Influence of the partial replacement of Fe by Mn on the electrocatalytic activity for oxygen evolution in the Li(1-0.5x)Fe(1.5x+1)Mn(1-x)O4 spinel system

Oxides of compositions Li(1 - 0.5x)Fe(1.5x + 1)Mn(1 - x)O4 (0 less than or equal to 1 - x less than or equal to 1) with a spinel structure have been c haracterized by XRD analysis and Mossbauer spectroscopy. The surface proper ties of the materials have been studied by OCP, pHz and XPS measurements. T he influence of the substitution of Fe by Mn on the electrocatalytic activi ty of the electrodes has been analyzed in terms of Tafel slopes and propose d cationic distribution. The oxygen evolution reaction depends on both OCP and pHz, and it is very sensitive to the iron/manganese ratio in the octahe dral sites of the spinel structure. (C) 2001 Elsevier Science Ltd. All righ ts reserved.