Nanocomposite Architecture for Rapid, Spectrally-Selective Electrochromic Modulation of Solar Transmittance

Two active electrochromic materials, vacancy-doped tungsten oxide (WO3–x ) nanocrystals and amorphous niobium oxide (NbO x ) glass are arranged into a mesostructured architecture. In a strategy applicable across electrochemical applications, the critical dimensions and interfacial connections in the nanocomposite are designed to optimize pathways for electrochemical charging and discharging. The result is an unprecedented optical range for modulation of visible and near-infrared solar radiation with rapid switching kinetics that indicate the WO3–x nanocrystal framework effectively pumps charge out of the normally sluggish NbO x glass. The material is durable for at least 2000 electrochemical cycles.