Chapter 2 - The Fundamentals of Fuel Cell Operation

Abstract

A basic fuel cell comprises an electrolyte and two electrodes. The electrolyte acts as a semi-permeable membrane that will allow some charged chemical species to pass through its structure but it will not conduct electrons. The electrodes, meanwhile, must be in intimate contact with the electrolyte where they provide a site for the hydrogen or oxygen fuel molecules to be adsorbed and react and an interface with the electrolyte so that charged ions can pass into or out of the latter during the cell reaction. Catalysts are also required to assist, and often to speed the reaction of the gaseous fuels. Since hydrogen is not readily available, most fuel cells produce hydrogen from natural gas using a device called a reformer.