Cryogenic Electron Microscopy for Characterizing and Diagnosing Batteries

Most battery materials are beam sensitive, especially after cycling, which can be hardly characterized by electron microscopy (EM) with a high-energy beam. Inspired by structural biology, cryogenic EM (cryo-EM) offers a way to preserve the native state and image the battery materials at the nano/atomic scale. In this perspective, we highlight strategies on how to preserve the pristine intrinsic information of battery materials in terms of sample preparation, transformation, and imaging. Some key technical breakthroughs for the development of the cryo-EM are briefly illustrated to demonstrate its working principles. Recent achievements on cryo-EM characterization of battery materials are reviewed, especially Li metal. These profound observations demonstrate the increasing essential role of cryo-EM on diagnosing and characterizing the chemical, morphological, and atomic structure of battery materials. The new insights and knowledge obtained through this emerging new toolset will benefit the battery research field tremendously.