Room-temperature synthesis of colloidal SnO2 quantum dot solution and ex-situ deposition on carbon nanotubes as anode materials for lithium ion batteries

Abstract

Colloidal SnO2 quantum dots (QDs) have been successfully prepared via a facile aqueous wet-chemical synthetic approach using tin dichloride as tin source and thiourea as accelerating and stabilizing agent under magnetic stirring at room temperature. The SnO2 QDs with average size of ∼3.5 nm are well-dispersed in the aqueous solution with high stability. A facile ex-situ deposition of SnO2 QDs on carbon nanotubes (CNTs) is developed, allowing large loading amount of SnO2 QDs on the CNTs with uniform distribution. When used as anode material for lithium ion batteries, the as-prepared SnO2-CNT nanocomposites exhibit superior lithium storage properties, delivering a stable discharge capacity of 845 mAh/g at 100 mA/g after 90 cycles. More importantly, the novel synthetic strategy is promising for the cost-effective and large-scale fabrication of SnO2-CNT nanocomposites as high-performance anodes for electrochemical energy-storage.