Upcycling of Spent LiCoO2 Cathode to Lithium Dual‐Ion Battery Anode

Abstract Owing to the paradigm shift of the automobile industry toward the electrification of vehicles, the aftermath of batteries that power these devices at the end of their lives has to be addressed strenuously. Since upcycling strategies are hardly in the limelight, this paper focuses on giving a second life to LiCoO 2 cathode as a dual‐ion battery (DIB) anode. Among many possible recovery approaches explored for cobalt, a microwave‐assisted green leaching method comprising mild leaching agents is chosen for this work. Cobalt is recovered as cobalt oxalate and converted to cobalt/cobalt oxide nanospheres embedded in a porous graphitic carbon matrix (Co 3 O 4 /Co@C). Due to the high working voltage, excellent safety, and environmental friendliness, DIBs are being considered as a replacement for lithium‐ion batteries in specific sectors. In an unconventional approach, the derived Co 3 O 4 /Co@C is effectively employed as an anode material for dual‐ion batteries. The half‐cell demonstrates a high discharge capacity of 550 mAh g −1 at 0.1 A g −1 . A full‐cell DIB fabricated using Co 3 O 4 /Co@C, derived from upcycled LiCoO 2 as an anode and graphite as a cathode, shows an appreciable capacity and remarkable cycling stability. This sustainable approach for upcycling exhausted LIBs can pave the way to improve the circular economy of batteries.