Electrochemical Intercalation of Sodium into Composites Based on Iron(III) Phosphate and Carbon

Abstract

Materials based on amorphous iron(III) phosphate have been prepared via precipitation in an aqueous medium and microemulsion, as well as in a microemulsion in the presence of a mesoporous carbon material. Heat treatment of amorphous FePO₄ leads to the formation of the hexagonal phase of crystalline FePO₄. It has been shown that sodium intercalation under operating conditions of sodium ion batteries is more effective in the case of materials based on amorphous FePO₄. The discharge capacity of the material based on amorphous FePO₄ synthesized by the microemulsion method in the presence of the G_157M mesoporous carbon material is ~183 mAh/g and is the sum of the capacity due to sodium intercalation into FePO₄ and that due to the reduction of functional groups on the surface of the mesoporous carbon.