Cells and Batteries

• Cell


  Two different metals placed in an electrolyte to produce electricity
• Producing electricity in a cell

  1. Chemical reaction taking place on the surface of the two metals

  2. Reactions producing electricity
• Cells can only produce electricity for a certain period of time as the chemicals in the cell eventually run out
• Cells only produce electricity if we use metals with different reactivity
• Reactivity series of metals

  • Reactive metals at the top (e.g. magnesium, aluminium)
  • Less reactive metals at the bottom (e.g. lead, copper)
• Difference in reactivity between the two metals

  Determines the size of the potential difference produced by the cell
• Battery

  Two or more cells connected in series to produce a greater voltage
• Types of batteries


  • Alkaline (non-rechargeable)
  • Rechargeable
• Alkaline (non-rechargeable) batteries


  Reactants run out, no way to reverse the reactions
• Rechargeable batteries


  Chemical reactions can be reversed by applying an electrical current