Mathematical Modeling and Optimization Studies on Development of Fuel Cells for Multifarious Applications

摘要

Direct borohydride fuel cells (DBFCs) are among the most energy dense power sources projected for futuristic portable applications. In this project, authors developed a three-dimensional, multicomponent steady-state model for liquid-feed solid polymer electrolyte DBFCs. These fuel cells use sodium borohydride (NaBH4) in alkaline media as fuel and acidified hydrogen peroxide (H2O2) as oxidant. The model employs implementation of phenomenological transport equations for the catalyst layers, diffusion layers and the polymer electrolyte membrane for a liquid feed DBFC. Diffusion of reactants within and between the pores is accounted under the framework of macrohomogeneous porous electrode theory. The kinetic treatment considered for porous structures of the catalyst layers is of Butler-Volmer type. Numerical solutions are achieved after coupling electrochemical reaction kinetics and transport mechanisms in the conservation laws, which explicitly include the effect of concentration and pressure gradients on cell polarization within the bulk catalyst layers. To understand fully the role of model parameters in simulating the performance of the DBFC, its parametric study is also carried out. A study has also been carried out for the experimental validation of the model.