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

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.