Hierarchical Nanotube-Constructed Porous TiO2-B Spheres for High Performance Lithium Ion Batteries.

ABSTRACT: Hierarchically structured porous TiO2-B spheres have been synthesized via a hydrothermal process using amorphous titania/oleylamine composites as a self-sacrificing template. The TiO2-B spheres are constructed by interconnected nanotubes and possess a high specific surface area of 295?m(2) g(-1). When evaluated as an anode material in lithium-half cells, the as-obtained TiO2-B material exhibits high and reversible lithium storage capacity of 270?mA h g(-1) at 1?C (340?mA g(-1)), excellent rate capability of 221?mA h g(-1) at 10?C, and long cycle life with over 70% capacity retention after 1000 cycles at 10?C. The superior electrochemical performance of TiO2-B material strongly correlates to the synergetic superiorities with a combination of TiO2-B polymorph, hierarchically porous structure, interconnected nanotubes and spherical morphology. Post-mortem structural analyses reveal some discrete cubic LiTiO2 nanodots formed on the outer surfaces of TiO2-B nanotubes, which might account for the slight capacity loss upon prolonged electrochemical cycling.

SUBMITTER: Cai Y 

PROVIDER: S-EPMC4501008 | biostudies-other | 2015

REPOSITORIES: biostudies-other