Sonochemically Synthesized V ₂ O ₅ –PEDOT Hybrids for Superior Charge Storage and Electrochromic Functions

Abstract Electrochromic active electrodes can exhibit significant specific charge‐storage capacity; however, their total stored energy is often limited by the limited thickness of the active coating. This restraint can be addressed by using layered materials capable of storing substantial amount of charge within their interlayer spaces. Various compositions of V 2 O 5 –PEDOT hybrid nanobelts were synthesized via an efficient sonochemical method, resulting in redox polymerization of EDOT monomers and subsequent PEDOT formation within V 2 O 5 interlayers. PEDOT incorporation expanded the V 2 O 5 interlayer spacing, enabling a higher diffusion coefficient, improved conductivity, faster intercalation kinetics, and enhanced charge storage. Electrodes fabricated from these hybrids demonstrated up to a 2.3‐fold increase in volumetric charge storage capacity. Electrochromic devices (ECDs) constructed with these materials achieved a notable CIELAB color difference of 41.75, a peak coloration efficiency of 80 cm 2 C −1 , and a peak bleaching efficiency of 114 cm 2 C −1 . Excessive PEDOT, however, was found to reduce crystallinity, compromising charge storage and electrochromic performance.