What is the difference between the various rechargeable batteries that are common today?

At present, nickel-cadmium, nickel-hydrogen, and lithium-ion rechargeable batteries are widely used in various portable electrical devices (such as notebook computers, video cameras and mobile phones, etc.), and each rechargeable battery has its own unique chemical properties. The main difference between NiCd and NiMH batteries is that NiMH batteries have a higher energy density. Compared with the same type of battery, the capacity of NiMH battery is twice that of NiCd battery. This means that the use of NiMH batteries can greatly extend the working time of the equipment without adding extra weight to the electrical equipment. Another advantage of NiMH batteries is that: A greatly reduces the problem of "memory effect" that exists in cadmium batteries, thus making NiMH batteries more convenient to use. NiMH batteries are more environmentally friendly than NiCd batteries because there are no toxic heavy metal elements inside.

Li-ion has also quickly become the standard power source for portable devices. Li-ion can provide the same energy as NiMH batteries, but it can be reduced by about 35% in weight, which is very suitable for electronic devices such as cameras and laptops. is crucial. Li-ion's complete lack of "memory effect" and the absence of toxic substances are also important factors that make it a standard power supply.