Washing Process for Nickel-rich Cathode Synthesized with Excessive Lithium Salts

Abstract

Excessive amount of lithium salts such as LiOH or Li₂CO₃ are usually used when synthesizing lithium nickel manganese cobalt dioxide cathodes such as LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) or similar to compensate for the loss of lithium salts at high temptations. Correspondingly, there will be salts left on the surface of as-synthesized NMC particle surface. A washing process is therefore necessary to remove the residual lithium salts which otherwise will cause the dehydroflourination of the poly(vinylidene fluoride) binder[1-3] during the slurry preparation forming “gel”.