Recovery Li/Co from spent LiCoO2 electrode based on an aqueous dual-ion lithium-air battery

Abstract

While lithium-ion batteries dominate the field of electronic devices and vehicles, recovery of LiCoO2 from spent batteries becomes a significant process. Aqueous lithium-air battery and dual-ion battery were blended into a novel electrochemical system as dual-ion lithium-air battery (DLAB) system to recover Li and Co elements from the spent LiCoO2 (acid solution). In the system, oxygen, LiCoO2 acid solution and Li2Ti2(PO4)3 (LTPO), which has Na+ superionic conductor structure and is synthesized by sol-gel method, were used as cathode, dual-ion electrolyte and anode. Relatively low voltage plateaus, stability and insolubility of LTPO make it to be a feasible candidate for this aqueous DLAB. By applying Pt/C as a catalyst for cathode, the full discharged system exhibits a Co ion recovering rate of up to 96.2%. Moreover, this system presents positive discharge plateaus at around 0.47 V and 0.10 V during recovering, demonstrating an output energy density of 43.88 Wh kg−1. The system shows a green and promising way for the recovery of spent LiCoO2 battery.