Water-enriched WO3 Nanostructures for Electrochromic Energy Storage and Photovoltaic Cell Integrated Electrochromic System

Water-enriched tungsten oxide (We-WO3), synthesized via extended ultrasonicationand electrochemical deposition, showed multifunctionality in electrochromic (EC) device andenergy storage system. As an EC film, it achieved 73.6% optical contrast, 3.3 s coloration time,and 93.1cm(2)/C coloration efficiency. Meanwhile, We-WO3 exhibited a charge transfer resistanceof 20.5 Omega, a reasonable capacitance of 35.6 mF/cm(2), and capacitance retention of 78.4%. Waterenrichment improved particle dispersion, altered its morphology, and intensified the Li+ ion activ-ity. Integrated with a quantum-dot-sensitized solar cell (QDSSC), the We-WO3 EC film functionedeffectively without an external power source using the QDSSC's 0.56 V open-circuit voltage.