Nickel-cadmium (NiCd) is a type of rechargeable battery that uses nickel oxide hydroxide and cadmium as its electrodes. Known for their durability and ability to deliver high discharge rates, NiCd batteries are commonly used in portable electronics, power tools, and emergency lighting systems. They can withstand a large number of charge and discharge cycles, making them a reliable choice for many applications. However, NiCd batteries have some drawbacks, including a tendency to suffer from the "memory effect," which can reduce their capacity over time if not fully discharged before recharging. Additionally, the use of cadmium raises environmental concerns, as it is a toxic heavy metal. As a result, many manufacturers are shifting towards alternative battery technologies, such as lithium-ion batteries.