Advanced Electron Microscopy for Li─S and Na─S Batteries

ABSTRACT Understanding the bulk and interfacial behaviors during the operation of Li─S and Na─S batteries (e.g., the conversion mechanism of S‐based cathodes and Li/Na deposition/stripping behavior), and the effect of various liquid or solid electrolyte components, hosts, mediators, and temperatures, is crucial for the continuous enhancement of battery performance. Benefiting from the atomic‐scale resolution of transmission electron microscopy and the large field of view of scanning electron microscopy in nanoscale and microscale, the development of advanced configurations (in situ open cell and liquid cell, cryogenic devices, and three‐dimensional reconstruction algorithm), advanced electron microscopy has facilitated the Li─S/Na─S battery studies in various aspects. Herein, a concise introduction to Li─S/Na─S batteries and advanced electron microscopy techniques, and a summary of recent progress in Li─S/Na─S battery research using various advanced electron microscopy methods, are outlined; finally, a perspective on the future development of electron microscopy techniques and their applications in Li─S/Na─S battery research is discussed.