Ethanol-controlled release strategy induced local solvation polymerization of silicates for high-performance...

Silicon (Si) is a promising anode material for next-generation lithium-ion batteries (LIBs) due to its exceptionally high theoretical specific capacity (4200 mAh g^-1), offering potential to replace traditional graphite in high-energy-density LIBs. However, Si anodes suffer from significant volume changes during lithiation/delithiation processes, posing a major challenge. In this study, we propose a reaction kinetics mechanism mediated by hydrogen-bond-induced local solvation effects for facilely obtaining coral-like nano-silicon (CN-Si). During the synthesis of SiO₂ using sodium silicate and ammonium chloride, the slow-release ethanol creates a localized solvation effect that regulates silicates polymerization, inducing its gradual growth into a coral-like structure. Following magnesiothermic reduction, the resulting nano-coral silicon demonstrates impressive performance as an anode material, exhibiting an initial reversible capacity of 2038 mAh g^-1 at a current density of 0.1 A g^-1, with a capacity retention of approximately 62.9 % after 100 cycles, and exhibited excellent rate performance across various current densities. The findings of this study clearly establish a novel concept of solvation-controlled, locally induced polymerization of silicates. Furthermore, the study provides a cost-effective route for the synthesis of high-performance nano-silicon anode materials.