Lithium-Ion-Assisted Ultrafast Charging Double-Electrode Smart Windows with Energy Storage and Display Applications

Lithium-ion-assisted ultrafast charging double-electrode smart windows with energy storage and a fluorescence display device (FTO/PB/Ru@SiO₂||Ru@SiO₂/WO/FTO) based on double electrochromic electrodes (cathode and anode) (FSDECEs) have been designed and fabricated. Here, Prussian blue (PB) and WO_red are selected as the electrochromic cathode and anode, respectively. There is a synergistic effect and a large potential difference between the two electrodes. They could be simultaneously and rapidly bleached after being connected with each other. Also, the fluorescence intensity of Ru@SiO₂ nanoparticles (NPs) could be regulated by the fluorescence resonance energy transfer effect (FRET). After discharging, the two electrochromic electrodes in the bleached state can be recharged by a Mg-O₂ battery with a FeN₅ single atomic catalyst to quickly recover the colored state. The double electrochromic electrodes can reversibly alter between coloring and bleaching states only by connecting and disconnecting the electrodes. The fluorescence intensity of FSDECEs can switch between quenching and emission, thus endowing the "on" and "off" functions. The system is concise, environmentally friendly, and easy to operate. The proposed FSDECEs demonstrate high fluorescence contrast, a fast response time, and long-term stability. Such an ingenious design of fluorescence switching based on the double electrochromic electrode in a single cell sheds light on next-generation transparent, portable, and self-powered electrochromic devices and electronic equipment.