Determination of Spinel Content in Cycled Li1.2Ni0.13Mn0.54Co0.13O2 Using Three-Dimensional Electron Diffraction and Precession Electron Diffraction

Among lithium battery cathode materials, Li1.2Ni0.13Mn0.54Co0.13O2 (LR-NMC) has a high theoretical capacity, but suffers from voltage and capacity fade during cycling. This is partially ascribed to transition metal cation migration, which involves the local transformation of honeycomb layered structure spinel-like nano-domains. Determination layered/spinel phase ratio powder X-ray diffraction data hindered by nanoscale functional material domains, diverse types twinning, stacking faults, possible presence rock salt phase. Determining transmission electron microscopy imaging can only be done for thin regions near surfaces crystals, intense beam that needed induces same spinel as cycling does. In this article, it demonstrated low dose sufficient allows collection without inducing transformation. Using calculated patterns, we demonstrate determine volume different phases in particles using pair-wise comparison intensities reflections. method, determined submicron sized crystal experimental three-dimensional (3D ED) precession (PED) data. Both twinning are taken into account. After 150 charge–discharge cycles, 4% LR-NMC was transformed irreversibly structure. The proposed method would applicable other multi-phase materials well.