Discharge performance of Zn‐air fuel cells under the influence of Carbopol 940 thickener

Abstract

A dynamic research endeavor has been performed in this research study by constructing and operating an innovative flowing type anode (zinc gel) along with Carbopol 960 additives as thickener in a zinc-air fuel cell. This gel constituted of a mixture of Zn powder, thickener, and potassium hydroxide (KOH) electrolyte, and it was fueled into the cell with a peristaltic pump. The flowing Zn anode allowed the reaction-produced water, carbonate, and zinc oxide (ZnO) to be discharged from the cell. Basic operating parameters of the fuel cell like the concentrations of the Zn powder, thickener, and electrolyte along with the number and grid density of the current collector grid, cell operation temperature, and air flow rate were all optimized for effective and enhanced fuel cell performance. It was determined based on voltage production along with current and energy density generation. The augmented experimental results were as follows; thickener concentration of 1 to 2 wt% was observed to be optimum above which the electrolyte acquired a solid state. The voltage production was stable at electrolyte concentrations of 60 to 65 wt% and Zn powder concentrations lower than 40 wt%, and concentrations greater than this resulted in reduced cell performance. The implementation of four current collector grids each with an opening density of 144 grid/cm2 had efficiently amplified cell performance. The ideal cell temperature was determined to be 40°C, and maximum cell production was attained at an air flow rate of 2 m/s. Consequently, effective improvement and advancement in the processes and operational parameters were achieved in this zinc-air fuel cell with a state-of-the-art anode fuel. This will surely provide great opportunities for their applications in the future.