Eco-friendly prepared mesoporous carbon encapsulated SnO2 nanoparticles for high-reversible lithium-ion battery anodes

Abstract

Tin oxide (SnO 2 ) with porous carbon has attracted significant interest as a negative electrode material for lithium-ion batteries (LIBs). High cost and complex carbon coating preparation procedures are hinder in the commercialization of carbon based SnO 2 anodes. In this work, we designed and synthesized SnO 2 nanoparticles encapsulated mesoporous carbon composite (SnO 2 @MPC) derived from low cost and easily available green microalgae by the simple hydrothermal process followed by Iron oxide etching. The BET analysis confirmed the SnO 2 @MPC composite material contains highly porous carbon matrix with high surface area of 798.9 m 2 g −1 . The SnO 2 @MPC delivered a high initial capacity of 1042 mAh g −1 and showed a reversible capacity up to 180 cycles at a 0.1 C, which indicate that the porous carbon covering up SnO 2 nanoparticles alleviates the stress from the volume expansion. In addition, the porous carbon enhances the overall electrical conduction of the electrode and facilitate the electrolyte pentation, resulting in the better rate capability compared to bare SnO 2 nanoparticles (SnO 2 _NP). Tin oxide (SnO 2 ) has attracted significant interest as an anode material for lithium-ion batteries (LIBs) because of its moderate working potential and high theoretical capacity (782 mAh g −1 ). Structural collapse during cycling due to enormous volume expansion (>300%) and low conductivity hinder the commercialization of SnO 2 anodes. Herein, we synthesized a bio templated mesoporous carbon structure derived from green microalgae and containing SnO 2 nanoparticles. BET analysis after iron oxide etching revealed large increase in the surface area and pore volume over that of non-etched material. The porous carbon structure plays an essential role in enhancing the electrical connectivity between SnO 2 nanoparticles and minimizing the stress from volume expansion during electrochemical reactions. We prove that the strategy using biotemplating is an environmentally friendly and cost-effective way to enhance the electrochemical properties of SnO 2 . • Environmentally friendly and cost-effective synthetic route was used to produce the composite material of nanosized SnO 2 and mesoporous carbon. • Green microalgae were used as a carbon precursor to generate mesoporous carbon structure. • Etching process increases the electrochemically active surface. • Superior electrochemical performances resulted from the mesoporous carbon matrix enabling facile electrolyte penetration and enhancing electrical conductivity of electrode. • EIS proved that the Li + diffusivity is enhanced due to high surface area and mesoporous carbon matrix.