The transfer of electrical energy into chemical energy and vice versa is the fundamental tenet of the rechargeable battery. The storage battery is made up of several separate cells that are linked in series to create the necessary voltage.
.png "Nickel Cadmium Battery")
Operation Principles(Electrochemistry):
✦ Each cell is made up of positive and negative plates that are submerged in a potassium hydroxide solution in DM/DI water with lithium hydroxide as an addition.
✦ The positive plates are made of nickel hydroxide as the active constituent and the cadmium hydroxide is used for negative plates.
✦ A nominal discharge voltage of 1.2 volts per cell is generated by the general electrochemical reaction, which is simplified and presented below.
✦ When the cell is charged, the active components that are initially present as hydroxides are changed. The cadmium hydroxide is converted to cadmium, and the oxidation level of nickel hydroxide increases. On discharged, the process is reversed and the active materials revert to their original state.
✦ The electrolyte of potassium hydroxide serves merely as an ion carrier and is not involved in these reactions. Since it benefits the positive electrodes, the lithium hydroxide additive in the electrolyte considerably lengthens the life of the cell. The beneficial effect is more pronounced at higher operational temperature.
- On charge, oxide reaction takes place in the positive electrode and reduction occurs in the negative electrode.
- On discharge, the opposite reaction take place. the reaction of charge and discharge can be illustrated by the following equations...
Maintenance:
A professional technician who is familiar with handling Nickel Cadmium batteries and electrical power systems should perform the maintenance tasks. People working on the battery system's maintenance must wear the proper personal safety gear.
Preventive maintenance.
The preventive maintenance practices extend the life of batteries. Battery breakdown maintenance can be avoided with this routine maintenance. Reliability will enhance with regular performance checks and battery maintenance in good condition. Hence periodic maintenance is mandatory.
Cleanliness: The battery must be kept dry and clean. This will enhance performance, extend service life, and prevent cell contamination during topping up.
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