Copper sheet flow diversion welding design and method for welding copper sheet and battery nickel top cover

Abstract

The invention discloses a copper sheet flow diversion welding design and a method for welding a copper sheet and a battery nickel top cover. A flow diversion trench is added at the welding position of the copper sheet, so that current passes through a loop formed by the lower nickel top cover and an electrode; alternating-current resistance welding is adopted, it is ensured that a molten core can be formed by the copper sheet and the nickel top cover, and the welding process is stable. It is ensured that the copper sheet and the battery nickel top cover can be directly welded, no soldering paste and other scaling powder need to be brushed for auxiliary welding, no cold solder joint is formed, no person is needed for brushing the soldering paste, the production efficiency is improved, cold solder joints are 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 a nickel top cover of the battery. Background technique [0002] At present, the resistance welding method used between the copper sheet and the nickel 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 method ...

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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 copper sheet has good conductivity and the lower nickel top cover has poor conductivity, the current basically flows from the electrode-copper sheet-electrode during welding, and it is difficult to flow through the lower nickel top cover, resulting in The heat only acts on the surface of the copper sheet, so the copper sheet and the nickel top cover cannot form a nugget, and the welding process is unstable. It needs to be soldered with solder paste and other fluxes to assist welding, and false welding occurs.

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