Influence of Mesoporosity and Carbon Electronic Wiring on Electrochemical Performance of Anatase Titania

The combined benefits of mesoporosity and in situ grown conductive amorphous carbon on lithium storage capacity of anatase TiO(2) are discussed here. Micron-sized anatase TiO(2) spheres with equal amount of carbon but different degree of mesoporosity and normal mesoporous TiO(2) are synthesized by solvothermal and sol-gel methods respectively. While the specific surface areas were 80, 35 and 85 m(2) g(-1) respectively for mesoporous carbon-TiO(2) sphere, carbon-TiO(2) sphere and mesoporous TiO(2), the primary size of the grains constituting the micrometer sized spheres was similar to 11 nm. The electrochemical lithium stored by all synthesized TiO(2) materials show strong dependency on mesoporosity and carbon. Mesoporous carbon-TiO(2) sphere exhibited a first discharge cycle capacity of 334 mAh g(-1) at current rate of 66 mAg(-1), whereas carbon-TiO(2) sphere and mesoporous TiO(2) stored 120 and 270 mAh g(-1) respectively. Demonstration of high lithium storage capacity and good cyclability in mesoporous carbon-TiO(2) sphere is attributed to the synergy of mesoporosity and in situ grown carbon in the formation of an effective percolation network for the conducting species (Li(+)/e(-)) around TiO(2) nanoparticles. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3574028]