Si-based materials derived from biomass: synthesis and applications in electrochemical energy storage

The attractive theoretical specific capacity of silicon (Si) makes it a strong candidate for use in electrochemical energy storage materials. Si exists in organisms in the form of silicic acid or SiO2, which is converted into simple Si or SiOx (0 < x < 2) by a simple reduction reaction. The synthesis of nano/micro structure Si-based materials from biomass with a high Si content has become an ideal method for their conversion into functional materials. Thus, the recovery of value-added products such as rice husks (RHs) and diatoms for the development of a green and economical way for the valorization of biomass material wastes has gained significant attention. In this review, the synthesis of Si-based materials derived from biomass and their applications in the field of electrochemical energy storage were summarized and the effect of their morphology was emphasized. Finally, in view of the application prospects and challenges of the biomass-derived Si-based materials, appropriate improvement schemes were proposed and prospects for the future practical applications of these materials were discussed.