A low-cost Si@C composite for lithium-ion batteries anode materials synthesized via freeze-drying process using kerf loss Si waste

Silicon-carbon (Si@C) composites are emerging as promising replacements for commercial graphite in lithium-ion battery (LIB) anodes. This study focuses on the development of Si@C composites using silicon waste from photovoltaic industry kerf loss (KL) as a source for LIB anodes. We extracted purified nanosilicon powder from KL Si wastes through a combined process of ball milling and acid leaching. The Si@C composites were then fabricated using a novel approach involving glucose coating and freeze-drying. This method ensures that the glucose effectively encapsulates the silicon, significantly mitigating volume fluctuations during charge/discharge cycles. Additionally, the freeze-drying process introduces a rich porosity to the composite, facilitating enhanced Li+ diffusion. Our results show that the synthesized Si@C electrode, designated as SC-13, delivers a stable discharge specific capacity of 792 mAh g−1 over 100 cycles at a current density of 0.1 A g−1. This study not only showcases a cost-effective technique for converting KL Si waste into a high-value material but also contributes to the advancement of energy storage solutions.