Silver reversible electrodeposition device under −40 °C condition

Silver reversible electrodeposition devices (SREDs) find wide applications in intelligent windows, automobiles, intelligent displays, and other fields. They can achieve a mirror state close to 100% reflectance and generate plasmon phenomena of different colors by controlling the driving voltage. However, the switchability of these devices is compromised below 0 °C due to the molecular properties of the solvent dimethyl sulfoxide (DMSO), making it impossible to work in severe cold areas. This work has discovered a solvent called N-methylpyrrolidone (NMP), which possesses weak intermolecular forces, low dipolarity, and high solubility. By developing a SRED using NMP as the solvent, we have achieved a lower opening voltage at room temperature compared to the DMSO system. This is advantageous for the preparation of large-area devices. Additionally, the NMP system device retains its switching ability even under extreme conditions of −40 °C, freezing only when temperatures reach −43 °C, which is currently the lowest reported SRED operating temperature. This breakthrough brings us closer to the practicality of SRED.