Volume 6 Issue 4 ( December 2019 )

Pages 275-279

O3-type Na(Fe1/3Mn1/3Co1/3)O2 as a Cathode Material with High Rate and Good Charge-Discharge Cycle Performance for Sodium-Ion Batteries

Takayuki Tsubota, Ayuko Kitajou, Shigeto Okada


O3-Na(Fe1/3Mn1/3Co1/3)O2 has been reported as a cathode material with a reversible capacity of 84mAh/g. This cathode active material shows excellent electrochemical performance with a high capacity retention of 95.0% after 100 cycles at 1C rate, and a discharge rate capability of 37mAh/g (47% of the initial capacity of 1C rate) at 50C rate. From the results of electrochemical impedance spectroscopy, an increase in reaction resistance was not confirmed between before and after the charge / discharge cycle test. TEM observation revealed that the crystal structure change on the surface of O3-Na(Fe1/3Mn1/3Co1/3)O2 after the charge / discharge cycle test was slight, and the change in the crystal structure was small compared with that of the lithium ion battery, so O3-Na(Fe1/3Mn1/3Co1/3)O2 has high crystal structure stability.

Keywords: sodium ion battery, cathode materials, electrochemical impedance spectroscopy