Fundamentals of fuel cells including polymer electrolyte fuel cell (PEFC), phosphoric acid fuel cell (PAFC), alkaline fuel cell (AFC), molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC), are presented. Three types of overpotential, activation overpotential, ohmic overpotential and concentration overpotential, are described. Polarization curves in PEFC and SOFC are also presented for better understanding of dominant factors that determine overall cell performance.
