Challenges and Advances in Wide-Temperature Electrolytes for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have gained widespread attention due to their numerous advantages, including high energy density, prolonged cycle life, and environmental friendliness. Nevertheless, their electrochemical performance deteriorates rapidly under extreme temperature conditions, accompanied by a series of safety issues. Electrolyte optimization has emerged as a crucial and feasible strategy to expand the operational temperature range of LIBs. This review comprehensively summarizes the challenges, advances, and characterization methodologies of electrolytes at both subzero and elevated temperatures. Initially, it discusses the degradation mechanisms of different types of electrolytes at extreme temperatures, integrates recent advances, and offers insights into future research directions. Subsequently, various experimental techniques are systematically presented to evaluate the fundamental physical properties, stability, and dynamic behaviors of electrolytes in non-ambient environments. Finally, it also provides relevant computational methods across the electronic, molecular, and macroscopic scales, and explores the application of high-throughput techniques in this field. This review offers valuable guidance for breaking the working temperature limits of electrolytes and promoting the development of next-generation LIBs. Lithium-ion batteries, the predominant energy storage technology, are increasingly challenged to function across a broad thermal spectrum. As essential carriers for ion transport, electrolytes necessitate adaptability to these extensive temperature variations. This review meticulously examines the constraints of various electrolyte types - liquid, solid, polymer, and unconventional - under extreme temperature conditions, outlining the current state of research and anticipating directions for future exploration and innovation. To extend the thermal versatility of liquid electrolytes, the creation of novel lithium salts, solvents, and additives is imperative, as well as harnessing the synergistic effects among current materials. For non-liquid electrolytes, promising approaches include the integration of liquid variants and the fusion of diverse electrolyte types. Afterward, this review summarizes methods for characterizing the electrolyte performance under such rigorous conditions. In the experimental aspect, the fundamental, stability, and dynamic properties of electrolytes are analyzed. To thoroughly comprehend the issues that electrolytes encounter at varied temperatures, developing in-situ techniques for real-time monitoring of interfacial interactions is essential. The computational realm is also explored, ranging from electronic, and molecular to macroscopic scales, alongside high-throughput computing. This review guides future research toward overcoming the thermal limitations of electrolytes, thereby enhancing the utility of lithium-ion batteries in a wide range of environments. image