Canadian Hydrogen and Fuel Cell Association

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What Types of Fuel Cells are There?

What Types of Fuel Cells are There?

Fuel cells are a family of technologies – there are several different types, typically classified by the kind of electrolyte they use.

The type of electrolyte determines the kind of chemical reaction, the kind of catalyst needed, the temperature range, and the type of fuel. All of these characteristics affect the applications the cells are most suitable for.

Low Temperature Fuel Cells

High Temperature Fuel Cells

DMFC

Direct Methanol Fuel Cell

PEMFC

Proton Exchange

AFC

Alkaline Fuel Cell

PAFC

Phosphoric Acid Fuel Cell

MCFC

Molten Carbon Fuel

SOFC

Solid Oxide Fuel Cell

Electrolyte Proton-conducting membrane Proton-conducting membrane Caustic potash solution Concentrated phosphoric acid Molten carbonate Ceramic
Temperature Range < 100°C < 100°C < 100°C ~ 200°C ~ 650°C 800-1,000°C
Fuel Methanol Hydrogen Hydrogen Hydrogen Natural gas, coal Natural gas, coal
Power Range Watts/kilowatts Watts/kilowatts Watts/kilowatts Kilowatts Kilowatts/megawatts Kilowatts/megawatts
Application Examples Vehicles, small appliances Vehicles, small generators, domestic supply, block-type heat, power stations Outer space Block type heat, power stations Power plants, combined heat and power Power plants, combined heat and power

 

Proton Exchange Membrane Fuel Cell (PEM)

In Canada, most fuel cell development focuses on Proton Exchange Membrane (PEM) or Polymer Electrolyte (PEFC) fuel cells. PEMs produce high-power density and are lighter and smaller than other fuel cells. In a PEM fuel cell, pure 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.

PEM fuel cells use a solid polymer, which looks like kitchen plastic wrap, 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 as electric current. Since they operate at low temperatures (approximate 80 degrees Celsius), PEM fuel cells are best for devices that require quick start-ups, such as vehicles, back-up power, and electronic devices.

Solid Oxide Fuel Cells (SOFC)

Solid Oxide Fuel Cells (SOFC) use a solid, nonporous metal oxide as an electrolyte and operate at very high temperatures (over 650 degrees Celsius). SOFCs are best suited for large-scale stationary power generators for factories or even towns. Being very stable when used continuously, SOFCs have the longest operating life of any fuel cell. In addition to the power generated by the fuel cell, SOFCs also create steam because of the high temperature. This steam can be reused, for instance, for powering turbines to generate even more electricity.