Chapter 1 - 1. Introduction

Abstract

This chapter discusses different aspects of fuel cells. A fuel cell is an electrochemical-energy converter that converts the chemical energy of fuel directly into DC electricity. At the heart of a polymer electrolyte membrane fuel cell is a polymer membrane that has some unique capabilities. It is impermeable to gases but it conducts protons. The membrane that acts as the electrolyte is squeezed between two porous, electrically conductive electrodes. These electrodes are typically made out of carbon cloth or carbon fiber paper. The chapter shows the timeline of fuel-cell-development history in a figure. Fuel cells can be grouped by the type of electrolyte they use—namely, alkaline fuel cells (AFC), polymer electrolyte membrane or proton exchange membrane fuel cells (PEMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), and solid oxide fuel cells (SOFC). The chapter summarizes the basic principles and electrochemical reactions in various fuel-cell types. The reasons fuel cells are needed are listed in the chapter along with a discussion of the applications of fuel cells—such as in back-up power, portable power, utility vehicles, golf carts, space, and airplanes.