Study On Air Electrode Of Zinc-Air Battery

Because of its steady performance, much more sources of raw material and low cost, the study and development of zinc-air battery are always paid more attention. As a part of zinc air battery, air electrode has become the key factor to the character of zinc-air battery, because of the stagnancy of the zinc electrode which is the anode electrode in the battery. So it is necessary to be done deep research in air electrode.Air electrode, in which NH₄HCO₃ is as pore former, is mainly studied in this paper. The manufacturing process of air electrode, the composition of waterproof and gas diffusion layer, the composition of catalysis layer, and two kinds of catalyst were studied by numbers. In the experiments, two series of catalysts were synthesized by co-deposition and sol-gel methods each. The composition of both waterproof and gas diffusion layer and catalysis layer were optimized by the orthogonal test. Meanwhile, quasi-steady cathode polarization curves, X-Ray Diffraction (XRD), Scanning Electronic Microscope (SEM) were used to analyst the relationship between the microstructure and the performance of air electrode.Orthogonal tests of waterproof and gas diffusion were taken to option the mass ratio of composition, and meticulous tests of each factor were taken too. Scanning electric microscope was used to observe the surface pattern. Finally the best composition was found. In the composition, actived cabon, PTFE, pore former and AB is 5.00:2.00:6.00:5.00 in mass. Orthogonal tests were also taken in the composition of catalysis layer. The best catalysis layer contained actived carbon, PTFE, MnO₂, pore former and AB in the mass ratio of 3.00:1.00:5.00:3.00:3.00. Two series of catalysts were preparated by co-deposition and sol-gel methods each. And each serie of catalysts was analysed by XRD spectrums, and was preparated to be air electrode with the optioned compoundings and manufacturing process. The cathode polarization curves were elementarily studied. And the catalysis layer of the best one was observed by SEM. Finally, Ni and Mn mol ratio in the series of co-deposition catalysts which is 2:8 is the best match. LaNi_0.5Mn_0.5O₃ is the best one of its series.