透射电镜表征中锂-氧气电池放电产物的辐照损伤研究

摘要

本文采用透射电子显微镜研究了锂－氧气电池相关放电产物Li2 O2、Li2 O、LiOH以及Li2 CO3在电子束辐照下的晶体结构和电子结构的变化。研究表明Li2 O2、Li2 O、LiOH以及Li2 CO3在电子束辐照下均存在辐照损伤现象；原位选区电子衍射和电子能量损失谱分析表明在电子束辐照下Li2 O的结构基本保持不变，而Li2 O2、LiOH以及Li2 CO3则向Li2 O发生转变，各产物的稳定程度依次为Li2 CO3≥LiOH≥Li2 O2。且Li2 CO3样品的电子束辐照具有取向依赖性，低指数[001]比高指数[103]带轴表现出更高的耐辐照损伤能力。随着辐照剂量增加，Li2 CO3样品耐辐照时间缩短，损伤程度加剧。%Transmission electron microscopy was employed to study the crystallographic evolution of discharge product Li2 O2 , Li2 O, LiOH and Li2 CO3 in Lithium⁃oxygen batteries under the electron beam irradiation. The irradiation damage phenomena of the Li2 O2 , Li2 O, LiOH and Li2 CO3 were observed under the electron beam irradiation. By the method of in⁃situ selected area electron diffraction and electron energy loss spectroscopy, the structure of Li2 O is found to remain unchanged under the electron beam irradiation, but the structures of Li2 O2 , LiOH and Li2 CO3 turned into Li2 O. Li2 CO3 is the most stable one, then LiOH and Li2 O2 . Li2 CO3 sample is directionally dependent on electron irradiation. The [ 001 ] direction performs a higher resistance on radiation damage than [ 103 ] direction. With the increase of electron radiation dose, Li2 CO3 sample has a shorter anti⁃radiation time and higher damage degree.