Nanocrystalline anatase TiO 2 was synthesized from a triethylene glycol solution of titanium isopropoxide ͓Ti͑O-iPr͒ 4 ͔ by refluxing at 270°C for 12 h. The thermal stability and effect of particle size on the corresponding electrochemical performances were investigated by annealing the prepared sample at various temperatures; namely, 300, 400, 500, 600, 700, 800, and 900°C. The X-ray diffraction patterns of the samples clearly revealed that the maximum temperature for the formation of pure anatase phase was 700°C beyond which the presence of rutile polymorph became significant. The field emission-transmission electron microscopy images of the obtained samples showed uniform and considerably dispersed particles with fairly homogeneous distributions and average sizes of 8-50 nm. The electrochemical measurements indicated considerable charge-discharge capacities devoid of major capacity fading during extended cycles, due to their electrochemically beneficial highly crystalline traits, nanosized particles, and uniform distribution.