Thin layer graphite confined nano-SnO2 formed in-situ for advanced lithium-ion batteries

Abstract

A composite material derived from graphite modified with high-specific-capacity metal oxides demonstrates significant enhancement in electrochemical performance for lithium-ion battery anodes. In this study, calcium carbide and tin (II) chloride dihydrate can be directly converted into graphite and elemental tin by a one-step thermochemical reaction. Subsequently, through a low-temperature heat treatment in air environment, thin-layer graphite-confined nano-SnO₂ (SnO₂@G) was obtained. The nano-sized tin dioxide generated in situ enhanced the lithium storage capacity, while the thin layer of graphite provided a flexible and tough base, effectively alleviating the volume expansion of tin dioxide. As an anode material for lithium-ion batteries, SnO₂@G₉₀₀ demonstrates excellent lithium storage performance, achieving a capacity of 913.5 mA h g⁻¹ at 0.1 A g⁻¹, and a capacity of 515.4 mA h g⁻¹ after 400 cycles at 2 A g⁻¹. This work proposes a simple and successful approach for producing SnO₂-thin layer graphite composites, which are anticipated to represent a novel generation of anode materials for lithium-ion batteries.