Fuel Cells
What are fuel cells?
Chemical cells use chemical reactions to convert and transfer energy to electrical energy.
They will produce a voltage only up until one of the reactants has been used up (we say the battery has "gone flat").
Fuel cells will produce a voltage continuously, provided they have a constant supply of fuel and oxygen (from the air).
Hydrogen-oxygen fuel cells
- In this type of fuel cell, hydrogen and oxygen are used to produce a voltage.
- The only product from this reaction is water.
- A hydrogen-oxygen fuel cell and electric motor are much quieter, and need less maintenance, than a petrol or diesel engine, but the hydrogen still needs to be stored in a container - like a tank.
Uses of Fuel Cells
- Hydrogen, diesel and petrol are all highly flammable fuels. Fuel cells have their advantages and disadvantages depending on the use.
Fuel cells in spacecraft
| strengths | weakness |
|---|---|
| no moving parts to maintain | have to be continuously supplied with oxygen and hydrogen \n \n although this could be rectified by using solar cells to electrolyse the water produced back into oxygen and hydrogen |
| small in size for the amount of electricity produced | |
| water they produce can be used for drinking water |
Fuel cells in vehicles
| strengths | weaknesses | |
|---|---|---|
| fuel cells | quiet in usewater is the only wastefewer moving parts | hydrogen is difficult to storenot many places to fill up with hydrogen fuel |
| petrol/diesel | easier to storea lot more places to fill up with fuel | noisy during usecarbon dioxide is a waste productmany moving parts |