context: Volumetric capacity and density are usually unreported for organic materials used in potassium batteries. Density for solid polar organic compounds containing only C, H, N and O ranges between roughly 1.1 and 1.7 g cm−3, and it is smaller than for inorganic cathode materials (calc. 2.3 g cm−3 for KMHCF, calc. 3.1 g cm−3 for KVPO4F, and 3.35 g cm−3 for V2O5 ( )). This limits the applicability of organic cathode materials where the low device volume is crucial, e.g., in portable electronics. However, in some electric vehicles and large-scale stationary applications the volume is supposed to be less restricted.
answer: KVPO4F