Li‐ion batteries are promising candidates for electrical energy storage in applications ranging from portable electronics to hybrid and electric vehicles. In this context, layered compounds in the Li1+δ(TMxMn1‐x)1‐δO2 family (TM = transition metal) have received much attention due to their high capacity and stability. In this Research News article we describe recent advances on structural characterization of Li‐ion electrode materials using state‐of‐the‐art electron microscopy. Direct evidence of the monoclinic nature of Li2MnO3 has been provided. It has been demonstrated that differences in Z‐contrast imaging between Li2MnO3 and LiTMO2 may be used to screen samples for phase separation in the 10–100 nm scale. Structure of (rhombohedral) layered lithium oxides consisting of a NaCl‐like stack of hexagonal close‐packed planes (O‐red, Li‐yellow, Metal‐blue). LiMn substitutionals (yellow dots) in Li2MnO3 arrange in regular hexagonal sublattices at Mn planes, resulting in a monoclinic structure which unit cell is indicated in the figure by a blue box.