Foam-like, microstructural SnO2-carbon composite thin films synthesized via a polyol-assited thermal decomposition method

Abstract

Foam-like, microstructural SnO2–carbon composite thin films were synthesized by refluxing SnCl2·2H2O in ethylene glycol (EG) at 195 °C for 4 h under vigorous stirring in air followed by thermal decomposition of the as-synthesized precursor solution, whereby the products were deposited onto stainless steel (SS) substrates. Subsequently, the decomposed product, which now consists only of the microstructural SnO2–carbon composite thin film, without the addition of any binder and carbon black conductive agent, was directly applied as an anode material for use in a Li-ion rechargeable battery. Physical and electrochemical characterizations of the as-synthesized thin films were carried out. The foam-like, microstructural SnO2–carbon composite thin films that undergo thermal decomposition in air at 300 °C demonstrated the best cyclability, delivering a specific discharge capacity of approximately 496 mAh g−1 beyond 100 cycles. We believe that the presence of a uniform, SnO2–carbon network throughout the foam-like thin film, acts not only as an improved conducting network but also buffered the volume expansion upon Li–Sn alloying, resulting in a much improved cycling of the composite thin film electrode