Interfacial layering in the electric double layer of ionic liquids

Abstract

Ions in ionic liquids and concentrated electrolytes reside in a crowded, strongly-interacting environment, leading to the formation of discrete layers of charges at interfaces. Here, we propose a continuum theory that captures the transition from overscreening-- alternating layers of excess charge at low surface potential, to overcrowding-- the formation of dense layers of charge of the same sign at high surface potential. The model outputs slowly-decaying oscillations in the charge density with a wavelength of single ion diameters, as shown by analysis of the gradient expansion. The gradient expansion suggests a new structure for partial differential equations describing the electrostatic potential at charged interfaces. We find quantitative agreement between the theory and molecular simulations in the differential capacitance and concentration profiles.

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• Noether's second theorem and covariant field theory of mechanical stresses in inhomogeneous ionic liquids
• Electrolytes structure near electrodes with molecular size roughness
• Ionic Associations and Hydration in the Electrical Double Layer of Water-in-Salt Electrolytes
• Correct scaling of the correlation length from a theory for concentrated electrolytes
• The Primitive Model in Classical Density Functional Theory: Beyond the Standard Mean-Field Approximation
• Theory of electrolyte solutions in a slit charged pore: effects of structural interactions and specific adsorption of ions
• Electric-field-induced oscillations in ionic fluids: a unified formulation of modified Poisson-Nernst-Planck models and its relevance to correlation function analysis
• Ionic liquid-electrode interface: classification of ions, saturation of layers, and structure-determined potentials
• Electric Field Induced Associations in the Double Layer of Salt-in-Ionic-Liquid Electrolytes
• Electric field based Poisson-Boltzmann: Treating mobile charge as polarization
• Toward Modeling the Structure of Electrolytes at Charged Mineral Interfaces using Classical Density Functional Theory
• Ionically charged topological defects in nematic fluids
• On the equivalence of self-consistent equations for nonuniform liquids: a unified description of the various modifications
• Theory of Cation Solvation in the Helmholtz Layer of Li-ion Battery Electrolytes
• Classical theory of electron-ion correlations at electrochemical interfaces: Closing the circuit from double-layer charging to ion adsorption
• Polar Liquids at Charged Interfaces: A Dipolar Shell Theory
• The impact of steric repulsion on the capacitance and total free energy of electrochemical systems