The overall reaction during
discharge is:
Cd (s) + 2Ni(OH)3 (s) ® CdO (s) + 2Ni(OH)2 (s) + H2O (l )
Production of electricity by thermal plants is not a very efficient method
and is a major source of pollution In such plants, the chemical energy
(heat of combustion) of fossil fuels (coal, gas or oil) is first used for
converting water into high pressure steam This is then used to run
a turbine to produce electricity We know that a galvanic cell directly
converts chemical energy into electricity and is highly efficient