Simplified Synthesis of Biomass-Derived Si/C Composites as Stable Anode Materials for Lithium-Ion Batteries

Graphical Electrodes from rice waste : A simplified process is developed to synthesize Si/C composites from biomass, by using a low-cost agricultural byproduct “rice husk (RH)-biomass”, without extra steps such as the removal of carbon from calcined biomass and then the deposition of carbon for Si/C. The final product with the optimized nanostructure exhibits enhanced electrochemical performance in terms of reversible capacity and long-term cycling stability. Synthesis of silicon/carbon (Si/C) composites from biomass resources could enable the effective utilization of agricultural products in the battery industry with economical as well as environmental benefits. Herein, a simplified process was developed to synthesize Si/C from biomass, by using a low-cost agricultural byproduct “rice husk (RH)” as a model. This process includes the calcination of RH for SiO 2 /C and the reduction of SiO 2 /C by Al in molten salts at a moderate temperature. This process does not need the removal of carbon before thermal reduction of SiO 2 , which is thought to be necessary to avoid the formation of SiC at elevated temperatures. Thus, carbon derived from biomass can be directly used for Si/C composites for anode materials. The resultant Si/C shows a high reversible capacity of 1309 mAh g −1 and long cycle life (300 cycles). This research advocates a new and simplified strategy for the synthesis of RH-based biomass-derived Si/C, which is beneficial for low-cost, environmentally friendly, and green energy storage applications.