Solvation structures in localized high-concentration electrolytes (LHCEs) critically govern ion transport and interfacial reactions. However, the temperature mismatch between characterization condition and actual operating environment has been usually overlooked, obscuring mechanistic interpretations of electrochemical performances. As a key parameter, temperature exerts a pronounced influence on intermolecular interactions in electrolytes. Here, we systematically elucidated the temperature responsiveness and underlying mechanism of solvation structures in LHCEs with varied compositions. It integrates in situ variable-temperature small-angle X-ray scattering (SAXS) and Raman spectroscopy with molecular dynamics (MD) simulations and density functional theory (DFT) calculations. Beyond conventional static descriptors including coordination number (CN), radial distribution function (RDF) and cluster population, dynamic metrics including activity factor, cluster lifetime and ligand-exchange event probability were also proposed to construct a unified static-dynamic framework for solvation-structure evolution with temperature variation. Results show that elevating temperature attenuates solvation-structure disparities arising from compositional difference. Moreover, high-diluent electrolytes display distinctly different temperature sensitivity in static structural parameters versus dynamic metrics. Meanwhile, an ordered sequence of cluster transition process was revealed, wherein incorporation of an anion precedes dissociation of a solvent molecule. This work disentangles the coupled concentration-temperature effects on solvation structures in LHCEs and establishes the comprehensive understanding of structural evolution across wide temperature ranges, which provides experimentally validated theoretical guidance for the rational design of advanced electrolytes with superior interfacial stability and cycling performances.
Zhang et al. (Mon,) studied this question.