Fuel cells

Hydrogen and oxygen

2 elements that are necessary for fuel cells

Heat and water

By-products created by fuel cell reactions

Fuel cells

Devices that convert chemical energy directly into electricity and heat, with high efficiency. Can be used anywhere/anytime as long as hydrogen and oxygen are supplied.

Types of fuel cells

Differentiated based on the electrolytes and fuel used. Temperature and the size of the fuel cell influence which will be used.

DMFC

Direct Methanol FC. Uses methanol instead of hydrogen. Methanol breaks down in to protons, electrons, water, and carbon dioxide.

Fuel cell stacks

Individual fuel cells that are combined in series to increase the power generated. Increasing the number of cells increases the voltage. Increasing the surface area of the cells increases the current. The cathode of one cell is connected the the anode of the next cell.

Fuel cell - basic composition

Many layers sandwiched together. An electrolyte layer (membrane) in between a porous anode and a cathode. Protons are transported from the anode to the cathode through the electrolyte membrane. Electrons are carried over an external circuit load.

Benefits of fuel cells

No limits to energy/elements needed to produce power. Hydrogen and oxygen are in plentiful supply.

Types of fuel cells

PEMFC - Polymer Electrolyte Membrane FC AFC - Alkaline FC PAFC - Phosphoric Acid FC SOFC - Solid Oxide FC MCFC - Molten Carbonate FC DMFC - Direct Methanol FC

PEMFC

Polymer Electrolyte/Exchange Membrane FC. Delivers high-power density with low weight/cost/volume.

SOFC

Solid Oxide FC. Constructed of a hard ceramic material and a small amount of Ytrria (zirconia), instead of a liquid electrolyte. Temperatures can be over 1000 degrees. Promising for large high-power applications. Can use many types of fuel but the most common is natural gas.

Electrolyte membrane

The heart of the fuel cell. It enables the fuel cell to conduct it's electrons properly by attracting the protons, and enabling them to travel through the layer while maintaining their proton state.

Anode

The negatively charged terminal of a fuel cell, or a battery that is supplying current.

Cathode

The positively charged terminal of a fuel cell, or a battery that is supplying current.

Applications of fuel cells

Transportation, Portable Power devices, Consumer electronics, Education/Toys sector, Stationary (businesses, homes, power plants)

Protons

Transported from the anode to the cathode through the electrolyte membrane.