▎ 摘　　要

In the on-going development of power sources and energy-storage devices, achieving both high power and large energy capacity with a high discharge rate is still a great challenge. In this paper, three dimension assembled graphene-LiFePO4 (G-LFP) composites were prepared by one-step hydrothermal method. LiFePO4 (LFP) particles became smaller and were dispersed uniformly on the graphene sheets after compositing with graphene. Compared to the pristine LFP, the electrochemical properties of the G-LFP are greatly improved, especially the rate capability and the cyclic performance. At 10 C, the G-LFP holds nearly 80 % of the initial capacity and has a flat voltage platform, while for the LFP, its capacity drops down to 65 % and its voltage platform is not noticeable. After 600 cycles at 10 C, the specific capacity of the G-LFP decreases from 135 to 125 mA hg(-1) with a capacity loss of 5.1 %, while it drops from 105 to 86 mA hg(-1) with a capacity loss of 30 % for the LFP. The reason for the improvement of the electrochemical performances could be ascribed to the introduction of graphene which enhances the conductivity and diminishes the LFP size which improves the diffusion of lithium ions.