The Na0.60CoO2 phase, a potential conductive additive for the positive electrode of Ni–MH cells

The Na0.60CoO2 phase, obtained by a classical solid-state reaction, is tested as a conductive additive in the nickel oxide electrode. Though the process was not optimised in terms of additive repartition, the experiments show a good efficiency of the Na0.60CoO2 phase even at low cobalt content, compared to usual additives like CoO. Moreover, it increases the stability of the electrode at low potential. The added Na0.60CoO2 phase is shown to transform, during the first cycles, into a γ-type cobalt oxyhydroxide phase that is more stable at low potential than the usual additives.