Fuel cells
Fig . Lead storage battery
Fig . Nickel-Cadmium cell o It is used extensively in automobiles and invertors . o
The lead cell contains a lead anode and a lead dioxide ( PbO2 ) cathode and sulphuric acid is used as an electrolyte . Anode : Pb ( s ) + SO4 2 – ( aq ) -- > PbSO4 ( s ) + 2e – Cathode : PbO2 ( s ) + SO4 2 – ( aq ) + 4H + ( aq ) + 2e – -- > PbSO4 ( s ) + 2H2O ( l )
o The net cell reaction is : Pb ( s )+ PbO2 ( s )+ 2H2SO4 ( aq ) -- > 2PbSO4 ( s ) + 2H2O ( l )
o While charging , the reaction within the battery is reversed and PbSO4 ( s ) on anode and cathode is converted into Pb and PbO2 , respectively . o
It has a longer life than lead storage cell and it requires more expenses to
o The net reaction is : Cd ( s )+ 2Ni ( OH ) 3 ( s ) -- > CdO ( s ) + 2Ni ( OH ) 2 ( s ) + H2O ( l )
Fuel cells
o
In this kind of cell the chemical energyof fossil fuels like coal , gas or oil is initially used to convertwater into high pressure steam and is used to run a turbine to generate