A facile and reliable route to the synthesis of high-performance LiFe2/3Mn1/3PO4@C/graphene for lithium-ion power batteries

LiFe2/3Mn1/3PO4@C/graphene with a regularly secondary spherical morphology and high-purity olivine-type structure was synthesized through a facile spray drying method. The primary crystal particles have an approximate size of 5 nm and are completely wrapped in disordered carbon, interconnected with graphene. EDS confirms the homogenous distribution of Mn and Fe within the LiFe2/3Mn1/3PO4@C/graphene sphere. The initial discharge capacity of LiFe2/3Mn1/3PO4@C/graphene is 162.1, 147.5, and 126.8 mAh g−1 at 0.5, 1 and 10 C, with corresponding capacity retentions of 91.1 %, 97.6 %, and 85.4 % after 100, 300, and 2000 cycles, respectively. Even at an ultrahigh rate of 20 C, LiFe2/3Mn1/3PO4@C/graphene is still capable of delivering 84.30 mAh g−1 of discharge capacity after 200 cycles. This exceptional electrochemical property is attributed to the homogeneous Mn and Fe distribution achieved through the spray drying method as well as the composite conductive networks constructed by disordered carbon and graphene sheets, which facilitate electron and Li+ transport.