Çinko-hava bataryalarının katalizör malzemelerinin geliştirilmesi ve karakterizasyonu

Recently, primary and secondary zinc-air batteries have attracted considerable attention due to their high energy density, safety, availability and low cost. Zinc-air batteries generate electricity through a redox reaction between zinc and oxygen in air. Zinc-air batteries have higher theoretical energy density due to abundant supply of oxygen from the atmosphere. However, poor efficiency of the oxygen reduction (ORR) and evolution reactions (OER) taking place at the cathode limits the use of zinc-air battery in demanding applications. The aim of this study is to produce and characterize a novel unifunctional and/or bifunctional catalyst material to be used in the cathode. The aim of this study is to investigate the electrochemical activity of Mn-based oxides, α-MnO2, Mn2O3 and Mn5O8, Ag-based oxides, Ag2XO4 (where X= Cr, Mo, and W), and Cu-based delafossite oxides, CuXO2 (where X= Co and Cr), to be used as a catalyst material. In this regard, precipitation, spray pyrolysis, sol-gel and hydrothermal methods were used to synthesize fine-sized powders. Structural characterizations were performed by SEM and XRD prior to use of synthesized powders. Then, linear sweep voltammograms of catalysts loaded rotating disk electrode and gas diffusion layer were investigated via a three-electrode cell in 0.1 M and 6 M KOH electrolyte, respectively. The most promising results for ORR were obtained from Ag2WO4 powders. The CuCrO2 powders synthesized through hydrothermal method at 210 oC gave the most promising results for OER activity which has the highest surface area. However, activity loss of CuCrO2 at high oxidative potentials were reported.