Microwave assisted synthesis of core-shell LiFe1/3Mn1/3Co1/3PO4/C nanocomposite cathode for high-performance lithium-ion batteries

A microwave assisted method is developed for synthesizing pure LiFe1/3Mn1/3Co1/3PO4 and LiFe1/3Mn1/3Co1/3PO4/C nanocomposite. Olivine LiFe1/3Mn1/3Co1/3PO4 coated with uniform amorphous carbon film of ∼5 nm in thickness with an average size of ∼200 nm is successfully obtained. Compared with pure LiFe1/3Mn1/3Co1/3PO4, LiFe1/3Mn1/3Co1/3PO4/C composite presents enhanced electrochemical Li-ion intercalation performances. It exhibits a high discharge capacity of 169 mA h g−1 at 0.1 C (theoretical capacity is 170 mA h g−1). The capacity retention is 99% after 30 cycles. Furthermore, the capacities are still retained 101 at 5 C and 76 mA h g−1 and 20 C, respectively. Carbon coating can significantly improve the Li-ion diffusion, the reversibility of lithium extraction/insertion and electrical conductivity of LiCo1/3Mn1/3Fe1/3PO4.