A Novel Porous Electronic Conducting Ceramics Loaded with Silver Nano Particles as Cathode for Zinc-Air Batteries

Abstract

Zinc-air battery has great advantages such as high energy density, low cost and environmentally friendliness. Air electrode plays an important role in electrochemical performance of a zinc-air battery. In this paper, we report our study of a novel air electrode on which a porous perovskite ceramic La0.7Sr0.3CoO3-δ(LSC) with Ag nanoparticles directly grown. The porous LSC is used as substrate while Ag as catalyst. The porous structure of substrate attributes to the amount and dispersion of Ag nanoparticles which affect the electrochemical performance of air electrode. Therefore, the property of the Ag-LSC electrode is optimized by adjusting the mass content of pore-former (starch). Experimental results show that the Ag-LSC electrode, with a porosity of ~32% and a Ag load of ~30 mg/cm2, exhibits the best performance in all tested samples, and a zinc-air battery assembled with such air electrode gives the maximum power density of 141 mW/cm. What's more, in order to ensure the gas diffusion channels, the hydrophilicity and hydrophobicity of the cathode is modified with PTFE to prevent flooding. After all that, the life-time of the zinc-air battery, with optimization by coating a PTFE layer as hydrophobic agent on the surface of the selected Ag-LSC electrode, prolongs significantly.