用于锂金属电池的聚合物固态电解质的研究进展

Recent Progress on Polymer Solid Electrolytes for Lithium Metal Batteries

聚合物固态电解质因其质轻安全、结构可设计以及优异的机械性能,成为高能量密度、高安全性全固态电池的潜在材料,逐渐成为研究的重点.但因其结晶度高、室温离子电导率低等缺陷也限制其进一步商业化.本综述梳理了近年来比较优越的聚合物固态电解质种类,包括聚醚类聚合物、聚碳酸酯类聚合物、氟化聚合物、聚离子液体聚合物、单离子传导聚合物,围绕如何提升离子电导率,重点回顾了针对不同基质的结构设计和合成工艺方面的创新.最后阐述了聚合物固态电解质目前面临的基础研究和应用问题,以期为新型聚合物固态电解质的设计与制备提供新思路.

Lithium metal is considered an ideal negative electrode material for its highest theoretical specific capacity and lowest redox potential.However,traditional lithium metal batteries have faced thorny challenges,primarily due to the growth of lithium dendrites and utilization of leaky,flammable organic liquid electrolyte,which would lead to battery failure and potential safety hazards.Replacing liquid electrolyte with solid-state electrolyte comes out to be a promising solution to the issues above.Recently,polymer solid electrolytes have garnered significant attention for their lightweight,safety,designable structure and excellent mechanical properties,which could restrain the uncontrollable growing of lithium dendrites.However,the high crystallinity and the resultant low ion conductivity at room temperature have impeded their widespread commercialization.Significant efforts have been directed towards the development of polymer solid electrolytes with superior performance.Herein,the recent development of polymer solid electrolyte is reviewed and summarized,including polyether polymers,polycarbonate polymers,fluorinated polymers,poly(ionic liquid)polymers,and single ion conductive polymers.Each of these polymer solid electrolytes offers unique advantages and challenges.The respective properties of different polymer electrolytes and the influence on the electrochemical performance are compared and discussed in detail.This article also focuses on the progress in structural designs and the innovation in synthesis process for different polymer matrixes in order to improve the ion conductivity at room temperature.For structural designs,grafting kinds of polar groups to the matrix structure,or designing various types of chain structures can reduce crystallinity,and thus enhance the ion transport.In addition to the conventional solution-casting method and phase inversion technique,electrospinning method,UV coating and other in-situ processes are utilized in the preparation of polymer solid electrolytes.Finally,in this paper,the existing fundamental research challenges and practical application issues associated with polymer solid electrolytes are thoroughly discussed.It is our sincere hope that this review will offer insights and references for the design,synthesis,and development of novel polymer solid electrolytes,which holds significant promise for electrochemical performance enhancement and safe operation of all-solid-state lithium metal batteries.