Recycling lithium cobalt oxide from its spent batteries: An electrochemical approach combining extraction and synthesis

LiCoO2 is still the most extensively used cathode material in Li-ion battery for portable electronics currently. The increasing usage of electronics has resulted in the growing discard of LiCoO2 with the stream of its spent battery. Current recycling approaches for LiCoO2 from spent batteries are dominantly based on hydrometallurgy and pyrometallurgy, which usually require multiple complicated steps and involve the use of high temperature or harmful chemicals, like acids and alkalis. There remains an urgent need for green and simple processes. Here we report a single step approach based on suspension electrolysis to directly recycle LiCoO2 in one reactor at atmospheric condition without any usage of acid and alkalis. The electrolyte of the suspension electrolysis system is only comprised of NH4HCO3, NH42SO3 and NaF. The reaction system of LiCoO2 leaching in the anode region and simultaneously re-synthesizing in the cathode region in the electrochemical system is established. Mechanism analysis indicates that NH4+ only serves as a provider for complexing agent of NH3 and is virtually not consumed. This work provides potentially meaningful strategies for recovering LiCoO2 in a shorter procedure and an environmentally friendly manner. [Display omitted] •LiCoO2 is recovered by NH4HCO3–(NH4)2SO3 suspension electrolysis system.•Cobalt is leached out from LiCoO2 in valence of + 3.•Metallic impurities impact negatively on recycling of LiCoO2.•Further research on demonstrating the process mechanisms is needed.