Ce/V mixed oxide thin films with molar ratio 1 were prepared by sol–gel method from CeCl 3 ·7H 2 O and NH 4 VO 3 with methanol or distilled water as a solvent and dip-coated on SnO 2 /F-covered glass. The electrochemical, optical and structural properties of thin films depend on the solvent and heat treatment. The ion-storage capacities of the films annealed at 500°C, prepared from methanol, 60nm thick, was approximately 13mCcm −2 and those prepared with distilled water, 40nm thick, more than 20mCcm −2 . The ion-storage capacity of the films annealed at 400°C was approximately 1mCcm −2 . X-ray absorption fine structure analysis showed that crystallization process of CeVO 4 occurs in temperature range between 400 and 500°C.