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EP-4742384-A1 - CELL AND BATTERY HAVING SAME

EP4742384A1EP 4742384 A1EP4742384 A1EP 4742384A1EP-4742384-A1

Abstract

The present invention provides a cell and a battery having the cell. The cell of the present invention includes a housing, a cap assembly and a wound core. The housing is of an elongated configuration and has an opening at a top end, the cap assembly is encapsulated at the opening of the housing and defines a receiving space together with the housing, and the wound core is adaptively shaped to be accommodated in the receiving space. The cap assembly and the wound core are in direct contact and fixedly connected to each other for direct electrical conduction between the wound core and the cap assembly. In the present invention, a conventional busbar between the wound core and the cap assembly is eliminated, thereby saving space. Under the condition of a constant battery length, this arrangement allows the wound core to be lengthened and the capacity to be increased. As the wound core and the cap assembly are directly conductively connected, an electron transport path is shortened, the internal resistance is reduced, and the battery power supply efficiency is increased.

Inventors

  • HUANG, XIN YUE
  • YI, Ding Xing
  • HAN, Zhi Qing
  • XU, GANG

Assignees

  • Techtronic Cordless GP

Dates

Publication Date
20260513
Application Date
20251106

Claims (12)

  1. A cell (100) for a battery, wherein the cell (100) comprises: a housing (12) being of an elongated configuration and having an opening (125) at a top end, a cap assembly (13) encapsulated at the opening (125) of the housing (12) and defining a receiving space together with the housing, and a wound core (11) adaptively shaped to be accommodated in the receiving space, wherein the cap assembly (13) and the wound core (12) are in direct contact and fixedly connected to each other for direct electrical conduction between the wound core (11) and the cap assembly (13).
  2. The cell as claimed in claim 1, wherein the cap assembly (13) is integrally formed as a flat plate structure, and the entire top surface of the wound core (11) is in surface contact with the cap assembly (13).
  3. The cell as claimed in either of claims 1 or 2, wherein the cap assembly (13) comprises a cap body (131) almost covering the opening (125), an annular plate (133) surrounding the cap body, and an annular seal ring (132) fitted between the annular plate (133) and the cap body (131) and electrically isolating the annular plate (133) from the cap body (131), wherein the wound core (11) is fixedly connected to the cap body (131), and a side wall (123) of the housing (12) is fixedly connected to the annular plate (133), in particular the wound core (11) and the cap body (131) are connected to each other by welding, and the side wall (123) of the housing (12) and the annular plate (133) are connected to each other by welding.
  4. The cell as claimed in 3, wherein the cap body (131) and the seal ring (132) are provided with mutually matching structures at a junction therebetween, the seal ring (132) and the annular plate (133) are provided with mutually matching structures at a junction therebetween, and the annular plate (133) and the side wall (123) of the housing (12) are provided with mutually matching structures at a junction therebetween.
  5. The cell as claimed in either of claims 3 or 4, wherein a circumferential side of the cap body (131) is formed with a first receiving groove (1311) which is open to the outside and extends entirely in a circumferential direction, and at least a portion of the seal ring (132) is disposed in the first receiving groove (1311), in particular, the seal ring (132) is provided along its entire circumference with a second receiving groove (1321) which is open to the outside, and at least a portion of the annular plate (133) is disposed in the second receiving groove (1321), and preferably, a radially inner end (1332) of the annular plate (133) is inserted into the second receiving groove (1321) and, together with at least a portion of the seal ring (132), into the first receiving groove (1311).
  6. The cell as claimed in claim 5, wherein the seal ring (132) has a seal ring top wall (1322), a seal ring bottom wall (1323), and a seal ring side wall (1324) connected between the seal ring top wall and the seal ring bottom wall, all of which define the second receiving groove (1321), wherein the seal ring top wall (1322) and the seal ring bottom wall (1323) both extend radially outwardly beyond the cap body (131), preferably the seal ring top wall (1322), the seal ring bottom wall (1323) and the seal ring side wall (1324) are equal in thickness.
  7. The cell as claimed in either of claims 5 or 6, wherein the annular plate (133) is engaged with the seal ring (132) in an interference fit manner, and/or the seal ring (132) is engaged with the cap body (131) in an interference fit manner, in particular, each of the annular plate (133) and the cap body (131) is formed as a flat plate of a uniform thickness.
  8. The cell as claimed in any one of claims 3-7, wherein the side wall (123) of the housing (12) is formed with a first step structure (122) at an open end of the housing, and a second step structure (1331) is also provided at a bottom circumferential position of the annular plate (133), the first step structure (122) and the second step structure (1331) being matched in a concave-convex manner, and preferably, the first step structure (122) comprises an outer step (1221) and an inner step (1222) adjacent to each other in a radial direction, and the outer step (1221) protrudes toward the top relative to the inner step (1222).
  9. The cell as claimed in any one of claims 2-8, wherein the cap assembly (13) is formed with an electrolyte inlet (1312) running through the cap body (131), and the cap assembly (13) also comprises an inlet cover plate (134) for covering the electrolyte inlet (1312), in particular, the wound core (11) and the cap body (131) are welded together along a welding trajectory (1313), the electrolyte inlet (1312) is provided to bypass the welding trajectory (1313), and in particular, the welding trajectory is in the form of a radial shape, discrete points, spirals or concentric circles extending along the cap body, and in particular, the electrolyte inlet (1312) is located in the center of the cap body (131) or near an edge of the cap body.
  10. The cell as claimed in any one of claims 3-9, wherein a thinned area acting as an explosion-proof valve is provided on the housing (12) and/or the cap assembly (13), preferably a thickness of the thinned area is 40%-90% of a thickness of its adjoining area, in particular, the side wall (123) of the housing (12) is formed with a circumferentially extending groove (121) as an explosion-proof valve, preferably the groove (121) is located at an axial center of the side wall (123) of the housing (12), and in particular, the cap assembly (13) comprises an inlet cover plate (134) for covering an electrolyte inlet (1312), and a thickness of the inlet cover plate (134) is less than a thickness of the cap body (131) so that the inlet cover plate (134) functions as an explosion-proof valve.
  11. The cell as claimed in any one of claims 1-10, wherein a bottom end of the wound core (11) and a bottom wall (124) of the housing (12) are fixedly connected to each other to achieve direct electrical conduction between the bottom wall (124) of the housing (12) and the wound core (11), in particular, there is no busbar between a top end of the wound core (11) and the cap assembly (13), and in particular, there is no busbar between the bottom end of the wound core (11) and the bottom wall (124) of the housing (12).
  12. A battery, wherein the battery comprises a cell (100) according to any one of claims 1-11, in particular, a plurality of cells are provided and are arranged in an array in a plane perpendicular to an axial direction (X) of the cell.

Description

Technical Field The present invention relates to the field of batteries, and in particular to a cell and a battery having the cell. Background Art Currently, a common cell for a battery on the market includes a wound core and a housing, and the wound core is usually placed in the housing to avoid damage to the wound core. The housing is usually composed of a cylinder with an opening on one side and a cap assembly for closing the opening of the cylinder, and when the cap assembly closes the opening of the cylinder, it generally requires a groove for sealing to be engraved in the cylinder, that is, a rolling groove. With fixed battery specifications, a receiving space of the cylinder is constant. The existence of components, such as the cap assembly and the groove, occupies part of the receiving space of the cylinder, and the space that can be occupied by the wound core is smaller than the receiving space of the cylinder, so that the capacity of the cell is limited. In addition, the cell is usually further provided with a busbar, which also occupies part of the receiving space of the cylinder, further reducing the receiving space for the wound core and affecting an increase in the capacity of the cell. At the same time, these structures also cause the processing of the cell to be more complex, increasing the production cost. In addition, there is a demand for low internal resistance batteries on the market, and the safety performance of existing batteries also needs to be improved. Therefore, there is a need to provide a cell and a battery having the cell, to at least partially solve the above problems. Summary An objective of the present invention is to provide a cell and a battery having the cell. A wound core and a cap assembly of the cell of the present invention are directly fixed by welding to achieve a conductive connection, eliminating a conventional busbar between the wound core and the cap assembly, thereby saving space. Under the condition of a constant battery length, this arrangement allows the wound core to be lengthened and the capacity to be increased. As the wound core and the cap assembly are directly conductively connected, an electron transport path is shortened, the internal resistance is reduced, and the battery power supply efficiency is increased. Further, the cap assembly of the cell of the present invention has a unique sealing structure at the periphery thereof, which enables a tight engagement between the cap assembly and the housing, thereby effectively improving the stability of the cell during use and extending the service life of the cell. The present invention also provides some preferred arrangements of an explosion-proof valve and an electrolyte filling port, which improve the overall performance of the cell, especially the safety performance, in various aspects. According to an aspect of the present invention, a cell for a battery is provided, the cell including: a housing being of an elongated configuration and having an opening at a top end,a cap assembly encapsulated at the opening of the housing and defining a receiving space together with the housing, anda wound core adaptively shaped to be accommodated in the receiving space,where the cap assembly and the wound core are in direct contact and fixedly connected to each other for direct electrical conduction between the wound core and the cap assembly. In an embodiment, the cap assembly is integrally formed as a flat plate structure, and the entire top surface of the wound core is in surface contact with the cap assembly. In an embodiment, the cap assembly includes a cap body almost covering the opening, an annular plate surrounding the cap body, and an annular seal ring fitted between the annular plate and the cap body and electrically isolating the annular plate from the cap body, wherein the wound core is fixedly connected to the cap body, and a side wall of the housing is fixedly connected to the annular plate, in particular the wound core and the cap body are connected to each other by welding, and the side wall of the housing and the annular plate are connected to each other by welding. In an embodiment, the cap body and the seal ring are provided with mutually matching structures at a junction therebetween, the seal ring and the annular plate are provided with mutually matching structures at a junction therebetween, and the annular plate and the side wall of the housing are provided with mutually matching structures at a junction therebetween. In an embodiment, a circumferential side of the cap body is provided with a first receiving groove which is open to the outside and extends entirely in a circumferential direction, and at least a portion of the seal ring is disposed in the first receiving groove, in particular, the seal ring is provided along its entire circumference with a second receiving groove which is open to the outside, and at least a portion of the annular plate is disposed in the second receiving gr