DMPQ: What is fuel cell? How Hydrogen fuel cell work? ( SCIENCE)

A fuel cell is a device which produces electric energy, through a chemical reaction. Fuel cells use positively charged ion(Hydrogen) and an oxidising agent (oxygen).There are many types of fuel cells, but they all consist of a cathode,an anode, and an electrolyte that allows positively charged( hydrogen) ions to move between the two sides of the fuel cell .

They differ from batteries as they require the continuous supply of fuel. And both battery and fuel cell produce direct current (D.C). the first fuel cell was used by NASA in its satellites and space capsules. Fuel cells can be used for power backup in commercial and residential buildings.


Fuel cells have to be supplied by an external source of fuel (e.g. hydrogen) and an oxidant e.g. oxygen or air.

  • The hydrogen or any other fuel is oxidised electrochemically inside the fuel cell to produce a potential difference i.e. a voltage capable of producing a working current.
  • The overall chemical reaction in a hydrogen fuel electrochemical cell involves the oxidation of hydrogen by oxygen to produce only water.
  • Hydrogen fuel cells offer an alternative to rechargeable cells and batteries.
  • A fuel cell will produce a potential difference (‘voltage’) and a workable electric current until one of the reactants is used up.
  • hydrogen + oxygen ==> water

2H2(g) + O2(g) ==> 2H2O(l)