Optimization study of electrochromic performance on porous Ni-doped V2O5 ion storage films for smart window

Abstract

Porous Ni-doped V₂O₅ ion storage films for electrochromic smart windows were synthesized by sol-gel dip-coating and heat treatment. The impacts of Ni doping, heat treatment temperature, and time on film properties were studied. At 9 mol % Ni doping, 350 °C, and 4 h, the film had an ion storage capacity of 96.42 mC/cm². Response surface methodology optimized the preparation parameters. The optimized film, with 10.3 mol % Ni doping, 348 °C, and 4.3 h, achieved 97.08 mC/cm² capacity close to the predicted 98.28 mC/cm², whose diffusion coefficients calculated from the I_p-v^1/2 fitting curves are 2.08×10⁻⁸ cm²/s (peak1) and 3.85×10⁻⁸ cm²/s (peak2), respectively. The optimized film showed a 23.94 % increase in optical modulation, faster response times, and over 80 % capacity retention after 5000 cycles.