Self-Recharging Reduced Graphene Oxide-Prussian Blue Electrodes for Transparent Batteries

Numerous applications are dependent on the preparation of transparent thin films, including electrochromic windows, touch screens, and solar cells; however, transparent batteries, an essential component in fully integrated transparent devices, have not yet been properly explored in the literature. Here, we report the preparation of a transparent rGO/Prussian blue self-rechargeable cathode battery. Through the combination of rGO, iron hexacyanoferrate electrode exhibits higher crystallinity, better electrical conductivity, and excellent electrochemical stability. Due to the singular interfacial method used for the film preparation, an intimate contact between PB nanoparticles and the carbonaceous material was provided, with superior electrochemical performance in potassium-ion batteries. As a cathode, the rGO/PB film yields an initial discharge capacity of 120 mA h g^–1 at a current of 173.7 mA g^–1, and an excellent specific capacity stability, with the maintenance of 95.5% of initial value after the application of 50 charge/discharge cycles. Moreover, the rGO/PB film can be used as a self-recharging electrode, that is, recovering 88% of the total specific capacity of PB cathode by reacting with oxygen in the air. Our results represent a step forward and make this material very attractive for use in self-recharging electronic devices made from transparent potassium-ion batteries.