Nanostructures and lithium electrochemical reactivity of lithium titanites and titanium oxides: A review

Being inherently safe and chemically compatible with the electrolyte, titanium oxide-based materials, including both Li-titanites and various TiO2 polymorphs, are considered alternatives to carbonaceous anodes in Li-ion batteries. Given the commercial success of the spinel lithium titanites, TiO2 polymorphs, in particular in nanostructured forms, have been fabricated and investigated for the applications. Nanostructuring leads to increased reaction areas, shortened Li+ diffusion and potentially enhanced solubility/capacity. Integration with an electron-conductive second phase into the TiO2-based nanostructures eases the electron transport, resulting in further improved lithium electrochemical activity and the overall electrochemical performance. This paper reviews structural characteristics and Li-electrochemical reactivity, along with synthetic approaches, of nanostructures and nano-composites based on lithium titanites and TiO2 polymorphs that include rutile, anatase, bronze and brookite.