Rutile TiO2 mesocrystals with tunable subunits as a long-term cycling performance anode for sodium-ion batteries

A facile, low-temperature hydrothermal synthetic route was designed for fabricating rutile TiO2 mesocrystals composed of ultra-tiny, rod-like subunits. Mesocrystals with tunable sizes and morphologies of the subunits can be simultaneously achieved through a hydrothermal re-treatment process at different temperatures. A probable mechanism for the formation of the self-assembled giant rutile TiO2 mesocrystals of various sizes and morphologies is proposed based on the experimental results. The rutile TiO2 giant mesocrystals as-fabricated were also tested as anode materials for sodium-ion storage, and exhibited a capacity of 129.6 mA h g(-1) with a capacity retention of 97% for over 1000 cycles at a charge -discharge rate as high as 5 degrees C and enhanced rate capability up to 30 degrees C (64.5 mA hg(-1) at 30 degrees C), effectually demonstrating superior sodium storage properties in terms of long-term cycling stability and rate capability. (C) 2016 Published by Elsevier B.V.