To begin, let's define the concept of polymer lithium batteries. 18650 manufacture These are batteries that use polymer as an electrolyte, and they can be categorized into two types: "semi-polymer" and "full polymer." "Semi-polymer" batteries have a layer of polymer, usually PVDF, on the isolation film to increase cell adhesion and make the battery more rigid. The electrolyte in these batteries is still liquid. On the other hand, "full polymer" batteries have a gel network created by using polymer inside the cell, and then the electrolyte is added. While these batteries also use liquid electrolyte, it is in a much smaller amount, greatly improving safety. Currently, SONY is the only company producing "full-polymer" lithium-ion batteries on a large scale.

For external lithium-ion batteries, polymer batteries use aluminum-plastic packaging, also called flexible packaging batteries. This film is composed of three layers of polypropylene, aluminum, and nylon. Since polypropylene and nylon are polymers, the battery is called a polymer battery.

From the point of view of the subject, it should refer to the latter - the so-called lithium-ion battery using polymer packaging materials - and the corresponding 18650 battery uses a steel shell as the outer packaging. Many domestic manufacturers advertise that their batteries are polymer batteries, but don't be fooled.

SONY Corporation of Japan is the inventor of 18650, a widely recognized lithium-ion battery model. This battery was created with the goal of reducing both time and cost. The name itself contains important information - "18" indicates a diameter of 10mm, "65" represents a length of 65mm, and the final "0" signifies its cylindrical shape. SONY has long strived to develop lithium-ion batteries with the same level of industrial standards as traditional alkaline batteries, such as No. 5 and No. 7 batteries, which are used globally. However, due to one of the main advantages of lithium-ion batteries - customization based on customer demand analysis - a standardized national model is not feasible. As a result, the industry has adopted 18650 as its standard model, and any other variations must be tailored to meet specific customer needs.

Polymer batteries have the following advantages over 18650 batteries:

High energy density. The general 18650 battery capacity is about 2200mAh, so the energy density is about 500Wh/L, and the polymer battery energy density is close to 600Wh/L at this stage of mass production.

It is common knowledge that lithium-ion batteries can undergo a violent chemical reaction when exposed to extreme conditions, such as overcharge or high temperatures. This reaction produces a significant amount of gas, which can result in serious safety hazards. To prevent accidents, the 18650 battery is equipped with a metal housing that provides strength to contain the pressure of the gas. However, if the internal air pressure reaches a critical point, the steel shell may explode. This is why multiple layers of protection are used during testing and there is a strict ban on entering the testing area. On the other hand, polymer batteries are considered safer because they have a lower risk of explosion even when their packaging film ruptures under slightly higher air pressure. In the worst-case scenario, polymer batteries may only combust rather than explode like 18650 batteries.

Ability to design according to customer needs. I won't repeat what has already been said.

the price can be sold relatively high... The international market price of 18650 is about 1USD/pcs, and if the capacity is calculated according to 2Ah, it is about 3RMB/pcs. A polymer battery as a lithium battery costs 4RMB/Ah for the low-end cottage factory, 5RMB/Ah for the middle factory, and 7RMB/Ah for the high-end battery. Force God is similar to ATL in that the average student can sell directly for 10RMB/Ah, and your single is small and people aren't willing to pick it up.

Despite their advantages, polymer batteries also have some drawbacks. One major drawback is their higher cost due to the ability to tailor the design to meet specific customer needs, which includes research and development expenses. Additionally, the variability in shape and wide variety of options leads to non-standard parts being used in the manufacturing process, resulting in increased costs. The lack of versatility of polymer batteries is a result of their flexible design, often requiring redesigning for even small differences of 1mm for each individual customer, leading to additional costs.

The 18650 has high-end applications, such as the Tesla Model S, which uses a Panasonic 18650 battery pack. This is not an absolute statement. There are some domestic cottage factories that make 18650 a low-end variety, but it does not represent low-end in general.