LiFePO4 Particles Coated with N-Doped Carbon Membrane

We prepared LiFePO4 particles coated with N-doped carbon membrane by microwave pyrolysis of ionic liquid 1-butyl-3-methylimidazolium dicyanamide ([BMIM]-[N(CN)2]). Because of the strong microwave absorbing property of ionic liquid [BMIM]-[N(CN)2], it can be heated and gradually carbonized in the microwave field. Uniform and network-like N-doped carbon membrane was formed on the surface of LiFePO4 particles after carbonization of [BMIM]-[N(CN)2]. The N-doped carbon membrane was beneficial to improve the electronic conductivity of LiFePO4. Therefore, the N-doped carbon coated LiFePO4 using [BMIM]-[N(CN)2] as a carbon source owned higher discharge capacity and cyclic performance than those using glucose as a carbon source.