Synthesis of silicon nanowire anode materials from forsterite by molten salt electrolysis

Silicon nanowires, which can be used as anodes in lithium-ion batteries, were synthesized from forsterite. SiO2 obtained from acid leaching of forsterite was electrolyzed in CaCl2 molten salt, in which silicon nanowire materials were generated. A surfactant (PEG-2000) was added to obtain uniform morphology features during the preparation of silica from etching forsterite. The molten salt electrolysis process was explored, and applicable conditions were proposed. Compared to the silicon produced from commercial silica, the silicon anode materials synthesized from forsterite showed a higher initial discharge specific capacity up to 2271 mAh g−1 at a discharge current density of 100 mA g−1, indicating satisfactory electrochemical performance. This method provides a new strategy for high value-added utilization of forsterite and low-cost preparation of anode materials for lithium-ion batteries.