Silica template-assisted synthesis of SnO2@porous carbon composites as anode materials with excellent rate capability and cycling stability for lithium-ion batteries

Abstract

In this study, a type of porous carbon-coated SnO₂ nanoparticle composite (SnO₂@PC) was produced in the presence of a silica template. The prepared SnO₂@PC composite displays a highly specific surface area (SSA) and large pore volume compared with common porous carbons. Electrochemical testing demonstrates that as an anode material the SnO₂@PC1 composite can deliver a specific capacity of 1130.1 m Ah g⁻¹ at a current density of 0.2 A g⁻¹ after 100 cycles, which is much higher than that of pure SnO₂ anodes. The specific capacity of the SnO₂@PC1 anode is as high as 770.3 m Ah g⁻¹ at a current density of 0.5 A g⁻¹ after 300 cycles, indicating excellent rate and cycling capability. The superior lithium storage performance of the SnO₂@PC1 composite can be attributed to the synergistic effect of the porous carbon and SnO₂ nanoparticles. In addition, the large specific surface area and pore volume of the SnO₂@PC1 composite can significantly shorten the diffusion path of lithium ions and provide a sufficient internal void space for volume change. The proposed synthetic approach is facile, controllable, and economical, and can be applied in producing carbon coatings for other transition metal oxide-based composite functional materials.