The Advancement of the Electrochromic Supercapacitor Properties of Interface-Engineered Hybrid Polyaniline/Prussian Blue Thin-Film Electrodes

There is an increasing demand for multifunctional devices, that can operate simultaneously as energy storage and electrochromic display devices, widely known as electrochromic supercapacitors. For instance, Prussian blue (PB) exhibits outstanding electrochromic properties; however, it has not been well explored for energy storage applications. Moreover, the electrochemical properties can be enhanced by surface engineering the host material via compositing with conducting polymers. In this work, we studied the electrochromic supercapacitor properties of composites such as Prussian blue-polyaniline (PB-PANI). The PB-PANI 90 composite thin-film electrode exhibited the highest coloration efficiency of 461.39 cm²/C and demonstrated superior electrochemical performance, with an aerial capacitance of 50.80 mF/cm² and an optical modulation of 19.4%. All samples achieved rapid switching times of less than 3 s. These findings highlight the potential of optimizing conducting polymer coatings on Prussian blue to achieve a well-balanced composite structure with enhanced morphological properties, paving the way for advanced multifunctional electrochromic supercapacitor devices in next-generation smart systems.