LAUSR

Li-rich NMC cathodes are considered as the next generation of Li-ion battery cathodes with capacities of ⁓300 mAhg[1]. However, they suffer from rapid capacity and voltage decay that is linked to their structural instability [2]. To understand the origins of such rapid degradation, the atomic structure of Li-rich cathodes should be fully comprehended. However, there is still an ongoing debate on the atomic structure of pristine Li-rich cathodes and their structure have been denoted in three opposing ways; (1) original (R3̅m) layered structure solid solution, where the extra Li ions are taking the transition metal sites, (2) a nano-composite of the R3̅m LiMO2 and the C2/m Li2MnO3 that is denoted as of xLi2MnO3-(1-x)LiMO2, (3) a C2/m Li2MnO3 solid solution phase with random Li/TM mixture[3]. In our research we have utilized aberration corrected scanning transmission electron microscopy (AC-STEM) and electron energy loss spectroscopy (EELS) to elucidate the atomic configuration of Li-rich cathode materials.