Olivine LiFePO4 nanocrystals grown on nitrogen-doped graphene sheets as high-rate cathode for lithium-ion batteries

摘要

The commercial LiFePO4 cathode has attracted great attention for large-scale energy storage because of its high safety, low cost, low toxicity and excellent thermal stability. Unfortunately, the poor electronic conductivity of LiFePO4 leads to bad lithium storage property. In this work, the nitrogen-doped graphene-decorated LiFePO4 was prepared via a facile hydrothermal method followed by a conventional solid-state route. Benefiting from the advantages of nitrogen-doped graphene, the conductivity of LiFePO4 is greatly improved. Therefore, the obtained composite shows excellent electrochemical performances, including high reversible capacity (163.1 mAh g(-1) at 0.1 C), good rate capability (113.7 mAh g(-1) at 10 C) and stable cycle-life (111.6 mAh g(-1) after 150 cycles at 10 C). These results reveal that the designed nitrogen-doped graphene-decorated LiFePO4 composite is a promising cathode material for rechargeable lithium-ion batteries.