A cathode, electrochemical cell and process for making either is disclosed. The cathode includes iron disulfide which exhibits multiple peaks representing distinct maxima of mean diameters for the volume-based particle size distribution. All of the maxima are less than 20 microns. A combination of natural pyrite ore and synthetic iron disulfide may be mixed to achieve the desired distribution, or a combination of natural pyrite ores may be processed in different manners to achieve the desired characteristics.