STEM characterization for lithium-ion battery cathode materials

This article briefly reviews the status and new progress on the characterization of popular cathode materials for lithium-ion batteries by scanning transmission electron microscopy (STEM) and presents some of our own research work in this field, especially the direct observation of light elements such as Li and H with atomic resolution using the annular bright-field imaging (ABF) technique. These results demonstrate that STEM combined with high-angle annular dark-field imaging, electron energy-loss spectroscopy (EELS) and ABF imaging is a powerful tool for investigation of the atomic level microstructure of various cathode materials and resolving many fundamental issues in the battery related research field and industries, such as the mechanism of capacity fading and diffusion behavior across the interface between electrode and electrolyte.