Self-Assembled TiO₂–Graphene Hybrid Nanostructures for Enhanced Li-Ion Insertion

TLDR

The study investigated Li‑ion insertion properties of TiO₂–graphene hybrid nanostructures. Anionic sulfate surfactants stabilized graphene in aqueous solution, enabling self‑assembly of nanocrystalline TiO₂ (rutile and anatase) onto graphene. The hybrids exhibited markedly enhanced Li‑ion insertion/extraction, more than doubling specific capacity at high charge rates compared with pure TiO₂, attributed to improved electrode conductivity from a percolated graphene network.

Abstract

We used anionic sulfate surfactants to assist the stabilization of graphene in aqueous solutions and facilitate the self-assembly of in situ grown nanocrystalline TiO2, rutile and anatase, with graphene. These nanostructured TiO2-graphene hybrid materials were used for investigation of Li-ion insertion properties. The hybrid materials showed significantly enhanced Li-ion insertion/extraction in TiO2. The specific capacity was more than doubled at high charge rates, as compared with the pure TiO2 phase. The improved capacity at high charge−discharge rate may be attributed to increased electrode conductivity in the presence of a percolated graphene network embedded into the metal oxide electrodes.