Applied Potentials in Variable-Charge Reactive Force Fields for Electrochemical Systems.

Area of Science:

• Computational Chemistry
• Materials Science
• Electrochemistry

Background:

• Understanding electrode-electrolyte interfaces is crucial for electrochemical applications.
• Simulating atomic-level dynamics and properties requires advanced computational methods.
• Existing models may not fully capture the effects of applied potentials.

Purpose of the Study:

• To present an atomic description of water dynamics and electrochemical properties at interfaces.
• To develop and validate a novel method for simulating externally applied potentials in electrochemical systems.
• To investigate the behavior of copper-water electrolytes with varying ion concentrations.

Main Methods:

• Utilized molecular dynamics simulations with the charge-optimized many-body (COMB3) potential framework.
• Simulated applied potentials by offsetting electronegativity on electrode atoms within a variable charge scheme.
• Investigated copper-copper electrode systems with water electrolytes containing hydroxyl (OH-) and proton (H+) ions.

Main Results:

• Analyzed the interplay between electronegativity offset and charge equilibration methods.
• Proposed a charge equilibration method for electrochemical applications, enforcing electrolyte charge neutrality.
• Demonstrated the method's ability to qualitatively capture electrochemistry and predict voltages accurately after precalibration.

Conclusions:

• The developed electronegativity offset method within COMB3 provides a robust framework for simulating electrochemical interfaces.
• The proposed charge equilibration approach offers a reliable way to model applied potentials and predict system voltages.
• This work advances the atomic-level understanding and computational modeling of electrochemical systems.