Reversible storage of Li-ion in nano-Si/SnO2 core–shell nanostructured electrode

Abstract

A core–shell nanostructured composite material consisting of nano-Si as the core and SnO₂ as the shell is synthesized by a sol–gel method. The reaction mechanism between Li and a nano-Si/SnO₂ core–shell nanostructured electrode is investigated, the partial reversible reaction between Li and SnO₂ during the first cycle is identified, and the reactivity of the Si core is investigated by ex situ analyses. The nano-Si/SnO₂ core–shell nanostructured electrode shows a reversible capacity of ca. 1000 mA h g⁻¹ and good cycle retention close to 80% of the first charge capacity over 50 cycles.