Composite-microfibrous cathodes for metal-air batteries

摘要

The fabrication and performance assessment of an oxygen reduction electrode were investigated using a composite electrode structure composed of high surface area activated carbon entrapped in a sinter-bonded matrix of nickel fibers. Electrodephysical properties including thickness, porosity, volume/mass fraction of constituent carbon and metal fibers, and loading of additional electrocatalyst are related to the polarization characteristics and can be independently manipulated. The ability tomanipulate independently the physical properties of the electrode allows additional degrees of freedom for design purposes.This paper focuses on the effects of systematically varying some physical parameters of the oxygen electrode, such as porosity and catalyst loading. Polarization characteristics of the oxygen electrode are shown and discussed. It is demonstrated thatthere exists an optimal balance of porosity, catalyst loading, and carbon positioning for efficient oxygen reduction.