Microwave-assisted and large-scale synthesis of SnO2/carbon-nanotube hybrids with high lithium storage capacity

Abstract

A novel SnO₂/carbon-nanotube hybrid has been successfully synthesized at large scale by an ultrafast and environmentally benign microwave-assisted technique under atmospheric condition. The as-synthesized hybrids feature a unique structure with ultrathin SnO₂ nanosheets and nanoparticles composited on multiwalled carbon nanotubes (CNTs). The specific surface area of the hybrids is as high as 145.46 m² g⁻¹ even with high SnO₂ loading percentage of ∼85 wt%. The SnO₂/carbon-nanotube hybrids used as anode material for LIB exhibit an ultrahigh initial capacity of 3247.5 mA h g⁻¹ with a large reversible capacity of 1616.5 mA h g⁻¹ at 200 mA g⁻¹. After 80 repeated discharge and charge cycles, a reversible capacity of 710.4 mA h g⁻¹ is maintained. As Compared to pure SnO₂ nanosheets, the SnO₂/carbon-nanotube hybrids exhibit enhanced electrochemical lithium ion storage, which could be ascribed to the unique architecture with more active sites and favorable channel for Li⁺ insertion/extraction. Hence, this microwave-assisted method demonstrates a high-efficiency and timesaving way to synthesize advanced SnO₂-based anode materials for promising scalable commercialization.