Electrochemical Energy Production Using Fuel Cell Technologies

Abstract

Fuel cells are highly efficient and environmentally friendly energy conversion devices that are receiving increasing attention and are steadily moving toward commercialization. Fuel cells deliver electricity and heat, based on the spontaneous electrochemical oxidation of fuels at the anode and the reduction of oxygen at the cathode, without combustion. In many ways, fuel cells are similar to batteries, although they do not require recharging and operate as long as fuel continues to be provided. There are four leading types of fuels reviewed in this chapter, proton exchange membrane fuel cells (PEMFCs) operating on clean hydrogen, direct alcohol (primarily methanol) fuel cells (DAFCs), solid oxide fuel cells (SOFCs), and molten carbonate fuel cells (MCFCs). PEMFCs and DAFCs normally operate at below 100 °C and are targeted primarily for transportation and mobile applications, while SOFCs and MCFCs, which run at temperatures above 600 °C, can run on a wide variety of fuels and are intended mostly for stationary combined heat and power applications. This review is focused primarily on a description of each of these technologies, with an emphasis on the materials used in the electrodes, the electrolyte that separates them, and the current collectors.