Empowering Zero-Energy Buildings with Cutting-Edge Self-Powered Electrochromic Smart Window Technology

The development of energy-efficient window technology is crucial for zero-energy building approaches, as windows play a pivotal role in minimizing heat loss, optimizing natural light utilization, and contributing to overall energy conservation. In this study, a self-powered electrochromic smart window is presented together and its application as a self-charging battery is showcased. The self-powered system is composed of a WOx electrochromic working electrode, an Al counter electrode, and an AlCl3 liquid electrolyte similar to a voltaic cell. This device generates an open circuit voltage of around 0.95 V. When two electrodes are connected, this voltage is applied as an external voltage and changes the color of the transparent WOx electrode into a blue state with approximately 62% transmittance modulation. However, if the two electrodes are connected via an light-emitting diode (LED), the LED lights up for up to 4 h. A WOx-based self-powered electrochromic device (ECD) works either as a self-powered electrochromic smart window or a self-rechargeable battery. The transparent WOx electrode changes color from transparent to deep blue by connecting with the Al electrode and in the presence of AlCl3 aqueous electrolyte functions as a voltaic cell thereby powering up other devices.image (c) 2024 WILEY-VCH GmbH