Electrochemical energy conversion and storage systems are set to play a major role in the scheme of providing clean and renewable energy to... Show moreElectrochemical energy conversion and storage systems are set to play a major role in the scheme of providing clean and renewable energy to the growing energy demands, both in the nearby and long-term future. PEM fuel cells are the widely tested energy conversion devices with hydrogen as fuel and air as oxidant. Li-ion batteries are commercialized for short and medium range energy demands. But for fulfilling the long range energy demands, research in some new technologies such as Li-air, Magnesium and Sodium batteries are in progress. Magnesium batteries have huge potential to be a high energy density battery suitable for long range electric vehicles and electrical grid energy storage. In PEM fuel cells, Oxygen reduction reaction is the performance limiting factor due to the sluggish reaction kinetics and expensive, but relatively stable Pt catalyst. In the present study, combined DFT modeling and experimental annealing procedure is being employed to improve the ORR activity of Pd by alloying with transition metal elements such as Ni, Cu and Fe. In Li-ion battery, LiFePO4 is the widely commercialized cathode material, but it suffers its limitation of possessing poor electronic conductivity, which affects the cell performance at high discharge rates. A simple isothermal, one-dimensional John Newman Li-ion battery model is being employed to study the effects of changes in LiFePO4, carbon and binder composition towards changes in electrode porosity, electrical conductivity and cell capacity. With the help of modeling results, an optimum composition zone is located for optimizing the high rate performance. In Magnesium batteries, a modified isothermal, one-dimensional John Newman battery model was employed to study the characteristics of the Mg intercalation reactions, predict the performance of the Bi anode electrode and also understand the underlying phenomena and properties that dictate the characteristics of the Mg intercalation in Bi electrode. PH.D in Chemical Engineering, July 2013 Show less
