Nickel-cadmium (NiCd)

History #

The nickel-cadmium (NiCd) battery was first developed in 1899 by Waldemar Jungner, a Swedish scientist. The first commercial NiCd battery was produced in 1946 by the Union Carbide Corporation. Since then, NiCd batteries have been used in a variety of applications, including portable electronics, power tools, and electric vehicles.

Typical Use #

NiCd batteries are commonly used in portable electronic devices such as radios, cameras, and laptops. They are also used in power tools such as drills and saws. NiCd batteries are also used in electric vehicles, such as golf carts and forklifts.

Design #

NiCd batteries are composed of two electrodes, a positive electrode made of nickel hydroxide and a negative electrode made of cadmium hydroxide. The electrodes are separated by a separator material, typically a porous plastic. The electrodes are immersed in an electrolyte solution, typically a mixture of potassium hydroxide and water.

When the battery is discharged, the nickel hydroxide on the positive electrode is oxidized, releasing electrons. The electrons travel through the external circuit to the negative electrode, where they are used to reduce the cadmium hydroxide. This reaction produces a voltage of 1.2 volts.

When the battery is recharged, the reverse reaction occurs. The electrons travel from the negative electrode to the positive electrode, where they are used to oxidize the nickel hydroxide. This reaction produces a voltage of 1.4 volts.

NiCd batteries are typically designed with a capacity of 1.2 to 1.4 Ah (ampere-hours). The capacity is determined by the amount of active material in the electrodes. The capacity can be increased by increasing the amount of active material, or by increasing the surface area of the electrodes.

NiCd batteries are also designed with a variety of safety features, such as pressure relief valves, thermal fuses, and overcharge protection circuits. These safety features help to prevent the battery from overheating, overcharging, or exploding.

NiCd batteries are typically designed with a life cycle of 500 to 1000 charge/discharge cycles. The life cycle is determined by the amount of active material in the electrodes and the number of charge/discharge cycles. The life cycle can be increased by increasing the amount of active material, or by using a lower charge/discharge rate.