Advancements in Cotton Fabric-Based Air Cathode Electrodes for Membraneless Alkaline Fuel Cell Prototypes

This study examined the development of air cathode electrodes using cotton fabric. Various compositions of PTFE (10, 15, 20 and 25 wt%) were mixed with Nafion and carbon powder to create cotton fabric electrodes that enhance air diffusion into the cathode. The initial analysis focused on the surface properties of the cotton fabric and the assessment of carbon within the fuel cell. The physical characteristics of the cathode were evaluated before the measurements, and the leakage-seepage behavior was examined using a 0.1 M KOH solution. The results revealed that the cotton fabric surface was smooth, which facilitated the adhesion of the ingredients when treated with Nafion, carbon powder and PTFE. Scanning transmission electron microscopy (STEM) revealed spherical catalyst shapes with clustering on the surface. No seepage or leakage of the KOH solution was observed with 20 wt% PTFE. Oxygen meter tests conducted with this composition displayed a high oxygen output of 98.0 %, indicating efficiency. A fuel cell constructed with carbon powder, 20 wt% PTFE and Nafion as the air cathode demonstrated optimal performance, similar to commercial air cathodes. Evaluation of the efficiency using the Pd/C catalyst anode and AgMnO2/C catalyst revealed a power output comparable to commercial air cathodes. HIGHLIGHTS Investigation of carbon fabric leakage in the membraneless alkaline fuel cell prototype revealed that the carbon cotton fabric from cotton with 20 wt% polytetrafluoroethylene (PTFE), both with and without Nafion, did not experience leakage of the KOH solution or oxygen gas. The performance of the constructed air cathode was similar to a commercially supplied air cathode from a Taiwanese company. GRAPHICAL ABSTRACT