Coating process for notch type lithium ion battery

Abstract

The invention discloses a coating process for a lithium ion battery and particularly relates to a coating process for a notch type lithium ion battery. The notch type lithium ion battery comprises a coating area and a non-coating area. When a pole piece is coated, some areas of the pole piece are not coated and the uncoated areas are used for welding with pole ears. By using the coating process, the capacity of the lithium ion battery is increased, the product quality is promoted, the process is simplified, the production cost is lowered, and the process is safe, reliable and pollution-free.

Description

technical field [0001] The invention relates to a coating process for a lithium ion battery, in particular to a notched lithium ion battery coating process. Background technique [0002] The coating process of lithium-ion batteries in the prior art mostly adopts two processes of continuous coating and gap coating. For the continuous coating process, it is simple and easy to operate, but it is difficult to weld the tabs on the coated pole pieces, so that the subsequent tabs There are difficulties in welding. Some technologies use laser scraping technology to scrape out an empty foil, and the empty foil is used for welding with tabs. This process has the following defects: [0003] (1) During laser scraping, some material powder is sputtered and adhered to the pole piece, which will cause problems such as short circuit in the finished battery and large self-discharge; [0004] (2) During laser scraping, the pole piece will go through the process of unwinding and rewinding, wh...

AI Technical Summary

Problems solved by technology

[0002] The coating process of lithium-ion batteries in the prior art mostly adopts two processes of continuous coating and gap coating. For the continuous coating process, it is simple and easy to operate, but it is difficult to weld the tabs on the coated pole pieces, so that the subsequent tabs There are difficulties in welding. Some technologies use laser scraping technology to scrape out an empty foil, and the empty foil is used for welding with tabs. This process has the following defects:

[0003] (1) During laser scraping, some material powder is sputtered and adhered to the pole piece, which will cause problems such as short circuit in the finished battery and large self-discharge;

[0004] (2) During laser scraping, the pole piece will go through the process of unwinding and rewinding, which will easily cause problems such as folding, breaking, and uneven winding of the pole piece, damage the pole piece, and affect the normal operation of the subsequent process ;

[0005] (3) Laser equipment is used, which has high cost, radiation, and is not environmentally friendly;

[0006] (4) The paint is not used rationally and there is waste;

[0008] (1) The length of the gap coating gap is the entire width of the foil (20cm-60cm), but the actual tab welding generally requires a space of 0.5cm-0.8cm foil width, and there is no coating on the empty foil, which reduces the capacity of the battery;

[0009] (2) The coating gap needs to be pasted with tape, which increases the cost;

[0010] (3) Tape is easy to react with electrolyte, reducing battery performance;

[0011] (4) The negative electrode adopts gap coating, which is easy to cause lithium dendrites;

[0012] (5) The adhesive tape increases the internal resistance of the battery, causing the battery to heat up, which may cause safety problems

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