High lithium storage in micrometre sized mesoporous spherical self-assembly of anatase titania nanospheres and carbon

Abstract

Composite of anatase titania (TiO₂) nanospheres and carbon grown and self-assembled into micron-sized mesoporous spheres via a solvothermal synthesis route are discussed here in the context of rechargeable lithium-ion battery. The morphology and carbon content and hence the electrochemical performance are observed to be significantly influenced by the synthesis parameters. Synthesis conditions resulting in a mesoporous arrangement of an optimized amount carbon and TiO₂ exhibited the best lithium battery performance. The first discharge cycle capacity of carbon-titania mesoporous spheres (solvothermal reaction at 150 °C at 6 h, calcination at 500 °C under air, BET surface area 80 m²g^-1) was 334 mAhg^-1 (approximately 1 Li) at current rate of 0.066 Ag^-1. High storage capacity and good cyclability is attributed to the nanostructuring of TiO₂ (mesoporosity) as well as due to formation of a percolation network of carbon around the TiO₂ nanoparticles. The micron-sized mesoporous spheres of carbon-titania composite nanoparticles also show good rate cyclability in the range (0.066–6.67) Ag^-1.