FeBO3 as a low cost and high-performance anode material for sodium-ion batteries

Abstract The research of borate materials as sodium-ion batteries (SIBs) anode is still in the early stages, but the boron polyoxoanions are attracting intense interest due to their low atomic weight and high electronegative features. In this work, FeBO3 was prepared with low-cost raw materials and evaluated as SIBs anode. The FeBO3 shows a high reversible capacity of 328 mA h/g at the current density of 0.4 A/g. In addition, the electrochemical performance of FeBO3 can be improved by carbon coating. The prepared carbon-coated FeBO3 composite has a reversible capacity of 426 mA h/g (at 0.4 A/g) and an outstanding rate capability of 272 mA h/g (at 1.6 A/g). Furthermore, the sodium storage mechanism of FeBO3 was studied by in-situ XRD and ex-situ XPS.