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

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.