Synthesis of Li2FeSiO4/C and its excellent performance in aqueous lithium-ion batteries

A carbon-coated Li2FeSiO4 (Li2FeSiO4/C) material was synthesized through a liquid-phase-assisted method. The obtained sample can be used as an anode material for aqueous lithium-ion batteries. The aqueous electrolyte cell system used in this study delivers a capacity of approximately 90 mA h g(-1) based on the total weight of the anode material Li2FeSiO4/C and an export voltage of 1.2 V. The aqueous electrolyte cell system also exhibits excellent cycling stability with a capacity loss of less than 10% after 30 cycles and a high coulombic efficiency of almost 100% in the preliminary 30 cycles. This study provides the most promising anode material for aqueous lithium-ion batteries because of its environmental inertness and low cost and since Fe and Si are among the most abundant and inexpensive elements.