18650 lithium 3.7 battery

　　18650 compared with polymer lithium battery

　　Compared with polymer lithium battery, 18650:

　　One, the price is lower.

　　The international price of 18650 is about 1USD/pcs, which is about 3RMB/Ah based on 2Ah. Compared with the price of polymer lithium batteries, the price of counterfeit factories in the middle and low end is 4RMB/Ah, the price of mid-range is 5~7RMB/Ah, and the price of high-end is more than 7RMB/Ah. Such as ATL, Lishen, etc., can generally be sold at around 10RMB/Ah, but when your order becomes smaller, others are not willing to accept it.

　　Second, it cannot be customized.

　　For a long time, SONY has hoped to make lithium batteries into dry batteries, and there are some national standards, such as AA batteries, AA batteries, and most of the rechargeable batteries in the world are like this. However, because one of the great advantages of lithium batteries is that they can be designed according to the needs of consumers, it is impossible to have a unified standard. Therefore, so far, most of the products in the lithium battery field have only the standard model of 18650. The rest are basically designed according to the requirements of customers.

　　3. Poor security

　　Under extreme conditions (such as charging, high temperature, etc.), lithium batteries will undergo strong chemical changes inside, which will generate a lot of gas. The plastic casing for the rechargeable battery has a certain strength. When the internal air pressure of the rechargeable battery reaches a certain level, the aluminum casing of the rechargeable battery will crack and explode, causing a terrible production safety accident.

　　Therefore, the room where the 18650 battery is inspected generally needs layer-by-layer protective measures, and it is absolutely forbidden to enter during the inspection process. This problem does not exist, even in extreme cases, because the film strength is low, as long as the gas pressure is slightly higher, it will crack, and it is not easy to explode, and the worst case is to ignite . Therefore, polymer lithium batteries are better than 18650 rechargeable batteries in terms of safety factor.

　　4. Low energy density

　　Generally, the volume of 18650 rechargeable battery can reach 2200mAh, so the calculated specific energy is about 500Wh/L. At present, the specific energy of polymer lithium battery can reach 600Wh/L.