Synthesis of Si/C Composites by Silicon Waste Recycling and Carbon Coating for High-Capacity Lithium-Ion Storage

Abstract

It is of great significance to recycle the silicon (Si) kerf slurry waste from the photovoltaic (PV) industry. Si holds great promise as the anode material for Li-ion batteries (LIBs) due to its high theoretical capacity. However, the large volume expansion of Si during the electrochemical processes always leads to electrode collapse and a rapid decline in electrochemical performance. Herein, an effective carbon coating strategy is utilized to construct a precise Si@CPPy composite using cutting-waste silicon and polypyrrole (PPy). By optimizing the mass ratio of Si and carbon, the Si@CPPy composite can exhibit a high specific capacity and superior rate capability (1436 mAh g−1 at 0.1 A g−1 and 607 mAh g−1 at 1.0 A g−1). Moreover, the Si@CPPy composite also shows better cycling stability than the pristine prescreen silicon (PS-Si), as the carbon coating can effectively alleviate the volume expansion of Si during the lithiation/delithiation process. This work showcases a high-value utilization of PV silicon scraps, which helps to reduce resource waste and develop green energy storage.

Bio‐Inspired Electrodes with Rational Spatiotemporal Management for Lithium‐Ion Batteries

“…Additionally, carbon shells enhance conductivity and significantly reduce the charge transfer resistance of Si‐based anodes. [ 154 , 311 , 312 , 313 ] The double‐shelled hollow structures effectively tune the vigorous volume change, facilitates the formation of a highly stable SEI layer, shortens the electron/lithium‐ion transport distances and provides fast electron transport in the interconnected hollow structure. [ 314 ] Thus, a compact micron‐sized composite anode with a tight binding and double‐shell architecture possesses superior deformation resistance and electrical conductivity, contributing to excellent cycling stability and good rate capability in a thick electrode.…”

Silicon kerf loss as a potential anode material for lithium-ion batteries

“…Various application areas are being considered, such as in thermoelectric modules, back into PV as silicon feedstock, in Al-Si alloys, for hydrogen production, and for silicon nitride production (Drouiche et al, 2014;Kao et al, 2016;Halvorsen et al, 2017;Jin et al, 2020;Wei et al, 2020;Huang et al, 2023). From a circularity viewpoint, the most beneficial option would be to produce a silicon feedstock material that goes back to the PV cycle from the silicon kerf.…”

“…However, this is an energy-intensive approach, as it would necessitate melting steps and several purification processes. Another attractive high-value application would be in lithium-ion batteries (LIBs) as an anode material (Wagner et al, 2019;Ma et al, 2020;Zheng et al, 2022;Hengsong et al, 2023;Huang et al, 2023).…”