This quality assurance problem co-exists with issues where different groups evaluating materials with nominally identical crystal structures obtained from different sources or different synthetic routes obtain widely varying cell performance and stability. The observed performance variation can be attributed to defects, porosity, surface impurities, coating homogeneity, crystallographic site occupancies, and other microstructural properties. While the academic literature refers to this class of active materials as a "single crystal" morphology, industry partners and the patent literature often prefer the term "monolithic" instead, which better acknowledges the internal structural diversity of the particles. Unfortunately, there are few tools suitable for determining the crystal microstructure of these cathode particles. The peak widths are generally much too sharp for lineshape analysis by conventional powder X-ray diffraction, but the micron-sized particles are still too small for even modern laboratory single crystal diffraction (≤ 30 µm). Scanning electron microscopy is commonly employed, but provides very little information about internal microstructure unless combined with serial focused ion beam (FIB) milling. Transmission electron microscopy yields high spatial resolution, but has the same drawback of using laborious ion milling to prepare ultrathin sections. Advanced characterization tools are urgently required to scale-up manufacturing of these materials, and guide development of new cathode chemistries. A variety of powerful synchrotron techniques are being optimized for these applications, towards higher throughput, quality, and ease of data analysis. In this work, we show how nano-focused Scanning X-ray Diffraction Microscopy (SXDM) and X-ray nano computed tomography (nano-CT) reveal different aspects of the microstructure hidden inside single crystal cathode particles. We demonstrate an example of state-of-the-art commercial LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC-622) which exhibits large internal heterogeneities that are nearly impossible to observe using conventional techniques. SXDM probes the variations in crystallographic ordering at the nanoscale, while nano-CT exposes voids, porosity, and microcracks throughout the crystals. Structural descriptors which allow universal, quantitative ranking of crystal quality are developed, and the inter-and intra-particle heterogeneities of the sample are explored.