Comparison of Battery Cells

Production of Materials‎ > ‎4. Electrochemical Methods‎ >

Gather and present information on the structure and chemistry of a lead-acid cell and evaluate it in comparison to a button cell in terms of:

  • chemistry
  • cost and practicality
  • impact on society
  • environmental impacts
Cell type
Lead-acid cellButton (silver oxide) cell

ChemistryCell diagram
Pb, PbSO4 | H2SO4 (aq) | PbO2, Pb 

Cathode reaction
PbO2 (s) + 4H+ + SO42- +2e → PbSO4 (s)2O + 2H (l)

Anode reaction
Pb (s) + SO42- → PbSO4 (s) + 2e

Cell voltage
2.2 V
Cell diagram
Zn, ZnO | KOH (paste) | Ag2O, Ag

Cathode reaction
Ag2O (s) + H2O (l) + 2e → 2Ag (s) + 2OH

Anode reaction
Zn (s) + 2OH → ZnO (s) + H2O + 2e

Overall reaction
Zn (s) + Ag2O (s) → 2Ag (s) + ZnO (s)

Cell voltage
1.3 V
Cost and practicality
  • Very large and heavy
  • Long life
  • Lead is a reasonably expensive metal, making the cell quite expensive
  • Rechargeable
  • Electrolyte must be checked regularly
  • Level of charge easily determined
  • Very small and light
  • Relatively long life
  • Silver is an expensive metal, making the cell reasonably expensive
  • Constant output voltage
  • Non-rechargeable
Impact on society
  • Ability to recharge makes cell suitable for vehicles, where the engine can recharge the cell
  • Allowed development of starters in vehicles
  • Able to store solar energy when connected to solar panels
  • Important for charge storage, such as in remote regions
  • Small size has allowed for miniature electric appliances
  • Non-toxic nature has allowed for use inside the body
Environmental impacts
  • Do not have to be discarded/recycled after one use.
  • Corrosive sulfuric acid can pollute the environment if spillages occur.
  • Lead is toxic and electrodes and casings must be recycled; lead causes anaemia and affects the brain.
  • Have to be discarded/recycled after one use
  • Potassium hydroxide electrolyte is caustic
  • No highly toxic materials that will harm the environment