The emergence of batteries has indeed solved many problems and greatly improved the efficiency of various life. The emergence of lithium batteries has made people’s understanding of electricity deeper and deeper. The 18650 lithium battery has the longest use time, and it still exists. A kind of lithium battery, the shadow of 18650 lithium battery can be seen in many areas.
Because this battery has obvious advantages over other batteries, and its safety is relatively good, and it has even been used in large equipment.
1. Advantages of 18650 lithium battery
It is generally believed that when the no-load voltage of the lithium battery is lower than 3.0V, it is considered to be exhausted (the specific value depends on the threshold value of the battery protection board, such as as low as 2.8V and 3.2V). Most lithium batteries can’t discharge the no-load voltage below 3.2V, otherwise over-discharge will damage the battery (generally, lithium batteries on the market are basically used with a protection board, so over-discharge will also cause the protection board to fail to detect To the battery, thus unable to charge the battery).
4.2V is the highest limit voltage for battery charging. It is generally considered that the battery is fully charged when the no-load voltage of the lithium battery is charged to 4.2V. During the battery charging process, the battery voltage gradually rises from 3.7V to 4.2V, and the lithium battery cannot be charged. Charge the no-load voltage above 4.2V, otherwise it will damage the battery. This is the special feature of lithium batteries. Generally speaking, 18650 lithium batteries have the following advantages.
1. Wide range of use
Notebook computers, walkie-talkies, portable DVDs, instrumentation, audio equipment, model airplanes, toys, camcorders, digital cameras and other electronic equipment.
2, series connection
can be combined in series or parallel to form a 18650 lithium battery pack.
3, small internal resistance
The internal resistance of polymer batteries is smaller than that of ordinary liquid batteries. The internal resistance of domestic polymer batteries can even reach 35m.
4. No memory effect
There is no need to empty the remaining battery before charging, which is easy to use.
5, high voltage
The voltage of 18650 lithium battery is generally 3.6V, 3.8V and 4.2V, which is much higher than the 1.2V voltage of nickel-cadmium and nickel-metal hydride batteries.
6, high safety performance
18650 lithium battery has high safety performance, non-explosive, non-combustible; non-toxic, non-polluting, and has passed RoHS trademark certification; various safety performances can be achieved in one go, and the number of cycles is greater than 500; high temperature resistance performance, discharge efficiency of 100% under 65 degrees . In order to prevent the battery from short-circuiting, the positive and negative electrodes of the 18650 lithium battery are separated. Therefore, the short-circuit phenomenon may have been reduced to the extreme. A protection board can be installed to avoid overcharge and overdischarge of the battery, which can also extend the service life of the battery.
7, long service life
The service life of 18650 lithium battery is very long, the cycle life can reach more than 500 times in normal use, which is more than twice that of ordinary batteries.
8. Large capacity
The capacity of 18650 lithium battery is generally between 1200mah and 3600mah, while the general battery capacity is only about 800. If 18650 lithium batteries are combined to form a 18650 lithium battery pack, the 18650 lithium battery pack can easily exceed 5000mah.
Two, 18650 lithium battery vs. polymer battery
The so-called polymer lithium battery refers to a lithium ion battery that uses a polymer as an electrolyte, and is divided into two types: "semi-polymer" and "all-polymer". "Semi-polymer" refers to coating a layer of polymer (usually PVDF) on the isolation membrane to make the cell's adhesion stronger, the battery can be made harder, and the electrolyte is still a liquid electrolyte.
"All polymer" refers to the use of polymer to form a gel network inside the cell, and then inject electrolyte to form an electrolyte. Although "all polymer" batteries still use liquid electrolyte, the amount is much smaller, which greatly improves the safety performance of lithium-ion batteries. As far as I know, only SONY is currently mass producing "all-polymer" lithium-ion batteries.
From another aspect, polymer batteries refer to lithium-ion batteries that use aluminum-plastic packaging film as the outer packaging, which is commonly known as soft-pack batteries. This kind of packaging film is composed of three layers, namely PP layer, Al layer and nylon layer. Because PP and nylon are polymers, this kind of battery is called polymer battery.
1, the price is lower
The international price of 18650 is about 1USD/pcs, which is about 3RMB/Ah if calculated according to 2Ah. The price of polymer lithium batteries is 4RMB/Ah for low-end copycat factories, 5~7RMB/Ah for mid-range, and more than 7RMB/Ah for mid-to-high end. Like ATL and Lishen, they can generally sell for around 10RMB/Ah, and you are not willing to pick them up when your order is small.
2, can not be customized
SONY has always wanted to make lithium-ion batteries like alkaline batteries. There are certain industry standards, just like AA batteries and AAA batteries, which are basically the same all over the world. However, one of the major advantages of lithium-ion batteries is that they can be designed according to customer needs, and there is no uniform standard. So far, the lithium-ion battery industry basically only has a standard model of 18650, and the others are based on customers. Need to be designed.
In the future, JUNLEE Energy, which has been committed to battery research and development, is a challenge and an opportunity. The R&D team of engineers will provide the world with more economical new energy batteries, and will improve lithium-ion battery technology to reduce the total cost.
JUNLEE Group is an integrated full power energy factory that specializes in Uninterruptible Power Supply (UPS), Lead-Acid Battery, Battery pack, EV battery, Energy Storage Battery, Energy storage power station, Power pack Gel battery, PV Inverter and Solar system.
Production capacity reach 200000 KVaH per month. Products apply to Electric vehicles,electric mobility, solar & wind energy storage system, UPS, backup power, telecommunication, medical equipment and lighting.
JUNLEE sets up "Power research center" with more High-tech products.More than 100 engineers provided in-time and efficient one-stop solutions.
They mission strives to bring green power to the world.
To learn more about Li-ion batteries, please refer to https://www.junleepower.com/