Honeycomb oxygen-generator with doped bismuth-oxide-based electrolyte and Ag electrode

This study reports a novel honeycomb oxygen-generator using Y-doped Bi2O3 as the electrolyte and Ag as the electrode. The oxygen generator with a honeycomb-type structure has the dimensions of 40 mm × 35 mm × 30 mm and consists of 13 × 12 channels. The external wire circuitries of the channels arrayed in series-parallel hybrid connections were evaluated to achieve the best efficiency of oxygen evolution, which facilitated the maximum oxygen output of 117 sccm and high purity of >99.9% at 550 °C under a current flow of 14 A. Five Ag electrodes with 5 wt% silane and various amounts of high-temperature glass up to 5 wt% were employed to increase the thermal stability of the modules during operation. The results indicated that the module with an Ag electrode having 3 wt% glass exhibits the best performance with the oxygen output per unit area of 0.87 cm/min at a current density of 0.385 A/cm2 and the lowest decay rate.