RuO2-wired high-rate nanoparticulate TiO2 (anatase):: Suppression of particle growth using silica

To enhance the high-rate capability (up to 120 C, 20 A/g) of nanoparticulate TiO2 (anatase) formed by thermal treatment of protonated TiO2 nanotubes, we used two types of additives: RuO2 as an electron-conductive material [Y.-G. Guo, Y.-S. Hu, W. Sigle, J. Maier, Adv. Mater. 19 (2007) 2087] and silica as a suppressant of particle growth during heat treatment. We show systematically that both additives, when used separately, improve the high-rate performance of anatase by 25-55 mA h/g at 60 C. The combined use of both additives in a total amount of merely 2.5 wt.% leads to an improvement of more than 70 mA h/g at 60 C. The underlying mechanisms for these significant effects are briefly discussed. (C) 2008 Elsevier B.V. All rights reserved.