18650 is the originator of 18650 Lithium Battery - a Japanese company in order to save costs and set a standard lithium-ion battery models, of which 18 said the diameter of 18mm, 65 said length 65mm, 0 for the cylindrical battery. Common 18650 battery is divided into lithium-ion battery, lithium iron phosphate battery. Lithium-ion battery voltage of 3.6V and 4.2V, lithium iron phosphate battery voltage of 3.2V, the capacity is usually 1200mAh-3000mAh, common capacity of 2200mAh-2600mAh.
18650 Lithium Battery life theory for the cycle of charging 1000 times. Because of the large capacity of the unit density, so most of the laptop battery, in addition, due to the stability of the 18650 in the work of very good, widely used in the major electronics areas: commonly used in high-end flashlight, portable Power, wireless data transmission, electric warm clothing, shoes, portable instrumentation, portable lighting equipment, portable printers, industrial equipment, medical equipment, and so on.
18650 means that the diameter of 18 mm, 65 mm long. While the No. 5 battery model is 14500, 14 mm in diameter, 50 mm long. General 18650 battery in the industry with more, very few civil, common in the laptop battery and high-end flashlight on the use of more.
18650 is only the size of the battery model, according to the type of battery can be divided into lithium-ion 18650, lithium iron phosphate 18650, nickel-hydrogen 18650 (rare), the common 18650 is lithium-ion.
Charge and discharge principle
18650 Lithium Battery works is the principle of its charge and discharge. When the battery is charged, the battery has a positive lithium ion generation, the generated lithium ions through the electrolyte movement to the negative. And the negative carbon as a layered structure, it has a lot of holes, to reach the negative lithium ions embedded in the carbon layer of the pores, the more lithium ions embedded, the higher the charge capacity.
The same token, when the 18650 Lithium Battery discharge (that is, we use the battery process), embedded in the negative carbon layer of lithium ions out, and movement back to the positive. The more lithium ions returned to the cathode, the higher the discharge capacity. What we usually call the battery capacity is the discharge capacity.
It is easy to see that in the lithium-ion battery charge and discharge process, the lithium ions from the positive → negative → positive movement of the state. If we likened the lithium-ion battery to a rocking chair, both ends of the rocking chair were the poles of the battery, and the lithium ion was like an excellent athlete, running back and forth at both ends of the rocking chair. So, the experts gave a lithium-ion battery a lovely name rocking chair battery.