Abstract: Manganese oxide was synthesized by the hydrothermal method through oxidizing MnSO4 withHMnO4at 150 ℃ using cetyltrimethylammonium bromide as template.X-raydiffraction and scanning electron microscopy showed that the product was β-MnO2 nanobelt. The β-MnO2 nanobelt and electrolytic manganese dioxide (EMD) were used as catalyst to make air diffusion electrodes by mixing activated carbon and polytetrafluoroethylene. In6 mol/LKOH aqueous solution, current-potential polarization curves showed that the air electrode potential with β-MnO2 nanobelt catalyst was more positive by 30-60 mV than that of EMD, and the optimal content of β-MnO2 nanobelts in the electrocatalyst was 35%. At the typical current density 40 mA/cm2 of a Zn/air battery, the cell with the β-MnO2 nanobelt catalyst had stable discharge voltage up to 1.12 V.

Key words: zinc/air battery, air diffusion electrode, oxygen reduction, hydrothermal synthesis, manganese dioxide catalyst