connected to the first wall 211 and the second wall 212 respectively, and the first wall 211 and the second wall 212 are arranged opposite to each other in the first direction X, so that the first wall 211 and the second wall 212 are the end walls of the shell 21 at the two ends in the first direction X.

[0188] Optionally, the structure of the shell 21 can be various, for example, the shell 21 can be integrally formed by the first wall 211 and the side wall 213, and the side wall 213 is enclosed at one end away from the first wall 211 in the first direction X to form an opening 2131, and the second wall 212 covers the opening 2131 of the side wall 213 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte; the shell 21 can also be integrally formed by the second wall 212 and the side wall 213, and the side wall 213 is enclosed at one end away from the second wall 212 in the first direction X to form an opening 2131, and the first wall 211 covers the opening 2131 of the side wall 213 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte; the shell 21 can also be that the side wall 213 is formed with openings 2131 at both ends in the first direction X, so that the side wall 213 is a hollow structure formed with openings 2131 at both ends in the first direction X, and the first wall 211 and the second wall 212 cover the openings 2131 at both ends of the side wall 213 in the first direction X, respectively.

[0189] Exemplarily, in Figure 4 、 Figure 5 and Figure 6 , the second wall 212 and the side wall 213 are integrally formed, and the side wall 213 is enclosed at one end away from the second wall 212 in the first direction X to form an opening 2131, and the first wall 211 covers the opening 2131 of the side wall 213 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0190] Wherein, the cylindrical battery cell 20 is in a cylindrical shape, and the central axis of the cylindrical battery cell 20 extends along the first direction X, that is, the cylindrical battery cell 20 is in a cylindrical structure, and the height direction of the cylindrical battery cell 20 is the first direction X, so that the projection of the cylindrical battery cell 20 in the first direction X is circular. Correspondingly, the side wall 213 of the shell 21 is also in a cylindrical structure, and the central axis of the side wall 213 of the shell 21 extends along the first direction X, so that the projections of the first wall 211 and the second wall 212 in the first direction X are both circular, that is, the first wall 211 and the second wall 212 are both in a disc structure.

[0191] It should be noted that the first direction X is perpendicular to the radial direction of the cylindrical battery cell 20, and the radial direction of the cylindrical battery cell 20 is the direction in which the central axis of the cylindrical battery cell 20 in the projection plane perpendicular to the axial direction of the cylindrical battery cell 20 points to the outer circumferential surface of the cylindrical battery cell 20 or the outer circumferential surface of the cylindrical battery cell 20 points to the central axis of the cylindrical battery cell 20.

[0192] The first wall 211 is provided with a pressure relief component, the pressure relief component is provided with a pressure relief groove 2111, and the pressure relief component is configured to be able to crack along at least part of the pressure relief groove 2111 when the cylindrical battery monomer 20 is relieved of pressure, so as to release the internal pressure of the cylindrical battery monomer 20, that is, the pressure relief component on the first wall 211 forms a weak structure for pressure relief in the region provided with the pressure relief groove 2111, so that when the cylindrical battery monomer 20 is in thermal runaway and releases internal pressure, at least part of the region of the pressure relief component on the first wall 211 provided with the pressure relief groove 2111 can crack, so that at least part of the region of the pressure relief component located on the inner circumferential side of the pressure relief groove 2111 can be opened and release the internal pressure of the cylindrical battery monomer 20.

[0193] It should be noted that the pressure relief component and the first wall 211 can be an integrally formed structure, or can be a split structure, for example, in Figure 6 , the pressure relief component and the first wall 211 are an integrally formed structure, and correspondingly, the pressure relief component is a part of the first wall 211, so that the pressure relief groove 2111 is a structure directly provided on the first wall 211, that is, the first wall 211 is configured to be able to crack along at least part of the pressure relief groove 2111 when the cylindrical battery monomer 20 is relieved of pressure, so as to release the internal pressure of the cylindrical battery monomer 20. Of course, in other embodiments, the pressure relief component and the first wall 211 can also be a split structure, and correspondingly, the pressure relief component can be connected to the first wall 211 by welding connection or other structure.

[0194] For example, the pressure relief groove 2111 is an annular structure extending along the circumference of the cylindrical battery monomer 20, that is, the pressure relief groove 2111 is a coaxial annular groove structure of the cylindrical battery monomer 20.

[0195] It should be noted that the electrode assembly 22 is a component that undergoes an electrochemical reaction in the cylindrical battery monomer 20, and the electrode assembly 22 includes a main body part 221, a first tab 222, and a second tab 223. The main body part 221 is the main component of the electrode assembly 22 that undergoes an electrochemical reaction in the cylindrical battery monomer 20, and the first tab 222 and the second tab 223 serve to output or input the electrical energy of the electrode assembly 22. The structure of the main body part 221 of the electrode assembly 22 can be various, for example, in Figure 4 , the electrode assembly 22 can include a positive electrode sheet, a separator, and a negative electrode sheet, and the main body part 221 of the electrode assembly 22 is a wound structure formed by winding the part of the positive electrode sheet, the separator, and the part of the negative electrode sheet, the main body part 221 of the electrode assembly 22 is in a cylindrical structure, and the center axis of the main body part 221 of the electrode assembly 22 extends along the first direction X.

[0196] Exemplarily, the isolation member is an isolation film, and a main material of the isolation film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride.

[0197] Optionally, the electrode assembly 22 accommodated in the shell 21 can be one or multiple. Exemplarily, in the embodiment shown in Figure 4 , only one electrode assembly 22 is arranged in the shell 21 of the cylindrical battery cell 20. Of course, the structure of the cylindrical battery cell 20 is not limited to this, and in other embodiments, the electrode assembly 22 accommodated in the shell 21 can also be two, three, four, five, six, seven, or eight, etc.

[0198] , the polarities of the first tab 222 and the second tab 223 are opposite, and in Figure 4 and Figure 5 , the first tab 222 and the second tab 223 are respectively connected to two ends of the main body part 221 in the first direction X, the first tab 222 is located at one end of the main body part 221 facing the first wall 211 and is electrically connected to the first current collecting member 23, and the second tab 223 is located at one end of the main body part 221 facing the second wall 212.

[0199] It should be noted that if the first tab 222 is a positive tab of the electrode assembly 22, the first tab 222 is a component formed by stacking the regions of the positive sheet on which the positive active material layer is not coated, and correspondingly, if the second tab 223 is a negative tab of the electrode assembly 22, the second tab 223 is a component formed by stacking the regions of the negative sheet on which the negative active material layer is not coated; conversely, if the first tab 222 is a negative tab of the electrode assembly 22, the first tab 222 is a component formed by stacking the regions of the negative sheet on which the negative active material layer is not coated, and correspondingly, if the second tab 223 is a positive tab of the electrode assembly 22, the second tab 223 is a component formed by stacking the regions of the positive sheet on which the positive active material layer is not coated.

[0200] In the embodiment of the present application, the first current collecting member 23 serves to electrically connect the electrode assembly 22 and the shell 21, and the material of the first current collecting member 23 can be various, such as copper, iron, aluminum, steel, or aluminum alloy, etc.

[0201] The first current collecting member 23 includes a body portion 231, a support portion 232, and a butt joint portion 233. The body portion 231 is a portion of the first current collecting member 23 located on a side of the electrode assembly 22 facing the first wall 211 in the first direction X and connected to the first tab 222. The butt joint portion 233 is a portion of the first current collecting member 23 located on a side of the body portion 231 facing the first wall 211 and connected to the shell 21 to achieve electrical connection between the electrode assembly 22 and the shell 21. It should be noted that, in the first direction X, the body portion 231 is located on a side of the electrode assembly 22 facing the first wall 211, i.e., the electrode assembly 22 and the first wall 211 are located on two sides of the body portion 231 in the first direction X, respectively. Correspondingly, the thickness direction of the first wall 211 is also the first direction X.

[0202] Optionally, the connection structure of the body portion 231 and the first tab 222 can be various, such as adhesive or welding connection, and the connection structure of the butt joint portion 233 and the shell 21 can also be various, such as adhesive or welding connection. Exemplarily, the body portion 231 is welded to the first tab 222, and the butt joint portion 233 is welded to the shell 21.

[0203] The support portion 232 is a structure connected between the body portion 231 and the butt joint portion 233. The support portion 232 is configured to be deformed when the body portion 231 and the butt joint portion 233 approach or move away from each other in the first direction X, i.e., the support portion 232 can be deformed when the body portion 231 and the butt joint portion 233 approach or move away from each other in the first direction X due to compression or stretching of the first current collecting member 23. It should be noted that the support portion 232 can be elastically deformed or plastically deformed when deformed.

[0204] Optionally, the body portion 231, the butt joint portion 233, and the support portion 232 of the first current collecting member 23 can be an integrally formed structure or a separate structure connected together. Exemplarily, in the embodiment shown in Figure 7 , the body portion 231, the butt joint portion 233, and the support portion 232 of the first current collecting member 23 are an integrally formed structure formed by an integrally forming process such as stamping and cutting.

[0205] In the projection plane perpendicular to the first direction X, the orthographic projection of the butt joint portion 233 extends along the circumference of the shell 21 and is located on the outer circumferential side of the orthographic projection of the body portion 231, i.e., the butt joint portion 233 is an arc-shaped structure or a ring-shaped structure extending along the circumference of the shell 21, and the orthographic projection of the butt joint portion 233 is arranged around the orthographic projection of the body portion 231 in the projection plane perpendicular to the first direction X. It should be noted that the circumference of the shell 21 is the circumference of the side wall 213 and the circumference of the cylindrical battery monomer 20.

[0206] Optionally, in the embodiment shown in Figure 7 , the orthographic projection of the butt joint portion 233 in the projection plane perpendicular to the first direction X is located on the outer circumferential side of the orthographic projection of the body portion 231, i.e., the orthographic projection of the butt joint portion 233 is located on the outer circumferential side of the orthographic projection of the body portion 231 in the projection plane perpendicular to the first direction X.Figure 8 In specific embodiments, the first current collecting member 23 is provided with a plurality of abutting portions 233 and a plurality of supporting portions 232, the plurality of supporting portions 232 are structures arranged along the circumference of the shell 21 and connected to the body portion 231, and the supporting portions 232 are arc-shaped structures extending along the circumference of the shell 21, and correspondingly, the plurality of abutting portions 233 are arranged along the circumference of the shell 21, each abutting portion 233 is connected to the body portion 231 through a supporting portion 232, and the plurality of abutting portions 233 are all connected to the shell 21, and correspondingly, in the projection plane perpendicular to the first direction X, the orthographic projection of the plurality of abutting portions 233 is arranged around the orthographic projection of the body portion 231.

[0207] For example, in Figure 8 In specific embodiments, the first current collecting member 23 is provided with four abutting portions 233 and four supporting portions 232, each abutting portion 233 is connected to the body portion 231 through a supporting portion 232. Of course, in other embodiments, the number of abutting portions 233 of the first current collecting member 23 can also be two, three, five or six, etc.

[0208] In the projection plane perpendicular to the first direction X, the orthographic projection of the abutting portion 233 and the orthographic projection of the body portion 231 are arranged along the radial direction of the cylindrical battery cell 20 to form an exhaust gap 234 between the orthographic projection of the abutting portion 233 and the orthographic projection of the body portion 231, that is, in the projection plane perpendicular to the first direction X, the exhaust gap 234 is located between the orthographic projection of the abutting portion 233 and the orthographic projection of the body portion 231 along the radial direction of the cylindrical battery cell 20, so as to facilitate the discharge of the thermal runaway gas outside the shell 21 when the cylindrical battery cell 20 is in thermal runaway, and the supporting portion 232 is connected between the body portion 231 and the abutting portion 233 along the radial direction of the cylindrical battery cell 20.

[0209] In the embodiments of the present application, referring to Figure 5 and Figure 6 As shown, the inner circumferential surface of the side wall 213 is provided with a protrusion 2132, the protrusion 2132 is an annular structure extending along the circumference of the side wall 213, and the protrusion 2132 is a circular ring structure coaxial with the cylindrical battery cell 20, along the first direction X, the protrusion 2132 is located between the electrode assembly 22 and the first wall 211, and the body portion 231 of the first current collecting member 23 is arranged between the protrusion 2132 and the electrode assembly 22 to support the electrode assembly 22, and the abutting portion 233 of the first current collecting member 23 is connected to the protrusion 2132 to electrically connect the electrode assembly 22 and the side wall 213 of the shell 21, so as to serve as another output pole of the cylindrical battery cell 20.

[0210] Optionally, the connection structure of the abutting portion 233 and the protrusion 2132 can also be various, such as adhesive or welding connection, etc. For example, the abutting portion 233 is welded to the protrusion 2132.

[0211] Of course, in other embodiments, the abutting portion 233 can also be a structure directly interconnected with the side wall 213, and can also be a structure connected with the first wall 211 or the second wall 212 to achieve the electrical connection between the electrode assembly 22 and the case 21.

[0212] In some embodiments, as shown in Figure 3 , Figure 4 and Figure 5 , the cylindrical battery cell 20 can further include an electrode terminal 24, which is insulatively mounted on the second wall 212 of the case 21, and is electrically connected with the second tab 223, so that the electrode terminal 24 serves as another output pole of the cylindrical battery cell 20, that is, the electrode terminal 24 can serve to input or output the electric energy of the cylindrical battery cell 20, so that the electric energy of the cylindrical battery cell 20 can be input or output through the electrode terminal 24 and the case 21.

[0213] In this case, the electrode terminal 24 is insulatively mounted on the second wall 212 of the case 21, that is, the electrode terminal 24 is mounted on the end of the case 21 away from the first wall 211 in the first direction X, and an insulating member is arranged between the electrode terminal 24 and the second wall 212, so that no electrical connection is formed between the electrode terminal 24 and the case 21.

[0214] As shown in Figure 5 , the electrode terminal 24 is a structure riveted on the second wall 212 of the case 21, that is, the second wall 212 of the case 21 is provided with a mounting hole penetrating through both sides of the second wall 212 in the first direction X, and a portion of the electrode terminal 24 is arranged in the mounting hole, and the electrode terminal 24 has a first clamping portion on the side of the second wall 212 facing the electrode assembly 22 and a second clamping portion on the side of the second wall 212 away from the electrode assembly 22, and at least part of the second wall 212 is located between the first clamping portion and the second clamping portion in the first direction X, so that the first clamping portion and the second clamping portion can clamp the second wall 212 to achieve the riveting of the electrode terminal 24 on the second wall 212 of the case 21. Of course, in other embodiments, the electrode terminal 24 can also be a structure clamped or adhered on the second wall 212.

[0215] Exemplarily, the material of the electrode terminal 24 can be various, for example, the material of the electrode terminal 24 can be copper, iron, aluminum, steel or aluminum alloy, etc.

[0216] In some embodiments, as shown in Figure 4 and Figure 5As shown, the cylindrical battery cell 20 can further include a second current collecting member 25 disposed between the second tab 223 of the electrode assembly 22 and the second wall 212 of the case 21 in the first direction X, the second current collecting member 25 connecting the second tab 223 and the electrode terminal 24 to electrically connect the electrode assembly 22 and the electrode terminal 24.

[0217] Optionally, the connection structure of the second current collecting member 25 with the second tab 223 and the second current collecting member 25 with the electrode terminal 24 can be various, such as a welding connection or an adhesive connection, etc.

[0218] Exemplarily, the material of the second current collecting member 25 can be various, such as copper, iron, aluminum, steel or aluminum alloy, etc.

[0219] It should be noted that in other embodiments, the second tab 223 of the electrode assembly 22 can also be a structure directly connected with the electrode terminal 24, such as a welding connection or an adhesive connection, etc.

[0220] In the embodiment, the first current collecting member 23 is provided with a body portion 231, a support portion 232 and a butt joint portion 233, the body portion 231 and the butt joint portion 233 are connected with the electrode assembly 22 and the shell 21 respectively, and the support portion 232 is connected between the body portion 231 and the butt joint portion 233 to realize the electrical connection between the electrode assembly 22 and the shell 21 through the first current collecting member 23. By setting the support portion 232 as a structure capable of deforming when the body portion 231 and the butt joint portion 233 move towards or away from each other along the first direction X, the support portion 232 can play a certain buffering role between the body portion 231 and the butt joint portion 233, so as to alleviate the rigid pulling between the body portion 231 and the butt joint portion 233, between the body portion 231 and the electrode assembly 22, and between the butt joint portion 233 and the shell 21 during the shaking or displacement of the electrode assembly 22, which is conducive to further reducing the risk of connection failure between the body portion 231 and the electrode assembly 22, and between the butt joint portion 233 and the shell 21, and reducing the damage of the first current collecting member 23 caused by pulling. In addition, in the projection plane perpendicular to the first direction X, by setting the butt joint portion 233 to have a positive projection and the body portion 231 to have a positive projection, which form an exhaust gap 234 in the radial direction of the cylindrical battery monomer 20, so that the thermal runaway gas inside the cylindrical battery monomer 20 enters the area of the first wall 211 through the exhaust gap 234 between the butt joint portion 233 and the body portion 231, and then passes through the pressure relief groove 2111 of the pressure relief component on the first wall 211 to be discharged, which can reduce the obstruction of the first current collecting member 23 to the internal exhaust path of the cylindrical battery monomer 20, and improve the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer 20, thereby reducing the risk of bursting or explosion of the cylindrical battery monomer 20 due to untimely pressure relief, and improving the use reliability of the cylindrical battery monomer 20.

[0221] According to some embodiments of the present application, referring to Figure 6 As shown in the figure, along the first direction X, at least part of the projection of the pressure relief groove 2111 is located in the exhaust gap 234. That is, at least part of the area of the pressure relief component on the first wall 211 provided with the pressure relief groove 2111 is a structure corresponding to the exhaust gap 234 between the body portion 231 and the butt joint portion 233 in the first direction X.

[0222] In the embodiment, by setting the pressure relief groove 2111 as a structure in which at least part of the projection in the first direction X is located in the exhaust gap 234, the pressure relief groove 2111 is a structure in which at least part in the first direction X is provided corresponding to the exhaust gap 234 between the butt joint portion 233 and the body portion 231, so as to further improve the internal exhaust smoothness and pressure relief smoothness of the cylindrical battery monomer 20, and further improve the pressure relief rate of the cylindrical battery monomer 20.

[0223] According to some embodiments of the present application, referring to Figure 7 and Figure 8 In the projection plane perpendicular to the first direction X, the diameter of the orthographic projection of the outer edge of the abutment portion 233 is D1, and the orthographic projection of the support portion 232 extends in the radial direction of the cylindrical battery cell 20 and has a length L1, and 1 / 15≤L1 / D1≤1 / 3 is satisfied.

[0224] In the projection plane perpendicular to the first direction X, the diameter of the orthographic projection of the outer edge of the abutment portion 233 is D1, i.e. D1 is the diameter of the circle in which the orthographic projection of the outer edge of the abutment portion 233 in the projection plane perpendicular to the first direction X lies.

[0225] In the projection plane perpendicular to the first direction X, the orthographic projection of the support portion 232 extends in the radial direction of the cylindrical battery cell 20 and has a length L1, i.e. the orthographic projection of the support portion 232 in the projection plane perpendicular to the first direction X is a strip-shaped structure extending in the radial direction of the cylindrical battery cell 20, and the size of the orthographic projection of the support portion 232 in the radial direction of the cylindrical battery cell 20 in the projection plane perpendicular to the first direction X is L1.

[0226] Optionally, in the projection plane perpendicular to the first direction X, the ratio of the length L1 of the orthographic projection of the support portion 232 in the radial direction of the cylindrical battery cell 20 to the diameter D1 of the orthographic projection of the outer edge of the abutment portion 233 can be 1 / 15, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 1 / 7, 0.15, 0.16, 0.18, 0.2, 0.22, 0.23, 0.25, 0.26, 0.28, 0.3, 0.31, 0.32, or 1 / 3, etc.

[0227] In the embodiment, in the projection plane perpendicular to the first direction X, by setting the orthographic projection of the butt joint portion 233 and the orthographic projection of the body portion 231 as a structure arranged at intervals in the radial direction of the cylindrical battery monomer 20, and setting the ratio of the length of the support portion 232 of the first current collecting member 23 in the radial direction of the cylindrical battery monomer 20 to the diameter of the orthographic projection of the outer edge of the butt joint portion 233 as 1 / 15 to 1 / 3, on the one hand, it can alleviate the phenomenon that the size occupied by the support portion 232 in the radial direction of the cylindrical battery monomer 20 is too small, and is beneficial to expand the exhaust space between the butt joint portion 233 and the body portion 231, so that the thermal runaway gas inside the cylindrical battery monomer 20 can pass through the exhaust space between the butt joint portion 233 and the body portion 231, and then be discharged through the area where the pressure relief component sets the pressure relief groove 2111 on the first wall 211, thereby improving the internal exhaust smoothness of the cylindrical battery monomer 20, and improving the pressure relief rate of the cylindrical battery monomer 20, and then the risk of bursting or explosion of the cylindrical battery monomer 20 due to untimely pressure relief can be reduced, on the other hand, it can alleviate the phenomenon that the size occupied by the support portion 232 in the radial direction of the cylindrical battery monomer 20 is too large, and the support strength of the support portion 232 in the body portion 231 and the butt joint portion 233 is insufficient, thereby effectively improving the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, so as to alleviate the phenomenon of excessive expansion or displacement of the electrode assembly 22, and then it is beneficial to improve the use stability and reliability of the cylindrical battery monomer 20.

[0228] In some embodiments, referring to Figure 8 As shown, 1 / 7≤L1 / D1≤1 / 4.

[0229] In the embodiment, by further setting the ratio of the length of the support portion 232 of the first current collecting member 23 in the radial direction of the cylindrical battery monomer 20 to the diameter of the orthographic projection of the outer edge of the butt joint portion 233 to be 1 / 7 to 1 / 4 in the projection plane perpendicular to the first direction X, on the one hand, the phenomenon that the size occupied by the support portion 232 in the radial direction of the cylindrical battery monomer 20 is too small can be further alleviated, and the exhaust space between the butt joint portion 233 and the body portion 231 can be further expanded, so as to facilitate the thermal runaway gas inside the cylindrical battery monomer 20 to be discharged through the area provided with the pressure relief groove 2111 of the pressure relief component on the first wall 211 after passing through the exhaust space between the butt joint portion 233 and the body portion 231, thereby further improving the internal exhaust smoothness of the cylindrical battery monomer 20, further improving the pressure relief rate of the cylindrical battery monomer 20, and further reducing the risk of explosion or explosion of the cylindrical battery monomer 20 due to untimely pressure relief. On the other hand, the phenomenon that the size occupied by the support portion 232 in the radial direction of the cylindrical battery monomer 20 is too large and causes the support strength of the support portion 232 between the butt joint portion 233 and the body portion 231 to be insufficient can be further alleviated, thereby further improving the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, further alleviating the phenomenon of excessive expansion or displacement of the electrode assembly 22, and further improving the use stability and reliability of the cylindrical battery monomer 20.

[0230] In some embodiments, please continue to refer to Figure 8 As shown, 3mm≤L1≤15mm.

[0231] Optionally, in the projection plane perpendicular to the first direction X, the length L1 of the orthographic projection of the support portion 232 in the radial direction of the cylindrical battery monomer 20 can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm or 15mm, etc.

[0232] In the embodiment, in the projection plane perpendicular to the first direction X, by setting the length of the support portion 232 of the first current collecting member 23 in the radial direction of the cylindrical battery cell 20 to 3 mm to 15 mm, on the one hand, setting the length of the support portion 232 in the radial direction of the cylindrical battery cell 20 to be greater than or equal to 3 mm can increase the exhaust space between the abutment portion 233 and the body portion 231, so as to facilitate the thermal runaway gas inside the cylindrical battery cell 20 to be discharged through the area on the pressure relief component provided with the pressure relief groove 2111 on the first wall 211 after passing through the exhaust space between the abutment portion 233 and the body portion 231, which is conducive to improving the smoothness of the internal exhaust of the cylindrical battery cell 20, on the other hand, setting the length of the support portion 232 in the radial direction of the cylindrical battery cell 20 to be less than or equal to 15 mm can alleviate the phenomenon that the support portion 232 is too long to cause insufficient support strength of the support portion 232 between the abutment portion 233 and the body portion 231, which is conducive to improving the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, so as to further alleviate the phenomenon of excessive expansion or displacement of the electrode assembly 22.

[0233] According to some embodiments of the present application, in combination with Figure 6 and Figure 8 It is shown that the thickness of the support portion 232 is T1, in the projection plane perpendicular to the first direction X, the orthogonal projection of the support portion 232 in the direction perpendicular to its extension direction is W, and satisfies, 0.3mm 2 ≤W×T1≤8mm 2 .

[0234] Wherein the thickness T1 of the support portion 232 is the thickness of any position of the support portion 232, in the embodiment where the support portion 232 includes a plurality of bending segments 2321 connected in sequence, the thickness of each bending segment 2321 is T1.

[0235] Optionally, the product of W and T1 can be 0.3mm 2 , 0.4mm 2 , 0.5mm 2 , 0.6mm 2 , 0.7mm 2 , 0.8mm 2 , 0.9mm 2 , 1mm 2 , 1.5mm 2 , 2mm 2 , 2.5mm 2 , 3mm 2 , 3.5mm 2 , 4mm 2 , 4.5mm 2 , 5mm 2 , 5.5mm2 6mm 2 6.5mm 2 7mm 2 7.5mm 2 or 8mm 2 etc.

[0236] In the present embodiment, the product of W and T1 is set to 0.3mm 2 to 8mm 2 On one hand, the product of W and T1 is set to be less than or equal to 8mm 2 to alleviate the phenomenon that W and T1 are too large to cause the deformation of the support portion 232 to be too difficult, thereby improving the ability of the support portion 232 to deform when the body portion 231 and the docking portion 233 approach or move away from each other in the first direction X, so that the support portion 232 can play a better buffering role between the body portion 231 and the docking portion 233, thereby reducing the rigid pulling phenomenon between the docking portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the docking portion 233 and the shell 21 during the process of the electrode assembly 22 shaking or shifting, on the other hand, the product of W and T1 is set to be greater than or equal to 0.3mm 2 to improve the structural strength of the support portion 232, which is conducive to alleviating the phenomenon that the support strength of the support portion 232 between the body portion 231 and the docking portion 233 is insufficient, so as to improve the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, and to improve the flow capacity of the support portion 232, which is conducive to improving the flow guiding effect and flow guiding demand of the first current collecting member 23.

[0237] In some embodiments, referring to FIGS. 2A and 2B, 2mm≤W≤10mm. Figure 7 Figure 8

[0238] Optionally, the width W of the projection of the support portion 232 in the first direction X can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0239] ​​In the embodiment, by setting the width of the projection of the supporting portion 232 of the first current collecting member 23 in the first direction X to 2mm to 10mm, on the one hand, setting the width of the projection of the supporting portion 232 in the first direction X to be greater than or equal to 2mm can improve the flow capacity of the supporting portion 232, improve the flow guiding effect of the first current collecting member 23, and improve the structural strength of the supporting portion 232, which is conducive to alleviating the phenomenon of insufficient supporting strength of the supporting portion 232 between the abutting portion 233 and the body portion 231, improving the supporting effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, and on the other hand, setting the width of the projection of the supporting portion 232 in the first direction X to be less than or equal to 10mm can effectively improve the deformation capacity of the supporting portion 232 when the abutting portion 233 and the body portion 231 move closer to or away from each other in the first direction X, so that the supporting portion 232 can play a better buffering role between the abutting portion 233 and the body portion 231, thereby reducing the rigid pulling phenomenon between the abutting portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the abutting portion 233 and the shell 21 during the shaking or displacement of the electrode assembly 22.

[0240] In some embodiments, referring to Figure 8 As shown in the figure, 3mm≤W≤5mm.

[0241] In the embodiment, by further setting the width of the projection of the supporting portion 232 of the first current collecting member 23 in the first direction X to 3mm to 5mm, on the one hand, setting the width of the projection of the supporting portion 232 in the first direction X to be greater than or equal to 3mm can further improve the flow capacity of the supporting portion 232, further improve the flow guiding effect of the first current collecting member 23, and further improve the structural strength of the supporting portion 232, which is conducive to further alleviating the phenomenon of insufficient supporting strength of the supporting portion 232 between the abutting portion 233 and the body portion 231, further improving the supporting effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, and on the other hand, setting the width of the projection of the supporting portion 232 in the first direction X to be less than or equal to 5mm can further improve the deformation capacity of the supporting portion 232 when the abutting portion 233 and the body portion 231 move closer to or away from each other in the first direction X, so as to improve the buffering effect of the supporting portion 232 between the abutting portion 233 and the body portion 231, thereby further reducing the rigid pulling phenomenon between the abutting portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the abutting portion 233 and the shell 21 during the shaking or displacement of the electrode assembly 22.

[0242] According to some embodiments of the present application, referring to Figure 6 and Figure 7As shown, the thickness of the support portion 232 is T1, satisfying 0.15 mm≤T1≤0.8 mm.

[0243] Optionally, the thickness T1 of the support portion 232 can be 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, 0.7 mm, 0.75 mm, or 0.8 mm, etc.

[0244] In the present embodiment, by setting the thickness of the support portion 232 to be 0.15 mm to 0.8 mm, on the one hand, setting the thickness of the support portion 232 to be greater than or equal to 0.15 mm can improve the flow capacity of the support portion 232, thereby improving the flow guiding effect of the first current collecting member 23 and improving the structural strength of the support portion 232, which is conducive to alleviating the phenomenon of insufficient support strength of the support portion 232 between the butt joint portion 233 and the body portion 231, thereby improving the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, and on the other hand, setting the thickness of the support portion 232 to be less than or equal to 0.8 mm can effectively improve the deformation capacity of the support portion 232 when the butt joint portion 233 and the body portion 231 move closer to or away from each other along the first direction X, so that the support portion 232 can play a better buffering role between the butt joint portion 233 and the body portion 231, thereby reducing the rigid pulling phenomenon between the butt joint portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the butt joint portion 233 and the shell 21 during the movement or displacement of the electrode assembly 22, and can save the space occupied by the support portion 232 in the first direction X, which is conducive to improving the internal space utilization rate of the cylindrical battery monomer 20.

[0245] In some embodiments, please continue to refer to Figure 6 and Figure 7 As shown, 0.3 mm≤T1≤0.5 mm.

[0246] In this embodiment, by further setting the thickness of the support portion 232 to be 0.3mm to 0.5mm, on one hand, setting the thickness of the support portion 232 to be greater than or equal to 0.3mm can further improve the flow capacity of the support portion 232, to further improve the flow guiding effect of the first current collecting member 23, and can further improve the structural strength of the support portion 232, which is beneficial to further alleviate the phenomenon of insufficient support strength of the support portion 232 between the abutting portion 233 and the body portion 231, to further improve the support effect of the first current collecting member 23 on the electrode assembly 22 and the effect of resisting the expansion of the electrode assembly 22 during use, on the other hand, setting the thickness of the support portion 232 to be less than or equal to 0.5mm can further improve the ability of the support portion 232 to deform when the abutting portion 233 and the body portion 231 move closer to or away from each other along the first direction X, to further improve the buffering effect of the support portion 232 between the abutting portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the abutting portion 233 and the shell 21, so as to further reduce the rigid pulling phenomenon between the abutting portion 233 and the body portion 231, between the body portion 231 and the electrode assembly 22, and between the abutting portion 233 and the shell 21 during the shaking or displacement of the electrode assembly 22, and can further save the space occupied by the support portion 232 in the first direction X, which is beneficial to further improve the internal space utilization rate of the cylindrical battery cell 20.

[0247] According to some embodiments of the present application, as shown in Figure 6 and Figure 7 , the thickness of the support portion 232 is less than the thickness of the body portion 231.

[0248] In this embodiment, by setting the thickness of the support portion 232 to be less than the thickness of the body portion 231, the ability of the support portion 232 to deform when the body portion 231 and the abutting portion 233 move closer to or away from each other along the first direction X can be improved while reducing the manufacturing cost and manufacturing difficulty of the first current collecting member 23, so that the support portion 232 can play a better buffering role between the body portion 231 and the abutting portion 233.

[0249] According to some embodiments of the present application, as shown in Figure 6 and Figure 7 , the thickness of the support portion 232 is less than the thickness of the abutting portion 233.

[0250] In this embodiment, by setting the thickness of the support portion 232 to be less than the thickness of the abutting portion 233, the ability of the support portion 232 to deform when the body portion 231 and the abutting portion 233 move closer to or away from each other along the first direction X can be improved while reducing the manufacturing cost and manufacturing difficulty of the first current collecting member 23, so that the support portion 232 can play a better buffering role between the body portion 231 and the abutting portion 233.

[0251] According to some embodiments of the present application, referring to Figure 6 The thickness of the body part 231 is T2, which satisfies 0.1 mm≤T2≤0.6 mm. Optionally, 0.2 mm≤T2≤0.4 mm.

[0252] The thickness T2 of the body part 231 is the thickness of the body part 231 in the first direction X. It should be noted that in the embodiment in which the body part 231 includes the main body region 2311 and the support region 2312, the thickness of the main body region 2311 and the support region 2312 is 0.1 mm to 0.6 mm.

[0253] Exemplarily, the thickness T2 of the body part 231 can be 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.32 mm, 0.35 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.45 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.55 mm, 0.58 mm, or 0.6 mm, etc.

[0254] In the present embodiment, on the one hand, setting the thickness of the body part 231 to be greater than or equal to 0.1 mm can effectively improve the structural strength of the body part 231, so as to improve the support effect of the body part 231 on the electrode assembly 22 along the first direction X, and also improve the effect of the body part 231 of the first current collecting member 23 on the electrode assembly 22 along the first direction X in the use process of the cylindrical battery cell 20. On the other hand, setting the thickness of the body part 231 to be less than or equal to 0.6 mm can reduce the manufacturing difficulty and cost of the body part 231 of the first current collecting member 23, and effectively reduce the space occupied by the body part 231 in the first direction X, which is beneficial to improving the internal space utilization rate of the cylindrical battery cell 20.

[0255] According to some embodiments of the present application, referring to Figure 7 As shown in the figure, the support part 232 is bent to form a plurality of bending segments 2321, and the plurality of bending segments 2321 are connected in sequence, and the bending segments 2321 at both ends of the plurality of bending segments 2321 are connected with the body part 231 and the butt joint part 233, respectively.

[0256] The support part 232 is bent to form a plurality of bending segments 2321, and the plurality of bending segments 2321 are connected in sequence, that is, the support part 232 is a structure in which a local region is bent, so that the support part 232 forms a plurality of bending segments 2321 connected in sequence, and each adjacent two bending segments 2321 are arranged at an acute angle, a right angle or an obtuse angle.

[0257] Exemplarily, in the present embodiment, the plurality of bending segments 2321 of the support part 232 are arranged at an acute angle, a right angle or an obtuse angle. Figure 7In some embodiments, the support portion 232 is bent to form three bent segments 2321 connected in sequence, and two bent segments 2321 at both ends of the three bent segments 2321 are connected to the body portion 231 and the abutting portion 233 respectively. Of course, in other embodiments, the number of bent segments 2321 formed by bending the support portion 232 can also be two, four, five, six, etc.

[0258] In the present embodiment, by setting the support portion 232 to be bent to form a plurality of bent segments 2321 connected in sequence, and connecting two bent segments 2321 at both ends of the plurality of bent segments 2321 to the body portion 231 and the abutting portion 233 respectively, the deformation capability of the support portion 232 when the body portion 231 and the abutting portion 233 move closer to or away from each other in the first direction X can be increased, so as to further improve the buffering effect of the support portion 232 between the body portion 231 and the abutting portion 233, thereby further reducing the phenomenon of rigid pulling between the body portion 231 and the abutting portion 233, between the body portion 231 and the electrode assembly 22, and between the abutting portion 233 and the shell 21.

[0259] According to some embodiments of the present application, with reference to Figure 6 , and further with reference to Figure 9 , Figure 9 a partial cross-sectional view of the shell 21 provided by some embodiments of the present application. The shell 21 can further include a side wall 213 surrounding the first wall 211, and one end of the side wall 213 in the first direction X is connected to the first wall 211, and a protrusion 2132 is protruding on the inner circumferential surface of the side wall 213. In the first direction X, the body portion 231 is arranged between the protrusion 2132 and the electrode assembly 22, and the abutting portion 233 is connected to the protrusion 2132.

[0260] In some embodiments, the shell 21 further includes a second wall 212 opposite the first wall 211 in the first direction X, and correspondingly, the side wall 213 surrounds the first wall 211 and the second wall 212, and both ends of the side wall 213 in the first direction X are connected to the first wall 211 and the second wall 212 respectively.

[0261] The protrusion 2132 is protruding on the inner circumferential surface of the side wall 213, i.e. the protrusion 2132 is a convex structure protruding on the side of the side wall 213 facing the electrode assembly 22.

[0262] Exemplarily, in Figure 6In the embodiment, the protrusion 2132 is located on the side of the electrode assembly 22 facing the first wall 211 in the first direction X, and the body part 231 of the first current collecting member 23 is located on the side of the protrusion 2132 away from the first wall 211, so that the body part 231 is located between the protrusion 2132 and the electrode assembly 22 in the first direction X to support the electrode assembly 22, and the butt joint part 233 of the first current collecting member 23 is connected to the protrusion 2132 to realize the electrical connection between the first current collecting member 23 and the side wall 213 of the shell 21.

[0263] Optionally, the butt joint part 233 can be a structure located on the side of the protrusion 2132 facing the first wall 211 in the first direction X and connected to the protrusion 2132 facing the first wall 211, or a structure located on the side of the protrusion 2132 away from the first wall 211 in the first direction X and connected to the protrusion 2132 away from the first wall 211.

[0264] In the embodiment, by protruding the protrusion 2132 on the inner circumferential surface of the side wall 213, the body part 231 is arranged between the protrusion 2132 and the electrode assembly 22 in the first direction X, and the butt joint part 233 of the first current collecting member 23 is connected to the protrusion 2132 to realize the electrical connection between the electrode assembly 22 and the shell 21. The cylindrical battery cell 20 adopting such a structure can, on the one hand, support and limit the electrode assembly 22 through the protrusion 2132, which is conducive to improving the support effect of the body part 231 of the first current collecting member 23 on the electrode assembly 22 in the first direction X, and on the other hand, can realize that the connection position of the butt joint part 233 and the pressure relief component are arranged on different regions of the shell 21, so as to alleviate the phenomenon that the stress of the first current collecting member 23 acting on the protrusion 2132 is transmitted to the region of the first wall 211 where the pressure relief component is arranged, which is conducive to reducing the risk of cracking or structural strength reduction of the region of the first wall 211 where the pressure relief groove 2111 of the pressure relief component is arranged, so as to improve the service life and use reliability of the battery cell.

[0265] According to some embodiments of the present application, as shown in Figure 6 , Figure 7 , Figure 8 and Figure 9 , the body part 231 can include a main body region 2311 and a plurality of support regions 2312 connected to the outer circumferential surface of the main body region 2311, the plurality of support regions 2312 are arranged at intervals along the circumference of the main body region 2311, at least part of the support regions 2312 are located between the electrode assembly 22 and the protrusion 2132 in the first direction X, and the support part 232 is connected to the main body region 2311.

[0266] The body part 231 comprises a main body area 2311 and a plurality of support areas 2312 connected to the outer peripheral surface of the main body area 2311, and the plurality of support areas 2312 are arranged at intervals along the circumference of the main body area 2311, that is, the body part 231 comprises the main body area 2311 and a plurality of support areas 2312 arranged around the main body area 2311 along the circumference of the main body area 2311, and each support area 2312 is connected to the outer edge of the main body area 2311 along the radial direction of the cylindrical battery monomer 20. It should be noted that the circumference of the main body area 2311 is also the circumference of the shell 21, and also the circumference of the side wall 213 and the circumference of the cylindrical battery monomer 20.

[0267] Exemplarily, in Figure 7 and Figure 8 , the body part 231 comprises four support areas 2312, which are uniformly and at intervals arranged on the outer peripheral side of the main body area 2311 along the circumference of the main body area 2311. Of course, in other embodiments, the number of support areas 2312 connected to the outer peripheral surface of the main body area 2311 can also be two, three, five, or six, etc.

[0268] At least part of the support area 2312 is located between the electrode assembly 22 and the protrusion 2132 in the first direction X, that is, at least part of the support area 2312 extends to between the electrode assembly 22 and the protrusion 2132 along the radial direction of the cylindrical battery monomer 20, so that at least part of the support area 2312 is located between the electrode assembly 22 and the protrusion 2132 in the first direction X.

[0269] Exemplarily, in Figure 6 , the support area 2312 is only partially located between the electrode assembly 22 and the protrusion 2132 in the first direction X. Of course, in other embodiments, the support area 2312 can also be entirely located between the electrode assembly 22 and the protrusion 2132 in the first direction X.

[0270] The support part 232 is connected to the main body area 2311, that is, the abutment part 233 is a structure connected to the main body area 2311 of the body part 231 through the support part 232. Exemplarily, in Figure 7 and Figure 8 , the support part 232 is connected to the outer peripheral surface of the main body area 2311. Wherein the abutment part 233 is located on the side of the main body area 2311 facing the first wall 211 in the first direction X, the abutment part 233 is connected to the protrusion 2132, the support part 232 is connected between the abutment part 233 and the main body area 2311 of the body part 231, and correspondingly, the support part 232 is connected to the outer peripheral surface of the main body area 2311. Exemplarily, the abutment part 233 is weldedly connected to the protrusion 2132.

[0271] Exemplarily, the first current collecting member 23 is provided with a plurality of supporting portions 232 and a plurality of abutting portions 233, the plurality of supporting portions 232 are arranged at intervals along the circumferential direction of the main body region 2311 and are all connected to the outer circumferential surface of the main body region 2311, the supporting portions 232 and the supporting regions 2312 are arranged alternately in the circumferential direction of the main body region 2311, so that in the circumferential direction of the main body region 2311, one supporting portion 232 is arranged between every two adjacent supporting regions 2312, and the abutting portions 233 and the supporting portions 232 are arranged one by one, each abutting portion 233 is connected to the main body region 2311 of the body portion 231 through one supporting portion 232, and correspondingly, the plurality of abutting portions 233 are also arranged at intervals along the circumferential direction of the main body region 2311, and exemplarily, the abutting portions 233 are arc-shaped structures extending along the circumferential direction of the main body region 2311.

[0272] Optionally, the main body region 2311 and the supporting region 2312 of the body portion 231 can be an integrally formed structure, or can be a structure arranged in a separate manner and connected, and exemplarily, in the Figure 7 , the main body region 2311 and the supporting region 2312 of the body portion 231 are an integrated structure formed by an integrally forming process such as stamping and cutting.

[0273] In the embodiment of the present application, the protrusion 2132 and the pressure relief groove 2111 are both annular structures extending along the circumferential direction of the side wall 213, that is, the protrusion 2132 is a circular ring structure coaxial with the cylindrical battery monomer 20, and the pressure relief groove 2111 is also an annular groove structure coaxial with the cylindrical battery monomer 20.

[0274] In the embodiment, the body portion 231 includes the main body region 2311 and a plurality of supporting regions 2312 connected to the outer circumferential surface of the main body region 2311, the plurality of supporting regions 2312 are arranged at intervals along the circumferential direction of the main body region 2311, and at least part of the supporting regions 2312 is located between the electrode assembly 22 and the protrusion 2132 in the first direction X, so that the body portion 231 of the first current collecting member 23 can not only support the electrode assembly 22 between the protrusion 2132 and the electrode assembly 22, but also enable the thermal runaway gas inside the cylindrical battery monomer 20 to be exhausted through the gaps between the plurality of supporting regions 2312, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery monomer 20.

[0275] According to some embodiments of the present application, please continue to refer to Figure 6 , Figure 7 , Figure 8 and Figure 9As shown, the protrusion 2132 and the pressure relief groove 2111 both extend along the circumferential direction of the side wall 213, and along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, the outer diameter of the main body area 2311 is D3, and the inner diameter of the pressure relief groove 2111 is D4, satisfying D2≥D3 and D4≥0.75D3, and optionally, D4≥0.85D3.

[0276] As shown, the protrusion 2132 and the pressure relief groove 2111 both extend along the circumferential direction of the side wall 213, and along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, the outer diameter of the main body area 2311 is D3, and the inner diameter of the pressure relief groove 2111 is D4, satisfying D2≥D3 and D4≥0.75D3, and optionally, D4≥0.85D3.

[0277] As shown, the protrusion 2132 and the pressure relief groove 2111 both extend along the circumferential direction of the side wall 213, and along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, the outer diameter of the main body area 2311 is D3, and the inner diameter of the pressure relief groove 2111 is D4, satisfying D2≥D3 and D4≥0.75D3, and optionally, D4≥0.85D3.

[0278] As shown, the protrusion 2132 and the pressure relief groove 2111 both extend along the circumferential direction of the side wall 213, and along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, the outer diameter of the main body area 2311 is D3, and the inner diameter of the pressure relief groove 2111 is D4, satisfying D2≥D3 and D4≥0.75D3, and optionally, D4≥0.85D3.

[0279] As shown, the protrusion 2132 and the pressure relief groove 2111 both extend along the circumferential direction of the side wall 213, and along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, the outer diameter of the main body area 2311 is D3, and the inner diameter of the pressure relief groove 2111 is D4, satisfying D2≥D3 and D4≥0.75D3, and optionally, D4≥0.85D3.

[0280] In the embodiment, by setting the inner diameter of the protrusion 2132 to be greater than or equal to the outer diameter of the main body region 2311 of the body portion 231, and setting the inner diameter of the pressure relief groove 2111 to be greater than or equal to 0.75 times the outer diameter of the main body region 2311 of the body portion 231, the main body region 2311 of the body portion 231 is configured such that the projection in the first direction X is located inside the protrusion 2132, and the pressure relief groove 2111 is configured such that the projection in the first direction X is located close to the outer edge of the main body region 2311 or outside the main body region 2311, thereby reducing the obstruction of the protrusion 2132 and the main body region 2311 to the exhaust path inside the cylindrical battery cell 20, so that the thermal runaway gas inside the cylindrical battery cell 20 can more smoothly enter the area where the pressure relief component on the first wall 211 is provided with the pressure relief groove 2111 through the gap between the plurality of support regions 2312, and then be discharged, thereby effectively improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, which is beneficial to reduce the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief, so as to improve the use stability and reliability of the cylindrical battery cell 20.

[0281] According to some embodiments of the present application, as shown in Figure 6 and Figure 9 , D2≥D4.

[0282] Wherein, D2≥D4, that is, in the projection plane perpendicular to the first direction X, the orthographic projection of the pressure relief groove 2111 is located on the inner circumferential side of the orthographic projection of the protrusion 2132, in combination with Figure 6 , Figure 8 and Figure 9 , in the embodiment of D4≥D3 and D2≥D3, then in the projection plane perpendicular to the first direction X, at least part of the orthographic projection of the pressure relief groove 2111 is located between the orthographic projection of the protrusion 2132 and the orthographic projection of the main body region 2311 in the radial direction of the cylindrical battery cell 20.

[0283] In the embodiment, by setting the inner diameter of the protrusion 2132 to be greater than or equal to the inner diameter of the pressure relief groove 2111, the pressure relief groove 2111 is configured to be arranged in the gap between the protrusion 2132 and the main body region 2311 of the body portion 231 in the first direction X, thereby further reducing the obstruction and obstruction of the protrusion 2132 and the main body region 2311 to the area of the first wall 211 for pressure relief, thereby further improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, which is beneficial to further reduce the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief, so as to further improve the use stability and reliability of the cylindrical battery cell 20.

[0284] According to some embodiments of the present application, in combination with Figure 6、 Figure 8 and Figure 9 As shown in FIG. 25, in the radial direction of the cylindrical battery monomer 20, the outer diameter of the body part 231 is D5, which satisfies D2≤0.95D5.

[0285] In the radial direction of the cylindrical battery monomer 20, the outer diameter D5 of the body part 231 is the diameter of a circle with the center at the center position of the body region 2311 and the radius being the distance from the end of the support region 2312 farthest away from the body region 2311 to the center position of the body region 2311, and is also the diameter of a circle with the center at the center position of the body region 2311 and the radius being the distance from the end of the support region 2312 farthest away from the body region 2311 to the center position of the body region 2311.

[0286] D2≤0.95D5, that is, the part of the projection of the body part 221 of the first current collecting member 23 in the first direction X overlaps with the protrusion 2132. It should be noted that in the embodiment where D2≥D3, the part of the projection of the support region 2312 of the body part 231 in the first direction X overlaps with the protrusion 2132.

[0287] In the present embodiment, by setting the inner diameter of the protrusion 2132 to be less than 0.95 times the outer diameter of the body part 231, the projection of the inner circumferential surface of the protrusion 2132 in the first direction X is a structure located inside the body part 231, so that the plurality of support regions 2312 connected on the outer circumferential surface of the body region 2311 of the body part 231 can better extend between the electrode assembly 22 and the protrusion 2132, thereby improving the lap joint effect of the plurality of support regions 2312 and the protrusion 2132, further improving the support effect of the body part 231 of the first current collecting member 23 on the electrode assembly 22, and also improving the effect of the body part 231 of the first current collecting member 23 on resisting the expansion of the electrode assembly 22 during use of the cylindrical battery monomer 20, thereby improving the use stability of the cylindrical battery monomer 20.

[0288] According to some embodiments of the present application, as shown in FIG. 25, the maximum proportion P of the plurality of support regions 2312 in the circumferential direction of the body region 2311 satisfies 40%≤P≤90%. Figure 8 In the radial direction of the cylindrical battery monomer 20, the maximum proportion P of the plurality of support regions 2312 in the circumferential direction of the body region 2311 is the maximum ratio of the sum of the arc lengths of the plurality of support regions 2312 cut by the same circle to the circumference of the corresponding circle in a plurality of circles with different radii and the center at the center position of the body region 2311.

[0289]

[0290] ​Exemplarily, the maximum proportion P of the plurality of support regions 2312 in the circumferential direction of the main body region 2311 can be 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, or 90%, etc.

[0291] In the present embodiment, on the one hand, by setting the maximum proportion of the plurality of support regions 2312 in the circumferential direction of the main body region 2311 to be greater than or equal to 40%, the maximum space occupied by the plurality of support regions 2312 in the circumferential direction is greater than or equal to 40%, thereby improving the effect of the main body portion 231 being overlapped with the protrusion 2132 through the plurality of support regions 2312, to improve the support effect of the main body portion 231 of the first current collecting member 23 on the electrode assembly 22, and also improve the effect of the main body portion 231 of the first current collecting member 23 resisting the expansion of the electrode assembly 22 during use of the cylindrical battery cell 20. On the other hand, by setting the maximum proportion of the plurality of support regions 2312 in the circumferential direction of the main body region 2311 to be less than or equal to 90%, the maximum space occupied by the plurality of support regions 2312 in the circumferential direction is less than or equal to 90%, thereby alleviating the phenomenon that the plurality of support regions 2312 are close in distance in the circumferential direction of the main body region 2311, to improve the size of the gap between the plurality of support regions 2312, so that the thermal runaway gas inside the cylindrical battery cell 20 can more smoothly pass through the gap between the plurality of support regions 2312 to the side of the main body portion 231 facing the first wall 211, thereby improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, which is conducive to reducing the risk of bursting or explosion of the cylindrical battery cell 20 due to untimely pressure relief.

[0292] In some embodiments, please continue to refer to Figure 8 As shown, the maximum proportion P of the plurality of support regions 2312 in the circumferential direction of the main body region 2311 satisfies 50%≤P≤80%.

[0293] In the embodiment, on one hand, by further setting the maximum proportion of the plurality of support areas 2312 in the circumferential direction of the body area 2311 to be greater than or equal to 50%, the maximum space occupied by the plurality of support areas 2312 on the circumference where they are located is greater than or equal to 50%, so as to further improve the effect of the body part 231 of the first current collecting member 23 being overlapped with the protrusion 2132 through the plurality of support areas 2312, so as to further improve the supporting effect of the body part 231 of the first current collecting member 23 on the electrode assembly 22, and further improve the effect of the body part 231 of the first current collecting member 23 resisting the expansion of the electrode assembly 22 during the use of the cylindrical battery cell 20. On the other hand, by further setting the maximum proportion of the plurality of support areas 2312 in the circumferential direction of the body area 2311 to be less than or equal to 80%, the maximum space occupied by the plurality of support areas 2312 on the circumference where they are located is less than or equal to 80%, so as to further alleviate the phenomenon that the plurality of support areas 2312 are close in the circumferential direction of the body area 2311, so as to further improve the size of the gap between the plurality of support areas 2312, so that the thermal runaway gas inside the cylindrical battery cell 20 can more smoothly enter the side of the body part 231 facing the first wall 211 through the gap between the plurality of support areas 2312, thereby further improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, which is beneficial to further reduce the risk of bursting or explosion of the cylindrical battery cell 20 due to untimely pressure relief.

[0294] According to some embodiments of the present application, as shown in Figure 6 , Figure 7 and Figure 9 , the size of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 in the radial direction of the cylindrical battery cell 20 is L2, the size of the part of the support area 2312 in the radial direction of the cylindrical battery cell 20, which is overlapped with the orthographic projection of the protrusion 2132 in the projection plane perpendicular to the first direction X, is L3, and 0.2L2≤L3≤0.9L2 is satisfied.

[0295] wherein L3 is the length of the part of the support area 2312 in the first direction X, which is located in the protrusion 2132, in the radial direction of the cylindrical battery cell 20, and is also the length of the support area 2312 extending between the electrode assembly 22 and the protrusion 2132 in the radial direction of the cylindrical battery cell 20.

[0296] Optionally, 0.3L2≤ L3≤ 0.8L2. Exemplarily, L3may be 0.3 times, 0.31 times, 0.32 times, 0.33 times, 0.35 times, 0.38 times, 0.4 times, 0.42 times, 0.45 times, 0.48 times, 0.5 times, 0.52 times, 0.55 times, 0.58 times, 0.6 times, 0.62 times, 0.65 times, 0.68 times, 0.7 times, 0.72 times, 0.75 times, 0.78 times, or 0.8 times of L2, etc.

[0297] In the present embodiment, the dimension of the portion where the projection of the support area 2312 in the first direction X overlaps with the protrusion 2132 in the radial direction of the cylindrical battery cell 20 is set to be 0.2 to 0.9 times of the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213, so that the length of the support area 2312 extending in the radial direction of the cylindrical battery cell 20 between the protrusion 2132 and the electrode assembly 22 is 0.2 to 0.9 times of the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213, on the one hand, setting the length of the support area 2312 extending in the radial direction of the cylindrical battery cell 20 between the protrusion 2132 and the electrode assembly 22 to be greater than or equal to 0.2 times of the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 can further improve the mutual lapping effect of the support area 2312 and the protrusion 2132, so as to further improve the support effect of the body portion 231 of the first current collecting member 23 on the electrode assembly 22, and further improve the effect of the body portion 231 of the first current collecting member 23 resisting the expansion of the electrode assembly 22 during the use of the cylindrical battery cell 20, on the other hand, setting the length of the support area 2312 extending in the radial direction of the cylindrical battery cell 20 between the protrusion 2132 and the electrode assembly 22 to be less than or equal to 0.9 times of the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 can alleviate the phenomenon of too much lapping of the support area 2312 and the protrusion 2132, so as to reduce the difficulty of assembling the first current collecting member 23 into the shell 21, and facilitate the body portion 231 of the first current collecting member 23 to be separated from between the protrusion 2132 and the electrode assembly 22 under the impact of the thermal runaway gas when the cylindrical battery cell 20 is depressurized, which is beneficial to improving the internal exhaust smoothness and the depressurization rate of the cylindrical battery cell 20, so as to further reduce the risk of bursting or explosion of the cylindrical battery cell 20 due to untimely depressurization.

[0298] In some embodiments, referring to Figure 6 As shown, 1mm≤ L2≤ 8mm. That is, the dimension of the protrusion 2132 in the radial direction of the cylindrical battery cell 20 is 1mm to 8mm, and optionally, 3mm≤ L2≤ 4mm.

[0299] Exemplarily, the dimension L2 of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 in the radial direction of the cylindrical battery cell 20 can be 1 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, or 8 mm, etc.

[0300] In the present embodiment, by setting the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 to be 1 mm to 8 mm, on the one hand, setting the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 to be greater than or equal to 1 mm can reduce the difficulty of the lap joint of the protrusion 2132 and the support area 2312, so as to reduce the difficulty of setting the body part 231 of the first current collecting member 23 between the protrusion 2132 and the electrode assembly 22, and can improve the support effect of the protrusion 2132 on the electrode assembly 22, on the other hand, setting the dimension of the protrusion 2132 protruding from the inner circumferential surface of the side wall 213 to be less than or equal to 8 mm can reduce the space occupied by the protrusion 2132 in the radial direction of the cylindrical battery cell 20, which is conducive to reducing the obstruction of the protrusion 2132 to the exhaust path inside the cylindrical battery cell 20, so as to effectively improve the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, which is conducive to reducing the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief, so as to improve the use stability and reliability of the cylindrical battery cell 20.

[0301] In some embodiments, in combination with Figure 6 and Figure 7 As shown, L3≥1 mm. That is, in the radial direction of the cylindrical battery cell 20, the length of the part of the support area 2312 extending between the electrode assembly 22 and the protrusion 2132 is greater than or equal to 1 mm.

[0302] Exemplarily, L3 can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, or 1.8 mm, etc.

[0303] In the present embodiment, by setting the dimension of the portion where the projection of the support region 2312 in the first direction X overlaps with the protrusion 2132 in the radial direction of the cylindrical battery cell 20 to be greater than or equal to 1 mm, the length of the support region 2312 extending in the radial direction of the cylindrical battery cell 20 between the protrusion 2132 and the electrode assembly 22 is greater than or equal to 1 mm, thereby being able to improve the effect of the support region 2312 and the protrusion 2132 overlapping with each other, to improve the support effect of the body portion 231 of the first current collecting member 23 on the electrode assembly 22, and further improve the effect of the body portion 231 of the first current collecting member 23 resisting the expansion of the electrode assembly 22 during use of the cylindrical battery cell 20.

[0304] According to some embodiments of the present application, reference is made to Figure 6 , Figure 7 and Figure 8 , and further reference is made to Figure 10 , Figure 10 a structural schematic diagram of the first connecting portion 26, the second connecting portion 27, and the third connecting portion 28 on the first current collecting member 23 provided by some embodiments of the present application. The electrode assembly 22 can include a body portion 221 and a first tab 222, and along the first direction X, the first tab 222 is connected to one end of the body portion 221 facing the first wall 211. The body region 2311 is welded to the first tab 222 and forms a plurality of first connecting portions 26, and the plurality of support regions 2312 are welded to the first tab 222 and form a plurality of second connecting portions 27, and the sum of the lengths of the plurality of second connecting portions 27 is greater than or equal to the sum of the lengths of the plurality of first connecting portions 26.

[0305] Among them, the first connecting portion 26 and the second connecting portion 27 are both strip-shaped structures, and correspondingly, the sum of the lengths of the plurality of second connecting portions 27 is greater than or equal to the sum of the lengths of the plurality of first connecting portions 26, that is, the total length of the plurality of second connecting portions 27 formed by the plurality of support regions 2312 welded to the first tab 222 is greater than or equal to the total length of the plurality of first connecting portions 26 formed by the body region 2311 welded to the first tab 222.

[0306] It should be noted that the first connecting portion 26 is a region where the body region 2311 of the body portion 231 and the first tab 222 are mutually welded to form mutual melting or welding marks, and similarly, the second connecting portion 27 is a region where the support region 2312 of the body portion 231 and the first tab 222 are mutually welded to form mutual melting or welding marks.

[0307] In this embodiment, the main body region 2311 of the body portion 231 is welded to the first electrode tab 222 to form a plurality of first connecting portions 26, and the plurality of support regions 2312 of the body portion 231 are welded to the first electrode tab 222 to form a plurality of second connecting portions 27. This results in both the main body region 2311 and the support regions 2312 being welded to the first electrode tab 222, thereby increasing the current-conducting area between the first electrode tab 222 and the body portion 231, and improving the connection stability and reliability between the body portion 231 of the first current collector 23 and the first electrode tab 222 of the electrode assembly 22. Furthermore, the outer ring length of the first electrode tab 222 is greater than the inner ring length of the first electrode tab 222. The current requirement of the outer ring of the first electrode 222 is greater than that of the inner ring of the first electrode 222. By setting the total length of the multiple second connecting parts 27 formed by welding multiple support areas 2312 to the first electrode 222 to be greater than the total length of the multiple first connecting parts 26 formed by welding the main body area 2311 to the first electrode 222, the current guiding area between the outer ring of the first electrode 222 and the main body 231 is greater than that between the inner ring of the first electrode 222 and the main body 231. This improves the current balance between the inner and outer rings of the first electrode 222 and helps to reduce the phenomenon of local lithium plating or increased internal resistance in the electrode assembly 22 during use.

[0308] In some embodiments, see Figure 8 and Figure 10 As shown, a plurality of first connecting portions 26 are arranged circumferentially along the sidewall 213, and the first connecting portions 26 extend radially along the cylindrical battery cell 20. That is, the plurality of first connecting portions 26 are arranged at intervals around the central axis of the cylindrical battery cell 20, and the extension direction of each first connecting portion 26 is radial to the cylindrical battery cell 20, so that the plurality of first connecting portions 26 are arranged radially.

[0309] For example, the main body region 2311 is welded to the first electrode tab 222 to form four first connection portions 26. Of course, in other embodiments, the number of first connection portions 26 formed by welding the main body region 2311 to the first electrode tab 222 can also be two, three, five, six, seven or eight, etc.

[0310] In this embodiment, by welding the main body region 2311 and the first tab 222 together, the multiple first connecting parts 26 are arranged in a circumferentially spaced manner along the sidewall 213, and each first connecting part 26 is a structure extending radially along the cylindrical battery cell 20. On the one hand, this reduces the welding difficulty between the main body region 2311 and the first tab 222, and optimizes the layout of the multiple first connecting parts 26, which helps to alleviate the interference between the multiple first connecting parts 26. On the other hand, it enables the first tab 222 to be connected to the main body region 2311 at multiple positions in the circumferential direction of the sidewall 213, and also enables the first tab 222 to be connected to the main body region 2311 at multiple positions in the radial direction of the cylindrical battery cell 20. This allows the multiple rings of the first tab 222 to be connected to the main body region 2311, thereby increasing the current conduction area between the first tab 222 and the main body region 2311, and also improving the overcurrent balance between the electrode assembly 22 and the main body region 2311, so as to reduce the risk of local lithium plating in the electrode assembly 22 during use.

[0311] In some embodiments, see Figure 8 and Figure 10 As shown, a plurality of second connecting portions 27 are arranged circumferentially along the sidewall 213, and the second connecting portions 27 extend radially along the cylindrical battery cell 20. That is, the plurality of second connecting portions 27 are arranged at intervals around the central axis of the cylindrical battery cell 20, and the extension direction of each second connecting portion 27 is radial to the cylindrical battery cell 20, so that the plurality of second connecting portions 27 are arranged radially.

[0312] In this embodiment, by welding multiple support regions 2312 to the first electrode tab 222 to form multiple second connecting portions 27, a structure is configured to be arranged circumferentially at intervals along the sidewall 213, and each second connecting portion 27 is a structure extending radially along the cylindrical battery cell 20. On the one hand, this reduces the welding difficulty between the multiple support regions 2312 and the first electrode tab 222, and optimizes the layout between the multiple second connecting portions 27, which helps to alleviate the interference between the multiple second connecting portions 27. On the other hand, it enables the first electrode tab 222 to achieve the desired effect. 2. The first tab 222 is connected to the support region 2312 at multiple positions in the circumferential direction of the side wall 213, and the first tab 222 is connected to the support region 2312 at multiple positions in the radial direction of the cylindrical battery cell 20. This allows the multi-ring structure of the first tab 222 to be connected to the support region 2312, thereby increasing the current conduction area between the first tab 222 and the support region 2312, and also improving the overcurrent balance between the electrode assembly 22 and the support region 2312, so as to reduce the risk of local lithium plating in the electrode assembly 22 during use.

[0313] In some embodiments, please continue to see Figure 8and Figure 10 As shown in FIG. 13, each support area 2312 is welded to the first tab 222 to form a second connecting portion 27. That is, any one of the plurality of support areas 2312 of the body portion 231 is welded to the first tab 222 to form a second connecting portion 27.

[0314] Exemplarily, each support area 2312 is welded to the first tab 222 to form two second connecting portions 27. Of course, in other embodiments, the number of second connecting portions 27 formed by welding each support area 2312 to the first tab 222 can also be one, three, four, etc.

[0315] In this embodiment, by welding each support area 2312 of the body portion 231 to the first tab 222, the plurality of support areas 2312 spaced apart in the circumferential direction of the main body area 2311 are welded to the first tab 222 and correspondingly form second connecting portions 27. On the one hand, this can further improve the connection stability and firmness between the first tab 222 and the body portion 231. On the other hand, it can achieve that the first tab 222 is connected to the support area 2312 at multiple positions in the circumferential direction of the side wall 213, which is beneficial to improve the flow balance between the electrode assembly 22 and the first current collecting member 23, so as to reduce the risk of local lithium precipitation of the electrode assembly 22 during use.

[0316] According to some embodiments of the present application, referring to Figure 8 As shown in FIG. 13, along the radial direction of the cylindrical battery cell 20, the outer diameter of the main body area 2311 is D3, and the length of the support area 2312 is L4, which satisfies 0.5D3≥L4. That is, the radius of the outer contour of the main body area 2311 is greater than or equal to the length of the support area 2312 in the radial direction of the cylindrical battery cell 20.

[0317] In this embodiment, by setting the radius of the main body area 2311 of the body portion 231 to be greater than or equal to the length of the support area 2312 of the body portion 231 protruding from the outer circumferential surface of the main body area 2311 in the radial direction of the cylindrical battery cell 20, the phenomenon that the space occupied by the support area 2312 in the body portion 231 is too much to cause insufficient structural strength of the body portion 231 can be alleviated. Thus, the phenomenon that the support effect of the body portion 231 on the electrode assembly 22 in the first direction X is poor can be further improved, and the effect of the body portion 231 resisting the expansion of the electrode assembly 22 during use of the cylindrical battery cell 20 can be further improved.

[0318] According to some embodiments of the present application, referring to Figure 6 , Figure 7 and Figure 8As shown, the protrusion 2132 extends circumferentially along the side wall 213. The first current collection member 23 includes multiple support portions 232 and multiple docking portions 233. The multiple docking portions 233 are arranged at intervals circumferentially along the side wall 213. Each docking portion 233 is connected to the main body portion 231 through a support portion 232, and the multiple docking portions 233 are all connected to the protrusion 2132.

[0319] Each docking part 233 is connected to the main body part 231 through a support part 232, and multiple docking parts 233 are connected to the protrusion 2132. That is, the support part 232 and the docking part 233 are in a one-to-one correspondence structure. The main body part 231 of the first current collecting member 23 is a structure connected to the protrusion 2132 through multiple docking parts 233. Correspondingly, in the embodiment where the main body part 231 includes a main body area 2311 and a support area 2312, multiple support parts 232 are connected to the outer peripheral surface of the main body area 2311, and the support parts 232 and the support area 2312 are arranged alternately along the circumference of the main body area 2311.

[0320] For example, in Figure 7 and Figure 8 In the first current collection component 23, four support parts 232 and four docking parts 233 are provided. The four support parts 232 are arranged at intervals along the circumference of the main body area 2311, and the four docking parts 233 are arranged at intervals along the circumference of the main body area 2311. Of course, in other embodiments, the number of support parts 232 and docking parts 233 of the first current collection component 23 can also be two, three, five or six, etc.

[0321] In this embodiment, by setting the protrusion 2132 as a structure extending circumferentially along the sidewall 213, and setting the first current collecting member 23 as including multiple support portions 232 and multiple docking portions 233, with the support portions 232 and docking portions 233 corresponding one-to-one, and the multiple docking portions 233 being arranged at intervals along the circumferential direction of the sidewall 213 and all connected to the protrusion 2132, the protrusion 2132 is connected to the docking portion 233 at multiple positions in the circumferential direction of the sidewall 213. On the one hand, this can further improve the connection stability and reliability between the first current collecting member 23 and the protrusion 2132. On the other hand, it can further improve the flow guiding area between the first current collecting member 23 and the protrusion 2132, and further improve the flow balance between the first current collecting member 23 and the protrusion 2132, so as to reduce the risk of local temperature rise of the protrusion 2132.

[0322] According to some embodiments of this application, see Figure 6 and Figure 10As shown, each of the plurality of butt joints 233 is welded to the protrusion 2132 and corresponds to form a plurality of third connecting portions 28, the third connecting portions 28 correspond to the butt joints 233 one by one, and the third connecting portions 28 extend along the circumferential direction of the side wall 213. In the projection plane perpendicular to the first direction X, the outer edges of the projections of the plurality of third connecting portions 28 are all located on a first circle, and the sum of the arc lengths of the outer edges of the projections of the plurality of third connecting portions 28 is L5, and the circumference of the first circle is L6, and L5≥0.5L6 is satisfied.

[0323] The third connecting portions 28 correspond to the butt joints 233 one by one, and the third connecting portions 28 extend along the circumferential direction of the side wall 213, that is, each butt joint 233 is welded to the protrusion 2132 to form a third connecting portion 28, and the third connecting portion 28 is an arc-shaped structure extending along the circumferential direction of the side wall 213. Correspondingly, the plurality of third connecting portions 28 formed by welding the plurality of butt joints 233 to the protrusions 2132 are structures arranged at intervals along the circumferential direction of the side wall 213. It should be noted that in other embodiments, the third connecting portion 28 formed by welding each butt joint 233 to the protrusion 2132 can also be a plurality, and the plurality of third connecting portions 28 formed by welding each butt joint 233 to the protrusion 2132 are arranged at intervals along the circumferential direction of the side wall 213.

[0324] It should be noted that the third connecting portion 28 is a region of mutual melting or a region of welding marks formed by mutual welding of the butt joint 233 and the protrusion 2132.

[0325] L5 is the sum of the arc lengths of the outer contours of the projections of the plurality of third connecting portions 28 in the first direction X. Correspondingly, L6 is the circumference of the circle on which the outer contour of the projection of the third connecting portion 28 in the first direction X is located, that is, the circumference of the first circle is L6.

[0326] L5≥0.5L6, that is, the proportion of the outer contour of the projection of the plurality of third connecting portions 28 in the first direction X on the first circle is greater than or equal to 50%.

[0327] For example, L5 can be 0.5 times, 0.51 times, 0.52 times, 0.53 times, 0.54 times, 0.55 times, 0.56 times, 0.57 times, 0.58 times, 0.59 times, 0.6 times, 0.61 times, 0.62 times, 0.63 times, 0.64 times, 0.65 times, 0.66 times, 0.67 times, 0.68 times, 0.69 times, 0.7 times, 0.71 times, 0.72 times, 0.73 times, 0.74 times, 0.75 times, 0.76 times, 0.77 times, 0.78 times, 0.79 times, 0.8 times, 0.81 times, 0.82 times, 0.83 times, 0.84 times, or 0.85 times of L6, etc.

[0328] In the embodiment, by setting the sum of the arc lengths of the outer edges of the orthographic projections of the plurality of third connecting portions 28 in the first direction X to be greater than or equal to 0.5 times the circumference of the first circle, the proportion of the plurality of third connecting portions 28 on the first circle is greater than or equal to 50%, so that the flow area between the first current collecting member 23 and the protrusion 2132 can be increased, the flow effect between the first current collecting member 23 and the shell 21 is improved, and the phenomenon of increased internal resistance of the cylindrical battery monomer 20 during use can be reduced.

[0329] In some embodiments, L5≥0.8L6.

[0330] In the embodiment, by further setting the sum of the arc lengths of the outer edges of the orthographic projections of the plurality of third connecting portions 28 in the first direction X to be greater than or equal to 0.8 times the circumference of the first circle, the proportion of the plurality of third connecting portions 28 on the first circle is greater than or equal to 80%, so that the flow area between the first current collecting member 23 and the protrusion 2132 can be further increased, the flow effect between the first current collecting member 23 and the shell 21 is further improved, and the phenomenon of increased internal resistance of the cylindrical battery monomer 20 during use can be further reduced.

[0331] In some embodiments, referring to Figure 6 , Figure 8 and Figure 10 , the abutting portion 233 is an arc-shaped structure extending in the circumferential direction of the side wall 213.

[0332] In the embodiment, the sum of the arc lengths of the outer edges of the orthographic projections of the plurality of third connecting portions 28 in the projection plane perpendicular to the first direction X is less than or equal to the sum of the lengths of the plurality of abutting portions 233 in the circumferential direction of the side wall 213. It should be noted that in the embodiment in which the first current collecting member 23 includes the plurality of abutting portions 233, the plurality of abutting portions 233 are structures arranged at intervals in the circumferential direction of the side wall 213.

[0333] In the embodiment, the abutting portion 233 is arranged as an arc-shaped structure extending in the circumferential direction of the side wall 213, so that the abutting portion 233 and the protrusion 2132 can be matched with each other. On the one hand, the abutting portion 233 and the protrusion 2132 can be welded to form the third connecting portion 28 extending in the circumferential direction of the side wall 213, which is conducive to reducing the welding difficulty between the abutting portion 233 and the protrusion 2132. On the other hand, the abutting portion 233 can be welded to the protrusion 2132 at multiple positions in the circumferential direction of the side wall 213, so that the rotation and positioning of the first current collecting member 23 can be reduced after the first current collecting member 23 is assembled into the shell 21, which is conducive to further reducing the welding difficulty between the first current collecting member 23 and the protrusion 2132, thereby effectively improving the assembly efficiency of the cylindrical battery monomer 20.

[0334] According to some embodiments of the present application, referring to Figure 5 and Figure 6 The inside of the shell 21 is formed with a containing cavity 214, the body part 231 is configured to separate the containing cavity 214 into a first cavity 2141 and a second cavity 2142 in communication with each other, the electrode assembly 22 is contained in the first cavity 2141, the second cavity 2142 is located between the body part 231 and the first wall 211 in the first direction X, and the pressure relief part is configured to be able to split along at least part of the pressure relief groove 2111 when the cylindrical battery cell 20 is relieved of pressure, so as to release the internal pressure of the second cavity 2142. In the first direction X, the maximum size of the second cavity 2142 is H1, and the maximum size of the shell 21 is H2, satisfying 0.003≤H1 / H2≤0.06.

[0335] The inside of the shell 21 is formed with a containing cavity 214, the body part 231 is configured to separate the containing cavity 214 into a first cavity 2141 and a second cavity 2142 in communication with each other, the electrode assembly 22 is contained in the first cavity 2141, the second cavity 2142 is located between the body part 231 and the first wall 211 in the first direction X, that is, the body part 231 of the first current collecting member 23 is arranged between the electrode assembly 22 and the protrusion 2132 in the first direction X, so that the space on the side of the body part 231 facing the electrode assembly 22 is the first cavity 2141, and the space between the body part 231 and the first wall 211 is the second cavity 2142, so that the first cavity 2141 and the second cavity 2142 are arranged in the first direction X and located on both sides of the body part 231, respectively.

[0336] The pressure relief part is configured to be able to split along at least part of the pressure relief groove 2111 when the cylindrical battery cell 20 is relieved of pressure, so as to release the internal pressure of the second cavity 2142, that is, at least part of the region of the pressure relief groove 2111 provided on the first wall 211 is split when the cylindrical battery cell 20 is relieved of pressure, so as to realize direct communication between the second cavity 2142 and the outside of the shell 21, so that the thermal runaway gas in the second cavity 2142 can be directly discharged.

[0337] It should be noted that in the embodiment in which the pressure relief part and the first wall 211 are integrally formed, the first wall 211 is configured to be able to split along at least part of the pressure relief groove 2111 when the cylindrical battery cell 20 is relieved of pressure, so as to release the internal pressure of the second cavity 2142, that is, at least part of the region of the pressure relief groove 2111 provided on the first wall 211 is split when the cylindrical battery cell 20 is relieved of pressure, so as to realize direct communication between the second cavity 2142 and the outside of the shell 21, so that the thermal runaway gas in the second cavity 2142 can be directly discharged.

[0338] Exemplarily, the first cavity 2141 and the second cavity 2142 are in communication with each other, and the pressure relief part on the first wall 211 is provided with a region of the pressure relief groove 2111 corresponding to the second cavity 2142 in the first direction X.

[0339] In the first direction X, the maximum size of the second cavity 2142 is H1, that is, H1 is the maximum height size of the second cavity 2142 in the first direction X.

[0340] In the first direction X, the maximum size of the second cavity 2142 is H1, that is, H1 is the maximum height size of the second cavity 2142 in the first direction X.

[0341] Exemplarily, in the first direction X, the ratio of the maximum size H1 of the second cavity 2142 to the maximum size H2 of the shell 21 can be 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.012, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.056, 0.057, 0.058, 0.059, or 0.06, etc.

[0342] Optionally, the maximum height size H2 of the shell 21 in the first direction X is 70mm to 140mm, and exemplarily, the maximum height size H2 of the shell 21 in the first direction X can be 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, or 140mm, etc.

[0343] In the embodiment, the body part 231 divides the accommodating cavity 214 inside the shell 21 into a first cavity and a second cavity arranged along the first direction X, the electrode assembly 22 is arranged in the first cavity, and the second cavity is located between the first wall 211 and the body part 231. By arranging the pressure relief component to be capable of being split along at least part of the pressure relief groove 2111 and releasing the internal pressure of the second cavity 2142 when the cylindrical battery monomer 20 is pressure relieved, the region of the first wall 211 where the pressure relief groove 2111 is arranged is a structure corresponding to the arrangement of the second cavity 2142. The cylindrical battery monomer 20 adopting this structure can realize the separation between the electrode assembly 22 and the pressure relief component through the second cavity 2142, so as to relieve the blocking and shielding of the electrode assembly 22 to the pressure relief component when the cylindrical battery monomer 20 is pressure relieved, so that the inside of the shell 21 has the second cavity 2142 for buffering and discharging the thermal runaway gas, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery monomer 20. The maximum size of the second cavity 2142 in the first direction X is 0.003 to 0.06 of the maximum size of the shell 21 in the first direction X. On the one hand, by arranging the maximum size of the second cavity 2142 in the first direction X to be greater than or equal to 0.003 times of the maximum size of the shell 21 in the first direction X, the body part 231 and the first wall 211 have sufficient space for buffering and discharging the thermal runaway gas, which is beneficial to improve the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer 20, so as to reduce the risk of explosion or explosion of the cylindrical battery monomer 20 due to untimely pressure relief. On the other hand, by arranging the maximum size of the second cavity 2142 in the first direction X to be less than or equal to 0.06 times of the maximum size of the shell 21 in the first direction X, the phenomenon that the second cavity 2142 occupies too much space for arranging the electrode assembly 22 in the accommodating cavity 214 is relieved, so as to improve the internal space utilization of the cylindrical battery monomer 20, and improve the energy density of the cylindrical battery monomer 20.

[0344] In some embodiments, please continue to refer to Figure 5 and Figure 6 It is shown that 0.01≤H1 / H2≤0.03.

[0345] In this embodiment, on the one hand, the maximum size of the second cavity 2142 in the first direction X is further set to be greater than or equal to 0.01 times the maximum size of the outer shell 21 in the first direction X, so that there is more space between the body 231 and the first wall 211 to buffer and discharge thermal runaway gas. This is beneficial to further improve the internal exhaust smoothness and depressurization rate of the cylindrical battery cell 20, thereby further reducing the risk of the cylindrical battery cell 20 bursting or exploding due to untimely depressurization. On the other hand, the maximum size of the second cavity 2142 in the first direction X is further set to be less than or equal to 0.03 times the maximum size of the outer shell 21 in the first direction X, so as to further alleviate the phenomenon that the second cavity 2142 occupies too much space in the accommodating cavity 214 for setting the electrode assembly 22, thereby further improving the internal space utilization of the cylindrical battery cell 20 and further improving the energy density of the cylindrical battery cell 20.

[0346] In some embodiments, see Figure 6 As shown, 0.4mm≤H1≤4mm.

[0347] For example, the maximum dimension H1 of the second cavity 2142 in the first direction X can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm or 4mm, etc.

[0348] In this embodiment, by setting the maximum size of the second cavity 2142 in the first direction X to 0.4mm to 4mm, on the one hand, more space can be provided between the body 231 and the first wall 211 to buffer and discharge thermal runaway gas. This reduces the obstruction of the exhaust path inside the cylindrical battery cell 20 by the electrode assembly 22 and the body 231 when the cylindrical battery cell 20 is depressurized, thereby further improving the smoothness of internal exhaust and the depressurization rate of the cylindrical battery cell 20. This reduces the risk of the cylindrical battery cell 20 bursting or exploding due to untimely depressurization. On the other hand, it alleviates the phenomenon that the second cavity 2142 occupies too much space in the accommodating cavity 214 for setting the electrode assembly 22, thereby further improving the internal space utilization of the cylindrical battery cell 20 and further improving the energy density of the cylindrical battery cell 20.

[0349] In some embodiments, see Figure 6 As shown, the capacity of the cylindrical battery cell 20 is C, which satisfies 0.005mm / Ah≤H1 / C≤0.2mm / Ah.

[0350] Exemplarily, a ratio of the maximum dimension H1 of the second cavity 2142 in the first direction X to the electric capacity C of the cylindrical battery cell 20 can be 0.005 mm / Ah, 0.006 mm / Ah, 0.007 mm / Ah, 0.008 mm / Ah, 0.009 mm / Ah, 0.01 mm / Ah, 0.02 mm / Ah, 0.03 mm / Ah, 0.04 mm / Ah, 0.05 mm / Ah, 0.06 mm / Ah, 0.07 mm / Ah, 0.08 mm / Ah, 0.09 mm / Ah, 0.1 mm / Ah, 0.11 mm / Ah, 0.12 mm / Ah, 0.13 mm / Ah, 0.14 mm / Ah, 0.15 mm / Ah, 0.16 mm / Ah, 0.17 mm / Ah, 0.18 mm / Ah, 0.19 mm / Ah, or 0.2 mm / Ah, etc.

[0351] In the present embodiment, on the one hand, by setting the ratio of the maximum dimension of the second cavity 2142 in the first direction X to the electric capacity of the cylindrical battery cell 20 to be greater than or equal to 0.005 mm / Ah, the second cavity 2142 has sufficient space to buffer and discharge the thermal runaway gas when the cylindrical battery cell 20 is depressurized, which is conducive to matching the space for exhaust in the housing 21 with the gas generation rate of the cylindrical battery cell 20 when thermal runaway occurs, so as to improve the internal exhaust smoothness of the cylindrical battery cell 20, thereby effectively reducing the risk of bursting or explosion of the cylindrical battery cell 20 due to untimely depressurization. On the other hand, by setting the ratio of the maximum dimension of the second cavity 2142 in the first direction X to the electric capacity of the cylindrical battery cell 20 to be less than or equal to 0.2 mm / Ah, the phenomenon of excessive waste of space for exhaust in the housing 21 is alleviated, thereby improving the internal space utilization of the cylindrical battery cell 20, so as to improve the energy density of the cylindrical battery cell 20.

[0352] In some embodiments, please continue to refer to Figure 6 As shown, the positive electrode material of the cylindrical battery cell 20 includes a lithium transition metal oxide, and H1, C further satisfy 0.01 mm / Ah≤H1 / C≤0.2 mm / Ah.

[0353] Wherein, the positive electrode material of the cylindrical battery cell 20 includes a lithium transition metal oxide, that is, the positive electrode material of the electrode assembly 22 of the cylindrical battery cell 20 includes at least one of a lithium cobalt oxide, a lithium nickel oxide, a lithium manganese oxide, a lithium nickel cobalt oxide, a lithium manganese cobalt oxide, a lithium nickel manganese oxide, a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide, and a modified compound thereof, etc.

[0354] In the present embodiment, when the positive electrode material of the cylindrical battery cell 20 comprises a lithium transition metal oxide, by further setting the ratio of the maximum dimension of the second cavity 2142 in the first direction X to the capacity of the cylindrical battery cell 20 to be 0.01 mm / Ah to 0.2 mm / Ah, the space for exhaust within the shell 21 can be further matched with the gas generation rate of the cylindrical battery cell 20 in thermal runaway, on the one hand, the internal exhaust smoothness of the cylindrical battery cell 20 can be further improved, so as to further reduce the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief, on the other hand, the phenomenon of excessive waste of the space for exhaust within the shell 21 can be further alleviated, so as to further improve the internal space utilization rate of the cylindrical battery cell 20, which is beneficial to further improve the energy density of the cylindrical battery cell 20.

[0355] In some embodiments, please continue to refer to Figure 6 As shown in , the positive electrode material of the cylindrical battery cell 20 comprises lithium-containing phosphate, H1, C further satisfies, 0.005 mm / Ah≤H1 / C≤0.1 mm / Ah.

[0356] Wherein, the positive electrode material of the cylindrical battery cell 20 comprises lithium-containing phosphate, that is, the positive electrode material of the electrode assembly 22 of the cylindrical battery cell 20 comprises at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0357] In the present embodiment, when the positive electrode material of the cylindrical battery cell 20 comprises lithium-containing phosphate, by further setting the ratio of the maximum dimension of the second cavity 2142 in the first direction X to the capacity of the cylindrical battery cell 20 to be 0.005 mm / Ah to 0.1 mm / Ah, the space for exhaust within the shell 21 can be further matched with the gas generation rate of the cylindrical battery cell 20 in thermal runaway, on the one hand, the internal exhaust smoothness of the cylindrical battery cell 20 can be further improved, so as to further reduce the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief, on the other hand, the phenomenon of excessive waste of the space for exhaust within the shell 21 can be further alleviated, so as to further improve the internal space utilization rate of the cylindrical battery cell 20, which is beneficial to further improve the energy density of the cylindrical battery cell 20.

[0358] According to some embodiments of the present application, please refer to Figure 5 , Figure 6 and Figure 9 As shown in , along the radial direction of the cylindrical battery cell 20, the inner diameter of the protrusion 2132 is D2, and the outer diameter of the electrode assembly 22 is D6, which satisfies, 0.7≤D2 / D6≤0.95.

[0359] The outer diameter of the electrode assembly 22 along the radial direction of the cylindrical battery monomer 20 is D6, that is, the diameter of the circle on which the outer contour of the orthographic projection of the main body part 221 of the electrode assembly 22 in the projection plane perpendicular to the first direction X is located.

[0360] Exemplarily, the ratio of the inner diameter D2 of the protrusion 2132 to the outer diameter D6 of the electrode assembly 22 along the radial direction of the cylindrical battery monomer 20 can be 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.78, 0.8, 0.82, 0.84, 0.85, 0.86, 0.88, 0.9, 0.91, 0.92, 0.93, 0.94, or 0.95, etc.

[0361] In the present embodiment, by setting the ratio of the inner diameter of the protrusion 2132 to the outer diameter of the electrode assembly 22 to be 0.7 to 0.95, on the one hand, the inner diameter of the protrusion 2132 is set to be greater than or equal to 0.7 times the outer diameter of the electrode assembly 22, so that most of the area of the electrode assembly 22 is a structure provided on the inner side of the protrusion 2132 in the first direction X, thereby being able to reduce the obstruction of the exhaust path inside the cylindrical battery monomer 20 by the protrusion 2132, and being conducive to improving the internal exhaust smoothness and pressure relief rate of the cylindrical battery monomer 20, and thereby being able to effectively reduce the risk of explosion or explosion of the cylindrical battery monomer 20 due to untimely pressure relief, on the other hand, the inner diameter of the protrusion 2132 is set to be less than or equal to 0.95 times the outer diameter of the electrode assembly 22, so that the electrode assembly 22 and the protrusion 2132 are a structure in which the projection parts in the first direction X overlap, thereby being able to improve the support effect of the protrusion 2132 on the electrode assembly 22 through the main body part 231, and also being able to improve the effect of the main body part 231 of the first current collecting member 23 against the expansion of the electrode assembly 22 during the use of the cylindrical battery monomer 20.

[0362] In some embodiments, please continue to refer to Figure 5 , Figure 6 and Figure 9 , 0.75≤D2 / D6≤0.9.

[0363] In the embodiment, on one hand, the inner diameter of the protrusion 2132 is further set to be greater than or equal to 0.75 times of the outer diameter of the electrode assembly 22, so as to further increase the area of the region of the electrode assembly 22 corresponding to the inner side of the protrusion 2132 arranged in the first direction X, thereby further reducing the obstruction of the protrusion 2132 to the exhaust path inside the cylindrical battery cell 20, and facilitating further improvement of the internal exhaust smoothness and pressure relief rate of the cylindrical battery cell 20, and thereby further reducing the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief. On the other hand, the inner diameter of the protrusion 2132 is further set to be less than or equal to 0.9 times of the outer diameter of the electrode assembly 22, so as to further increase the area of the region of the electrode assembly 22 and the protrusion 2132 overlapping with each other in the first direction X, thereby further improving the support effect of the protrusion 2132 on the electrode assembly 22 through the body portion 231, and further improving the effect of the body portion 231 of the first current collecting member 23 against the expansion of the electrode assembly 22 during use of the cylindrical battery cell 20.

[0364] According to some embodiments of the present application, referring to Figure 6 As shown in the figure, along the first direction X, the projection of the pressure relief groove 2111 is located in the second cavity 2142. That is, in the first direction X, the region of the first wall 211 where the pressure relief groove 2111 is arranged is a structure corresponding to the second cavity 2142.

[0365] In the embodiment, by arranging the pressure relief groove 2111 as a structure whose projection in the first direction X is located in the second cavity 2142, the region of the pressure relief member on the first wall 211 where the pressure relief groove 2111 is arranged is a structure corresponding to the second cavity 2142 in the first direction X, thereby facilitating the exhaust of the thermal runaway gas in the second cavity 2142 when the cylindrical battery cell 20 occurs thermal runaway and the pressure relief member is split along at least part of the pressure relief groove 2111 to relieve pressure, facilitating further improvement of the exhaust rate of the thermal runaway gas in the second cavity 2142, and thereby further improving the pressure relief rate of the cylindrical battery cell 20 to further reduce the risk of explosion or explosion of the cylindrical battery cell 20 due to untimely pressure relief.

[0366] According to some embodiments of the present application, referring to Figure 6 As shown in the figure, along the first direction X, the abutment portion 233 is arranged on the side of the protrusion 2132 away from the electrode assembly 22 and connected with the protrusion 2132.

[0367] The abutting portion 233 is located on the side of the protrusion 2132 facing away from the electrode assembly 22 in the first direction X, such that the abutting portion 233 and the body portion 231 are located on the two sides of the protrusion 2132 in the first direction X, and the supporting portion 232 is connected between the abutting portion 233 and the main body region 2311 of the body portion 231, so that the supporting portion 232 is located on the inner circumferential side of the protrusion 2132, and the supporting portion 232 and the protrusion 2132 share part of the space in the first direction X. Of course, in other embodiments, the abutting portion 233 can also be a structure located on the side of the protrusion 2132 facing the electrode assembly 22, and the abutting portion 233 is connected to the side of the protrusion 2132 facing the electrode assembly 22.

[0368] In this embodiment, by setting the abutting portion 233 of the first current collecting member 23 to be located on the side of the protrusion 2132 facing away from the electrode assembly 22 in the first direction X, such that the abutting portion 233 and the body portion 231 are structures located on the two sides of the protrusion 2132 in the first direction X, and the abutting portion 233 and the side of the protrusion 2132 facing away from the electrode assembly 22 are connected to each other, the cylindrical battery cell 20 adopting this structure can on the one hand realize that the first current collecting member 23 and the protrusion 2132 can share part of the space in the first direction X, which is beneficial to improve the internal space utilization rate of the cylindrical battery cell 20, so as to improve the energy density of the cylindrical battery cell 20, and on the other hand, the assembly connection between the abutting portion 233 and the protrusion 2132 is not affected by the interference of the electrode assembly 22, which is beneficial to reduce the assembly difficulty of the abutting portion 233 and the protrusion 2132, and can be beneficial to optimize the production process of the cylindrical battery cell 20.

[0369] According to some embodiments of the present application, as shown in Figure 4 , Figure 5 and Figure 6 , a groove 2133 is formed on the side of the side wall 213 facing away from the electrode assembly 22 and corresponding to the position of the protrusion 2132 in the radial direction of the cylindrical battery cell 20.

[0370] Exemplarily, the protrusion 2132 formed on the side of the side wall 213 facing the electrode assembly 22 is a structure formed by a stamping process, so as to form the protrusion 2132 on the surface of the side of the side wall 213 facing the electrode assembly 22, and form the groove 2133 on the surface of the side of the side wall 213 facing away from the electrode assembly 22 and corresponding to the position of the protrusion 2132. Of course, the forming method of the protrusion 2132 formed on the side of the side wall 213 facing the electrode assembly 22 is not limited to this, and in other embodiments, the protrusion 2132 formed on the side of the side wall 213 facing the electrode assembly 22 can also be formed by casting or milling and other machining processes.

[0371] It should be noted that, in the embodiment in which the protrusion 2132 is an annular structure extending along the circumference of the side wall 213, correspondingly, the groove 2133 is also an annular groove structure extending along the circumference of the side wall 213.

[0372] In the present embodiment, by forming the groove 2133 on the side of the side wall 213 away from the electrode assembly 22 and corresponding to the position of the protrusion 2132, the protrusion 2132 formed on the side of the side wall 213 facing the electrode assembly 22 is a structure that can be formed by stamping processing, so as to form the protrusion 2132 on the side of the side wall 213 facing the electrode assembly 22 and form the groove 2133 on the other side and corresponding to the position of the protrusion 2132. The cylindrical battery monomer 20 adopting such a structure can on the one hand reduce the difficulty of forming the protrusion 2132 on the side of the side wall 213 facing the electrode assembly 22, and on the other hand can realize that the inside of the protrusion 2132 is a hollow structure, so that the protrusion 2132 can have the ability of elastic deformation, which is conducive to relieving the rigid pulling between the butt joint part 233 and the protrusion 2132, so as to reduce the risk of connection failure between the butt joint part 233 and the protrusion 2132.

[0373] According to some embodiments of the present application, as shown in Figure 4 , Figure 5 and Figure 6 , the shell 21 can further include a second wall 212, which is arranged opposite to the first wall 211 in the first direction X, and the second wall 212 is integrally formed with the side wall 213. In the first direction X, one end of the side wall 213 is connected to the second wall 212, and the other end encloses the opening 2131. The side wall 213 and the second wall 212 jointly define a containing cavity 214, and the electrode assembly 22 is contained in the containing cavity 214. The first wall 211 closes the opening 2131.

[0374] Among them, the second wall 212 is arranged opposite to the first wall 211 in the first direction X, that is, the first wall 211 and the second wall 212 are respectively the end walls of the two ends of the shell 21 in the first direction X, so that the first wall 211 and the second wall 212 are respectively located at the two ends of the side wall 213 in the first direction X.

[0375] The second wall 212 is integrally formed with the side wall 213, that is, the side wall 213 and the second wall 212 of the shell 21 are structures formed by integral molding process, such as stamping or casting, etc.

[0376] The first wall 211 closes the opening 2131, that is, the first wall 211 is arranged at the opening 2131 of the end of the side wall 213 away from the second wall 212 in the first direction X and is sealingly connected with the side wall 213. Optionally, the connection structure of the first wall 211 and the side wall 213 can be various, such as welding connection, clamping, etc.

[0377] In this embodiment, by setting the sidewall 213 of the outer casing 21 to form an opening 2131 at the end away from the second wall 212 in the first direction X, and the first wall 211 to close the opening 2131, the first current collector 23 is positioned on the side of the electrode assembly 22 facing the opening 2131 in the first direction X. This reduces the difficulty of assembling the body 231 of the first current collector 23 to the electrode assembly 22 and the protrusion 2132, and also reduces the difficulty of connecting the mating part 233 and the protrusion 2132. This reduces the assembly difficulty of the cylindrical battery cell 20 and optimizes the manufacturing process of the cylindrical battery cell 20, which is beneficial to improving the production efficiency of the cylindrical battery cell 20.

[0378] In some embodiments, see Figure 6 and Figure 9 As shown, the sidewall 213 is bent at the end away from the second wall 212 in the first direction X to form a flange 2134, which encloses the opening 2131. Along the first direction X, a portion of the first wall 211 is located between the flange 2134 and the protrusion 2132, which are configured to cooperate in clamping the first wall 211.

[0379] The flange 2134 is a flange structure formed by bending one end of the side wall 213 away from the second wall 212 in the first direction X toward the side close to the receiving cavity 214. The flange 2134 surrounds and forms an opening 2131, that is, the flange 2134 is an annular structure, so that the opening 2131 is formed on the inner circumference of the flange 2134.

[0380] In this embodiment, the outer edge of the first wall 211 extends between the flange 2134 and the protrusion 2132, so that the flange 2134 and the protrusion 2132 can cooperate to clamp and assemble a portion of the first wall 211, thereby realizing the assembly connection between the first wall 211 and the side wall 213.

[0381] In this embodiment, a flange 2134 is formed by bending the end of the side wall 213 away from the second wall 212 along the first direction X, and a portion of the first wall 211 is positioned between the protrusion 2132 and the flange 2134 in the first direction X. This allows the protrusion 2132 and the flange 2134 to also serve to assemble and fix the first wall 211, thereby achieving the assembly between the first wall 211 and the side wall 213. The cylindrical battery cell 20 with this structure can reduce the assembly difficulty between the first wall 211 and the side wall 213, thereby improving the production efficiency of the cylindrical battery cell 20.

[0382] According to some embodiments of this application, see Figure 4 , Figure 6 andFigure 9 As shown, the cylindrical battery cell 20 can further include a sealing member 29 disposed at least partially between the side wall 213 and the first wall 211 in the radial direction of the cylindrical battery cell 20, and the sealing member 29 is configured to seal the gap between the first wall 211 and the side wall 213.

[0383] In this way, at least part of the sealing member 29 is disposed between the side wall 213 and the first wall 211 in the radial direction of the cylindrical battery cell 20, i.e., at least part of the sealing member 29 is located between the outer circumferential surface of the first wall 211 and the inner circumferential surface of the side wall 213, so that the sealing member 29 can seal the gap between the outer circumferential surface of the first wall 211 and the inner circumferential surface of the side wall 213.

[0384] Optionally, the sealing member 29 is made of insulating material, so that the sealing member 29 can also serve to insulate and separate the first wall 211 and the side wall 213. For example, the material of the sealing member 29 can be rubber, silicone or plastic, etc.

[0385] In this embodiment, the cylindrical battery cell 20 is further provided with a sealing member 29, by disposing at least part of the sealing member 29 between the side wall 213 and the first wall 211 in the radial direction of the cylindrical battery cell 20, so that the sealing member 29 can seal the gap between the first wall 211 and the side wall 213, to reduce the risk of leakage of the cylindrical battery cell 20 during use, and to improve the use stability and reliability of the cylindrical battery cell 20.

[0386] In some embodiments, as shown in Figure 6 and Figure 9 As shown, along the first direction X, part of the sealing member 29 is disposed between the first wall 211 and the protrusion 2132. That is, part of the sealing member 29 is located between the outer circumferential surface of the first wall 211 and the inner circumferential surface of the side wall 213, and part of the sealing member 29 extends between the first wall 211 and the protrusion 2132, so that part of the sealing member 29 is located between the first wall 211 and the protrusion 2132 in the first direction X, so that the sealing member 29 can also separate the first wall 211 and the protrusion 2132.

[0387] It should be noted that in the embodiment in which the butt joint portion 233 of the first current collecting member 23 is located on the side of the protrusion 2132 facing the first wall 211 and connected with the protrusion 2132, as shown in Figure 6 , part of the sealing member 29 is located between the butt joint portion 233 and the first wall 211, so that the sealing member 29 can also separate the butt joint portion 233 and the first wall 211.

[0388] In the embodiment, the part of the sealing member 29 is arranged to extend between the first wall 211 and the protrusion 2132, so that the sealing member 29 can also seal the gap between the first wall 211 and the protrusion 2132, which is beneficial to further improve the sealing effect of the sealing member 29 on the gap between the first wall 211 and the side wall 213, and the protrusion 2132 and the first wall 211 can also clamp the sealing member 29 to some extent, which is beneficial to improve the assembly stability of the sealing member 29.

[0389] In some embodiments, please continue to refer to Figure 6 and Figure 9 , along the first direction X, the part of the sealing member 29 is arranged between the first wall 211 and the flange portion 2134. That is, the part of the sealing member 29 is located between the outer circumferential surface of the first wall 211 and the inner circumferential surface of the side wall 213, and the part of the sealing member 29 extends between the first wall 211 and the flange portion 2134, so that the part of the sealing member 29 is located between the first wall 211 and the flange portion 2134 in the first direction X, so that the sealing member 29 can also separate the first wall 211 and the flange portion 2134.

[0390] Optionally, in Figure 6 , the sealing member 29 is an annular structure arranged around the first wall 211, and the sealing member 29 can include a first part, a second part and a third part arranged along the first direction X and connected in sequence, the first part is located between the protrusion 2132 and the first wall 211 in the first direction X, the second part is located between the outer circumferential surface of the first wall 211 and the inner circumferential surface of the side wall 213, and the third part is located between the flange portion 2134 and the first wall 211 in the first direction X.

[0391] In the embodiment, the part of the sealing member 29 is arranged to extend between the first wall 211 and the flange portion 2134, so that the sealing member 29 can also seal the gap between the first wall 211 and the flange portion 2134, which is beneficial to further improve the sealing effect of the sealing member 29 on the gap between the first wall 211 and the side wall 213, and the protrusion 2132 and the first wall 211 can also clamp the sealing member 29 to some extent, which is beneficial to improve the assembly stability of the sealing member 29.

[0392] Of course, the structure of the cylindrical battery cell 20 is not limited to this, and in some embodiments, the cylindrical battery cell 20 can also be of other structures. For example, the shell 21 can further include a second wall 212 opposite the first wall 211 in the first direction X, and the side wall 213 can be integrally formed with the first wall 211, with one end of the side wall 213 connected to the first wall 211 and the other end enclosing an opening 2131 in the first direction X. The side wall 213 and the first wall 211 jointly define a receiving cavity 214 in which the electrode assembly 22 is received, and the second wall 212 closes the opening 2131.

[0393] In this embodiment, the side wall 213 is integrally formed with the first wall 211, i.e., the side wall 213 and the first wall 211 of the shell 21 are formed by an integral forming process, such as stamping or casting.

[0394] One end of the side wall 213 is connected to the first wall 211, and the other end encloses the opening 2131, and the second wall 212 closes the opening 2131. That is, the opening 2131 of the side wall 213 is formed at the end of the side wall 213 away from the first wall 211 in the first direction X.

[0395] Optionally, the connection structure between the second wall 212 and the side wall 213 can be various, such as welding connection, clamping, etc.

[0396] In this embodiment, by arranging the first wall 211 and the side wall 213 as an integrally formed structure, and arranging the side wall 213 to enclose the opening 2131 for assembling the electrode assembly 22 at the end of the side wall 213 away from the first wall 211 in the first direction X, and arranging the second wall 212 to close the opening 2131, the cylindrical battery cell 20 with this structure can first form the protrusion 2132 on the inner circumferential surface of the side wall 213 and then assemble the electrode assembly 22 into the receiving cavity 214 formed by the side wall 213 and the first wall 211, which is beneficial to reduce the damage to the electrode assembly 22 caused by the protrusion 2132 during the forming process, thereby improving the production quality of the cylindrical battery cell 20.

[0397] According to some embodiments of the present application, as shown in Figure 6 and Figure 9 The protrusion 2132 is an annular structure extending in the circumferential direction of the side wall 213, i.e., the protrusion 2132 is a circular ring structure extending in the circumferential direction of the side wall 213 and connected end to end.

[0398] In the embodiment, by arranging the protrusions 2132 in a ring structure connected end to end, on the one hand, the support effect of the protrusions 2132 on the electrode assembly 22 through the first current collecting member 23 is improved, and on the other hand, the protrusions 2132 can be connected to the docking portion 233 at any position in the circumferential direction, which is beneficial to reduce the positioning difficulty and assembly difficulty between the docking portion 233 and the protrusions 2132.

[0399] According to some embodiments of the present application, please continue to refer to Figure 6 and Figure 9 As shown, the pressure relief groove 2111 is an annular structure extending in the circumferential direction of the side wall 213, that is, the pressure relief groove 2111 is a circular ring structure extending in the circumferential direction of the side wall 213 and connected end to end.

[0400] In the embodiment, by arranging the pressure relief groove 2111 in a ring structure connected end to end, the cylindrical battery cell 20 can blow open the entire area of the pressure relief component located in the pressure relief groove 2111 when pressure relief, which is beneficial to improve the pressure relief area of the cylindrical battery cell 20, so as to improve the pressure relief rate of the cylindrical battery cell 20.

[0401] According to some embodiments of the present application, please refer to Figure 5 and Figure 7 As shown, the electrode assembly 22 is provided with a center through hole 224 which penetrates both ends of the electrode assembly 22 along the first direction X, and the body portion 231 is provided with an exhaust hole 2313 which penetrates both sides of the body portion 231 along the first direction X, and the exhaust hole 2313 is in communication with the center through hole 224. Along the first direction X, the projection of the hole wall surface of the center through hole 224 is located in the exhaust hole 2313.

[0402] Among them, the center through hole 224 is located at the center position of the electrode assembly 22 and penetrates both ends of the electrode assembly 22 along the first direction X, so that the internal gas of the electrode assembly 22 flows and discharges, and in the embodiment that the electrode assembly 22 includes the body portion 221, the first tab 222 and the second tab 223, then the center through hole 224 penetrates the first tab 222, the body portion 221 and the second tab 223 in turn along the first direction X.

[0403] Along the first direction X, the projection of the hole wall surface of the center through hole 224 is located in the exhaust hole 2313, that is, the exhaust hole 2313 provided on the body portion 231 of the first current collecting member 23 is a structure corresponding to the center through hole 224 in the first direction X, and the hole diameter of the exhaust hole 2313 is greater than or equal to the hole diameter of the center through hole 224.

[0404] Exemplarily, in the embodiment that the body part 231 includes the main body area 2311 and the support area 2312, the exhaust hole 2313 is arranged on the main body area 2311, and the exhaust hole 2313 penetrates the surfaces of both sides of the main body area 2311 along the first direction X.

[0405] In the embodiment, by arranging the exhaust hole 2313 penetrating the body part 231 along the first direction X on the body part 231 of the first current collecting member 23, the exhaust hole 2313 and the center through hole 224 of the electrode assembly 22 are connected with each other, and the projection of the hole wall surface of the center through hole 224 in the first direction X is arranged to be located in the exhaust hole 2313, so that the hole diameter of the exhaust hole 2313 is greater than or equal to the hole diameter of the center through hole 224, thereby facilitating the hot runaway gas in the center through hole 224 to enter the side of the body part 231 facing the first wall 211 through the exhaust hole 2313 and then directly pass through the area of the pressure relief part of the first wall 211 provided with the pressure relief groove 2111 for pressure relief when the cylindrical battery monomer 20 occurs thermal runaway, which is beneficial to improve the internal exhaust smoothness of the cylindrical battery monomer 20, and thus can effectively reduce the risk of bursting or explosion of the cylindrical battery monomer 20 due to untimely pressure relief, so as to improve the use stability and reliability of the cylindrical battery monomer 20.

[0406] In some embodiments, referring to Figure 5 As shown, the hole diameter of the center through hole 224 is D7, and the hole diameter of the exhaust hole 2313 is D8, which satisfies D8≥1.5D7.

[0407] Exemplarily, the hole diameter D8 of the exhaust hole 2313 can be 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times or 2.6 times of the hole diameter D7 of the center through hole 224, etc.

[0408] In the embodiment, by further arranging the hole diameter of the exhaust hole 2313 to be greater than or equal to 1.5 times of the hole diameter of the center through hole 224, the smoothness of the hot runaway gas in the center through hole 224 entering the side of the body part 231 facing the first wall 211 through the exhaust hole 2313 can be further improved when the cylindrical battery monomer 20 occurs thermal runaway, which is beneficial to further improve the internal exhaust smoothness of the cylindrical battery monomer 20, and thus can further reduce the risk of bursting or explosion of the cylindrical battery monomer 20 due to untimely pressure relief, so as to further improve the use stability and reliability of the cylindrical battery monomer 20.

[0409] According to some embodiments of the present application, referring to Figure 6 and Figure 9As shown, the pressure relief component is integrally formed with the first wall 211, that is, the pressure relief component and the first wall 211 are in an integrated structure, the pressure relief component is a part of the first wall 211, and correspondingly, the pressure relief groove 2111 is a structure directly arranged on the first wall 211, so that the first wall 211 is configured to be split along at least part of the pressure relief groove 2111 to release the internal pressure of the cylindrical battery cell 20 when the cylindrical battery cell 20 is relieved of pressure.

[0410] In this embodiment, by arranging the pressure relief component in an integrally formed structure with the first wall 211, so that the pressure relief component is a part of the first wall 211, and the pressure relief groove 2111 is a structure directly arranged on the first wall 211, so that there is no need to arrange the process of assembling the pressure relief component and the first wall 211 with each other, which is beneficial to optimizing the processing technology of the cylindrical battery cell 20, so as to improve the production efficiency of the cylindrical battery cell 20.

[0411] It should be noted that the structure of the cylindrical battery cell 20 is not limited to this, and in other embodiments, the cylindrical battery cell 20 can also have other structures, for example, the pressure relief component is arranged separately from the first wall 211, and the pressure relief component is connected to the first wall 211. That is, the pressure relief component and the first wall 211 are two independent components, and the pressure relief component and the first wall 211 are connected to each other, and correspondingly, the pressure relief groove 2111 is arranged on the pressure relief component.

[0412] In this embodiment, by arranging the pressure relief component in a structure separate from the first wall 211, the difficulty of directly machining the pressure relief groove 2111 on the first wall 211 can be reduced, and the influence on the structural strength of the first wall 211 can be reduced.

[0413] According to some embodiments of the present application, the present application also provides a battery device 100, which comprises the cylindrical battery cell 20 of any one of the above schemes.

[0414] Among them, referring to Figure 2 As shown, the battery device 100 can also include a box body 10, and the cylindrical battery cell 20 is contained in the box body 10.

[0415] In some embodiments, the box body 10 can include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 are overlapped with each other, and the first box body 11 and the second box body 12 together define an assembly space for containing the cylindrical battery cell 20.

[0416] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate structure, which is covered on the open side of the second box body 12 to jointly define the assembly space with the second box body 12; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 is covered on the open side of the second box body 12.

[0417] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can have various shapes, such as a cylinder or a cuboid, and the like. Exemplarily, in the embodiment shown in Figure 2 , the box body 10 is a cuboid structure.

[0418] Optionally, the cylindrical battery cell 20 arranged in the box body 10 can be one or multiple. Exemplarily, in the embodiment shown in Figure 2 , multiple cylindrical battery cells 20 are arranged in the box body 10 of the battery device 100, and the multiple cylindrical battery cells 20 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple cylindrical battery cells 20 are connected in series and in parallel. The multiple cylindrical battery cells 20 can be directly connected in series, in parallel, or in a mixed manner, and then the whole is accommodated in the box body 10; of course, the battery device 100 can also be that the multiple cylindrical battery cells 20 are connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box body 10.

[0419] The battery device 100 can further include other structures, for example, the battery device 100 can further include a current collecting component, which is connected to the multiple cylindrical battery cells 20 to realize electrical connection between the multiple cylindrical battery cells 20.

[0420] It should be noted that in some embodiments, the battery device 100 can also not be provided with the box body 10, and the battery device 100 includes the multiple cylindrical battery cells 20, and the battery device 100 composed of the multiple cylindrical battery cells 20 can be directly assembled to the electric device to provide electric energy for the electric device by the multiple cylindrical battery cells 20. That is, the box body 10 can be part of the electric device. Taking the vehicle 1000 as an example, the box body 10 can be part of the chassis structure of the vehicle 1000, for example, part of the box body 10 can be at least part of the floor of the vehicle 1000, or part of the box body 10 can be at least part of the cross beam and the longitudinal beam of the vehicle 1000.

[0421] According to some embodiments of the present application, the present application also provides an electric device, which includes the cylindrical battery cell 20 of any of the above schemes, and the cylindrical battery cell 20 is used to provide electric energy for the electric device.

[0422] The electric device can be a device or system of any of the aforementioned cylindrical battery cells 20.

[0423] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict.

[0424] The above only is the preferred embodiment of the present application, and is not used to limit the present application, and for the person skilled in the art, the present application can have various changes and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cylindrical battery cell, an axial direction of which is a first direction, characterized by, The cylindrical battery cell comprises: a housing having a first wall, the first wall being provided with a pressure relief component, the pressure relief component being provided with a pressure relief groove; an electrode assembly accommodated in the housing; and a first current collecting member comprising a body portion, a support portion and an abutting portion, along the first direction, the body portion is located on a side of the electrode assembly facing the first wall and connected with the electrode assembly, the abutting portion is located on a side of the body portion facing the first wall and connected with the housing, the support portion connects the body portion and the abutting portion, and the support portion is configured to be capable of deforming; wherein, in a projection plane perpendicular to the first direction, the orthographic projection of the abutting portion extends along the circumference of the housing and is located on the outer circumferential side of the orthographic projection of the body portion, and the orthographic projection of the abutting portion and the orthographic projection of the body portion are arranged in the radial direction of the cylindrical battery cell, so as to form an exhaust gap between the orthographic projection of the abutting portion and the orthographic projection of the body portion.

2. The cylindrical battery cell according to claim 1, characterized in that, Along the first direction, at least part of the projection of the pressure relief groove is located in the exhaust gap.

3. The cylindrical battery cell of claim 1, wherein, In the projection plane perpendicular to the first direction, the diameter of the orthographic projection of the outer edge of the abutting portion is D1, the orthographic projection of the support portion extends along the radial direction of the cylindrical battery cell and the length is L1, and 1 / 15≤L1 / D1≤1 / 3 is satisfied.

4. The cylindrical battery cell of claim 3, wherein, 1 / 7≤L1 / D1≤1 / 4.

5. The cylindrical battery cell of claim 3, wherein, 3mm≤L1≤15mm.

6. The cylindrical battery cell of claim 1, wherein, The thickness of the support portion is T1, and the width of the orthogonal projection of the support portion in a direction perpendicular to the extending direction thereof in a projection plane perpendicular to the first direction is W, satisfying, 0.3mm 2 ≤W×T1≤8mm 2 .

7. The cylindrical battery cell of claim 6, wherein, 2mm≤W≤10mm.

8. The cylindrical battery cell of claim 7, wherein, 3mm≤W≤5mm.

9. The cylindrical battery cell of claim 6, wherein, 0.15mm≤T1≤0.8mm.

10. The cylindrical battery cell according to claim 9, characterized in that 0.3mm≤T1≤0.5mm.

11. The cylindrical battery cell of claim 1, wherein, The thickness of the support portion is less than the thickness of the body portion; and / or The thickness of the support portion is less than the thickness of the abutting portion.

12. The cylindrical battery cell of claim 1, wherein, The thickness of the body portion is T2, and 0.1mm≤T2≤0.6mm is satisfied.

13. The cylindrical battery cell of claim 1, wherein, The support portion is bent to form a plurality of bending segments, the plurality of bending segments are connected in sequence, and the bending segments at both ends of the plurality of bending segments are connected with the body portion and the abutting portion respectively.

14. The cylindrical battery cell according to any one of claims 1 to 13, characterized in that, The housing further comprises a side wall, the side wall is arranged around the first wall, and one end of the side wall in the first direction is connected with the first wall, and a protrusion is arranged on the inner circumferential surface of the side wall; wherein, along the first direction, the body portion is arranged between the protrusion and the electrode assembly, and the abutting portion is connected with the protrusion.

15. The cylindrical battery cell of claim 14, wherein, The body portion comprises a main body region and a plurality of support regions connected to the outer circumferential surface of the main body region, the plurality of support regions are arranged at intervals along the circumference of the main body region, at least part of the support regions is located between the electrode assembly and the protrusion in the first direction, and the support portion is connected with the main body region.

16. The cylindrical battery cell of claim 15, wherein, The protrusion and the pressure relief groove both extend along the circumference of the side wall; wherein, along the radial direction of the cylindrical battery cell, the inner diameter of the protrusion is D2, the outer diameter of the main body region is D3, and the inner diameter of the pressure relief groove is D4, and D2≥D3 and D4≥0.75D3 are satisfied.

17. The cylindrical battery cell of claim 16, wherein, D2≥D4.

18. The cylindrical battery cell of claim 16, wherein, Along the radial direction of the cylindrical battery cell, the outer diameter of the body portion is D5, and D2≤0.95D5 is satisfied.

19. The cylindrical battery cell of claim 15, wherein, A maximum proportion of the plurality of support regions in a circumferential direction of the main body region is P, and 40%≤P≤90% is satisfied.

20. The cylindrical battery cell of claim 19, wherein, 50%≤P≤80%。 21. The cylindrical battery cell of claim 15, wherein, A dimension of the protrusion protruding from an inner circumferential surface of the side wall in a radial direction of the cylindrical battery cell is L2, a dimension of a portion of a normal projection of the support region overlapping with a normal projection of the protrusion in a projection plane perpendicular to the first direction is L3, and 0.2L2≤L3≤0.9L2 is satisfied.

22. The cylindrical battery cell of claim 21, wherein, 1mm≤L2≤8mm.

23. The cylindrical battery cell of claim 21, wherein, L3≥1mm.

24. The cylindrical battery cell of claim 15, wherein, The electrode assembly includes a main body portion and a first tab, and the first tab is connected to one end of the main body portion facing the first wall in the first direction. The main body region and the first tab are welded to form a plurality of first connection portions, and the plurality of support regions and the first tab are welded to form a plurality of second connection portions, and a sum of lengths of the plurality of second connection portions is greater than or equal to a sum of lengths of the plurality of first connection portions.

25. The cylindrical battery cell of claim 24, wherein, The plurality of first connection portions are arranged at intervals in a circumferential direction of the side wall, and the first connection portions extend in a radial direction of the cylindrical battery cell.

26. The cylindrical battery cell of claim 24, wherein, The plurality of second connection portions are arranged at intervals in a circumferential direction of the side wall, and the second connection portions extend in a radial direction of the cylindrical battery cell.

27. The cylindrical battery cell of claim 24, wherein, Each of the support regions is welded to the first tab to form the second connection portion.

28. The cylindrical battery cell of claim 15, wherein, In the radial direction of the cylindrical battery cell, an outer diameter of the main body region is D3, and a length of the support region is L4, and 0.5D3≥L4 is satisfied.

29. The cylindrical battery cell of claim 14, wherein, The protrusion extends in a circumferential direction of the side wall, the first current collecting member includes a plurality of support portions and a plurality of butt joint portions, the plurality of butt joint portions are arranged at intervals in the circumferential direction of the side wall, each of the butt joint portions is connected to the main body portion through one of the support portions, and the plurality of butt joint portions are connected to the protrusion.

30. The cylindrical battery cell of claim 29, wherein, The plurality of butt joint portions are welded to the protrusion to form a plurality of third connection portions, the third connection portions correspond to the butt joint portions one by one, and the third connection portions extend in the circumferential direction of the side wall. In a projection plane perpendicular to the first direction, outer edges of normal projections of the plurality of third connection portions are located on a first circle, and a sum of arc lengths of the outer edges of the normal projections of the plurality of third connection portions is L5, a circumference of the first circle is L6, and L5≥0.5L6 is satisfied.

31. The cylindrical battery cell of claim 30, wherein, L5≥0.8L6.

32. The cylindrical battery cell of claim 30, wherein, The butt joint portion is an arc-shaped structure extending in the circumferential direction of the side wall.

33. The cylindrical battery cell of claim 14, wherein, An inner portion of the shell forms an accommodation cavity, the main body portion is configured to divide the accommodation cavity into a first cavity and a second cavity that are in communication with each other, the electrode assembly is accommodated in the first cavity, the second cavity is located between the main body portion and the first wall in the first direction, and the pressure relief component is configured to be split along at least part of the pressure relief groove to release an internal pressure of the second cavity when the cylindrical battery cell is relieved of pressure. In the first direction, a maximum dimension of the second cavity is H1, a maximum dimension of the shell is H2, and 0.003≤H1 / H2≤0.06 is satisfied.

34. The cylindrical battery cell of claim 33, wherein, 0.01≤H1 / H2≤0.

03.

35. The cylindrical battery cell of claim 33, wherein, 0.4mm≤H1≤4mm.

36. The cylindrical battery cell of claim 33, wherein, The cylindrical battery cell has an electric capacity C, and satisfies 0.005mm / Ah≤H1 / C≤0.2mm / Ah.

37. The cylindrical battery cell of claim 36, wherein, The positive electrode material of the cylindrical battery cell comprises lithium transition metal oxide, and the H1 and C further satisfy 0.01mm / Ah≤H1 / C≤0.2mm / Ah; or The positive electrode material of the cylindrical battery cell comprises lithium-containing phosphate, and the H1 and C further satisfy 0.005mm / Ah≤H1 / C≤0.1mm / Ah.

38. The cylindrical battery cell of claim 33, wherein, Along the radial direction of the cylindrical battery cell, the inner diameter of the protrusion is D2, and the outer diameter of the electrode assembly is D6, and satisfy 0.7≤D2 / D6≤0.

95.

39. The cylindrical battery cell of claim 38, wherein, 0.75≤D2 / D6≤0.

9.

40. The cylindrical battery cell of claim 33, wherein, The projection of the pressure relief groove in the first direction is located in the second cavity.

41. The cylindrical battery cell of claim 14, wherein, The butt joint portion is arranged on the side of the protrusion away from the electrode assembly and connected with the protrusion in the first direction.

42. The cylindrical battery cell of claim 14, wherein, Along the radial direction of the cylindrical battery cell, a groove is formed on the side of the side wall away from the electrode assembly and corresponding to the protrusion.

43. The cylindrical battery cell of claim 14, wherein, The shell further comprises a second wall arranged opposite to the first wall in the first direction, the second wall is integrally formed with the side wall, one end of the side wall is connected to the second wall in the first direction, and the other end of the side wall encloses an opening, and the side wall and the second wall jointly define a containing cavity in which the electrode assembly is contained. The first wall encloses the opening.

44. The cylindrical battery cell of claim 43, wherein, The side wall is bent to form a flange portion at the end away from the second wall in the first direction, and the flange portion encloses the opening. Part of the first wall is located between the flange portion and the protrusion in the first direction, and the flange portion and the protrusion are configured to cooperate to clamp the first wall.

45. The cylindrical battery cell of claim 44, wherein, The cylindrical battery cell further comprises: A sealing member arranged at least partially between the side wall and the first wall in the radial direction of the cylindrical battery cell, and configured to seal the gap between the first wall and the side wall.

46. The cylindrical battery cell of claim 14, wherein, The shell further comprises a second wall arranged opposite to the first wall in the first direction; The side wall is integrally formed with the first wall, one end of the side wall is connected to the first wall in the first direction, and the other end of the side wall encloses an opening, and the side wall and the first wall jointly define a containing cavity in which the electrode assembly is contained, and the second wall encloses the opening.

47. The cylindrical battery cell of claim 14, wherein, The protrusion is an annular structure extending along the circumferential direction of the side wall.

48. The cylindrical battery cell of claim 1, wherein, The pressure relief groove is an annular structure extending along the circumferential direction of the shell.

49. The cylindrical battery cell of claim 1, wherein, The electrode assembly is provided with a central through hole penetrating through both ends of the electrode assembly in the first direction, and the body portion is provided with an exhaust hole penetrating through both sides of the body portion in the first direction, and the exhaust hole is in communication with the central through hole. The projection of the hole wall surface of the central through hole in the first direction is located in the exhaust hole.

50. The cylindrical battery cell of claim 49, wherein, A pore size of the center through hole is D7, and a pore size of the exhaust hole is D8, satisfying D8≥1.5D7.

51. The cylindrical battery cell of claim 1, wherein, The pressure relief component is integrally formed with the first wall.

52. The cylindrical battery cell of claim 1, wherein, The pressure relief component is separately provided from the first wall and connected to the first wall.

53. A battery device, comprising: A cylindrical battery cell as claimed in any one of claims 1 to 52.

54. An electrical device, comprising: A cylindrical battery cell as claimed in any one of claims 1 to 52 for providing electrical energy.

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