Hydrogen-titanate-protected SnO2@C coaxial nanocables as new nanocomposite anode materials for lithium-ion batteries

Abstract

The core–shell design can effectively overcome the problems of Sn-based anode used in lithium-ion battery by buffering the volume change and stabilizing the electrode/electrolyte interface. The choice of a protective shell with a durable physical structure and chemical stability is thus important for preparing desirable Sn-based anodes. Herein, we introduce hydrogen titanate (HTO) as a new external shell to wrap SnO2@C for targeting the goal. The SnO2@C-HTO core–shell nanocomposite was directly prepared via a facile alkaline hydrothermal method without the need for a secondary coating process. Due to the high specific surface area and two-dimensional Li+-diffusion pathways provided by the HTO shells, the SnO2@C-HTO electrode showed stable lithium uptake/release at high rates, i.e., it delivered a reversible capacity of 175 mA h g−1 at a high rate of 5 A g−1 and displayed a long-term operating stability (330 mA h g−1 at 1 A g−1 for 500 cycles). This study offers a broad vision for designing novel Sn-based core–shell nanoarchitectures for safe and reliable lithium-ion batteries with high-energy densities.