Constant-Potential Modeling of Electrical Double Layers Accounting for Electron Spillover

作者：Zhenxiang Wang, Ming Chen, Jiedu Wu, Xiangyu Ji, Liang Zeng, Jiaxing Peng, Jiawei Yan, Alexei A. Kornyshev, Bing‐Wei Mao, Guang Feng · 发表于：Physical Review Letters · 年份：2025 · DOI：10.1103/physrevlett.134.046201 · 被引用次数：24 · 研究领域：Electron and X-Ray Spectroscopy Techniques、Machine Learning in Materials Science、Nuclear Physics and Applications

Constant-potential molecular dynamics (MD) simulations are indispensable for understanding the structure, capacitance, and dynamics of electrical double layers (EDLs) at the atomistic level. However, the classical constant-potential method, relying on the so-called "fluctuating charges" to keep electrode equipotential, overlooks quantum effects on the electrode and always underestimates EDL capacitance for typical metal electrode and aqueous electrolyte interfaces. Here, we propose a constant potential method accounting for electron spillover on the outermost nuclei of the electrode. For EDLs at Au(111) electrodes, our MD simulation reveals bell-shaped capacitance curves in magnitude and shape both quantitatively consistent with experiments. It unveils the electrode-polarization-dependent local electric fields, agreeing with experimental observations of redshift vibration of interfacial water under negative polarization and predicting a blueshift under positive polarization, and further identifies geometry dependence of two timescales during charging.