Synthesis of in situ network-like vapor-grown carbon fiber improved LiFePO4 cathode materials by microwave pyrolysis chemical vapor deposition

The low electronic conductivity of LiFePO4 currently limits its use in lithium ion batteries. In order to solve the problem, in situ network-like vapor-grown carbon fiber (VGCF) improved LiFePO4 cathode materials have been prepared in one step by microwave pyrolysis chemical vapor deposition. The phase, microstructure and electrochemical performances of the composites were investigated. Compared with the cathodes without in situ VGCF, the initial discharge capacity of the composite electrode increases from 84 mAh g−1 to 123 mAh g−1 at 3.0 C rate, and the charge transfer resistance varies from 420 Ω to 75 Ω. The possible reasons of those are proposed.

• MCVD could prepare in situ VGCFs enhanced LiFePO4 in one step. • In situ VGCFs improve the electronic conductivity of cathode materials effectively. • In situ VGCFs enhanced LiFePO4 shows better electrochemical properties.