Utilization of Cu-Foil Waste as a High-Capacity Anode Material for High Performance LiNi_0.8Co_0.1Mn_0.1O₂/ CuO@Graphite Batteries

Abstract

Significant demand of Li-ion batteries (LIBs) is raising awareness of future LIBs wastes which are highly required to be reprocessed, reused or recycled. In this research, copper foil waste from spent LIBs are upcycled as an anode material, CuO. Hydrometallurgical route was applied to selectively dissolve copper foils where nitric acid, maleic acid and acetic acid were used as the leaching agents while oxalic acid were used to precipitate copper into copper oxalate which is a precursor to CuO. CuO was obtained by calcination of copper oxalate at high temperature. Based on XRD and FTIR analysis, Copper (II) oxalate dihydrates is successfully obtained while SEM images of the samples confirmed micron sized agglomerates which is consist of submicron primary particles. XRD analysis of CuO samples obtained from various leaching process confirmed that a pure CuO is successfully synthesized from nitric acid leaching process while CuO from acetic acid and maleic acid leaching has Cu2O and Cu phase. CuO and 10%CuO@graphite sample from nitric acid leaching were used as sole anode and composite anode in a LiNi0.8Co0.1Mn0.1O2(NCM) battery, respectively. The initial columbic efficiency of CuO anode was far inferior to CuO@graphite. However, CuO@graphite had higher specific charge-discharge capacity with the value of 347.8 mAh/g compared to pure graphite (286.5 mAh/g). In conclusion, Cu-foils are a promising source of CuO to enhance the capacity of commercial graphite anode.