MnO2/MCMB electrocatalyst for all solid-state alkaline zinc-air cells

Nanostructured MnO₂/mesocarbon microbeads (MCMB) composite has been prepared successfully for use in zinc-air cell as electrocatalyst for oxygen reaction. The scanning electron microscope (SEM) images showed that the MnO₂ nanorods were formed and covered on the surface of MCMB in bird’s nest morphology. X-ray diffraction (XRD) pattern indicated that the MnO₂ has the hollandite structure with a composition approximating KMn₈O₁₆. By the cathodic polarization curve tests, the nanostructured material demonstrated excellent electrocatalytic activity as a kind of oxygen electrode electrocatalyst compared with electrolytic MnO₂. An all solid-state zinc-air cell has been fabricated with this material as electrocatalyst for oxygen electrode and potassium salt of cross-linked poly(acrylic acid) as an alkaline polymer gel electrolyte. The cell has good discharge characteristics at room temperature.