Lithium polymer battery (Li-polymer, also known as polymer lithium battery): It is also a kind of lithium ion battery, but compared with liquid lithium battery (Li-ion), it has higher energy density, smaller size and ultra-thin , Lightweight, and high safety, and many other obvious advantages, is a new type of battery. In shape, the lithium polymer battery has ultra-thin characteristics, which can be made into batteries of any shape and capacity to meet the needs of various products. The minimum thickness that this type of battery can reach can reach 0.5mm. Its nominal voltage is the same as Li-ion's nominal voltage of 3.7V, without memory effect.
When an ordinary lithium-ion battery is overcharged or short-circuited, the internal temperature of the battery may rise, the positive electrode material decomposes, and the negative electrode and electrolyte materials are oxidized, which will cause gas expansion and increase the internal pressure of the battery. When the pressure reaches a certain level After the degree, an explosion may occur. And because the polymer lithium ion battery uses a colloidal electrolyte, it will not produce a large amount of gas due to the boiling of the liquid, thereby preventing the possibility of a violent explosion.
At present, most of the domestic polymer batteries are only soft-pack batteries, using aluminum plastic film as the outer shell, but the electrolyte has not changed. This kind of battery can also be thinner, its low-temperature discharge characteristics are better than polymer batteries, and the material energy density is basically the same as that of liquid lithium batteries and ordinary polymer batteries, but because of the use of aluminum plastic film, it is better than ordinary liquid lithium batteries. light. In terms of safety, when the liquid just boils, the aluminum-plastic film of the soft pack battery will naturally bulge or rupture, and it will not explode.
It should be noted that the new battery may still burn or swell and crack, and safety is not foolproof.
Compared with liquid lithium-ion batteries, polymer lithium-ion batteries are not only safe, but also have the advantages of being thinner, arbitrarily shaped, and arbitrarily shaped. The outer shell also uses a lighter aluminum-plastic composite film. However, its low-temperature discharge performance may have room for improvement.
