IEC TS 62607-4-2:2016(E), which is a Technical Specification, provides a standardized method for the determination of the density of cathode nanomaterials in powder form used for electrical energy storage devices. This method provides users with a key control characteristic to decide whether or not a cathode nanomaterial is usable, or suitable for their application. This document includes definitions of terminology used in this document, recommendations for sample preparation, outlines of the experimental procedures used to measure cathode nanomaterial properties, methods of interpretation of results and discussion of data analysis, case studies, and references.