A supercritical methanol route for the synthesis of sodium iron oxide submicron plates for use as a cathode material for sodium-ion batteries.

Highly crystalline, phase-pure NaFeO 2 submicron plates are synthesized using a facile and simple supercritical methanol route. The synthesized NaFeO 2 submicron plates are 160 to 680 nm in width and 90 nm in thickness. Because of their two-dimensional structure, the NaFeO 2 submicron plates exhibit excellent electrochemical performance with smaller polarization compare to micron-sized NaFeO 2 particles synthesized using a solid-state method; the initial charge capacity is 94 mAh g −1 at 10 mA g −1 and high-rate capacity of 34 mAh g −1 at 50 mA g −1 , which is 180% higher than that of solid-state synthesized NaFeO 2 . The enhanced charge-discharge characteristics are attributed to the low charge transfer resistance and high Na-ion diffusivity. [ABSTRACT FROM AUTHOR]