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Coupled concentration-charge dynamics in 1:1 electrolytes with unequal diffusion coefficients: Local transient
Thê Hoang Ngoc Minh1,2, Sleeba Varghese2, Benjamin Rotenberg2,3
1Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, USA.
The Journal of Chemical Physics
|May 18, 2026
Summary
Ionic diffusion asymmetry in electrolytes couples charge and number transport, altering relaxation modes. External electric fields further modulate these dynamics, impacting ion transport in devices.
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Materials Science
Background:
- Electrolytes are crucial in various electrochemical systems.
- Understanding ion transport dynamics is key for device performance.
- Asymmetric electrolytes present complex coupled transport phenomena.
Purpose of the Study:
- To investigate coupled charge and concentration dynamics in asymmetric electrolytes.
- To analyze the influence of diffusion asymmetry and external electric fields on ion transport.
- To develop a theoretical framework for predicting electrolyte behavior.
Main Methods:
- Brownian dynamics simulations.
- Linearized stochastic density functional theory (SDFT).
- Analysis of transient and steady-state responses to electric fields.
Main Results:
- Diffusion asymmetry introduces coupling between charge and number transport.
- External fields enhance diffusion, modify screening lengths, and induce oscillations.
- SDFT accurately predicts density fluctuations and cross-correlations, validated by simulations.
Conclusions:
- Diffusion asymmetry and electric fields critically tune electrolyte transport properties.
- Findings have implications for nanofluidics, energy harvesting, and iontronics.
- The study provides a robust theoretical framework for asymmetric electrolyte systems.
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