In addition, when the active material bulk is a sintered body as in FIG. 5, the cut particulates may mean having a shape in which internal particles are cut along one optional plane, based on the shape of the electrode active material particles (internal particles) which are positioned in the inner center of the active material bulk and are in the state of being bound to each other. As described above and as an example shown in FIG. 5, when the active material bulk is a sintered body, the active material bulk is advantageously a sintered body at an initial sintering stage in which the interparticle neck of the electrode active material particles 110 contained as a raw material is formed. Accordingly, when the active material bulk is a sintered body, the active material bulk may mean a shape in which the electrode active material particles 110 contained as a raw material are cut along one optional plane, based on the shape of the electrode active material particles 110 contained as a raw material. In the shape which has been cut based on the electrode active material particles contained as a raw material, the cut particles should not be interpreted precisely as the cut particle form of the electrode active material particles 110 contained as a raw material. During a heat treatment for producing the sintered body, mass transfer occurs by densification or particle growth and a concave curvature region is produced at a contact point between particles, and thus, a neck region which is the concave curvature region may be appropriately considered in the cut shape, of course.
