Explain the working of nickel-cadmium storage cell.

Explanation

In nickel- cadmium sotrage cell, cadmium acts as anode while nickel metal containing `NiO_(2)` acts as cathode. KOH acts as electrolyte. Following reaction take place during discharging and recharging:
At anode : `Cd(s)+2OH^(-)(aq)underset("Recharging")overset("Discharging")iffCd(OH)_(2)(s)+2e^(-)`
At cathode : `NiO_(2)(s)+2H_(2)O(l)+2e^(-)underset("Recharging")overset("Discharging")iffNi(OH)_(2)(s)+2OH^(-)(aq)`
Overall cell reaction : `Cd(s)+NiO_(2)(s)+2H_(2)O(l)underset("Recharging")overset("Discharging")iffCd(OH)_(2)(s)+Ni(OH)_(2)(s)`