Eutectic electrolytes have been widely used in low-temperature metal-ion batteries (MIBs) due to their good performance regardless of seasonal and regional changes. Durable low-temperature MIBs rely on the constitution, proportion, and solvation-structure construction of eutectic electrolytes to maintain high ionic conductivity and electrochemical stability. Despite the rapid advances in eutectic electrolytes, some key issues, including fundamental mechanisms, theoretical models, aqueous/non-aqueous controversies, and challenges at sub-zero temperatures, need to be addressed. This Review first gives an overview of eutectic chemistry by presenting fundamental analysis and proposing new models to demonstrate the variety of interactions and anti-freezing mechanisms. Then, the thermodynamics and mass transfer, Helmholtz electric double-layer configuration, and electrode–electrolyte interphase are discussed to uncover the influence of the eutectic structure on the electrochemistry of low-temperature MIBs. Finally, a summary and perspectives are provided to guide the design principles and requirements of eutectic systems for applications of MIBs in low-temperature scenarios.

中文翻译：

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共晶电解质保护低温金属离子电池

共晶电解质因其不受季节和地区变化的良好性能而被广泛应用于低温金属离子电池（MIB）。耐用的低温 MIB 依赖于共晶电解质的组成、比例和溶剂化结构结构来保持高离子电导率和电化学稳定性。尽管共晶电解质取得了快速进展，但仍需要解决一些关键问题，包括基本机制、理论模型、水/非水争议以及零下温度下的挑战。本综述首先通过提出基础分析并提出新模型来展示各种相互作用和防冻机制，从而概述了共晶化学。然后，讨论了热力学和传质、亥姆霍兹双电层结构和电极-电解质界面，以揭示共晶结构对低温 MIB 电化学的影响。最后，提供了总结和展望，以指导 MIB 在低温场景下应用的共晶系统的设计原则和要求。