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

LiCoO 2 ${\mathrm{LiCoO}}_2$ 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 LiCoO 2 ${\mathrm{LiCoO}}_2$ with the stream of its spent battery. Current recycling approaches for LiCoO 2 ${\mathrm{LiCoO}}_2$ 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 LiCoO 2 ${\mathrm{LiCoO}}_2$ in one reactor at atmospheric condition without any usage of acid and alkalis. The electrolyte of the suspension electrolysis system is only comprised of NH 4 HCO 3 ${\mathrm{NH}}_4{\mathrm{HCO}}_3$ , NH 4 2 SO 3 ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_3$ and NaF $\mathrm{NaF}$ . The reaction system of LiCoO 2 ${\mathrm{LiCoO}}_2$ leaching in the anode region and simultaneously re-synthesizing in the cathode region in the electrochemical system is established. Mechanism analysis indicates that NH 4 + ${\mathrm{NH}}_4^{+}$ only serves as a provider for complexing agent of NH 3 ${\mathrm{NH}}_3$ and is virtually not consumed. This work provides potentially meaningful strategies for recovering LiCoO 2 ${\mathrm{LiCoO}}_2$ in a shorter procedure and an environmentally friendly manner.