Technology

Introduction

The fuel cell is an electrochemical energy conversion device. That means that it converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity.

The other electrochemical device that we are all familiar with is the battery. A battery has all of its chemicals stored inside, and it converts those chemicals into electricity. This means that a battery eventually "dies" and you either throw it away or recharge it.

With a fuel cell, chemicals constantly flow into the cell so it never dies -- as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Fuel cells use hydrogen and oxygen as the chemicals. The fuel cell provides a DC (direct current) voltage that is used to power the car.

There are several different types of fuel cells, each using a different chemistry. Fuel cells are usually classified by the type of electrolyte they use. Some types of fuel cells work well for use in stationary power generation plants. Others are used to power cars.

The proton exchange membrane fuel cell (PEMFC) is the type we will focus on. This is the type that powers cars, buses and, one day, maybe even the house that you live in! The PEMFC uses one of the simplest reactions among any fuel cell. There are four main parts to this fuel cell.