High capacity WO3 film as efficient charge collection electrode for solar rechargeable batteries

In this work, we demonstrated the dye-sensitized solar rechargeable batteries devices sharing a structure of Dye-TiO2/electrolyte/Ni/WO3. The WO3 film was prepared by a simple sol-gel process exhibit high cavities and large surface area allowing efficient chemical/electrical reactions. The WO3 films with 2 ± 0.5 μm in thickness as charge collection electrodes exhibited a high energy density over other materials reported thus far. Under irradiation energy of 7.5 mWcm−2 in the photo-charging, the discharging time sustained 1758 s at the current density of 0.05 mA cm−2 in dark, the first specific discharge capacities of WO3 nano-film reach 40.6 mAh g−1 (0.0244 mAh cm−2). This work substantially pushes forward the easy processing solar rechargeable batteries for future potential applications.