Year: 2026
Type: article
Abstract: Water-in-salt electrolytes (WISE) defy classical transport models by maintaining high ionic conductivity despite extreme viscosities. Here, we uncover the multiscale mechanisms behind this anomaly in superconcentrated aqueous Lithium bis(trifluoromethane)sulfonimide (LiTFSI) solutions. Using viscosity and conductivity measurements alongside pulsed-field gradient nuclear magnetic resonance and Quasi Elastic Neutron Scattering (QENS), we reveal a pronounced decoupling between species mobility and bulk viscosity. Lithium species and protons retain high mobility, while TFSI − anions are increasingly hindered. QENS identifies transient, water-rich nanodomains that enable rapid local diffusion and dynamic interdomain exchange. This work provides direct experimental evidence for hierarchical, decoupled transport in WISE, offering a new framework for designing high-performance electrolytes for energy storage.
Source: Journal of Physics Energy
Institutions: Institut polytechnique de Grenoble, Centre National de la Recherche Scientifique, Université Savoie Mont Blanc, Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Laboratoire de physique des Solides, CEA Paris-Saclay - Etablissement de Saclay, Laboratoire Léon Brillouin, Laboratoire Interdisciplinaire de Physique, Paul Scherrer Institute, Institut Laue-Langevin, CEA Grenoble
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,900
Funder: Paul Scherrer Institut
OpenAlex ID: W7213608594