Power supply devices can be divided into physical power supply and chemical power supply. Batteries in the usual sense mainly refer to chemical power sources, which use active substances to store energy and then use their chemical reactions to release electricity. According to the properties and use methods of chemical power storage active substances can be divided into
① Primary battery (galvanic cell) A battery in which the active substance can only be used once. Such as zinc manganese battery, alkaline manganese battery, silver zinc battery, lithium manganese battery and so on.
② Secondary battery (storage battery)- a battery that can be reused after being discharged and recharged. Such as lead-acid battery, nickel-cadmium battery, nickel-hydrogen battery, lithium ion battery and so on.
③The active substance of fuel cell is continuously supplied to the electrode cell from the outside.
