An ordered mesoporous network consisting of carbon‐coated ultrasmall SnO ₂ nanoparticles with enhanced Lithium storage

Abstract An unique ordered mesoporous network consisting of carbon‐coated SnO ₂ nanoparticles (NPs) is developed by a facile self‐assemble strategy via a solvethermal route in which employs N,N‐dimethylformamide/H ₂ O as mixture solvent and polyvinyl pyrrolidone as barrier agent and carbon source. The SnO ₂ ‐NPs with an uniform dimension of ~5 nm are observed to interconnect with each other, and assemble into high‐compact blocks where abundant mesopores with an average diameter of ~4 nm are found throughout the body. The carbon coating with a thickness of <1 nm are confirmed to exist on these SnO ₂ ‐NPs, which is of great importance to avoid the severe sintering that occurs in the case of bare SnO ₂ ‐NPs. Furthermore, the carbon coating plays roles in enhancing conductivity and keeping the active particles from being directly contacted with electrolyte, and thus contributes to enhanced reversible capacity of 949 mAh g ⁻¹ and improved initial Coulombic efficiency. The composite electrode with a high tap density of 2.0 g cm ⁻³ exhibits substantially elevated electrochemical performances, such as a charge capacity of 565 mAh g ⁻¹ vs 223 mAh g ⁻¹ of common SnO ₂ ‐NPs after 60 cycles and greatly improved rate capability, indicating the promising applications of this advanced micro‐nano architecture for next‐generation lithium‐ion batteries.