In situ TEM studies of electrochemistry of high temperature lithium-selenium all-solid-state batteries. (1st February 2022)

• Record Type: Journal Article
• Authors: Guo, Baiyu; Chen, Jingzhao; Wang, Zaifa; Su, Yong; Li, Hui; Ye, Hongjun; Zhang, Liqiang; Tang, Yongfu; Huang, Jianyu
• Is Part Of: Electrochimica acta. Volume 404(2022)
• Publication Date: 2022-02-01
• Subjects: TEM Transmission Electron Microscopy -- MEMS Micro-electromechanical System -- ASSB All Solid State Battery; In situ TEM -- MEMS -- High temperature -- Li-Se ASSBs; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139773
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: We show explicitly that it is the ionic conductivity, not the electronic conductivity that prevents the decomposition of Li2 Se. We show also that discharge at elevated temperatures leads to more complete reaction of Se than at room temperature, thus can potentially improve the capacity of Li-Se batteries. We found that different from liquid electrolyte, polyselenides were absent during discharge and charge of Li-Se all-solid-state batteries. Abstract: Lithium sulfur (Li-S) battery has very high theoretical specific capacity, which is a potential "beyond lithium" energy storage technology for electrical vehicle and grid energy storage applications. However, the poor electronic conductivity of sulfur has plagued the performance of Li-S battery. This prompts the research in lithium selenium (Li-Se) battery, in which the electronic conductivity of Se is more than 25 orders of magnitude higher than that of S. Herein, we have investigated the electrochemistry of Li-Se all-solid-state batteries (ASSBs) at different temperatures using in situ transmission electron microscopy (TEM) technique equipped with a microelectromechanical systems (MEMS) heating device. We found that different from liquid electrolyte, polyselenides were absent during discharge and charge of Li-Se ASSBs. Moreover, we revealed that the discharge products of Li2 Se cannot be decomposed at room temperature. However, Li2 Se was decomposed easily at high temperatures because of increased Li + ion conduction, indicating conclusively that it is the Li + ion conductivity rather than the electronic conductivity that dictates the performance of Li-Se ASSB. Our studies provide not only new understanding to the Li2 Se electrochemistry, but also an important strategy to boost the performance of Li-Se ASSBs for energy storage applications. Graphical abstract: Image, graphical abstract