Fuel cells are a energy technology that uses an electrochemical reaction to directly transform chemical energy into electrical energy. Fuel cells need an oxidant and fuel to keep the reaction ON. Because of their great efficiency and environmental friendliness, these cells are being investigated as a potential fossil fuel substitute for a number of uses.
Basic Working Principle
A fuel cell functions as similar as a battery, however it differs greatly in that it produces electricity as long as fuel is available rather than storing energy internally. The hydrogen-oxygen fuel cell, in which hydrogen functions as the fuel and oxygen as the oxidizer, is the most widely used type of fuel cell. An electrolyte and two electrodes (anode and cathode) are present during the reaction.
How it works:
At the Anode: After being supplied into the anode, hydrogen gas (H₂) is oxidized. Protons (H⁺) and electrons (e⁻) are produced when the hydrogen molecules split.
Reaction at anode:
Electrolyte Function: Electrons are blocked by the electrolyte, which only permits protons (H⁺) to flow through it.
Electron Flow: Unable to move through the electrolyte, the electrons move through an external circuit to provide an electric current that can power gadgets.
The cathode receives oxygen (O₂), which reacts with protons (H⁺) that have passed through the electrolyte and returning electrons to produce water (H₂O) as a byproduct.
Reaction at cathode:
Types of Fuel Cells: Depending on the type of electrolyte and operating temperature, fuel cells can be classified into numerous types. Among the significant kinds are:
PEMFC, or proton exchange membrane fuel cell: The electrolyte is a polymer membrane. Low operating temperatures (–80°C) are used. Fit for applications in cars and portable devices.
Alkaline Fuel Cell (AFC): In this alkaline electrolyte is being utilises, such as potassium hydroxide solution.
Effective but susceptible to CO2 pollution.
The electrolyte in a phosphoric acid fuel cell (PAFC) is liquid phosphoric acid.Functions between 150 and 200°C.
Utilised in the production of stationary power.
Molten Carbonate Fuel Cell (MCFC):
Melted carbonate salts are used as an electrolyte.
Functions at temperatures between 600 and 700°C.
Large-scale power plants can use it.
A solid electrolyte based on ceramic is used in solid oxide fuel cells (SOFCs).
Functions at extremely high temperatures (about 1000°C).
Very effective but pricey.
Advantages of Fuel Cells
Fuel cells are a promising future technology because of their many advantages:
• High Efficiency: Minimal losses occur with the direct conversion of chemical energy into electrical energy.
• Eco-Friendly: Reduces pollution by producing water as the sole consequence.
Potential for Renewable Energy: Compatible with hydrogen produced from renewable sources.
• Silent Operation: Fuel cells run quietly, in contrast to conventional generators.
• Scalability: Suitable for both big power plants and little portable devices.
Disadvantages of Fuel Cells
Fuel cells have certain drawbacks.
• High Cost: The total cost is raised by costly materials (like platinum).
• Transportation and Storage: Because hydrogen is flammable and has a low density, it is difficult to store.
• Infrastructure Problems: There are not many hydrogen filling stations.
• Durability and Lifespan: Over time, some fuel cells deteriorate, which lowers their efficiency.
Applications of Fuel Cells
Applications for fuel cells are numerous:
Automobiles: Found in hydrogen fuel cell cars, such as the Hyundai Nexo and Toyota Mirai.
Portable Power: Found in backup power systems, smart phones and computers.
Spacecraft: NASA utilises fuel cells to provide astronauts with drinking water and energy.
Industrial Power Plants: Clean energy is supplied to companies by large-scale fuel cells.
