However, in the present invention, the sintered body may not be interpreted limitedly as being a state of being connected by the interparticle neck of an electrode active material, and as described above, the sintered body may be interpreted as a product obtained by subjecting the molded body or the raw material to heat, specifically heat energy capable of mass transfer, substantially a heat treatment at 300° C. or higher, more substantially a heat treatment at 500° C. or higher, and still more substantially a heat treatment at 600° C. or higher.
In addition, depending on the specific material of the raw material, burn-out of a pore forming agent, binding of a conductive material and an active material (including melt binding of the conductive material), burn-out of a binder, carbonization of the binder, conversion of an electrode active material precursor into an electrode active material, conversion of a carbon precursor into carbon (pyrocarbon), and/or graphitization treatment of pyrocarbon, and the like may be performed, by heat application for sintered body production or if necessary, by a separate independent heat treatment process after producing the sintered body.