Designing Weakly Solvating Electrolytes for Low-Temperature Lithium Batteries

The reliable operation of lithium-based batteries (LBBs) under subzero conditions remains a fundamental challenge due to sluggish ion transport, increased interfacial impedance, and unstable solid–electrolyte interphases (SEIs). Popular high- and localized high-concentration electrolytes partially alleviate these issues but still suffer from excessive viscosity and strong Li⁺-solvent binding that hinder low-temperature kinetics. Weakly solvating electrolytes (WSEs) offer a new paradigm by weakening Li⁺ coordination, promoting anion-dominated solvation, and accelerating desolvation and interfacial charge transfer. This review provides a comprehensive review of WSEs, focusing on working mechanisms, structural design strategies, and interfacial chemistries. We also address molecular-level solvation insights with electrolyte engineering to discuss how WSEs promote uniform lithium deposition, inorganic-rich SEIs, and stable cycling at subzero temperatures. Finally, the review highlights future research directions—from quantitative solvation–performance correlations and data-driven electrolyte design to interfacial diagnostics and scalability. By integrating molecular-level understanding with predictive modeling and engineering validation, WSEs offer a transformative route toward all-climate rechargeable batteries capable of stable and efficient operation from arctic to desert environments.