Abstract: The correlation between microstructure and properties is a fundamental issue in material science. The success of aberration-corrected transmission electron microscopy has provided an unprecedented opportunity to characterize the atomic-scale structure of materials and to elucidate the relationship between microstructure and performance. In this paper, we review the recent progress in investigations of the surface and/or interface structure of electrode materials after lectrochemical cycling and their reaction mechanisms through atomic-resolved spherical aberration-corrected scanning transmission electron microscopy. The inherent correlation between the atomic-scale structure of electrode materials and their performance is also discussed.