Facile synthesis of high capacity P2-type Na2/3Fe1/2Mn1/2O2 cathode material for sodium-ion batteries

P2-type Na2/3Fe1/2Mn1/2O2 was synthesized by a facile sol−gel method, and the effect of calcination temperature on the structure, morphology and electrochemical performance of samples was investigated. The results show that the sample obtained at 900 °C is pure P2-type Na2/3Fe1/2Mn1/2O2 phase with good crystallization, which consists of hexagon plate-shaped particles with the size and thickness of 2−4 µm and 200−400 nm, respectively. The sample exhibits an initial specific discharge capacity of 243 mA·h/g at a current density of 26 mA/g with good cycling stability. The high specific capacity indicates that P2-type Na2/3Fe1/2Mn1/2O2 is a promising cathode material for sodium- ion batteries.