Controllable synthesis of nano-LiFePO_4 on graphene using Fe_2O_3 precursor for high performance lithium ion batteries

摘要

LiFePO_4 (LFP) nanocrystals directly grown on graphene sheets (GS) was developed by an in-situ transformation approach using Fe_2O_3 as precursor. This novel strategy ensured intimate contact between LiFePO_4 and graphene sheets, the uniform distribution of both components within the composite. Moreover, the presence of graphene controlled the growth of LiFePO_4 nanocrystals (30-100 nm) and significantly increased electrical conductivity (0.6 S m~(-1)). Consequently, LFP-GS delivered a high specific capacity (165, 160 and 140 mAh g~(-1) at 0.1 C, 1 C and 5C, respectively), outstanding cycling stability (160 mAh g~(-1) at 1 C with no capacity fading after 100 cycles) and rate capability (121 mAh g~(-1) at 20 C).