Constructing Biomass-Based Ultrahigh-Rate Performance SnO_y @C/SiO_x Anode for LIBs via Disproportionation Effect

To break the stereotype that silica can only be reduced via a magnesiothermic and aluminothermic method at low-temperature condition, the novel strategy for converting silica to SiO_x using disproportionation effect of SnO generated via low-temperature pyrolysis coreduction reaction between SnO₂ and rice husk is proposed, without any raw materials waste and environmental hazards. After the low-temperature pyrolysis reaction, SnO_y @C/SiO_x composites with unique structure (Sn/SnO₂ dispersed on the surface and within pores of biochar as well as SiO_x residing in the interior) are obtained due to the exclusive biological properties of rice husk. Such unique structural features render SnO_y @C/SiO_x composites with an excellent talent for repairing the damaged structure and the highly electrochemical storage ability (530.8 mAh g^-1 at 10 A g^-1 after 7500 cycles). Furthermore, assembled LiFePO₄ ||SnO_y -50@C/SiO_x full cell displays a high discharge capacity of 463.7 mAh g^-1 after 100 cycles at 0.2 A g^-1 . The Li⁺ transport mechanism is revealed by density functional theory calculations. This work provides references and ideas for green, efficient, and high-value to reduce SiO₂ , especially in biomass, which also avoids the waste of raw materials in the production process, and becomes an essential step in sustainable development.