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CN-119404347-B - Battery cell, battery and electricity utilization device

CN119404347BCN 119404347 BCN119404347 BCN 119404347BCN-119404347-B

Abstract

The application discloses a battery unit, a battery and an electricity utilization device, wherein the battery unit comprises a shell component and a battery core component, the shell component comprises a shell and a first polar column, the shell is provided with a first wall, a mounting hole is formed in the first wall, the first polar column is arranged in the mounting hole, the first polar column comprises a first welding surface, the battery core component comprises an active substance coating part and a conductive part electrically connected with the active substance coating part, the active substance coating part is accommodated in the shell, the conductive part comprises a second welding surface which is in contact with the first welding surface, part of the second welding surface is welded with part of the first welding surface through the welding part, the surface where the cross section of the mounting hole is located is taken as a projection surface, and the outer contour of the projection of the second welding surface on the projection surface is located in the outer contour range of the projection of the first welding surface on the projection surface along the direction perpendicular to the projection surface. According to the battery cell, the quick charge performance, the reliability and the stability of the battery cell are improved.

Inventors

  • LIN WENFA
  • ZHANG SHENGWU
  • CHEN CONGSHENG
  • TANG MINGHAO
  • DING YU
  • Wen Yaoling

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260505
Application Date
20230303

Claims (20)

  1. 1. A battery cell, comprising: The shell assembly comprises a shell and a first pole, wherein the shell is provided with a first wall, a mounting hole is formed in the first wall, the first pole is arranged in the mounting hole, and the first pole comprises a first welding surface; The battery cell assembly comprises an active material coating part and a conductive part electrically connected with the active material coating part, wherein the active material coating part is accommodated in the shell, the conductive part comprises a second welding surface which is contacted with the first welding surface, and part of the second welding surface is welded with part of the first welding surface through the welding part; the outer contour of the projection of the second welding surface on the projection surface is positioned in the outer contour range of the projection of the first welding surface on the projection surface along the direction perpendicular to the projection surface by taking the surface of the cross section of the mounting hole as the projection surface; Further comprises: the support is positioned in the shell and at one side of the active material coating part, which is close to the first pole, and is provided with an avoidance hole for avoiding the conductive part, and the conductive part is suitable for extending to one side of the support, which is far away from the active material coating part, through the avoidance hole; the inner insulating piece is positioned in the shell and wrapped outside the active substance coating part and is connected with the bracket; The support comprises a body part and an extension part, wherein the body part is positioned on one side of the active material coating part, which is close to the first pole, and the extension part is connected with the body part and positioned in the peripheral area of the active material coating part; the extension part is provided with a positioning groove at one side far away from the sexual substance coating part, the end part of the inner insulating part is embedded in the positioning groove, and the inner insulating part is not protruded out of the body part along the thickness direction of the inner insulating part.
  2. 2. The battery cell according to claim 1, wherein, The first pole comprises a pole body, a first limiting table and a second limiting table, the pole body penetrates through the mounting hole, the first limiting table and the second limiting table are arranged at two ends of the pole body along the direction perpendicular to the projection surface, the first limiting table is in limiting fit with the outer side of the shell, and the second limiting table is in limiting fit with the inner side of the shell; the second limiting table is close to the end face of the battery cell assembly to form the first welding surface.
  3. 3. The battery cell according to claim 2, wherein, The length dimension of the pole body in a first direction is greater than or equal to 1/3 of the length dimension of the first wall in the first direction, and/or, The width dimension of the pole body in the second direction is greater than or equal to 1/2 of the width dimension of the first wall in the second direction, and/or, The ratio of the circumferential length of the pole body matched with the mounting hole to the circumferential length of the first wall is in the range of 25% -40%, and/or, The cross-sectional area of the portion of the pole body mated with the mounting hole is greater than or equal to 10% of the area of the first wall, and/or, Along the axial direction of the mounting hole, the ratio of the thickness dimension of the pole body to the thickness dimension of the first wall is greater than 1 and less than 1.5.
  4. 4. The battery cell according to claim 2, wherein, The ratio of the length dimension of the first limiting platform in the first direction to the length dimension of the first wall in the first direction is within the range of 1/3-1/2, and/or, The ratio of the width dimension of the first limiting platform in the second direction to the width dimension of the first wall in the second direction is within the range of 1/2-3/4, and/or, The first limiting table is columnar, the ratio of the perimeter size of the periphery of the first limiting table to the perimeter size of the first wall is in the range of 30% -50%, and/or, The ratio of the cross-sectional area of the first limiting table to the area of the first wall is in the range of 9% -25%, and/or, And the ratio of the thickness dimension of the first limiting table to the thickness dimension of the first wall is in the range of 0.6-1.5 along the axial direction of the mounting hole.
  5. 5. The battery cell according to claim 2, wherein, The ratio of the length dimension of the second limiting platform in the first direction to the length dimension of the first wall in the first direction is within the range of 1/3-1/2, and/or, The ratio of the width dimension of the second limiting platform in the second direction to the width dimension of the first wall in the second direction is within the range of 1/2-3/4, and/or, The second limiting table is columnar, the ratio of the perimeter size of the periphery of the second limiting table to the perimeter size of the first wall is in the range of 30% -50%, and/or, The ratio of the cross-sectional area of the second limiting table to the area of the first wall is in the range of 9% -25%, and/or, And the ratio of the thickness dimension of the second limiting table to the thickness dimension of the first wall is in the range of 0.6-1.5 along the axial direction of the mounting hole.
  6. 6. The battery cell according to claim 1, wherein, The conducting part comprises a plurality of pole lugs connected with the active material coating part, one ends of the pole lugs, which are close to the active material coating part, are folded to form a first folding part, one ends of the pole lugs, which are far away from the active material coating part, are folded and connected to form a second folding part, the first folding part is connected with the second folding part and the active material coating part, and the end face, which is close to one side of the first pole, of the second folding part forms a second welding surface.
  7. 7. The battery cell according to claim 6, wherein, And taking the plane of the cross section of the mounting hole as a projection plane, and along the direction perpendicular to the projection plane, at least part of the projection outline of the first gathering part on the projection plane is positioned in the projection outline range of the first welding plane on the projection plane.
  8. 8. The battery cell according to claim 1, wherein, The conductive part comprises a plurality of tab pieces connected with the active material coating part and a switching piece, wherein one ends of the tab pieces, which are close to the active material coating part, are folded to form a first folding part, one ends of the tab pieces, which are far away from the active material coating part, are folded and connected to form a second folding part, the first folding part is connected with the second folding part and the active material coating part, the switching piece is connected with the second folding part and the first pole, and the part, which is close to the end face of the first pole, of the switching piece forms a second welding surface.
  9. 9. The battery cell according to claim 8, wherein, Taking the surface of the cross section of the mounting hole as a projection surface, and along the direction perpendicular to the projection surface, at least part of the outer contour of the projection of the second gathering part on the projection surface is positioned in the range of the outer contour of the projection of the first welding surface on the projection surface, and/or, And taking the plane of the cross section of the mounting hole as a projection plane, and along the direction perpendicular to the projection plane, at least part of the projection outline of the first gathering part on the projection plane is positioned in the projection outline range of the first welding plane on the projection plane.
  10. 10. The battery cell according to any one of claims 1-9, wherein the first pole is provided with a receiving portion, at least a portion of the conductive portion being received within the receiving portion.
  11. 11. The battery cell according to claim 10, wherein the housing portion has a first housing groove, a surface of the first electrode column on a side facing the active material application portion is an electrode column inner end surface, a notch of the first housing groove is formed on the electrode column inner end surface, and at least part of the conductive portion is housed in the first housing groove.
  12. 12. The battery cell of claim 11, wherein a wall of the first receiving groove has a first countersink, and the conductive portion is at least partially positioned within the first countersink at a location that is electrically connected to the first post.
  13. 13. The battery cell according to claim 11, wherein the first electrode post has a first groove, a side surface of the first electrode post remote from the active material coating portion is an electrode post outer end surface, and a notch of the first groove is formed on the electrode post outer end surface.
  14. 14. The battery cell of claim 13, further comprising a slot cover disposed on the first post and closing a slot of the first recess.
  15. 15. The battery cell according to claim 10, wherein the housing portion has a second housing groove, a surface of the first electrode on a side away from the active material application portion is an outer end surface of the electrode, a notch of the second housing groove is formed on the outer end surface of the electrode, the second housing groove communicates with the inside of the case through a first through hole, and the conductive portion is provided through the first through hole and at least partially housed in the second housing groove.
  16. 16. The battery cell of claim 15, wherein the second receiving groove has a second countersink, the conductive portion being electrically connected to the first post at least partially within the second countersink.
  17. 17. The battery cell of claim 15, wherein the housing assembly further comprises a first cover plate that mates with the first post and closes the notch of the second receiving groove, the first cover plate being electrically connected with the first post.
  18. 18. The battery cell of claim 15, wherein the housing assembly further comprises a second cover plate covering the first aperture and the conductive portion within the second receiving slot.
  19. 19. The battery cell according to claim 10, wherein the bracket is provided with a guide portion surrounding at least a portion forming the escape hole, the guide portion extending at least partially to the receiving portion.
  20. 20. The battery cell according to claim 10, wherein the relief hole comprises a first hole section and a second hole section, the second hole section is located on one side of the first hole section, which is close to the active material coating portion, and the cross-sectional area of the second hole section is gradually increased along a direction away from the first hole section, the active material coating portion comprises a current collector and an active material layer arranged on the current collector, the conductive portion comprises a tab portion electrically connected with the current collector, the tab portion comprises a plurality of tab pieces, the positions of the tab pieces, which are close to the current collector, are converged to form a first converging portion, the positions of the tab pieces, which are far away from the current collector, are converged and are connected to form a second converging portion, the first converging portion is connected with the second converging portion and the active material coating portion, and at least part of the first converging portion is accommodated in the second hole section, and the second converging portion is arranged through the first hole section.

Description

Battery cell, battery and electricity utilization device Technical Field The application relates to the technical field of batteries, in particular to a battery monomer, a battery and an electric device. Background In recent years, new energy automobiles have been developed dramatically, and in the field of electric automobiles, batteries play an important role as a power source of the electric automobiles. In general, a battery includes a plurality of battery cells, and the current battery cells are difficult to raise in charging speed, resulting in a certain limitation in use of the vehicle. Disclosure of Invention The present application is directed to solving at least one of the technical problems existing in the related art. Therefore, the application provides a battery cell, a battery and an electric device with higher charging speed. The embodiment of the application provides a battery cell, which comprises a shell assembly and a first pole, wherein the shell comprises a first wall, a mounting hole is formed in the first wall, the first pole is arranged in the mounting hole, the first pole comprises a first welding surface, the battery cell assembly comprises an active substance coating part and a conductive part electrically connected with the active substance coating part, the active substance coating part is contained in the shell, the conductive part comprises a second welding surface welded with the first welding surface, part of the second welding surface is welded with part of the first welding surface through the welding part, the surface where the cross section of the mounting hole is located is taken as a projection surface, and the projected outline of the second welding surface on the projection surface is located in the projected outline range of the first welding surface on the projection surface along the direction perpendicular to the projection surface. According to the technical scheme, the surface where the cross section of the mounting hole is arranged is the projection surface, the projection outline of the second welding surface on the projection surface is located in the projection outline range of the first welding surface on the projection surface along the direction perpendicular to the projection surface, the welding area of the first electrode column and the conductive part is larger than the welding area of the conductive part and the first electrode column so as to realize oversized arrangement of the first electrode column, on one hand, under the condition that the size of the conductive part is unchanged, the first electrode column is made to be large, the overcurrent area of the conductive part can be ensured, and the overcurrent area of the first electrode column is improved, and meanwhile, the oversized arrangement of the first electrode column can enable a bus assembly electrically connected with the first electrode column to be relatively large, so that the area of the bus assembly for being electrically connected (for example, welding) with the first electrode column can be set to be large, and the overcurrent area of the bus assembly can be improved. Meanwhile, the oversized arrangement of the first pole can provide a larger welding space, the welding space of the first pole and the conductive part can be increased, and the welding space of the first pole and the converging component is increased, so that the welding reliability and stability are higher, and the reliability and stability of the battery monomer can be further improved. In some embodiments, the first pole comprises a pole body, a first limiting table and a second limiting table, the pole body is arranged in the mounting hole in a penetrating mode, the first limiting table and the second limiting table are arranged at two ends of the pole body along the direction perpendicular to the projection surface, the first limiting table is in limiting fit with the outer side of the shell, the second limiting table is in limiting fit with the inner side of the shell, and the end face, close to the battery cell assembly, of the second limiting table forms a first welding surface. In the technical scheme, the structure of the first pole comprises the pole body, the first limiting table and the second limiting table, so that the first pole can be riveted on the shell, the assembly of the first pole and the shell is facilitated, the manufacturing procedure is simplified, meanwhile, the reliability and stability of the connection of the first pole and the shell are improved, meanwhile, the first pole and the shell are riveted, the reliable connection of the first pole and the shell can be conveniently realized without adopting other connection modes, the structure of a shell assembly is facilitated, and the assembly procedure of the shell assembly is simplified. In some embodiments, the length dimension of the post body in the first direction is greater than or equal to 1/3 of the length dimension of the first wa