The nickel-cadmium accumulator is similar in construction to that of nickel iron accumulator. The positive plates of both types of accumulators are similar n every detail; the negative plate differed in the active material they employ-the negative plates of nickel cadmium accumulators consist of spongy cadmium, Cd where as the negative plates of nickel-iron accumulators consist of spongy iron, Fe. The most important difference between the nickel-cadmium accumulators and nickel-iron accumulators is the arrangement of the plates. Where as in nickel-iron accumulators the extreme plates are negative, but in the nickel-cadmium accumulators the extreme plates are positive. The reason for this is that, for proper operation, the positive active material of the nickel-cadmium accumulators must occupy more space than the negative active material. Seen form outside, the positive plates of nickel-cadmium accumulators’ are little thicker than the negative plates. The extreme negative plates of a nickel-iron accumulator are electrically connected to the container, the nickel-cadmium accumulator on the contrary has its container electrically container, the nickel-cadmium accumulator on the contrary has its container electrically connected to the cadmium accumulators are shown in.


The electro-chemical process in the nickel-cadmium accumulators is expressed by the equation

+VE PLATE     - VE PLATE          DISCHARGE        - VE PLATE            + VE PLATE
2Ni(OH)₂+2KOH+Cd                           - →                 2Ni(OH)+2KOH+Cd(OH)₂+electrical energy
                                                         ←  -
The equation should be read from left to right for discharge and from right to left for charge.

The nickel-cadmium accumulator is superior to nickel iron accumulator and has low internal resistance and a longer life. The disadvantage is that it is heavier in weight and expensive in cost than the nickel-iron cell. Like the nickel-iron battery, the nickel cadmium battery is mainly used of industrial services, where its ruggedness, long life and low maintenance cost outweigh the fact that the original cost of the nickel battery is as much as four times of that lead acid battery.

For more help in Nickel-Cadmium Accumulators click the button below to submit your homework assignment