Abstract: The invention relates to a compound having a high conductivity for electrons, characterized in that it is of the type ABCO(x-?)Hal(y-?) with a potassium nickel fluorite structure, where x+y=4, and ? and ? lie between ?0.7 and +0.7, and wherein A comprises at least one metal selected from the group consisting of Na, K, Rb, Ca, Ba, La, Pr, Sr, Ce, Nb, Pb, Nd, Sm and Gd, and wherein B comprises at least one metal selected from the same group, and wherein C comprises at least one metal selected from the group consisting of Cu, Mg, Ti, V, Cr, Mn, Fe, Co, Nb, Mo, W and Zr and/or a metal selected from the group consisting of Pt, Ru, Ir, Rh, Pd and Ni, wherein A and B are not identical and wherein A and C are not both Nb and wherein Hal comprises at least one halogen atom selected from the group consisting of F, Cl, Br and I. The invention also describes an electrode for an electrochemical cell; a method for preparing an electrode of this type and an electrochemical cell formed with an electrode of this type.