Let's know more about 18650 lithium battery
If you know the mobile power source, you should know that the lithium-ion battery inside the mobile power source can be divided into two types: lithium battery and li-polymer battery. The positive and negative materials used in the two are the same. The positive electrode materials include lithium cobaltate, nickel cobalt manganese and lithium iron phosphate materials, and the negative electrode is graphite. The working principle of the battery is basically the same. The main difference between them is the difference in electrolytes, in which liquid lithium-ion batteries use liquid electrolytes and polymer lithium-ion batteries are replaced by solid polymer electrolytes. Such polymers may be "dry" or "colloidal" and most currently employ polymeric colloidal electrolytes.
Today, let's talk about the lithium ion 18650 battery used:
Lithium cobaltate is a well-known liquid lithium-ion battery. The common form is 18650 and square shape. The 18650 battery is a cylindrical battery with a diameter of 18 mm and a height of 65 mm (like an enlarged version of the No. 5 battery), which is widely used in laptop batteries. Because it is compatible with laptop batteries, more than 60% of mobile power supplies on the market today use 18650 batteries.
At present, commercial lithium-ion batteries basically use a layered structure of lithium cobalt oxide as a positive electrode material, and its theoretical capacity is 274 mAh/g, and the actual capacity is about 140 mAh/g. It has also been reported that the actual capacity has reached 155 mAh/g.
The positive electrode material has a high working voltage (average working voltage is 3.7V), stable charging and discharging voltage, small volume, high specific energy, good cycle performance, high electrical conductivity, simple production process and easy manufacture.
Main advantages: mature technology, wide application range and small size.
The main disadvantages: the cycle life is about 300 times, the safety performance is low, the overcharge resistance is poor, it is not suitable for high rate charge and discharge, and the environment is polluted after disposal.
18650 cells used in power supplies in the mobile power market
There are: imported 18650 batteries, domestic 18650 batteries
Imported 18650 batteries:
The batteries produced by foreign manufacturers are generally produced by Sanyo, Samsung, Panasonic, Sony and other large manufacturers. Because these products have been tested by the market and the manufacturers have certain technical strength, the quality of the products is relatively Higher.
Domestic 18650 batteries:
This is also the battery core produced by domestic brand manufacturers. There are also many manufacturers in China that produce 18650 batteries, such as BYD, BAK, Bangkai, Shenli, etc. It cannot be denied that the domestic quality level is getting higher and higher, and the price is higher than abroad. It is also much lower, so it is increasingly recognized by the public.
