金属锂在固态电池中的沉积机理、策略及表征  

Mechanism,strategies,and characterizations of Li plating in solid state batteries

作　　者：曹文卓 李泉[1] 王胜彬 李文俊 李泓[1,2] Cao Wen-Zhuo;Li Quan;Wang Sheng-Bin;Li Wen-Jun;Li Hong(Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Beijing WeLion New Energy Technology Co.,LTD,Beijing 102402,China)

机构地区：[1]中国科学院物理研究所,可再生能源重点实验室,北京100190 [2]中国科学院大学,材料科学与光电技术学院,北京100049 [3]北京卫蓝新能源科技有限公司,北京102402

出　　处：《物理学报》2020年第22期107-120,共14页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2016YFB0100100);北京市科技计划(批准号:Z191100004719001)资助的课题。

摘　　要：全固态金属锂电池的能量密度有望达到现有商业化锂离子电池的2—5倍,且有可能从本质上解决现有液态电解质锂离子电池的安全性问题.要想实现全固态金属锂电池这一颠覆性技术,克服金属锂/固态电解质界面存在的副反应严重、界面接触差、锂枝晶生长等一系列挑战至关重要.本文探讨了金属锂在有机、无机固态电解质中的沉积机理及其控制策略,以及金属锂负极的表征手段等,为固态锂电池的实用化研究提供了建议.在固态电池中,电解质与负极之间固-固接触不良、缺陷、晶界、裂纹、孔隙、尖端附近较强的电场以及固态电解质自身的电子电导都可导致金属锂沉积,进而演变成锂枝晶.针对这些诱因,可以通过提高固态电解质的机械强度,增大并改善固态电解质和负极的界面接触,减少固态电解质内部及表面的缺陷、杂质和孔隙,限制固态电解质内部的阴离子运动,诱导锂的均匀沉积,修复不均匀沉积形成的锂枝晶等方法均匀化锂沉积.固态锂电池走向应用仍然存在诸多挑战,需要扎实的基础研究,有目标导向的设计思路和全面、系统、创新的综合解决方案.Commercial lithium-ion batteries have inherent safety problems due to the usage of non-aqueous electrolyte as the electrolytes.The development of solid state lithium metal batteries is expected to solve these problems while achieving higher energy density.However,the problem of lithium plating still exists.This article reviews the deposition behavior of lithium metal anodes in solid-state batteries,and provides suggestions for highenergy-density and high-safety solid-state lithium batteries.This paper systematically summarizes the mechanism of Li deposition in polymers and inorganic solid state electrolytes,and discusses the strategies of controlling lithium deposition and preventing lithium dendrites and the characterization of Li metal anodes.In solid-state batteries,poor solid-solid contact between the electrolyte and the anode,defects,grain boundaries,cracks,pores,enhanced electric and ionic fields near the tip,and high electronic conductivity of the solid state electrolyte can all lead to lithium deposition,which may evolve into lithium dendrites.There are several strategies to control lithium deposition:1).Use functional materials and structure design to induce uniform deposition of lithium,such as improving the solid state electrolyte/anode interfacial contact,using lithiophilic coatings or sites,and designing three-dimensional structure electrodes and solid state electrolytes.2).Suppress the generation of lithium dendrites,such as limiting the free movement of anions in solid state electrolytes(especially polymer solid electrolytes),to reduce local space charge which induces lithium dendrites.In addition,optimizing the solid electrolyte synthesis process to reduce lithium dendrites caused by defects is also an important method.3).Strategies for dendrites already formed are essential for safety concern.The dendritic deposition is one of the intrinsic properties of lithium.Thus,there is no guarantee that there will be no lithium dendrites,especially at high current density.Once lithium dendrites are formed,

关 键 词：金属锂 沉积 固态电池 固态电解质 

分 类 号：TM912[电气工程—电力电子与电力传动]