Search

CN-120261735-B - Winding needle mechanism and battery winding equipment

CN120261735BCN 120261735 BCN120261735 BCN 120261735BCN-120261735-B

Abstract

A winding needle mechanism and battery winding equipment belong to the technical field of batteries. The needle winding mechanism comprises a base, a needle winding ring and a movable piece, wherein the needle winding ring is arranged on the base and comprises a plurality of connecting pieces which are sequentially connected, the movable piece is arranged on the base and can drive the needle winding ring to switch between a first shape and a second shape. In the application, the winding needle ring can be switched between the first shape and the second shape, so that the winding needle ring can be switched into different shapes for different winding stages in the process of winding the membrane layer to produce the electrode assembly, thereby obtaining the electrode assembly with better use performance and reliability. Meanwhile, the perimeter of the outer contour of the cross section of the winding needle ring can not change or change less in the process of switching the first shape and the second shape, so that the risk that a film layer close to the center of the electrode assembly is broken or wrinkled can be reduced, and the safety performance and the service performance of the battery device are improved.

Inventors

  • LUO ZHONGPING
  • XIE MING
  • GUO TONGSHUN
  • HUANG FUQIANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260512
Application Date
20250603

Claims (11)

  1. 1. A needle winding mechanism, comprising: A base; the needle winding ring is arranged on the base and comprises a plurality of connecting pieces which are sequentially connected; The movable piece is arranged on the base and can drive the needle winding ring to switch between a first shape and a second shape, and comprises a first section and a second section, and the movable piece is configured to move between a first position and a second position; The first section is inserted into the needle winding ring at the first position, the second section is positioned outside the needle winding ring so as to form a first shape of the needle winding ring, and the second section is inserted into the needle winding ring at the second position so as to form a second shape of the needle winding ring; The connecting piece is provided with an adsorption hole, a vacuum flow path is formed in the connecting piece, and the adsorption hole is connected with an external vacuum source through the vacuum flow path; A communication hole is formed on one side, facing the adjacent connecting piece, of the connecting piece, and the communication hole is communicated with the vacuum flow path; the first section and the second section are smoothly connected through a transition curved surface; The cross section of the first section is rectangular or elliptical, and the cross section of the second section is circular; the winding needle ring is switched into different shapes at different winding stages, and is prismatic or elliptic when the film layer close to the middle of the electrode assembly is wound, the obtained gap between the positive pole piece and the negative pole piece of the electrode assembly close to the winding center of the electrode assembly is smaller, and the winding needle ring is cylindrical when the film layer of the rest part of the electrode assembly is wound.
  2. 2. The needle winding mechanism of claim 1, wherein the base includes a telescoping rod that telescopes to drive the moveable member between the first position and the second position.
  3. 3. The needle winding mechanism according to any one of claims 1-2, wherein a plurality of said connectors comprise a plurality of first connectors and a plurality of second connectors, said first connectors and said second connectors being alternately arranged in sequence, said first connectors having hinge seats at both ends thereof, said hinge seats being hinged to two adjacent second connectors, respectively.
  4. 4. The needle winding mechanism according to any one of claims 1-2, further comprising hinge seats provided at both ends of said connecting members, at least one of said connecting members being hingedly connected to said hinge seat for two adjacent connecting members.
  5. 5. The needle winding mechanism according to any one of claims 1-2, further comprising hinge seats at both ends of each of said connectors, said hinge seats being hinged to an adjacent other of said connectors.
  6. 6. The needle winding mechanism of any one of claims 1-2, wherein the sidewall surface of the connector includes a planar surface, the planar surfaces of the plurality of connectors collectively forming a circumferentially outer side of the needle winding ring.
  7. 7. The needle winding mechanism of any one of claims 1-2, wherein the first shape is prismatic or elliptical and the second shape is cylindrical.
  8. 8. The needle winding mechanism according to any one of claims 1-2, wherein the needle winding ring of the first shape has a dimension L1 in a first direction, the needle winding ring of the first shape has a dimension L2 in a second direction, and a ratio of L1 to L2 is 1:1 to 5:1, wherein the second direction is a direction in which an outer contour minimum dimension of the needle winding ring is located, and the second direction is perpendicular to the first direction.
  9. 9. The needle winding mechanism of any one of claims 1-2, further comprising a connecting rod, wherein two ends of the connecting rod are movably connected to the needle winding ring and the base, respectively, and wherein the connecting rod is configured to be extendable and contractible.
  10. 10. The needle winding mechanism of claim 9, wherein one end of the connecting rod is fixedly connected with the needle winding ring, the base is formed with a sliding groove, and the other end of the connecting rod is in sliding fit with the sliding groove.
  11. 11. A battery winding apparatus comprising the winding needle mechanism as claimed in any one of claims 1 to 10.

Description

Winding needle mechanism and battery winding equipment Technical Field The application relates to the technical field of batteries, in particular to a winding needle mechanism and battery winding equipment. Background In the battery production technology, an electrode assembly of a battery cell is generally manufactured in a winding manner to form an electrode assembly of a winding type structure, and the electrode assembly of the winding type structure is generally wound using a winding needle. In the related winding process, the winding needle of the winding machine is generally cylindrical in design. However, there are some disadvantages in the winding process of the cylindrical winding needle, for example, after the cylindrical winding needle is wound and discharged, a gap between the negative electrode sheet and the positive electrode sheet near the winding center of the electrode assembly may become large, and the gap may easily cause uneven distribution of lithium ions in the subsequent use process of the battery, and even a lithium precipitation phenomenon occurs at the winding center of the electrode assembly, so that lithium precipitation may not only cause loss of battery capacity, but also cause potential safety hazards, such as short circuit or thermal runaway. Disclosure of Invention The embodiment of the application provides a winding needle mechanism and battery winding equipment, wherein the electrode assembly obtained by winding the winding needle mechanism has good usability and reliability. In a first aspect, an embodiment of the application provides a needle rolling mechanism, which comprises a base, a needle rolling ring, a movable piece and a needle rolling ring, wherein the needle rolling ring is arranged on the base and comprises a plurality of connecting pieces, the connecting pieces are sequentially connected, the movable piece is arranged on the base, and the movable piece can drive the needle rolling ring to switch between a first shape and a second shape. In the above technical solution, the winding needle ring can be switched between the first shape and the second shape, so that in the process of winding the membrane layer by the winding needle ring to produce the electrode assembly, the winding needle ring can be switched into different shapes at different winding stages, so as to obtain the electrode assembly with better use performance and reliability. The circumference of the outer contour of the cross section of the rolling needle ring can not be changed or is changed slightly in the process of driving the rolling needle ring to switch between the first shape and the second shape, so that the risk that a film layer close to the center of the electrode assembly is broken or wrinkled can be reduced, and the safety performance and the service performance of the battery device are improved. In some embodiments, the moveable member includes a first section and a second section, the second section being positioned between the first section and the base, the moveable member being configured to be moveable between a first position in which the first section is inserted in the needle winding ring and a second position in which the second section is positioned outside the needle winding ring to form the needle winding ring into a first shape, and the second section is inserted in the needle winding ring to form the needle winding ring into a second shape. In the technical scheme, different sections of the movable piece have different shapes, and when the shape of the needle rolling ring is required to be changed, the position of the movable piece is directly changed, so that the different sections of the movable piece are inserted into the needle rolling ring. The process can be completed rapidly, the circumference or the perimeter of the outer contour of the cross section of the winding needle ring can not be changed only slightly, the continuity and the stability of the winding process are ensured, and the accuracy and the reliability of shape conversion are also ensured. Meanwhile, the moving distance of the movable piece is not required to be accurately controlled in the switching process, and the movable piece is only required to be inserted into the needle winding ring, so that the control difficulty of the movable piece can be reduced. In some embodiments, the first segment and the second segment are smoothly joined by a transition surface. In the above technical scheme, through setting up the transition curved surface, transition curved surface smooth connection is between the outer peripheral face of first section and the outer peripheral face of second section, like this, when the moving part switches between first position and second position, can more smooth and easy, can accomplish the switching in very short time, reduces the condition of card and appears. In some embodiments, the first section is rectangular or elliptical in cross-section and the second section is ci