High performance lithium ion battery cathode based reduced holey graphene oxides from spent lithium ion batteries

The search of alternatives to the commercial electrodes is a key to the development of advanced lithium ion batteries (LIBs). Compared to extensive efforts and progress made on their anode applications for LIBs, the graphene and its derivatives as cathodes have attracted less concerns. Herein, a series of reduced holey graphene oxides (rhG-x) with different "worm-like" and holey structures were synthesized based on the modified Hummer's treatment and thermal reduction of graphite anode from spent LIBs. Benefiting form the rhG-x annealed at x = 400 °C with optimized oxygen-containing groups and electronic conductivity, as well as the "worm-like" and holey structures, the rhG-400 as cathode for LIBs delivers a high reversible capacity (e.g., 109.6 mAh g−1 at 0.05 A g−1) and excellent rate capability (e.g., 75.0, 68.2, 50.3 and 37.0 mAh g−1 at 2, 5, 10 and 20 A g−1, respectively) and maintains an ultra-long cycling life over 2000 cycles with high reversible capacity of 137.4 mAh g−1.