Fuel cell: Fuel cell is an electrochemical cell which converts the chemical energy of fuel directly into the electrical energy by an electrochemical process, in which the fuel is oxidized at the anode.
OR Fuel cells are the devices which convert the energy produced during combustion of fuels directly into electrical energy (electricity).
Advantages of H2-O2 fuel cell:
1. Used in Space shuttles, Space Stations.
2. Remote, off-grid locations (telecom towers, weather stations).
3. Public, industrial, Marine and Military transportation.
4. They can be used in small personal vehicles.
5. By product i.e. water can be used for drinking by astronauts.
Limitations of H2-O2 fuel cell:
1. They are carbonized when the air is blown through them.
2. The reduction of oxygen in alkaline solutions may lead to the formation of H2O2 instead of H2O.
3. High initial cost.
4. High cost of pure hydrogen.
5. Lack of infrastructure for distributing hydrogen.
6. Liquefaction of hydrogen requires 30% of the stored energy.
7. Life span of the cells is not accurately known.