Cells, Batteries and Fuel Cells

  • Created by: Davwi
  • Created on: 20-02-19 18:16


  • An electrochemical cell is made up of two electrodes and an electrolyte.
  • The two electrodes must be able to conduct electricity, and so are ususally metals.
  • Th electrolyte is a liquid that contains ions that react with the electrodes.
  • The chemical reactions between the electrodes and the electrolyte set up a charge difference between the electrodes.
  • If the electrodes are then connected by a wire, the charge is able to flow and electricity is produced. A voltmeter can also be added to the circuit to measure the voltage of the cell.
  • Different metals react differently with a given electrolyte- this is what causes the charge difference, or the voltage, of the cell. So the type of electrodes used will determine the voltage of the cell.
  • The bigger the difference in reactivity between the metal electrodes, the bigger the voltage of the cell.
  • The electrolyte used in a cell will also affect the size of the voltage since different ions in solution will react differently with the metal electrodes used.
  • A battery is formed by connecting 2+ cells together in series. The voltages of the cells in the battery are combined so there is a bigger voltage overall.
  • In some cells, the reactions that happen in the electrodes are irreversible.
  • Over time the reacting particles- the ions in the electrolyte and the metal ions on the electrode- get used up and turned into products of the reaction.
  • Once any one of the reactants get used up, the reaction can't happen so no electricity is produced.
  • The products can't be turned back into the reactants, so the cell can't be recharged.
  • In rechargeable cells, the reaction can be reversed by…


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