Comparison between 18650 battery and lithium polymer battery?
Generally speaking, there are two types of batteries in the mobile power market: 18650 batteries and polymer batteries. These two types of batteries dominate the lithium battery industry market. In this article, we will focus on mobile power battery cells and analyze which of these two lithium battery cells is more suitable.
18650 battery cell
In fact, 18650 is a standard lithium-ion battery model set by Sony Corporation in Japan to save costs, where 18 represents a diameter of 18 millimeters, 65 represents a length of 65 millimeters, and 0 represents a cylindrical battery. Ordinary 18650 batteries are divided into lithium-ion batteries and lithium iron phosphate batteries.
18650 Capacity Regular Size
There are generally capacity standards of 2200, 2400, and 2600 milliamps. According to industry insiders, currently, the 18650 has reached its maximum single machine capacity of 3400 milliampere hours. If the mobile power bank uses 18650 as the battery cell, the above specifications are basically connected together.
18650 packaging
18650 is usually packaged in a steel shell, which means that the lithium ions in 18650 are liquid, like a cup filled with water, similar to this understanding. Therefore, 18650 can only be cylindrical. If you see a large and thick portable power bank when purchasing, it is basically an 18650 battery.
18650 Security
Due to the special packaging of
18650 batteries (using steel shells), if the quality of the produced products does not meet the standards, the biggest danger is explosion. The explosion of laptops a few years ago was due to quality control issues with Sony laptop batteries (usually 18650).
Lithium polymer battery cell
Lithium polymer batteries are typically made of lithium cobalt oxide, lithium manganese oxide, and ternary lithium. Made by a certain proportion of mixture and following a certain process flow, the outer packaging is mainly aluminum-plastic film, with lithium material in the middle in a paste like form. Therefore, the shape can be customized arbitrarily. Meanwhile, ultra-thin batteries such as 0.33mm and 0.50mm can be manufactured.
Lithium polymer battery cell capacity
Due to the fact that polymer batteries can be of any size, there is no standard shape, and the volume is generally marked as length * width * thickness. In addition, the battery has positive and negative tolerances, with a length and width of 0.5 millimeters for positive tolerances and a thickness of 0.55 millimeters for negative tolerances (these two positive and negative tolerances). Therefore, the capacity of the polymer depends on its volume and is also related to the proportion of lithium raw materials used.
Lithium polymer battery cell safety
The polymer battery is coated with a layer of aluminum-plastic film and a layer of high-temperature adhesive tape. The greatest safety of polymers is found to be liquid leakage and short circuits, which can cause battery expansion. The worst-case scenario is combustion and flames. Therefore, compared to 18650, polymer batteries have better safety. However, burning can also pose safety hazards, so it is recommended that users of portable power banks avoid placing them on pillows and beds as much as possible.
