Simulating electrochemical systems by combining the finite field method with a constant potential electrode

Abstract

A better understanding of interfacial mechanisms is needed to improve the performances of electrochemical devices. Yet, simulating an electrode surface at fixed electrolyte composition remains a challenge. Here we apply a finite electric field to a single electrode held at constant potential and in contact with an aqueous ionic solution, using classical molecular dynamics. The polarization yields two electrochemical interfaces on opposite sides of the same metal slab. While the net charge on one electrode surface is the opposite of the net charge on the other, maintaining overall charge neutrality of the metal. The electrode surface charges fluctuations are compensated by the adsorption of ions from the electrolyte, forming a pair of electric double layers with aligned dipoles. This opens the way towards the efficient simulation of electrochemical interfaces using any flavor of molecular dynamics, from classical to first principles-based methods.

arXiv comment6 pages, 7 figures (including SI)

References in corpus (7)

• A First-Principles Approach to Insulators in Finite Electric Fields
• Electric displacement as the fundamental variable in electronic-structure calculations
• Charge fluctuations in nano-scale capacitors
• Continuum models of the electrochemical diffuse layer in electronic-structure calculations
• Finite Field Methods for the Supercell Modelling of Charged Insulator-Electrolyte Interfaces
• First-Principles Calculations at Constant Polarization
• Charge compensation at the interface between the polar NaCl(111) surface and a NaCl aqueous solution

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