Preparation Of Nanometer Perovskite-Type Oxide And Application In Oxygen Electrode

Oxygen electrode is one of the important components in metal-air cell. The main effect factors on performance of oxygen electrode are catalysts′ oxidation and deoxidization capability and structure of oxygen electrode. Nanometer perovskite-type catalysts La_1-xSr_xMnO₃ are preparation by malic acid sol-gel method that add surface-active agent. The baking condition of perovskite-type oxide is confirmed by means of DTA-TG. It is verified that the oxide have obvious characteristic diffraction peaks and less impurity by XRD. Surface tension of nanometer particle La(1-x)Sr_xMnO₃ can be reduced remarkably that adding un-ionic surface-active agent. It prevent colloidal particle from growing up and original particle reuniting, thereby minish effectively particle size of oxide and improve its dispersing. The analyze of TEM indicate that OP-10 and PVA are added during preparation of sol may improve the dispersing of nanometer particle La_1-xSr_xMnO₃, and PVA is superior to OP-10. There are the best disperse effect when PVA's quantity is 20% compare with the amount of nitrate. The crystal particle size of oxide is about 17 nm by FWHM with Scherrer formula. Combined with transfer mechanism on the surface of oxygen electrode, the porous, waterproof and ventilative oxygen electrode are made. The optimum condition is: active carbon which was baked for 15 min in 900 ℃ as carrier for catalyst, bond is 65 wt% PTFE liquor. The mixture ratio of catalysis layer and waterproof layer is respectively active carbon : catalyst : PTFE : colloid graphite = 3:10:4:3, active carbon: Na₂SO₄: PTFE =3:5:2, thickness of catalysis and waterproof layer are all 0.2 mm. The electrode that was prepared with above method can discharge with 70 mA/cm² for 9 hours.