| The development of high-performance, cyclically stable bifunctional air cathodes is critical for the commercial deployment of rechargeable Zn-air batteries. Amongst other requirements, the air electrode should exhibit characteristics, such as superior electrochemical performance, cycle life and high surface area, and low material cost. This study addresses the effect of transition metal doping in LaNiO3 on the performance in carbon-based cathodes, as well as the effect of the crystallite size of NiCo2O4 on the performance of carbon-free, NiCo2O4-based cathodes.;In this study, LaNi1-yXyO3 (X = Co, Mn: y = 0.1 or 0.2) with good electrochemical performance was evaluated as the catalyst material for the carbon-based cathodes. Experimental details that were specified were gathered from literature and prior research for synthesizing these catalysts. A comprehensive study regarding the effects of transition metal doping on the performance on the cycle life and the relevant degradation mechanism for the carbon-based air cathode was conducted in this thesis. In addition, NiCo2O4 was synthesized using the glycine nitrate process (GNP) and tested as an air electrode material for rechargeable metal-air batteries. The unsupported, bifunctional, NiCo2O 4-based cathodes were evaluated with regard to electrochemical performance, stability, and cycle life. The cathodes exhibited reduced overpotentials for both oxygen evolution and reduction, compared to the carbon-based cathodes. Furthermore, it was discovered that as the NiCo2O4 crystallite size decreased, the cycle life of the carbon-free cathodes increased significantly. |
