23.6 Storage and fuel cells

• Fuel cells converts chemical energy from redox reactions into electrical energy
• Primary cells are used until the chemicals have fully reacted
• Secondary cells can be recharged by reversing the reaction that used it up in first place
• A fuel cell uses the energy from the reaction of a fuel with oxygen to create a voltage

  • oxygen is at the positive electrode where reduction takes place
  • the fuel is at the negative electrode where oxidation takes place
• Hydrogen fuel cells can operate with an acid or alkali electrolyte

  • water is the only product