空気電池用活性炭電極の特性評価

抄録

Teflon-bonded active carbon electrodes were prepared using Pittsburgh active carbon, acetylene black and manganese oxide consisting of Mn₅O₈ and Mn₃O₄, and their characteristics as an air electrode in alkaline solutions were discussed in connection with the resistance and activation polarization accompanying with the oxygen-reduction reaction, and the decomposition rate of HO₂^-ion. As the results, the active carbon electrode containing 20 wt% of acetylene black exhibited a good performance because of its low resistance polarization. By the addition of manganese oxide to the carbon electrode, the activation polarization was reduced, i.e., the magnitude of exchange current density for the electrode containing manganese oxide was about twice as much as that for the original carbon electrode. The voltage-recovery characteristics of the active carbon electrode was largely improved in the presence of manganese oxide. This seemed to be ascribable to the contribution of the catalyst effect of manganese oxide in the decomposition of HO₂^-ion.