Two-electron migration orthosilicate cathode materials for Na-ion batteries

Abstract

For the first time, sodium iron orthosilicates were obtained through electrochemical Li–Na ion-exchange and tested as cathode materials for Na-ion batteries. Discharge capacities as high as 330 mA h g⁻¹ could be reached in the Na cells at the rate of 10 mA g⁻¹ and at room temperature, it showed that two Na⁺ ions per molecule could intercalate into these orthosilicates.