Nanostructured Non-precious Metal Electrocatalysts for Oxygen Reduction Reaction in Alkaline Solutions

Abstract

Advanced electrical energy storage systems play a vital role in efficient use of electricity in micro-grids or smart-grids to bridge the gaps between demand and supply, especially for renewable energy sources of intermittent and cyclic nature (e.g., solar, wind, and geothermal energy). In the transportation sector, the transition from the current hybrid electric vehicles to all-electric vehicles hinges critically on the development of electrical energy storage systems with dramatically improved energy and power density, durability, and reduced cost. Therefore, new electrochemical systems with higher energy density are being sought, and metal-air batteries with conversion chemistry have the greatest potential to offer the highest energy density and to meet the ever-increasing demands for clean and secure energy. However, the commercialization of metal-air batteries depends critically on the creation of novel air-breathing electrodes with much higher levels of functionality and performance. For example, efficient catalysts for oxygen reduction reaction (ORR) at the air-electrode are yet to be developed to significantly reduce the polarization loss in metal-air batteries. In this thesis, I started with a brief overview of the critical issues relevant to overall zinc-air batteries in chapter 1 and then discussed fundamental aspects of ORR and highlight some recent advancement in the development of non-precious catalysts for ORR in zinc-air batteries, including transition metal oxides, low-dimensional carbon-based structures, and other catalysts in chapter 2. Finally, I introduced my research papers studying electrocatalysts for ORR in alkaline solutions in the rest chapters.