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 SiOx 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, SnOy @C/SiOx composites with unique structure (Sn/SnO2 dispersed on the surface and within pores of biochar as well as SiOx residing in the interior) are obtained due to the exclusive biological properties of rice husk. Such unique structural features render SnOy @C/SiOx 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 ||SnOy -50@C/SiOx 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.
Keywords: SiO x; disproportionation reactions; lithium-ion batteries; low-temperature pyrolysis coreduction; rice husk.
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