What is a Fuel Cell?

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What is a Fuel Cell? Blog Image

Overview:

ISRO recently said it has successfully tested a futuristic fuel cell-based power system.

About Fuel Cell

  • A fuel cell is a device that generates electricity by a chemical reaction.
  • Fuel cells can be used in a wide range of applications, providing power for applications across multiple sectors, including transportation, industrial/commercial/residential buildings, and long-term energy storage for the grid in reversible systems.
  • Working:
    • A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode).
    • Both electrodes must be immersed in and separated by an electrolyte, which may be a liquid or a solid but must, in either case, conduct ions between the electrodes in order to complete the chemistry of the system. 
    • A fuel, such as hydrogen, is supplied to the anode, where it is oxidized, producing hydrogen ions and electrons. 
    • An oxidizer, such as oxygen, is supplied to the cathode, where the hydrogen ions from the anode absorb electrons from the latter and react with the oxygen to produce water. 
    • The difference between the respective energy levels at the electrodes (electromotive force) is the voltage per unit cell.
    • The amount of electric current available to the external circuit depends on the chemical activity and amount of the substances supplied as fuel.
    • A single fuel cell generates a tiny amount of direct-current (DC) electricity. In practice, many fuel cells are usually assembled into a stack. 
  • Advantages of Fuel Cells:
    • Fuel cells have lower or zero emissions compared to combustion engines. Hydrogen fuel cells emit only water, addressing critical climate challenges as there are no carbon dioxide emissions.
    • There are also no air pollutants that create smog and cause health problems during the operation of a fuel cell.
    • They are quiet during operation as they have few moving parts.
    • They can operate at higher efficiencies than combustion engines.
    • A fuel cell resembles a battery in many respects, but it can supply electrical energy over a much longer period of time.
      • This is because a fuel cell is continuously supplied with fuel and air (or oxygen) from an external source, whereas a battery contains only a limited amount of fuel material and oxidant that are depleted with use.

Q1) What are electrodes?

An electrode is a conductor that is used to make contact with a nonmetallic part of a circuit. Electrodes are commonly used in electrochemical cells (see Figure 1), semiconductors like diodes, and in medical devices. The electrode is the place where electron transfer occurs.

Source: Isro tests futurist fuel cell system that could power space station