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Fuel Cells - Coggle Diagram
Fuel Cells
What are Fuel Cells?
Produce electricity continuously
Require fuel supply
Require oxygen supply
Fuel is oxidised electrochemically
Produce electrical energy
Advantages
Only produces water
Less pollution than petrol
No recharging needed
Continuous electricity supply
Useful for vehicles
Hydrogen-Oxygen Fuel Cell
Fuel
Hydrogen
Oxidant
Oxygen from air
Product
Water only
Overall Equation
2H₂ + O₂ → 2H₂O
How it Works
Anode (-)
Hydrogen oxidised
Produces electrons
Electrons
Flow through circuit
Generate electricity
Cathode (+)
Oxygen reduced
End Product
Water
Disadvantages
Hydrogen is flammable
Difficult to store hydrogen
Hydrogen production is expensive
Most hydrogen produced from fossil fuels
Exam Questions
State overall equation
Explain advantages
Explain disadvantages
Compare with batteries
Higher Tier
Oxidation
Loss of electrons
Reduction
Gain of electrons
Half Equations
H₂ → 2H⁺ + 2e⁻
O₂ + 4H⁺ + 4e⁻ → 2H₂O
Compared with Batteries
Fuel Cells
Constant fuel supply needed
Generate electricity continuously
Batteries
Store fixed amount of energy
Must be recharged