Solvothermal Synthesis of LiFePO_4/C Nanoplate-Built Hierarchical Nest-like Microstructures for Lithium-Ion Batteries

摘要

Self-assembled hierarchical nest-like LiFePO_4/C microstructures from nanoplates have been synthesized by an ethylene glycol (EG)-mediated solvothermal route using Li_2SO_4, Fe(NO_3)_3 9H_2O and P_2O_5 as raw materials. It was found that EG not only played multifold roles in the formation process of such unique LiFePO_4 hierarchical microstructures, but also acted as carbon source during the heat treatment and forms conductive carbon coating on the surface of the LiFePO_4 nanoplates. In addition, employing P_2O_5 instead of other phosphorus sources was necessary for the formation of such unique microstructures. As the cathode material for lithium batteries, the as-prepared LiFePO_4/C architectures exhibit excellent cycle stability (158 mAhg~(-1) at 0.1 C up to 100 cycles) and good rate capacity (120 mAhg~(-1), 10 C). The desirable electrochemical performance can be attributed to such unique microstructure, which could remain structural stability for long-term cycling and improve the electrochemical reaction kinetics and finally promote the rate performance.