金属表面におけるテラヘルツ波照射による界面単分子層水のイオン伝導性制御

Monolayer water (MW) on metal electrode surfaces commonly functions as a physical barrier that hinders the approach of molecules and ions onto the metal surface, thereby markedly diminishing interfacial ionic conductivity in aqueous ion batteries. This so-called "water poisoning" phenomenon is particularly pronounced in aqueous zinc-ion batteries, due to the larger hydrated radius of zinc ions compared to lithium or sodium ions. Using molecular dynamics simulations, we demonstrate that frequency-specific terahertz stimulation (TS) can disrupt the hydrogen-bond networks of interfacial MW through resonance mechanism, facilitating zinc ions transport onto the platinum electrode surface and boosting the ionic conductivity by up to 17-fold, as calculated from the Nernst-Einstein equation. Interestingly, the conductivity can rapidly drop to the initial level within hundreds of nanoseconds after the TS removal, indicating a reversible response. These findings offer molecular-level insights into the role of TS strategy in governing aqueous ion battery performance, while elucidating the frequency-selective regulation of confined interfacial water and suggesting broader implications for transport phenomena in nanoconfined environments, where interfacial water structure critically governs fluid mobility and solute transport dynamics.