Thermodynamics alternative to Debye–Hückel theory

To achieve carbon neutrality, performance of electrochemical energy storage and conversion systems must be maximized through sophisticated design concepts. In electrochemical systems, electrode potential provides a fundamental guideline for dictating the driving force of redox reactions. However, the classical Debye–Hückel theory (1923), grounded in a “paper-and-pencil”-based approximation of Coulombic interactions in electrolyte solutions, is valid only under infinitely dilute conditions. Here, we present an explicit calculation protocol for determining total free energies of target ions using molecular dynamics, applicable to all concentration regimes. Adoption of suitable computational models describing electrostatic Coulombic, van der Waals, and entropic components of Gibbs energy enabled accurate reproduction of experimental potential shifts. A comprehensive and rigorous in-silico physicochemical framework alternative to the century-old Debye–Hückel theory is now established.