Performance of Graphite/SiO2 Composites as Cathode Electronic Active Layer in Al-Air Batteries

In this study, the graphite/SiO2 composite performance used as an active electronic layer in an air cathode of an aluminum-air battery (Al-air battery) has been investigated. The effects of the guar gum (GG) binder content of the samples on their characteristic impedance and discharge capacity of an Al-air battery have been analyzed in the interval from 10 to 40%. The characterization of their experimental data was obtained using Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetric (CV), and Battery Testing System (BTS). It has been found that the characteristic impedance increases with increasing of the binder content. The sample with the lowest GG content provides the larger discharge capacity of the battery up to 42.54 mAh/g. This observation has been collaborated by an analysis of the CV curve, and it provides an explanation for the increase in the integrated area of the voltammetric curve by a decreased content of the GG binder. As a whole, the experimental results demonstrate that the graphite/SiO2 composite is an appropriate electronic active material for air cathodes in Al-air batteries. The obtained data can be used for an envisaged further optimization of the properties of this promising material.