A minimal electrostatic theory for the Seebeck coefficient in liquids

Abstract

The Seebeck coefficient in liquids often reaches the mV/K range, yet its microscopic origin remains unclear due to the complexity of electrolyte systems. Here we propose a minimal electrostatic theory focusing on solvation entropy. Using a core-shell extension of the Born equation with temperature-dependent dielectric response, we provide an alternative electrostatic interpretation of the mV/K-scale solvent-structuring contribution extracted for a cobalt redox electrolyte. The theory clarifies that large valence, small cationic radius, small dielectric constant, and large magnitude of $\frac{d\epsilon }{dT}$ are key factors for enhanced liquid Seebeck response.