Sökning: "electrolyte fuel-cells"
Visar resultat 21 - 25 av 77 avhandlingar innehållade orden electrolyte fuel-cells.
21. Adding Utility to Carbon Materials: Introducing Dopants Using Highly Soluble Metal Salts and Functionalizing Surfaces via Bromomethylation
Sammanfattning : Carbon-based materials have received intense research interest over the past few decades due to their unique combination of properties including porosity, non-toxicity, chemical inertness, low density, and electrical conductivity, which has allowed them to find a wide array of applications including supercapacitors, batteries, CO2 capture, fuel cells, and catalysis. To expand their utility, a variety of techniques have been developed to enhance their reactivity and functionality. LÄS MER
22. Neutron scattering for sustainable energy materials: investigations of proton dynamics in acceptor doped barium zirconates
Sammanfattning : Proton conducting oxides are currently receiving considerable attention for their present or potential use as electrolytes in technological devices such as sensors and electrolysers and, in particular, solid oxide fuel cells, which are among the most promising apparatuses for energy conversion. One of the main challenges for these latter devices is to combine the advantages of a solid electrolyte with those of operational temperatures below 750 °C, which is currently hampered by insufficient conductivities in the targeted temperature range. LÄS MER
23. Thin-Film Electrocatalysts for Polymer Electrolyte Fuel Cells - Activity, Durability and Proton Conduction
Sammanfattning : The polymer electrolyte membrane fuel cell (PEMFC) is a potential technology for future energy conversion in sustainable energy systems. By using hydrogen from renewable energy sources and oxygen from the air, the fuel cell produces electricity with water as the only exhaust. LÄS MER
24. Mathematical Modeling of Transport Phenomena in Polymer Electrolyte and Direct Methanol Fuel Cells
Sammanfattning : This thesis deals with modeling of two types of fuel cells:the polymer electrolyte fuel cell (PEFC) and the directmethanol fuel cell (DMFC), for which we address four majorissues: a) mass transport limitations; b) water management(PEFC); c) gas management (DMFC); d) thermal management. Four models have been derived and studied for the PEFC,focusing on the cathode. LÄS MER
25. Ceria-based Nanostructured Materials for Low-Temperature Solid Oxide Fuel Cells
Sammanfattning : As one of the most efficient and environmentally benign energy conversion devices, solid oxide fuel cells (SOFC) have attracted much attention in recent years. Conventional SOFC with yttria-stabilized zirconia as electrolyte require high operation temperature (800-1000 °C), which causes significant problems like material degradation, as well as other technological complications and economic barrier for wider applications. LÄS MER
