Cobalt and lithium recovery from spent LiCoO using a free-standing potassium zinc hexacyanoferrate/carbon cloth composite electrode

Rapid rejuvenation and extensive utilization of mobile electronic devices lead to the excessive accumulation of waste lithium-ion batteries (LIBs), specifically spent LiCoO 2 cathode materials. Considering the shortage of metal resources and the surging price of raw materials in the battery industry, an efficient strategy for selectively extracting valuable metals from spent LiCoO 2 is urgently required. Herein, nanocube-like potassium zinc hexacyanoferrate (denoted as KZHCF) was successfully fabricated on a carbon cloth (CC) substrate for selective Co 2+ adsorption from a spent LiCoO 2 cathode via the combination of simple electrodeposition and hydrothermal treatment. Under optimal operational conditions, 98.6% of Co 2+ was effectively extracted within 120 min at a constant potential of −0.4 V ( vs. Ag/AgCl) with the CC/KZHCF composite as the working electrode, accompanied with a Co 2+ electrosorption capacity of 130.9 mg g −1 . Further, lithium ions in the electrolyte were separated and recovered in the form of Li 2 CO 3 via simple chemical precipitation, highlighting the feasibility of the developed electrochemical system toward cobalt and lithium recovery. Significantly, the CC/KZHCF electrode materials could be regenerated through simple potential inversion, while adsorbed Co 2+ ions were facilely desorbed from the electrode surface and recovered as Co(OH) 2 . This work will provide a meaningful guidance for the separation and recovery of various metals from waste LIBs. A free-standing CC/KZHCF composite can be directly employed as the working electrode for effective separation and recovery of Co 2+ and Li + from waste LiCoO 2 cathode.