A fuel cell is used to produce the electrical current required to power various gadgets by converting chemical energy into electrical energy. This is done when the fuel and the oxidizing agent undergo a series of redox reactions resulting in the production of electrons, water, carbon-di-oxide, and heat as by-products. On the basis of the type of fuel used, a fuel cell can be classified into various categories such as alkaline fuel cell, phosphoric acid fuel cell, molten carbohydrate fuel cell, solid oxide fuel cell, direct-methanol fuel cell, etc.
Working of a Fuel Cell
A fuel cell typically consists of two electrodes, namely an anode and cathode separated by an electrolyte membrane. The organic fuel that can be used in a fuel cell to produce electricity includes hydrogen, methane, ethane, ethanol, etc. These fuels underdo combustion and release energy in form of heat. Most of such reactions produce water and carbon-di-oxide as by-products and are prominently redox reactions. Since redox reactions involve the transfer of electrons, chemical energy can be converted into electrical energy. An electrolyte material is present between the electrodes. Fuel is supplied to both the electrodes individually. For instance, let us say that in a fuel cell the hydrogen is fed to the anode, while air is fed to the cathode. Here, the catalyst present at the anode side of the cell tends to break the hydrogen molecules into smaller particles, i.e., protons and electrons. Both the elements try to move towards the cathode following different paths. The electrons reach the cathode following an external path thereby, producing the current; whereas, the protons travel through the electrolyte membrane and reach the cathode to combine with oxygen molecules and electrons to produce water and heat as by-products.
Advantages of a Fuel Cell
1. A fuel cell does not require any sort of recharging. A fuel cell is able to reproduce the energy till it is supplied with fuel.
2. If hydrogen is used as the input fuel, then the only byproducts observed are water, heat, and electricity. Thereby, producing electrical energy with utmost efficiency and with no release of toxic substances.
3. Fuel cells are highly efficient as they are able to directly convert chemical energy into electrical energy. In comparison to the other alternatives available in the market, fuel cells are 60% more efficient.
4. Fuel cells do not contribute to air pollution in any way.
5. Fuel cells are not hazardous and do not lead to health problems as the working of fuel cells does not lead to the formation of smoke or smog.
6. A fuel cell does not have any mechanical part; therefore, they are noiseless.
Disadvantages of a Fuel Cell
1. Fuel cells are expensive in nature.
2. Fuel cells are difficult to store as the fuel used in the cells require a particular temperature and pressure level to be maintained.
3. Fuel cells are comparatively more durable.
4. The average lifespan of fuel cells is not quite high.
Applications of a Fuel Cell
Fuel cells are widely used in transportation vehicles such as buses, trucks, cars, etc. This is because fuel cells do not release toxic gases; therefore, are cleaner alternatives to power vehicles. The use of fuel cells in vehicles tends to significantly increase reliability. It is also used to power FCEVs.
Material Handling Equipment
Fuel cells are prominently employed in material handling equipment to ease the process of transporting heavy goods from one place to another.
Backup Power Generation
A number of backup power generation systems make use of fuel cells for their operation. Stationary fuel cells are a crucial element of the uninterrupted power supply devices installed in hospitals, residential buildings, industries, offices, etc.
Hydrogen fuel cells provide a versatile option to power various electronic gadgets and communication devices such as mobile phones, laptops, etc.
Fuel cells are often used to power rockets and space shuttles as they do not release much toxic waste into the environment.