An alloy of stoichiometric formula MmNi(3.55)AL(0.3)Mn(0.4)Co(0.75), where Mm was a metal mixt. (29.7% La, 49.9% Ce, 15.4% Nd and 5.0% Pr by mass) was made by arc melting and milled with C nanotubes or graphite for different mass proportions of ingredients to produce electrode materials. The addn. of 2.5% C resulted in increasing the electro-chem. efficiency of the tested electrodes.