Abstract :

Battery powered electric vehicles which can be considered as affordable for a common buyer suffer from severe range limitation and have a substantial charging time which are preventing such vehicles from competing with or replacing current internal combustion engine-based vehicles. An electric motor-propelled vehicle powered by a hydrogen fuel cell for generating electricity appears to be the only functionally viable solution which has zero emissions and can yet outperform conventional vehicles in terms of driving range with a refuelling time which can be comparable to those vehicles. However, the large-scale usage of fuel cells has been stymied by their high cost coupled with insufficient infrastructure for hydrogen production and distribution, and the potential risk of carrying on-board extremely high pressure (of the order of 350-700 bar) hydrogen storage tanks in vehicles. One way to make a fuel cell stack more economical would be to optimize its design which can be achieved best by resorting to advanced Computer-Aided Engineering (CAE) techniques as implemented in a commercial multi-physics finite element analysis solver e.g. COMSOL. It is noted in this context that materials play a key role in the effective realization of a fuel cell comprising components such as gas diffusion layers, porous catalyst-coated electrodes and a solid polymer electrolyte membrane. Using the relevant physical and electro-chemical properties of the components mentioned as well as of hydrogen and oxygen, a multi-physics simulation has been carried out in the current study with the aid of COMSOL for predicting the experimental polarization curve of a single fuel cell. The single cell model is then expanded to two cells connected in parallel for scaling up the power of a fuel cell system. An approach is finally shown for arriving at the specifications of a fuel cell stack for powering an electric vehicle.