Enhanced electrochemical performance of LiFePO4 cathode with in-situ chemical vapor deposition synthesized carbon nanotubes as conductor

Abstract In this paper, carbon nanotubes (CNTs) are added in order to investigate their influence on the electronic conductivity of LiFePO 4 cathode. CNTs/LiFePO 4 composites are prepared by in-situ chemical vapor deposition method and the traditional mechanical mixture method respectively in order to investigate the influence of CNTs as an additive on the electrochemical performance of LiFePO 4 cathode. The particle morphology and electrochemical performances of the CNTs/LiFePO 4 composites are characterized and compared with commercial cathodes, LiFePO 4 mixed with carbon black. The in-situ synthesized CNTs/LiFePO 4 composite by chemical vapor deposition method maintains full retaining ratio after 100 cycles at 1C and 94.5% retention after 20 cycles at 10C, which precede the CNTs/LiFePO 4 composite fabricated by the mechanical mixture method as well as the commercial cathode. The enhanced electrochemical performance is due to the excellent interface bonding between LiFePO 4 and CNT in in-situ synthesized CNTs/LiFePO 4 composites. The interface benefits the electronic conductivity of the composites, as well as the polarization reduction.