Electrochemical hydrogen storage in LaMO3 (M = Cr, Mn, Fe, Co, Ni) nano-perovskites

In this work, a comparative study has been demonstrated on the effect of several transition metal cations including Cr3+, Mn2+, Fe3+, Co2+, and Ni2+ in LaMO3 perovskite-type structures at its M position on their electrochemical hydrogen sorption/storage process. The nano-sized LaMO3 perovskites were synthesized using sol-gel method and then, they were calcined under the optimal experimental conditions at air atmosphere at 900 °C for 5 h. The electrochemical studies indicate that the LaFeO3 nanoparticles with uniform size and shape, in a 6 M KOH alkaline electrolyte after 15th cycles, generate the highest discharge capacity of 13,500 mAh/g compared to other nano-perovskites, which is due to their higher surface reactivity and faster electron transfer. Furthermore, after twenty cycles, this electrode displays an additional increase in discharge capacity along with superior cycling stability; hence it can be a good candidate for battery applications.