Hydrothermal fabrication of Sn/SnO/SnO2 hybrid nanocomposites as highly reliable anodes for advanced lithium-ion batteries

Abstract

A novel hybrid nanocomposite (HNC) material consisting of Sn, SnO, and SnO₂ was successfully synthesized via a modified hydrothermal technique using urea and SnCl₂ as the precursors. The Sn/SnO/SnO₂ ratio and the structure of the HNC, which can easily be controlled by varying the concentration of the SnCl₂ salt, greatly influence the electrochemical properties of the HNC electrodes when applied as lithium-ion battery anode materials. The highest electrochemical performance was achieved when the concentration of SnCl₂ was 22.5 × 10⁻³ M, denoted as sample M3. For instance, the M3 electrode delivered a reversible capacity of 1056 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles. Its impressive electrochemical performance was achieved due to the nano-size of Sn/SnO/SnO₂ particles, the highly reversible conversion reaction between the tin oxides and Li₂O, and a suitable ratio of the components in the M3 sample. This synergistic effect can maintain the stability of the electrode structure and improve the pseudo-capacitance process, leading to excellent Li-ion storage and highly durable cycling of the HNCs.