低温锂电池电解液的发展及展望

Low-temperature lithium battery electrolytes:Progress and perspectives

锂电池因具有工作电压高、能量密度高、循环寿命长以及成本低等优点,在便携式电子产品及电动汽车等领域得到广泛使用。然而,在低温条件下,充电困难、放电容量低和寿命短等问题极大地限制了其在低温环境中的应用。因此,探究锂电池低温失效机制并改善其低温性能势在必行。本文从电解液设计角度,总结了电解液对低温锂电池的影响及失效机制,着重介绍了提升锂电池低温性能的策略及机理。在低温条件下,变缓的锂离子扩散、激增的电池内阻、不稳定的电极/电解液界面和潜在的锂沉积等是造成锂电池性能衰退的主要原因。电解液工程(如优化电解液溶剂、锂盐和添加剂等组分)可以拓宽电解液的液程、构建稳定的电极/电解液界面和加快脱溶剂化速率,能够有效地改善锂电池的低温性能。此外,本文强调了低温高性能电解液设计需同时满足高的离子电导率、稳定的电极/电解液界面膜和快速脱溶剂化能力3个条件,为未来新型溶剂合成与电解液设计提供了理论指导。

Lithium batteries are extensively used in portable electronic products and electric vehicles owing to their high operating voltage,high energy density,long cycle life,and low cost.However,their performance is critically limited under low-temperature conditions,posing challenges such as difficult charging,reduced discharge capacity,and shortened lifespan.Therefore,exploring the failure mechanisms of lithium batteries at low temperatures and enhancing their performance in such environments is crucial.This mini review discusses the impacts and failure mechanisms of electrolytes on lithium batteries at low temperatures,emphasizing the design of electrolytes.It highlights strategies and mechanisms to enhance lithium battery performance in cold climates.Key issues include sluggish lithium ion diffusion,increased electrical resistance,unstable electrode/electrolyte interphases,and potential lithium deposition,collectively degrading battery performance.Through electrolyte engineering—optimizing solvents,lithium salts,and additives—the operational temperature range of the electrolyte can be expanded,stable electrode/electrolyte interfaces can be constructed,and the desolvation process can be accelerated,thereby considerably improving performance.Furthermore,this review underscores that high-performance low-temperature electrolytes should fulfill three criteria:high ionic conductivity,stable electrode/electrolyte interphase,and rapid desolvation capability.This provides theoretical guidance for future synthesis of new solvents and electrolyte design.