Electrochemical effect of AB 3 alloy on CoB alloy in CoB- x wt.% AB 3 mixture electrodes

Abstract

CoB alloy prepared by arc melting possesses excellent cyclic stability but low discharge capacity, while AB 3 hydrogen storage alloy prepared by inductive melting exhibits high discharge capacity but poor cyclic stability as negative electrode materials of alkaline rechargeable nickel-based batteries. A series of CoB- x wt.% AB 3 mixtures were synthesized by simple mixing of CoB alloy powders and AB 3 alloy powders. Electrochemical measurements revealed that the reversible discharge capacity and cycle stability of the mixture electrodes were largely improved, compared with CoB alloy electrode and AB 3 alloy electrode. The CoB- x wt.% AB 3 ( x = 20) electrode displays the highest discharge capacity of the 40th cycle and the CoB- x wt.% AB 3 ( x = 10) electrode displays the highest discharge capacity of the 100th cycle among all the mixture electrodes. The electrochemical effect of AB 3 alloy on CoB alloy in mixture electrodes was also systematically investigated.