18650 lithium 3.7 battery.18650 compared with polymer lithium battery

　　18650 compared with polymer lithium battery:

　　First, the price is lower.

　　The international price of 18650 is about 1USD/pcs. Calculated based on 2Ah, it is about 3RMB/Ah. Comparing the prices of polymer lithium batteries, mid- to low-end counterfeit ones cost 4RMB/Ah, mid-range ones cost 5~7RMB/Ah, and high-end ones cost more than 7RMB/Ah. Products such as ATL and Lishen can generally be sold for around 10RMB/Ah, but if your order becomes smaller, others will not be willing to accept it.

　　2. It cannot be customized.

　　SONY has always been looking forward to turning lithium batteries into dry batteries, and has some national standards, such as AA batteries and AA batteries. Most of the rechargeable batteries in the world are like this. However, since one of the major advantages of lithium batteries is that they can be designed according to customer needs, it is impossible to have a unified standard. Therefore, so far, most products in the lithium battery field only have the 18650 standard model. Everything else is basically designed according to customer requirements.

　　3. Poor security

　　When lithium batteries are exposed to extreme conditions (such as charging, high temperatures, etc.), strong chemical changes will occur inside them, resulting in a large amount of gas. The plastic shell of the rechargeable battery has a certain compressive strength. When the internal standard air pressure of the rechargeable battery reaches a certain level, the aluminum shell of the rechargeable battery will crack and explode, causing a very horrific production safety accident.

　　Therefore, the room where 18650 rechargeable batteries are inspected generally requires layer-by-layer protective measures, and entry must be prohibited during the inspection process. This problem does not exist, even in extreme cases, because the packaging film has low strength, it will crack as long as the gas pressure is slightly higher, and it will not explode or, in the worst case, ignite. . Therefore, polymer lithium batteries are better than 18650 rechargeable batteries in terms of safety.

　　4. Low energy density

　　Generally, the capacity of 18650 rechargeable batteries can reach 2200mAh, so the specific energy is calculated to be about 500Wh/L. The current specific energy of polymer lithium batteries can reach 600Wh/L.

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