A storage element for a solid electrolyte battery is provided. The storage element has a main member having a porous matrix of sintered ceramic particles in which particles that are made of a metal and/or a metal oxide and jointly form a redox couple are embedded. Along a preferred direction, the storage element has a certain concentration gradient of the particles made of the metal and/or the metal oxide and/or a certain gradient of a pore density and/or a pore size, thereby allowing the diffusion behavior of oxygen ions within the main member to be controlled and thus the charge and discharge kinetics, the life and the capacity of the battery to be improved.