What is a fuel cell?

A fuel cell is a device that produces electricity through a chemical reaction, without combustion. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode.

The reactions that produce electricity take place at the electrodes. Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodes.

Fuel cells are classified primarily by the kind of electrolyte they use. This determines the kind of chemical reactions that take place in the cell, the kind of catalysts required to enable the reaction, the temperature range in which the cell operates, and the fuel required. These characteristics, in turn, affect the applications for which these cells are most suitable. There are several types of fuel cells, each with its own advantages, limitations, and potential applications, including:

• Superior energy efficiency (for example, fuel cells are 2-3 times as efficient as international combustion engines and for co-generation applications, fuel cells can achieve energy efficiencies of over 80 percent)
• Utilizes a variety of fuels including: hydrogen, methanol, natural gas, formic acid, ethanol
• Zero to near-zero emissions
• Versatile and scalable - can be applied in micro, portable, stationary, and transportation power applications
• Low maintenance costs, design freedoms and quiet operation

In BC, the majority of development is focused on Proton Exchange Membrane (PEM) fuel cells, which deliver high-power density and offer the advantages of low weight and volume, compared with other fuel cells.

PEM fuel cells use a solid polymer as an electrolyte and porous carbon electrodes containing a platinum catalyst. The electrolyte layer acts as a one-way door, allowing either positive or negative ions to travel across, but not electrons. This forces electrons to travel through the external circuit (electric current). As operating temperatures are at a low temperature (approximate 80 degrees Celsius), PEM fuel cells are ideally suitable for devices that require quick start-ups such as vehicles, back-up power, and electronic devices. In a PEM fuel cell, hydrogen fuel is combined with oxygen from air to produce electrical energy. The conversion process is environmentally safe – only heat and water are emitted as by-products.

There are numerous applications for fuel cells. Think of cases where batteries can't meet mounting demands of personal electronics, or where continuous fuel cell power would be advantageous. Wherever you need power, a fuel cell could be the solution.

Fuel cells are similar, yet unique, from batteries, internal combustion engines and generators. The following chart explains some of the similarities and differences:

Fuel cell vehicles are electric, similar to battery vehicles. Gaseous hydrogen is pumped into a tank in the car, similar to gasoline. The hydrogen is then fed into the fuel cell where it is electrochemically converted into electricity. There is no combustion and no emissions other than water vapour. The electricity generated is used to power the vehicle. A fuel cell is also 2-3 times more energy efficient than a gasoline engine.