Preparation of Si/TiSi2 as high-performance anode material for lithium-ion batteries by molten salt electrolysis

Abstract

The photovoltaic industry has generated a large amount of silicon cutting waste (SiCW), whose disposal presents an urgent environmental issue. In this study, micron-sized flaky silicon cutting waste was transformed into silicon nanowires, and Si/TiSi2 nanocomposites were synthesized through molten salt electrolysis using photovoltaic SiCW and TiO2 as precursors. Lithium-ion batteries using the resulting composites as an anode exhibited an initial discharge specific capacity of 1936.1 mAh g⁻¹ and an initial Coulombic efficiency (ICE) of 83.99 %. After 200 cycles, its reversible specific capacity reached 1133.8 mAh g⁻¹, surpassing that of the molten salt electrolytic pre-oxidized SiCW (535.5 mAh g⁻¹) and untreated SiCW (385.0 mAh g⁻¹). This study presents a novel approach for modifying silicon-based anode materials while offering a sustainable and environmentally friendly method for recycling photovoltaic silicon waste.