Nickel-Cadmium Cell - Voltage 1.2 volts

This NiCad electrodes are made of two flat plates. The anode plate is made of cadmium hydroxide, and the cathode plate is made of nickel hydroxide. Thus the name: Nickel-Cadmium. There is an alkaline electrolyte, generally made of KOH, which also acts as a plate spacer. The plates and the electrolyte are sandwiched together. The sandwich is then spiral rolled into a coil and placed inside a steal can and sealed. The output voltage is lower at 1.2 volts per cell but the voltage output remains level over the life of the cell charge.

This cell is rechargeable, and can be fully discharged and stored for long periods of time without damaging the cell. When recharging a NiCad battery the power is applied in reverse and the chemical reaction is reversed until the cell is fully charged. Heat is also produces as a result of the chemical reaction. This discharge/charge cycle can happen for many cycles. Over time this recharging ability will steadily diminish until the cell is not able to be recharged (dead).

Chemically this reaction takes place.

2 NiO(OH) + Cd + 2 H2O < - - - > 2 Ni(OH)2 + Cd(OH)2

During the depletion cycle and the cell energy is being used, this reaction goes from left to right. When the cell is being recharged, the chemical reaction moved from right to left.