Current collector, electrode assembly and battery pack

Abstract

Provided in the present application are a current collector, an electrode assembly and a battery pack. A terminal section of the current collector is configured to be electrically connected to terminals; a tab section of the current collector is provided on one side of the terminal section and is configured to be electrically connected to tabs; a first bent section of the current collector is bent and connected between the terminal section and the tab section; and the projections of two ends of the first bent section on a plane where the terminal section is located at least partially overlap. When subjected to an axial impact, the first bent section deforms elastically, such that kinetic energy from the impact on the current collector is converted into elastic potential energy, and then the elastic potential energy is converted into the kinetic energy, thereby preventing the current collector from fracturing.

Description

Current collector, electrode assembly and battery pack

[0001] This application claims priority to Chinese Patent Application No. 202422558451.9 and 202422558425.6, filed on October 22, 2024, with the Chinese Patent Office, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a current collector, an electrode assembly and a battery pack. BACKGROUND

[0003] A battery is a device that converts chemical energy into electrical energy, usually including a core package, a pole and a current collector. The tab of the core package is electrically connected to the pole through the current collector, so that the battery can supply power to external electrical equipment through the pole. SUMMARY

[0004] In related technologies, the strength of the current collector is low, so it is easy to break during use, causing the battery to malfunction.

[0005] In a first aspect, the embodiments of the present application provide a current collector, comprising:

[0006] a pole segment, the pole segment being configured to be electrically connected to a pole;

[0007] a tab segment, disposed on one side of the pole segment, the tab segment being configured to be electrically connected to a tab;

[0008] a first bending segment, the first bending segment being bent and connected between the pole segment and the tab segment, and projections of both ends of the first bending segment on a plane in which the pole segment is located at least partially coincide.

[0009] In a second aspect, the present application provides an electrode assembly, comprising:

[0010] a core package, comprising a tab and a pole;

[0011] a top cover, connected to the pole;

[0012] a current collector as described above, the current collector being mounted on the top cover, the pole segment being electrically connected to the pole, and the tab segment being electrically connected to the tab.

[0013] In a third aspect, the embodiments of the present application provide a battery pack, comprising:

[0014] a shell, provided with a mounting cavity;

[0015] an electrode assembly as described above, the core package and the current collector being disposed in the mounting cavity, and the top cover being provided on the shell to close the mounting cavity. Beneficial effects

[0016] The current collector provided in this application includes a terminal section, a tab section, and a first bending section. The terminal section is electrically connected to a terminal, and the tab section is disposed on one side of the terminal section and electrically connected to the tab. The first bending section bends and connects the terminal section and the tab section, and the two ends of the first bending section at least partially overlap in the projection of the two ends onto the plane of the terminal section. When subjected to axial impact, the end of the first bending section connected to the tab section undergoes elastic deformation to the other end, converting the kinetic energy of the impact on the current collector into elastic potential energy. During the energy conversion process, the first bending section can absorb and release this energy, causing the vibration of the current collector to gradually decay, thus avoiding the problem of current collector breakage during battery use or vibration testing. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the current collector provided in an embodiment of this application;

[0018] Figure 2 is a schematic diagram of the current collector provided in an embodiment of this application;

[0019] Figure 3 is a planar schematic diagram of the current collector shown in Figure 1 without bending.

[0020] Figure 4 is a schematic diagram of the current collector shown in Figure 1 after it has been folded up;

[0021] Figure 5 is a second schematic diagram of the current collector shown in Figure 1 after it has been folded up;

[0022] Figure 6 is a schematic diagram of the current collector provided in an embodiment of this application;

[0023] Figure 7 is a second planar schematic diagram of the current collector shown in Figure 1 without bending;

[0024] Figure 8 is a schematic diagram of the first bend of the folded section of the current collector shown in Figure 7;

[0025] Figure 9 is a schematic diagram of the second bend of the folded section of the current collector shown in Figure 7;

[0026] Figure 10 is a schematic diagram of the third bend of the folded section of the current collector shown in Figure 7;

[0027] Figure 11 is a schematic diagram of the first bend of the clearance section of the current collector shown in Figure 7;

[0028] Figure 12 is a schematic diagram of the second bend of the clearance section of the current collector shown in Figure 7;

[0029] Figure 13 is a top view of the current collector shown in Figure 1;

[0030] Figure 14 is a cross-sectional view of the current collector shown in Figure 13 along AA.

[0031] Fig. 15 is an enlarged schematic view of a partial A of the current collector shown in Fig. 14;

[0032] Fig. 16 is a schematic view of a cross-section along A-A of the current collector shown in Fig. 13, II;

[0033] Fig. 17 is an enlarged schematic view of a partial B of the current collector shown in Fig. 16;

[0034] Fig. 18 is a schematic view of a cross-section along A-A of the current collector shown in Fig.13, III;

[0035] Fig. 19 is an enlarged schematic view of a partial C of the current collector shown in Fig. 18;

[0036] Fig. 20 is a schematic view of a cross-section along A-A of the current collector shown in Fig.12, IV;

[0037] Fig. 21 is an enlarged schematic view of a partial D of the current collector shown in Fig. 20;

[0038] Fig. 22 is a schematic view of a structure of an electrode assembly according to an embodiment of the present application;

[0039] Fig. 23 is a side view of an electrode assembly according to an embodiment of the present application.

[0040] Explanation of reference numerals:

[0041] 100: current collector

[0042] 10: pole post segment; 11: through hole; 110: first connecting segment; 112: first side edge; 113: second side edge; 114: first end; 115: second end; 116: bevel edge; 120: second connecting segment; 121: third side edge; 122: fourth side edge; 1110: first ring groove; 1120: second ring groove

[0043] 20: tab segment; 21: welding portion; 211: end portion; 2111: first circular arc portion; 2112: second circular arc portion; 22: clearance portion; 220: clearance space; 221: first connecting sub-segment; 222: second connecting sub-segment

[0044] 31: first bent segment; 32: second bent segment; 33: first extended segment; 331: first folded edge; 332: second folded edge; 34: second extended segment; 341: third folded edge; 342: fourth folded edge; 35: notch

[0045] 200: electrode assembly; 2001: top cover; 202: pole post; 203: tab; 204: core wrap Embodiments of the present application

[0046] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between 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.

[0047] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, and the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, and the horizontal height of the first feature is less than that of the second feature.

[0048] In the description of the present embodiment, the terms "up", "down", "left", "right", "front", "back" and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, which is for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are arranged to distinguish the description, and have no special meaning.

[0049] Please refer to FIG. 1, which is a structural schematic diagram of the current collector provided by the embodiment of the present application. The present application provides a current collector 100, which should be arranged as an electrode assembly 200, the current collector 100 includes a pole segment 10 and a tab segment 20, the pole segment 10 is arranged to be electrically connected with a pole 202. The tab segment 20 is arranged on one side of the pole segment 10, and the tab segment 20 is arranged to be electrically connected with a tab 203. A first bending segment 31 is bent and connected between the pole segment 10 and the tab segment 20, and the projections of the two ends of the first bending segment 31 on the plane of the pole segment 10 at least partially coincide. Among them, the first bending segment 31 after bending is located below the pole segment 10 along the direction of gravity, and the two ends of the first bending segment 31 can be the end close to the pole segment 10 along the direction of gravity and the end away from the pole segment 10 along the direction of gravity.

[0050] In existing technologies, the tab section of the current collector 100 is mostly a straight structure, with only a rounded transition to the terminal section. When subjected to a large axial impact force, since the impact force is entirely distributed at the rounded transition point, the deformation cannot be recovered when the force exceeds the bearing capacity, easily leading to breakage. In this application, the two ends of the first bending section 31 at least partially overlap the projections on the plane of the terminal section 10, with a larger bending arc, and a gap for displacement is formed between the two ends of the first bending section 31, forming an overall C-shaped structure. When subjected to an axial impact, the end of the first bending section 31 connected to the tab section 20 undergoes elastic deformation to the other end, converting the kinetic energy of the impact on the current collector 100 into elastic potential energy. The first bending section 31 can absorb this energy, causing the vibration of the current collector 100 to gradually decay, avoiding the problem of the current collector 100 breaking during battery use or vibration testing.

[0051] Please refer to Figures 2 and 3. Figure 2 is a schematic diagram of the current collector provided in an embodiment of this application. In some embodiments, the current collector 100 further includes a second bent section 32, which is bent and connected between the tab section 20 and the first bent section 31. The projections of the two ends of the second bent section 32 onto the plane where the pole section 10 is located at least partially overlap. It can be understood that since the second bent section 32 is connected to the first bent section 31, when the first bent section 31 undergoes elastic deformation, the second bent section 32 will undergo elastic deformation under the influence of the first bent section 31. The multi-layered bending structure can increase elastic deformation and reduce the impact of forces in the height direction, thereby avoiding deformation or breakage caused by excessive local stress.

[0052] In some embodiments, the current collector 100 further includes a first extension 33, which includes a first folded edge 331 and a second folded edge 332. The first folded edge 331 is connected to the first bent section 31, and the second folded edge 332 is connected to the second bent section 32. The projection of the first extension 33 onto the plane where the pole section 10 is located partially coincides with the pole section 10.

[0053] The current collector 100 also includes a second extension section 34, which includes a third fold 341 and a fourth fold 342. The third fold 341 connects to the second bending section 32, and the fourth fold 342 connects to the tab section 20. The projection of the second extension section 34 onto the plane where the pole section 10 is located partially coincides with the pole section 10.

[0054] It can be understood that when the tab section 20 is subjected to an external force perpendicular to the second extension section 34, if the external force is perpendicular to the axis, the second extension section 34 is deformed in bending, and is rotated by a certain angle away from the tab section 20. The displacement of the second extension section 34 perpendicular to the axis is the rotation angle multiplied by the length of the second extension section 34. When the length of the second extension section 34 increases, the elastic deformation of the second extension section 34 increases, and more kinetic energy can be converted into elastic potential energy. Similarly, when the length of the first extension section 33 increases, the elastic deformation of the first extension section 33 increases.

[0055] Specifically, the first bending section 31 can be a first curved surface, and the second bending section 32 can be a second curved surface. One end of the first extension section 33 is connected to the first curved surface, and the other end is connected to the second curved surface. One end of the second extension section 34 is connected to the second curved surface, and the other end is connected to the tab section 20.

[0056] In some embodiments, the first extension section 33 is arranged in parallel with the pole section 10, and the second extension section 34 is arranged in parallel with the pole section 10. Specifically, since the first extension section 33 and the second extension section 34 are located at the top end of the core wrap 204, the parallel structure can increase the structural consistency and avoid the installation difficulty caused by the inclined or misaligned structure.

[0057] Referring to FIGS. 3-5, FIG. 3 is a plan view of the current collector shown in FIG. 1 before being bent; FIG. 4 is a schematic view of the current collector shown in FIG. 1 after being flipped; and FIG. 5 is a schematic view of the current collector shown in FIG. 1 after being bent. Embodiments of the present application provide a current collector 100, which includes a first connecting section 110 and a second connecting section 120.

[0058] Referring to FIG. 3, the first connecting section 110 is a flat strip-shaped structure. The first connecting section 110 is made of a metal material, such as copper and aluminum. The first connecting section 110 is provided with a through hole 11, and the number of the through hole 11 can be one or more. In some embodiments, the shape of the through hole 11 can be circular, rectangular, waist-shaped, hexagonal, or other irregular shapes. The first connecting section 110 has a first side edge 112 and a second side edge 113 arranged oppositely, and the first side edge 112 and the second side edge 113 extend along the length direction of the first connecting section 110. The first side edge 112 has a first end 114, and the second side edge 113 has a second end 115. The first end 114 is closer to the through hole 11 than the second end 115. The first connecting section 110 is provided with an arc-shaped chamfer at one end of the first end 114 and the second end 115.

[0059] Referring to FIG. 3 and FIG. 5, the second connecting section 120 is a flat strip structure, and the material of the second connecting section 120 is the same as that of the first connecting section 110. One end of the second connecting section 120 is connected with the end where the first end 114 and the second end 115 of the first connecting section 110 are located. The first connecting section 110 and the second connecting section 120 are integrally formed, such as by stamping, cutting and the like. The second connecting section 120 has a third side edge 121 and a fourth side edge 122 arranged oppositely. The third side edge 121 and the fourth side edge 122 extend along the length direction of the second connecting section 120. The first side edge 112 is located on the same side as the third side edge 121, and the first end 114 of the first side edge 112 is connected with the third side edge 121. The second side edge 113 is located on the same side as the fourth side edge 122, and the second end 115 of the second side edge 113 is connected with the fourth side edge 122. In the width direction of the current collector 100, the first side edge 112 is closer to the second side edge 113 than the third side edge 121, and the fourth side edge 122 is closer to the third side edge 121 than the second side edge 113. It can be understood that the vertical distance between the straight line where the first side edge 112 and the second side edge 113 are located is smaller than the vertical distance between the straight line where the third side edge 121 and the second side edge 113 are located, and the vertical distance between the straight line where the fourth side edge 122 and the third side edge 121 are located is smaller than the vertical distance between the straight line where the second side edge 113 and the third side edge 121 are located.

[0060] In the embodiments of the present application, referring to FIG. 4 and FIG. 5, the first connecting section 110 has a virtual line segment connecting the first end 114 and the second end 115. After the first connecting section 110 is bent 180° along the virtual line segment relative to the second connecting section 120, the second connecting section 120 is bent 90° along the straight line where the second side edge 113 is located to prepare the current collector 100. The first side edge 112 of the first connecting section 110 is arranged in a staggered manner with the third side edge 121 of the second connecting section 120, and the second side edge 113 of the first connecting section 110 is arranged in a staggered manner with the fourth side edge 122 of the second connecting section 120, so as to provide sufficient space for the first connecting section 110 to be flipped. The probability of interference occurring when the first connecting section 110 is flipped relative to the second connecting section 120 is reduced, and the current collector 100 is conveniently bent to prepare the current collector 100. The current collector 100 has good structural strength and is not easy to crack, thereby improving the overcurrent capacity of the battery.

[0061] In some embodiments, referring to FIG. 3, the distance between the straight line where the first side edge 112 and the third side edge 121 are located is D1, and the distance between the straight line where the second side edge 113 and the fourth side edge 122 are located is D2, wherein D1=D2.

[0062] In the embodiments of the present application, the sizes of the avoiding grooves formed on both sides of the first connecting section 110 are the same, which facilitates processing and ensures the forming effect.

[0063] In some embodiments, the thickness of the first connecting section 110 is the same as the thickness of the second connecting section 120. The structural strength of the current collector 100 is made as consistent as possible to ensure the flow effect.

[0064] In some embodiments, referring to FIG. 3, the distance between the straight line where the first side edge 112 and the third side edge 121 are located and the distance between the straight line where the second side edge 113 and the fourth side edge 122 are located is D1, and the thickness of the current collector 100 is D, wherein D1=D2≥D. Because the current collector 100 has a certain thickness, interference is easy to occur at the turning position of the current collector 100, and protrude to both sides, affecting the reliability of the current collector 100. In the embodiments of the present application, D1=D2≥D is set, the avoidance groove formed is large enough to reduce the interference during the preparation of the current collector 100, which is beneficial to the processing of the current collector 100.

[0065] In some embodiments, referring to FIG. 3, the distance between the straight line where first side edge 112 and third side edge 121 are located and the distance between the straight line where second side edge 113 and fourth side edge 122 are located is D1, and the distance between the straight line where second side edge 113 and fourth side edge 122 is D2, 0<D1≤1mm, and / or, 0<D2≤1mm. Wherein, the value of D1 can be 0.1, 0.3, 0.4, 0.5, 0.6, 0.7, 0.9, 1 or other listed values. The value of D2 can be 0.1, 0.3, 0.4, 0,5, 0.6, 0.7, 0.9, 1, or other listed values.

[0066] In some embodiments, referring to FIG. 3, the angle formed between the virtual straight line connecting the first end 114 and the second end 115 and the second side edge 113 is α1, wherein α1=45°.

[0067] It can be understood that when α1=45°, the first connecting section 110 is turned 180° relative to the second connecting section 120, and the first connecting section 110 forms a 90° angle relative to the second connecting section 120, which is beneficial to the processing of the current collector 100.

[0068] In some embodiments, referring to FIG. 3, a bevel 116 is arranged near the first end 114 of the first side edge 112, and the bevel 116 connects the third side edge 121; and / or, a bevel 116 is arranged near the second end 115 of the second side edge 113, and the bevel 116 connects the fourth side edge 122.

[0069] For example, referring to FIG. 3, the first side edge 112 includes a straight edge and a bevel edge 116, the bevel edge 116 of the first side edge 112 is arranged close to the first end 114, and the bevel edge 116 of the first side edge 112 is arranged close to one end of the third side edge 121 as the first end 114. The bevel edge 116 of the first side edge 112 connects the straight edge and the third side edge 121. The second side edge 113 includes a straight edge and a bevel edge 116, the bevel edge 116 of the second side edge 113 is arranged close to the second end 115, the bevel edge 116 of the second side edge 113 is arranged close to one end of the fourth side edge 122 as the second end 115, and the bevel edge 116 of the second side edge 113 connects the straight edge and the fourth side edge 122. At least one side of the first connecting section 110 is provided with a bevel edge 116, which facilitates the bending of the first connecting section 110.

[0070] For example, referring to FIGS. 3, 4 and 5, the first connecting section 110 has a virtual line segment connecting the first end 114 and the second end 115, and after the first connecting section 110 is bent by 180° along the virtual line segment relative to the second connecting section 120, the second connecting section 120 is bent by 90° along the straight line where the second side edge 113 is arranged to prepare the current collector 100.

[0071] In the embodiments of the present application, the first side edge 112 of the first connecting section 110 is arranged in a staggered manner with the third side edge 121 of the second connecting section 120, and the second side edge 113 of the first connecting section 110 is arranged in a staggered manner with the fourth side edge 122 of the second connecting section 120, which provides sufficient space for the first connecting section 110 to be flipped. The current collector 100 has good structural strength and is not easy to crack, thereby improving the overcurrent capacity of the battery.

[0072] The present application also provides another bending mode of the current collector 100, please refer to FIGS. 6-7, FIG. 6 is a structural schematic view III of the current collector according to the embodiments of the present application, and FIG. 7 is a plan view of the current collector shown in FIG. 1 without being bent. In some embodiments, the current collector 100 is originally a plane, that is, the tab section 20 and the pole section 10 are in the same plane, and the strip-shaped current collector 100 is bent and formed through three times of bending. Please refer to FIGS. 8-10, FIG. 8 is a first bending schematic view of the folding section of the current collector shown in FIG. 7, FIG. 9 is a second bending schematic view of the folding section of the current collector shown in FIG. 7, and FIG. 10 is a third bending schematic view of the folding section of the current collector shown in FIG. 7. The first bending is 180° bending, the third bending is 90° bending, the pole section 10 includes a short edge connected to the first bending section 31, the first side edge 112 is connected perpendicularly to the short edge, the bending line of the first bending is perpendicular to the first side edge 112, the bending line of the third bending is perpendicular to the short edge, and the bending line of the second bending can be between 30°-60° with respect to the first side edge 112 of the tab section 20. The tab section 20 is bent again after the three times of bending to form the arc-shaped clearance 22 structure.

[0073] In some embodiments, the second bending section 32 comprises a third bending section 341 connected with the second extending section 34, the first side edge 112 of the pole section 10, the second bending section 332 and the first side edge 112 form an angle between 30° and 60°; the third bending section 341 and the fourth bending section 342 form an angle between 30° and 60°. Specifically, since the fourth bending section 342 of the tab section 20 is parallel to the first side edge 112 of the pole section 10 after the third bending, the second bending section 332 can form an angle a2 between 30° and 60° with the first side edge 112, and the third bending section 341 can form an angle a3 between 30° and 60° with the fourth bending section 342, and the two angles are of the same size. The angle can be 30°, 40°, 45°, 50°, 60°, etc., which are not limited herein.

[0074] In some embodiments, the pole section 10 comprises the first side edge 112, the second bending section 332 and the first side edge 112 form an angle a2 between 30° and 60°; or the third bending section 341 and the fourth bending section 342 form an angle a3 between 30° and 60°.

[0075] Specifically, since the fourth bending section 342 of the tab section 20 can form an offset with the first side edge 112 of the pole section 10 after the third bending, the second bending section 332 can form an angle a2 between 30° and 60° with the first side edge 112, and the third bending section 341 can form an angle a3 between 30° and 60° with the fourth bending section 342. The angle can be 30°, 40°, 45°, 50°, 60°, etc., which are not limited herein.

[0076] Please refer to FIG. 11-12 in combination with FIG. 2, FIG. 11 is a first bending schematic diagram of the clearance section of the current collector shown in FIG. 7, and FIG. 12 is a second bending schematic diagram of the clearance section of the current collector shown in FIG. 7. In some embodiments, the tab section 20 comprises a welding section 21 and a clearance section 22, the clearance section 22 is connected with the second extending section 34, the welding section 21 is connected with one end of the clearance section 22 away from the second extending section 34, and the clearance section 22 forms a clearance space 220 configured to avoid the electrode assembly 200.

[0077] In some embodiments, the avoidance portion 22 includes a first connecting sub-portion 221 parallel to the welding portion 21 and a second connecting sub-portion 222 connected to the welding portion 21, the second connecting sub-portion 222 and the second extending portion 34 are located on the same side of the first connecting sub-portion 221 to form an avoidance space 220. Specifically, the first connecting sub-portion 221 is parallel to the tab portion 20 and located on the side of the pole portion 10 away from the core pack 204, the second connecting sub-portion 222 is connected to the first connecting sub-portion 221 at one end and is obliquely arranged and connected to the tab portion 20 at the other end to match the shape of the tab 203. In some embodiments, the widths of the first bending portion 31 and the second bending portion 32 are smaller than the widths of the pole portion 10 and the tab portion 20. Specifically, as shown in FIG. 7, a notch 35 is arranged at the position of the edge of the current collector 100 corresponding to the first bending portion 31 and the second bending portion 32, and in the process of multiple bending, the sharp corners of the bending can be avoided to pierce the insulation structure of the core pack 204 or the battery, thereby improving the safety of the battery.

[0078] Please continue to refer to FIG. 3, in some embodiments, the tab portion 20 includes an end portion 211 away from the pole portion 10, the end portion 211 includes a first arc portion 2111 and a second arc portion 2112 oppositely arranged along the width direction of the tab portion 20, the first arc portion 2111 is located on the side of the second arc portion 2112 toward the electrode assembly 200, and the arc radius of the first arc portion 2111 is greater than the arc radius of the second arc portion 2112.

[0079] Specifically, the first arc portion 2111 and the second arc portion 2112 are respectively located on the two sides of the end portion 211, the first arc angle of the first arc portion 2111 is R1, and the second arc angle of the second arc portion 2112 is R2, R1 is greater than R2. It can be understood that the first arc angle greater than the second arc angle can avoid the welding portion 21 of the current collector 100 close to the side of the core pack 204 and press the core pack 204, causing the damage of the core pack 204 tab and leading to internal short circuit safety problems.

[0080] In some examples, an avoidance opening can also be arranged at the first arc portion 2111 of the tab portion 20, or an inclined edge can be arranged at the position of the welding portion 21 close to the core pack 204, the avoidance opening or the inclined edge is arranged to avoid the core pack 204.

[0081] Referring to FIGS. 13-15, FIG. 13 is a top view of the current collector shown in FIG. 1, FIG. 14 is a cross-sectional view of the current collector shown in FIG. 13 along A-A, and FIG. 15 is an enlarged view of portion A of the current collector shown in FIG. 14. In some embodiments, the pole post segment 10 is provided with a through hole 11 that penetrates the pole post segment 10 in a first direction, and the through hole 11 is configured to mount and electrically connect the pole post 202. The pole post 202 can be mounted by being inserted into the through hole 11 during assembly. The through hole 11 can be configured to be welded to the pole post 202, such as to form a fusion weld, a friction weld, a laser weld, or an ultrasonic weld, and embodiments of the present application are not limited in this respect.

[0082] Referring to FIGS. 16-17, FIG. 16 is a cross-sectional view of the current collector shown in FIG. 13 along A-A, FIG. 17 is an enlarged view of portion B of the current collector shown in FIG. 16. In some examples, the pole post segment 10 is further provided with a first ring groove 1110, which is disposed at an end of the pole post segment 10 that is distal from the tab segment 20 and surrounds the through hole 11. Specifically, the first ring groove 1110 is configured to accommodate a flange of the pole post 202 so that a top surface of the flange is flush with a top surface of the pole post segment 10, thereby avoiding the flange of the pole post 202 protruding from the pole post segment 10 and maintaining a flat structure surface for subsequent assembly.

[0083] Referring to FIGS. 18-19, FIG. 18 is a cross-sectional view of the current collector shown in FIG. 13 along A-A, which is a third cross-sectional view of the current collector shown in FIG. 13 along A-A, and FIG 19 is an enlarged view of portion C of the current collector shown in FIG. 18. In some examples, the pole post segment 10 is provided with a second ring groove 1120, which is disposed at an end of the pole post segment 10 that is proximal to the tab segment 20 and surrounds the through hole 11. Specifically, when the flange of the pole post 202 is welded to the tab segment 20, a certain protrusion, which is a weld reinforcement, is formed. The weld reinforcement refers to a portion of the weld material that accumulates and solidifies above the surface of the base material during welding. The second ring groove 1120 disposed at the end of the pole post segment 10 that is proximal to the tab segment 20 can accommodate the weld reinforcement, thereby avoiding a reduction in the fatigue life of the weld and reducing the reliability of the overall structure.

[0084] Referring to FIGS. 20-21, FIG. 20 is a cross-sectional view of the current collector shown in FIG. 13 along A-A, that is a fourth cross-sectional view of the current collector shown in FIG. 13 along A-A, and FIG.

[0085] It can be understood that the first ring groove 1110 and the second ring groove 1120 are arranged at the same time, the flange of the pole post 202 is matched with the first ring groove 1110 above, and the second ring groove 1120 provides space for the weld reinforcement when welding the bottom, which can increase the assembly effect of the pole post 202 and the pole post segment 10.

[0086] Please refer to FIG. 22-23, FIG. 22 is a structural schematic diagram of the electrode assembly provided by the embodiment of the present application, and FIG. 23 is a side view of the electrode assembly provided by the embodiment of the present application. The present application also provides an electrode assembly 200, which comprises a core package 204, a top cover 2001 and a current collector 100, the core package 204 comprises a pole post 202 and a tab 203. The current collector 100 is installed on the top cover 2001, the pole post segment 10 is clamped between the core package 204 and the top cover 2001, the pole post 202 is connected to the top cover 2001 and is electrically connected with the pole post segment 10, and the tab segment 20 is electrically connected with the tab 203, so that the battery cell can smoothly perform the charging and discharging function.

[0087] In some embodiments, the second connecting sub-segment 222 and the welding part 21 form an included angle β, wherein 115°≤β<180°. The value of β can be 115°, 120°, 130°, 140°, 150°, 160°, 170°, 179° or other unlisted values.

[0088] The present application also provides a battery pack, which comprises a shell, the shell is provided with a mounting cavity, the core package 204 and the current collector 100 are arranged in the mounting cavity, and the top cover 2001 is connected to the shell to close the mounting cavity. The pole post segment 10 of the current collector 100 and the pole post 202 of the core package 204 are connected. Thus, the external equipment can be powered by the pole post 202.

Claims

1. A current collector (100) arranged in an electrode assembly (200), the electrode assembly (200) comprising a jelly-roll (204), the jelly-roll (204) comprising a tab (203) and a pole (202), the electrode assembly (200) comprising: a pole segment (10) arranged to be electrically connected with the pole (202) ; a tab segment (20) arranged on one side of the pole segment (10), the tab segment (20) arranged to be electrically connected with the tab (203) ; a first bending segment (31) bently connected between the pole segment (10) and the tab segment (20), both ends of the first bending segment (31) at least partially coincide in projection on a plane where the pole segment (10) is located. 2.The current collector (100) of claim 1, further comprising a second bending segment (32) bently connected between the tab segment (20) and the first bending segment (31), both ends of the second bending segment (32) at least partially coincide in projection on the plane where the pole segment (10) is located. 3.The current collector (100) of claim 2, further comprising a first extension segment (33) comprising a first fold (331) and a second fold (332) connected with each other, the first fold (331) connected with the first bending segment (31), the second fold (332) connected with the second bending segment (32), the first extension segment (33) partially coinciding in projection on the plane where the pole segment (10) is located and the pole segment (10). 4.The current collector (100) of claim 3, further comprising a second extension segment (34) comprising a third fold (341) and a fourth fold (342) connected with each other, the third fold (341) connected with the second bending segment (32), the fourth fold (342) connected with the tab segment (20), the second extension segment (34) partially coinciding in projection on the plane where the pole segment (10) is located and with the pole segment (10). 5.The current collector (100) of claim 4, wherein the first extension segment (33) is arranged in parallel with the pole segment (10) ; the second extension segment (34) is arranged in parallel with the pole segment (10). 6.The current collector (100) of claim 4, comprising: a first connecting segment (110) having a first side (112) and a second side (113) arranged oppositely, the first side (112) having a first end (114), the second side (113) having a second end (115), the first end (114) being closer to the through hole (11) than the second end (115). A second connecting section (120) is connected with the first connecting section (110) and has oppositely arranged third and fourth side edges (121, 122). The first side edge (112) is located on the same side as the third side edge (121), and the second side edge (113) is located on the same side as the fourth side edge (122). In the width direction of the current collector (100), the first side edge (112) is closer to the second side edge (113) than the third side edge (121), and the fourth side edge (122) is closer to the third side edge (121) than the second side edge (113).

7. The current collector (100) according to claim 6, a distance between the first side (112) and a straight line on which the third side (121) lies is D1, and a distance between the second side (113) and a straight line on which the fourth side (122) lies is D2, wherein D1 = D2.

8. The current collector (100) of claim 6, a distance between a straight line on which the first side (112) and the third side (121) lie is D1, a distance between a straight line on which the second side (113) and the fourth side (122) lie is D2, and a thickness of the current collector (100) is D, wherein D1 < D2 < D. D1 = D2 ≥ D. ​ 9. The current collector (100) according to claim 6, wherein the distance between the first side edge (112) and the straight line on which the third side edge (121) is located is D1, and the distance between the second side edge (113) and the straight line on which the fourth side edge (122) is located is D2, 0 < D1 ≤ 1 mm, and / or 0 < D2 ≤ 1 mm.

10. The current collector (100) of claim 6, an angle a1 formed between a virtual straight line connecting the first end (114) and the second end (115) and the second side (113) is a1, wherein, α1=45°。 11. The current collector (100) according to claim 6, wherein the first side edge (112) is provided with a bevel (116) near the first end (114), and the bevel (116) connects the third side edge (121); and / or the second side edge (113) is provided with a bevel (116) near the second end (115), and the bevel (116) connects the fourth side edge (122).

12. The current collector (100) according to claim 6, wherein the pole section (10) comprises a short edge connected to a first bending section (31), the first side edge (112) is connected to the short edge, and the included angle a2 between the first side edge (112) and the second bending edge (332) is between 30° and 60°; and / or the included angle a3 between the third bending edge (341) and the fourth bending edge (342) is between 30° and 60°.

13. The current collector (100) according to claim 4, wherein the tab section (20) comprises a welding portion (21) and a clearance portion (22), the clearance portion (22) is connected to the second extending section (34), and the welding portion (21) is connected to one end of the clearance portion (22) away from the second extending section (34), and the clearance portion forms a clearance space (220) configured to avoid the core package (204).

14. The current collector according to claim 13, wherein the clearance portion comprises a first connecting sub-section (221) and a second connecting sub-section (222), the first connecting sub-section (221) is parallel to the welding portion, and the second connecting sub-section (222) is connected to the welding portion, and the second connecting sub-section (222) and the second extending section are protruded on the same side of the first connecting sub-section (221) to form the clearance space (220).

16. The current collector (100) according to claim 2, wherein the widths of the first bending section (31) and the second bending section (32) are smaller than the widths of the pole section (10) and the tab section (20). ​ 15. The current collector (100) of claim 14, the first connection sub-segment (221) forms an angle β with the weld (21), wherein 115°≤β＜180°。 ​ 17. The current collector (100) according to any one of claims 1-16, wherein the tab section (20) comprises an end portion (211) distal to the post section (10), the end portion (211) comprising a first arc portion (2111) and a second arc portion (2112) oppositely arranged along a width direction of the tab section (20), the first arc portion (2111) being located on a side of the second arc portion (2112) toward the jelly roll (204), and a radius of the first arc portion (2111) being greater than a radius of the second arc portion (2112).

18. The current collector (100) according to any one of claims 1-16, wherein the post section (10) is provided with a through hole (11) extending through the post section (10) along a first direction; the post section (10) is further provided with a first annular groove (1110) arranged on a side of the post section (10) distal to the tab section (20) and surrounding the through hole (11); and / or the post section is further provided with a second annular groove (1120) arranged on a side of the post section (10) proximal to the tab section (20) and surrounding the through hole (11).

19. An electrode assembly (200), comprising: a jelly roll (204) comprising a tab (203) and a post (202); a top cover (2001) connected to the post (202); the current collector (100) according to any one of claims 1-18, the current collector (100) being mounted to the top cover (2001), the post section (10) being electrically connected to the post (202), and the tab section being electrically connected to the tab (203).

20. A battery pack, comprising: a housing provided with a mounting cavity; the electrode assembly (200) according to claim 19, the jelly roll (204) and the current collector (100) being arranged in the mounting cavity, and the top cover (2001) being arranged on the housing to close the mounting cavity.

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