Constructing a Sheet-Stacked Si/C Composite by Recycling Photovoltaic Si Waste for Li-Ion Batteries

Massive silicon (Si) waste is generated during the diamond wire cutting process in the photovoltaic industry. Recycling the Si waste to prepare anode materials for lithium-ion batteries is an important way to realize its value-increment utilization. However, controlled preparation of a waste-derived Si/C anode with superior performance still remains a great challenge. Herein, focusing on the pristine sheet-like morphology of Si waste from diamond wire cutting, Mg reduction is employed to reduce the size in the lamellar direction to form a sheet-stacked structure. Combined with CO2-derived carbon coating, a sheet-stacked Si/C composite anode with a porous structure is successfully constructed via subtle optimization of the Mg reduction time. The optimized Si/C electrode can release a remaining capacity of 693 mA h g–1 after 300 cycles at 1.0 A g–1. This work provides an efficient way for recycling Si waste as anode materials for LIBs.