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CN-121972800-A - Composite laser welding method and device for battery shell and battery core

CN121972800ACN 121972800 ACN121972800 ACN 121972800ACN-121972800-A

Abstract

The invention provides a compound laser welding method and device for a battery shell and a battery core, and relates to the technical field of battery welding, wherein the compound laser welding method comprises the steps of tightly attaching the battery core to a to-be-welded part of the battery shell through a clamping and positioning mechanism; starting a pulse laser, adjusting the laser beam to focus on the part to be welded of the battery cell and the battery shell, performing pulse laser welding according to a preset welding path to form an initial welding spot, after the initial welding spot is welded, keeping the positions of the battery cell and the battery shell unchanged, starting a continuous laser, adjusting the laser beam to focus on the initial welding spot area, performing continuous laser welding according to a preset welding track to form a covering layer, and finishing the welding. After the primary welding is realized rapidly by the pulse laser, the continuous laser is utilized to carry out full coverage, so that the advantage of high pulse laser welding efficiency is reserved, the characteristic of stable continuous laser energy is utilized to effectively eliminate the explosion point defect, and the problem of liquid leakage is fundamentally solved.

Inventors

  • RAN CHANGLIN
  • LIANG BIN
  • CHENG RUIZHEN
  • LIU SHUIZHOU
  • HU QI
  • GONG TENGBIAO

Assignees

  • 武汉逸飞激光智能装备有限公司

Dates

Publication Date
20260505
Application Date
20260203

Claims (10)

  1. 1. A method for composite laser welding of a battery case and a battery cell, comprising: the battery core (5) is tightly attached to the part to be welded of the battery shell (4) through the clamping and positioning mechanism (3); Starting a pulse laser (1), adjusting a laser beam to focus on a part to be welded of the battery cell (5) and the battery shell (4), and performing pulse laser welding according to a preset welding path to form an initial welding spot; After the initial welding spot is welded, the positions of the battery cell (5) and the battery shell (4) are kept unchanged, a continuous laser (2) is started, laser beams are adjusted to focus on the initial welding spot area, continuous laser welding is carried out according to a preset welding track, a covering layer is formed, and the welding is completed.
  2. 2. The method for hybrid laser welding of a battery housing and a battery cell of claim 1, wherein, The continuous laser welding according to the preset welding track comprises the following steps: And starting the single-mode annular continuous laser (2) to control the laser beam to swing, scan and weld according to a preset track through a galvanometer system.
  3. 3. The method for hybrid laser welding of a battery housing and a battery cell of claim 1, wherein, The battery cell (5) is tightly attached to the part to be welded of the battery shell (4) through the clamping and positioning mechanism (3), and the welding device comprises: the battery shell (4) and the battery core (5) are respectively arranged on the clamping and positioning mechanism (3); the battery cell (5) and the battery shell (4) are conveyed to a welding station through the clamping and positioning mechanism (3); The clamping and positioning mechanism (3) applies pressure to enable the battery cell (5) to be tightly attached to the part to be welded of the battery shell (4).
  4. 4. A composite laser welding device for a battery case and a battery cell, comprising: the pulse laser (1) is used for carrying out pulse laser welding on the part to be welded of the battery cell (5) and the battery shell (4) through a laser beam; the continuous laser (2) is used for carrying out continuous laser welding on the to-be-welded parts of the battery cell (5) and the battery shell (4) through laser beams; and the clamping and positioning mechanism (3) is connected with the battery cell (5) and the battery shell (4) and enables the battery cell (5) to be tightly attached to a part to be welded of the battery shell (4), and the battery cell (5) and the battery shell (4) are conveyed to a welding station.
  5. 5. The device for hybrid laser welding of battery housings and cells according to claim 4, characterized in that said clamping and positioning mechanism (3) comprises: A base (31); A carrier (32) mounted on the base (31), and provided with a receiving cavity (321) on the end surface for receiving the battery cell (5) and the battery case (4); The pressing mechanism (33) is arranged on the base (31) and is opposite to the carrier (32) and is used for tightly attaching the battery cell (5) to the battery shell (4); and the driving mechanism (34) is used for driving the pressing mechanism (33) to move along the first direction and the second direction simultaneously so as to press the battery shell (4) and the battery cell (5) in the carrier (32).
  6. 6. The battery casing and cell hybrid laser welding device of claim 5, wherein the drive mechanism (34) comprises a lift assembly (341) and a power assembly; the lifting assembly (341) is slidably mounted on the base (31) along a first direction, and the pressing mechanism (33) is mounted on the base (31) through the lifting assembly (341); The pressing mechanism (33) is slidably mounted on the lifting assembly (341) along a second direction; The power assembly is used for driving the lifting assembly (341) to move so as to enable the pressing mechanism (33) to move in a first direction and a second direction at the same time.
  7. 7. The device for hybrid laser welding of a battery housing and a battery cell of claim 6, wherein, A guide limit hole (311) is formed in the base (31); The pressing mechanism (33) comprises a mounting plate (331) and a riding wheel (332), the mounting plate (331) is slidably mounted on the lifting assembly (341) along the second direction, and the riding wheel (332) is fixedly mounted on the mounting plate (331); the riding wheel (332) is arranged in the guide limiting hole (311) in a rolling mode.
  8. 8. The device for hybrid laser welding of a battery housing and a battery cell of claim 6, wherein, The lifting assembly (341) comprises a lifting plate (3411) and a first elastic piece (3412), wherein one end of the first elastic piece (3412) is connected with the lifting plate (3411), and the other end of the first elastic piece is connected with the base (31).
  9. 9. The device for hybrid laser welding of a battery housing and a battery cell of claim 5, wherein, An installation groove (322) is formed on the inner wall of the accommodating cavity (321); The carrier (32) comprises a propping assembly (323), and the propping assembly (323) is rotatably arranged in the mounting groove (322) to elastically prop against the battery shell (4).
  10. 10. The device for hybrid laser welding of a battery housing and a battery cell of claim 9, The abutting assembly (323) comprises a profiling positioning block (3231), a rotating shaft (3232) and a second elastic piece (3233); The rotating shaft (3232) is arranged in the mounting groove (322), and the profiling positioning block (3231) is rotatably arranged in the mounting groove (322) through the rotating shaft (3232); opposite ends of the second elastic piece (3233) are respectively connected with the profiling positioning block (3231) and the mounting groove (322); When the battery shell (4) is loaded in the carrier (32), the profiling positioning block (3231) is stressed and attached to the outer wall of the battery shell (4).

Description

Composite laser welding method and device for battery shell and battery core Technical Field The invention relates to the technical field of battery welding, in particular to a composite laser welding method and device for a battery shell and a battery core. Background The connection of the battery shell/pole, the current collecting disc and the electric core is one of the key links in the battery structure, and has decisive influence on the performance, the safety, the service life and the reliability of the battery. At present, the connection of the battery shell/pole, the current collecting disc and the battery core is basically realized by adopting a laser welding mode. Laser welding can provide a high strength connection between the two. In order to reduce the cost of battery materials and avoid laser welding of copper materials, the existing battery structure cancels the design of a negative electrode current collecting disc and directly connects a shell with a battery cell negative electrode. However, when the structure is used for laser welding, once the process parameters are improper or other factors are wrong, the welding through of the shell is caused, the leakage of the internal electrolyte is caused, and the safety, the reliability and the service life of the battery are directly affected. In the prior art, attempts to solve the problem have been mainly focused on optimizing laser parameters, but the effect is limited, for example, in a welding method, a welding device and a manufacturing method of a battery disclosed in patent CN 201280073198.5, a pulse laser is used for welding the battery, a light receiving device is used for detecting defects of a welding part in laser welding, and then the laser parameters are adjusted to improve the welding stability, but when the pulse laser is used for welding a battery steel can and a battery core, the situation of explosion point cannot be completely avoided by simply adjusting the laser parameters, so that electrolyte in the battery leaks. Disclosure of Invention The invention aims to overcome the defect and problem of low welding quality in the prior art and provides a composite laser welding method and device for a battery shell and a battery core, wherein the welding quality of the composite laser welding method and device is higher. In order to achieve the above purpose, the technical solution of the invention is that a composite laser welding method of a battery shell and a battery core comprises the following steps: The battery core is tightly attached to the part to be welded of the battery shell through a clamping and positioning mechanism; Starting a pulse laser, adjusting laser beams to focus on the to-be-welded parts of the battery cell and the battery shell, and performing pulse laser welding according to a preset welding path to form an initial welding spot; after the initial welding spot is welded, the positions of the battery core and the battery shell are kept unchanged, a continuous laser is started, laser beams are adjusted to focus on the initial welding spot area, continuous laser welding is carried out according to a preset welding track, a covering layer is formed, and the welding is completed. The continuous laser welding according to the preset welding track comprises the following steps: And starting the single-mode annular continuous laser, and controlling the laser beam to swing, scan and weld according to a preset track through a galvanometer system. The battery cell is closely attached to the to-be-welded part of the battery shell through the clamping and positioning mechanism, and the battery cell comprises: The battery shell and the battery core are respectively arranged on the clamping and positioning mechanism; The battery cell and the battery shell are conveyed to a welding station through the clamping and positioning mechanism; And the clamping and positioning mechanism applies pressure to enable the battery cell to be tightly attached to the part to be welded of the battery shell. The pulse laser is used for carrying out pulse laser welding on the to-be-welded part of the battery cell and the battery shell through a laser beam; the continuous laser is used for carrying out continuous laser welding on the battery cell and the part to be welded of the battery shell through laser beams; And the clamping and positioning mechanism is connected with the battery cell and the battery shell, enables the battery cell to be tightly attached to the part to be welded of the battery shell, and conveys the battery cell and the battery shell to a welding station. The clamping and positioning mechanism comprises: A base; the carrier is arranged on the base, and the end face of the carrier is provided with a containing cavity for bearing the battery cell and the battery shell; the compressing mechanism is arranged on the base and is opposite to the carrier, and is used for tightly attaching the battery cell to the battery shell; an