Low-temperature fuel cell technology for green energy

Abstract

Fuel cells convert chemical energy to electrical energy via an electrochemical reaction. They are more efficient than traditional heat engine-based power systems and can have zero or near-zero emissions during operation. A leading alternative green energy technology, fuel cells are finding applications in many areas, including transportation, portable power, and stationary power generation. These divergent uses have driven development of several different types of fuel cell technologies. A brief overview of these will be provided in this chapter; however, the focus will be on low-temperature proton exchange membrane (PEM) technologies predominant in portable power and automotive applications. Fuel cell operating principles will be reviewed, focusing on thermodynamics, efficiency, reaction kinetics, and transport phenomena in order to develop a framework for evaluating different fuel cells and comparing them with other power systems. Theoretically, much improvement in fuel cell performance is possible, and is needed along with means of lowering economic costs in order for fuel cells to see more widespread use. Some of the major technical challenges in these regards are outlined along with approaches being investigated to meet these challenges. Life cycle assessment and its application to fuel cells will be discussed to evaluate environmental impacts associated with manufacturing, operation, and disposal.