Nickel-cadmium battery

Nickel-cadmium battery

The nickel-cadmium battery (NiCd or NiCad) is a type of rechargeable battery using nickel oxide hydroxide and cadmium as electrodes. The abbreviation NiCd is derived from the chemical symbols of nickel (Ni) and cadmium (Cd), though it is often mistakenly referred to as a "NiCad" battery. NiCd batteries have a wide range of applications from portable devices to power tools and aviation.

History

The nickel-cadmium battery was invented by Swedish engineer Waldemar Jungner in 1899. The technology was further developed and commercialized in the 20th century. Despite its long history, the use of NiCd batteries has declined due to environmental concerns and the rise of other rechargeable technologies, such as nickel-metal hydride (NiMH) and lithium-ion (Li-ion) batteries.

Design and Operation

A typical nickel-cadmium battery consists of a positive electrode (anode) made of nickel oxide hydroxide and a negative electrode (cathode) made of cadmium. The electrolyte is usually potassium hydroxide (KOH). The basic chemical reaction in a NiCd battery during discharge is the oxidation of cadmium and the reduction of nickel hydroxide, which reverses during charging.

NiCd batteries are known for their robustness, long life cycle, and good performance at low temperatures. They are available in a variety of sizes and capacities, from small AA cells to large industrial batteries.

Advantages and Disadvantages

Advantages:

• High power density
• Good performance in extreme temperatures
• Long shelf life when stored properly
• Can be rapidly charged

Disadvantages:

• Memory effect, leading to reduced capacity if not fully discharged before recharging
• Environmental concerns due to cadmium, a toxic heavy metal
• Heavier and less energy-dense compared to newer technologies like Li-ion

Environmental Impact

Cadmium is a toxic heavy metal, and improper disposal of NiCd batteries can lead to environmental contamination. Many countries have implemented recycling programs and regulations to reduce the impact of cadmium on the environment. Consumers are encouraged to recycle NiCd batteries properly to minimize their environmental footprint.

Applications

Historically, NiCd batteries were used in a wide range of applications, including portable electronics, power tools, emergency lighting, and backup power systems. However, their use has declined in favor of batteries with higher energy densities and less environmental impact.

See Also

• Battery recycling
• Battery
• Nickel-metal hydride battery
• Lithium-ion battery

Nickel-cadmium battery Resources
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