▎ 摘　　要

A novel green and low-cost synthesis route converting spent graphite anode from lithium-ion batteries (LIBs) into graphene nanosheets was reported for the first time. The impurities in spent graphite were eliminated by calcining and acidic leaching. Compared with the typical Hummers method, notable oxidation efficiency enhancement was observed through introducing a 5 : 1 mixed suspension of H2SO4 and H3PO4 with slightly increased KMnO4, then high-quality graphene sheets were obtained through glucose, thermal reduction and subsequent liquid exfoliation. By simply and efficiently chemical nitrogen doping, graphene sheets showed excellent oxygen reduction catalytic performance, which is even better than commercial Pt/C catalyst, allowing it to be a promising low-cost catalyst candidate for fuel cells. Since LIBs and fuel cell are considered as the major two power sources for electric vehicles in very near future, we believe that synthesizing few-layer graphene with few defects and functionalized graphene catalyst from spent LIBs paves a path towards to the full utilization of battery materials and thus reduces impacts on environment from developing electric vehicles.