Self-Powered Electrochromic Smart Window Driven By Transparent Triboelectric Nanogenerators Via Harvesting Wind and Rain Energies

Self-powered system is one of promising electronic concepts in upcoming future due to its independent and sustainable operations without a battery. To realize this idea, triboelectric nanogenerator (TENG) was recently invented that could effectively convert the ambient mechanical energy into electricity to power up portable electronics. In this work, the concept of self-powered smart window system was realized through integrating an electrochromic device (ECD) with a transparent TENG driven by wind blowing and raindrops The ECD consisted of Prussian blue and zinc hexacyanoferrate as the electrochromic material and the ion storage layer, respectively. Driven by the sustainable output of the TENG, the optical properties, especially the transmittance of the ECD displays reversible variations due to electrochemical redox reactions. The maximum transmittance change can reach up to 32.4% at 695 nm which is comparable to that operated by conventional electrochemical potentialstation (32.5%). This research is a substantial advancement towards the practical application of nanogenerators and self-powered systems, and it paves the way for the development of fully independent smart windows or high-performance displays.