Chitosan assisted synthesis of LiFePO4/Graphene/C composite and its electrochemical performance

LiFePO4/graphene/C composite was prepared using chitosan (CS) and graphene oxide (GO) as carbon sources via a facile solid state method. CS can bond with GO through electrostatic force between amino group on CS and carboxy group on GO. With high temperature treatment, GO can be reduced to graphene and CS can be decomposed into carbon. By adding chitosan, severe agglomeration of graphene can be prevented. As a result, a continuous conductive framework was formed. The good conductivity facilitates electron migration, contributing to excellent electrochemical performance especially the high-rate performance. Consequently, the composite LiFePO4/graphene/C exhibited higher initial discharge capacity of 145.2 mAh.g(-1) at the low rate of 0.1 C and retained 62.6 mAh.g(-1) at high rate of 10 C, while the LiFePO4 merely coated with graphene (LFP/G) was 125.9 mAh.g(-1) (0.1 C) and 6.5 mAh.g(-1) (10 C), respectively.