Cost-effective production of SiO2/C and Si/C composites derived from rice husk for advanced lithium-ion battery anodes

Rice husk, an agricultural waste, was chosen as the low-cost source to synthesize silica/carbon (SiO2/C) and silicon/carbon (Si/C) composite materials through a simple calcination and magnesiothermic reduction reaction, respectively. After rice husk was calcined, SiO2 and C coexisted in the sample in which the nanosized SiO2 particles were distributed on C plate. When Si/C composite was fabricated by magnesiothermic reduction reaction, Si and C were obtained together with small amount of SiC phase. The rice husk-derived SiO2/C and Si/C composites provided different specific characteristics in which good cycling stability was found in SiO2/C composite while Si/C gave high specific capacity. This work suggested that the facile preparation strategy with environmental friendliness and low-cost effective can be used to produce SiO2/C and Si/C composites with good electrochemical characteristics. The preparation technique used in this work may be available for other biomass anode materials.