Converting micro-sized kerf-loss silicon waste to high-performance hollow-structured silicon/carbon composite anodes for lithium-ion batteries

The low-cost feedstock and rationally designed structures are the keys to determining the lithium-storage performance and practical applications of Si-based anodes for lithium-ion batteries (LIBs). Herein, we employ the low-cost micro-sized kerf-loss silicon (KL-Si) as the cheap feedstock and melamine resin as the carbon resource to prepare hollow-structured Si@void@C composite. The naturally formed SiOx film and the organic layer on the surface of KL-Si during diamond wire slicing process serves as a natural sacrificial double template to create voids between the Si core and a melamine resin-derived carbon coating. The as-prepared hollow-structured Si@void@C composite anode delivers 1164.4 mAh g-1 at 1 A g-1 after 300 cycles with a retentive capacity of 927 mAh g-1 after 500 cycles at 3 A g-1. The full cell with the prelithiated Si@void@C anode and a Li(Ni0.6Co0.2Mn0.2)O2 cathode boasts a high a capacity retention of 81.5% after 150 cycles. This paper presents a straightforward approach to converting the low-cost KL-Si waste to value-added LIB anodes, enabling the full utilization of Si feedstock in the photovoltaic industry.