Advanced characterization enables a deeper understanding of cathode microstructure, and can help explain not only the inter-and intraparticle heterogeneity, but also justify the range in reported performance for nominally identical NMC active materials. SXDM and nano-CT are demonstrated to be powerful probes for strain/tilt mosaicity, morphology, and internal voids in single crystal cathode materials. While the influence of these microstructural motifs must be thoroughly validated in actual devices, optimization and commercialization of these materials requires new heuristic tools which can predict the performance of active materials to guide their development. Layered active materials with higher nickel content are being aggressively pursued due to their higher energy density and lower cost. However, Ni-rich single crystals are even more difficult to manufacture, and we therefore expect these quality control issues to expand in the near term. Because both SXDM and nanoCT utilize hard X-rays, their in situ capabilities offer promising routes towards optimizing the annealing/synthesis of advanced cathode materi-als including NMC, and understanding degradation dynamics in operational cells. Recent advances in synchrotron microscopy allow these techniques to provide unprecedented insight towards the rational design of single crystal cathode active materials used in high performance lithium ion batteries.