TiO2 Microboxes with Controlled Internal Porosity for High-Performance Lithium Storage.

Titanium dioxide (TiO2) is considered a promising anode material for high-power lithium ion batteries (LIBs) because of its low cost, high thermal/chemical stability, and good safety performance without solid electrolyte interface formation. However, the poor electronic conductivity and low lithium ion diffusivity of TiO2 result in poor cyclability and lithium ion depletion at high current rates, which hinder them from practical applications. Herein we demonstrate that hierarchically structured TiO2 microboxes with controlled internal porosity can address the aforementioned problems for high-power, long-life LIB anodes. A self-templating method for the synthesis of mesoporous microboxes was developed through Na2 EDTA-assisted ion exchange of CaTiO3 microcubes. The resulting TiO2 nanorods were organized into microboxes that resemble the microcube precursors. This nanostructured TiO2 material has superior lithium storage properties with a capacity of 187 mAh g(-1) after 300 cycles at 1 C and good rate capabilities up to 20 C.