Design of diversion welding of copper sheet and welding method with battery copper top cover

Abstract

The invention discloses copper sheet flow guiding welding design and a welding method for a battery copper top cover. A flow guiding groove is added in the welding position of a copper sheet, a loop can be formed by current between the copper top cover below and an electrode, intermediate-frequency inversion direct-current resistance welding is adopted, it is ensured that a molten core can be formed by the copper sheet and the copper top cover, and the welding process is stable. According to the copper sheet flow guiding welding design and the welding method for the battery copper top cover, it can be ensured that the copper sheet can be directly welded to the battery copper top cover, soldering flux such as soldering paste does not need to be brushed for auxiliary welding, pseudo soldering does not happen, soldering paste brushing personnel are reduced, the production efficiency is improved, pseudo soldering is avoided, the product quality is improved, and the soldering paste purchasing cost is saved.

Description

technical field [0001] The invention relates to the field of resistance welding of lithium-ion batteries, in particular to a copper sheet diversion welding design and a welding method with the copper top cover of the battery. Background technique [0002] At present, the resistance welding method used between the copper sheet and the copper top cover of the battery is generally an energy storage type DC resistance welding, and its performance is as follows: [0003] Since the energy stored in the capacitor needs to be released to the welding circuit at one time, the output energy adjustment is completed by controlling the charging energy of the capacitor. The output current is a pulse current, and the welding current and time cannot be adjusted by electronic control, so the welding is unstable. The chip needs to be soldered with flux such as solder paste to be soldered, and there will be false soldering. [0004] In the energy storage direct current resistance welding metho...

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Problems solved by technology

[0003] Since the energy stored in the capacitor needs to be released to the welding circuit at one time, the output energy adjustment is completed by controlling the charging energy of the capacitor. The output current is a pulse current, and the welding current and time cannot be adjusted by electronic control, so the welding is unstable. The chip needs to be brushed with solder paste and other flux to solder, and there will be false soldering

[0004] In the energy storage direct current resistance welding method adopted above, since the upper layer copper sheet has good conductivity, but the lower layer copper top cover has poor conductivity, the current basically flows from electrode-copper sheet-electrode during welding, and it is difficult to flow through the lower layer copper top cover, resulting in The heat only acts on the surface of the copper sheet, so the copper sheet and the copper top cover cannot form a nugget, and the welding process is unstable. It is necessary to brush solder paste and other fluxes to assist welding, and there will be false welding.

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