How does a fuel cell work?

Newest discoveries in fuel cell technology.

We all hear a lot about fuel cells on the news, but what exactly is a fuel cell? Simply, a fuel cell is a device that takes stored chemical energy and converts it into electrical energy. A fuel cell is an electrochemical conversion device. It is a kind of a device that produces electricity from the fuel that acts as the anode and is the positive part in a cell and it is an oxidant that acts as a cathode, which is the negative part in a cell. Now, the oxidizer and fuel react in the presence of an electrolyte, which acts as the medium. Now, a reactant flows into the cell reagents and products flow out, and electrolyte remain within the cell.

The principle on which the fuel cell works is the principle of catalysis. According to this principle, the reagent fuel is separated into two components electrons and protons, electrons are forced to go through a path that is pre-specified and, hence, the electrons are converted into electricity. Today, the catalyst that is used in this reaction of fuel and oxidizer used is generally composed of a metal of the platinum group or alloy. There is now another catalytic process in which electrons are taken and these electrons combine with the protons and oxidants which ultimately develop waste products. These wastes are simple compounds such as water and carbon dioxide.

There is a classic hydrogen-oxygen design of fuel cells which is also known as proton exchange membrane fuel cell (PEMFC) design. A proton-conducting polymer membrane (electrolyte), separates the anode and cathode sides.

At the anode, there is a diffusion of hydrogen to diffuse the anode and catalyst later; it dissociates itself into protons and electrons. The protons are conducted through the membrane to the cathode; on the other hand, the electrons are forced to move in an external circuit (energy supply) because there is an electrically insulating membrane. At the cathode catalyst there are oxygen molecules that react with electrons. These electrons are those who have traveled through the external circuit and protons to form water – for example, waste products that are generated, are either liquid or steam.

Other than the type of pure hydrogen, hydrocarbons for fuel cells can also be used. These are fuels such as diesel or methanol and chemical hydrides can also be used as fuel in fuel cells. The waste produced in these types of fuel is carbon dioxide and water.

There are many combinations of fuel cells, because there are many possible combinations of fuels and oxidants. To name a few we have “a metal hydride fuel cell”. The electrolyte used in this fuel cell is an alkaline aqueous solution such as potassium hydroxide. Then there is a merger of carbonate fuel cell. The electrolyte used in this cell is alkaline, molten carbonate, such as sodium bicarbonate.

There is a difference in behavior of fuel cells. It is due to the electrochemical batteries in use for some reasons. The first reason is that fuel cells consume reagents and it is necessary to rebuild these reagents from time to time. The second reason is that the electrodes of fuel cells are a catalyst and it is therefore relatively more stable than the electrochemical batteries.