High performance electrochromic supercapacitors powered by perovskite-solar-cell for real-time light energy flow control

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-02, Vol.430, p.133082, Article 133082
• Main Authors: Ling, Huan, Wu, Jianchang, Su, Fengyu, Tian, Yanqing, Jun Liu, Yan
• Format: Article
• Language: English
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.133082

•An highly-stable ECD capable of adjusting visible-infrared light was prepared.•An automatic self-powered ECD with excellent stability has been developed.•The self-powered ECD exhibits fast response time and large optical contrast. Electrochromic devices (ECDs) can alter their optical transmittances under external electrical power but are unable to spontaneously modulate the light flow in real-time along with the intensity change of surrounding light. To address this problem, a module of smart perovskite solar cell (PSC)-powered all-in-one gel ECDs was reported. The PSC-powered ECDs could modulate their transmittance swiftly in visible-infrared regions, hence regulating the photo energy flow in real time according to the surrounding light intensity. The ECD based on 4, 4′-(thiophene- 2, 5-diyl)bis(1-ethylpyridin-1-ium) diiodide (TEV) showed large optical contrast (79.7% at 570 nm, 64.9% at 908 nm), excellent coloration efficiency (231.2 cm2/C), and outstanding stability (only 1.1% ΔT change after 60,000 cycles). The PSC-powered ECDs showed fast response time (≤5 s) and high stability (negligible degradation after 5000 s consecutive switching between bright and dark conditions in air). Meanwhile, the stored power accompanied with the electrochromic process could drive a red LED with high cyclic stability (95.6% of areal capacitance maintained after 10,000 charging-discharging cycles), indicating that ECDs can serve as ideal electrochromic supercapacitors (ECSs). In addition, the fabricated ECD with large area (5.0 cm × 5.4 cm) showed excellent thermal regulation (7 °C of temperature difference between colored and bleached states). We expect this work would pave a new way to save energy and improve energy efficiency in modern buildings and automobiles.