Growing vertical graphene sheets on natural graphite for fast charging lithium-ion batteries

Abstract

A goal of extreme fast charging less than 15 min recharge time while maintaining high energy density has been pursued to meet fast-charging and high-energy-density demand on lithium ion batteries used in electric vehicles, which is still a challenge. Here, in order to realize the goal vertical graphene sheets are grown on surface of graphite by thermal chemical vapor deposition. The vertical graphene sheets not only can greatly boost lithium-ion transport rate due to its intrinsically high electrical conductivity but also can significantly reduce tortuosity of lithium ion transport due to its highly preferential lithium-ion insertion paths. In half cells, the vertical graphene sheets/graphite can endure 3000 cycles in 3 min of charge time per cycle. More remarkably, a full cell with vertical graphene sheets/graphite anode and LiFePO4 cathode exhibits an ultrahigh energy density of 312.1 Wh kg−1 in 10 min of charge time per cycle at 4 C, indicating that the vertical graphene sheets/graphite anode possesses ability of extreme fast charging while maintaining high energy density.