What is a polymer lithium-ion battery?
Based on the different electrolyte materials used, lithium-ion batteries are divided into liquid lithium-ion batteries and polymer lithium-ion batteries or plastic lithium-ion batteries. The positive and negative electrode materials used in polymer lithium-ion batteries are the same as those in liquid lithium-ion batteries. The positive electrode materials include lithium cobalt oxide, lithium manganese oxide, ternary materials, and lithium iron phosphate materials, while the negative electrode is graphite. The working principle of these batteries is also basically the same.
Features of polymer lithium-ion batteries
Composition and structure: Polymer lithium-ion batteries use aluminum-plastic soft packaging, which is different from the metal shell of liquid cells. In the event of a safety hazard, liquid cells are prone to explosion, while polymer cells will at most bulge.
Volume and thickness: Ultra-thin, the battery can be assembled into a credit card. Conventional liquid lithium batteries use a method of first customizing the casing and then inserting the positive and negative electrode materials, and there is a technical bottleneck in achieving a thickness of less than 3.6mm. Polymer cells do not have this problem, and the thickness can be less than 1mm.
Battery weight: Batteries using polymer electrolytes do not require a metal casing for protection. Polymer batteries are 40% lighter than steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries.
Cell internal resistance: The internal resistance of polymer cells is lower than that of ordinary liquid cells. Currently, the internal resistance of domestically produced polymer cells can even be below 35m, which greatly reduces the self-discharge of the battery.
Model customization: Polymer batteries can have their cell thickness increased or decreased according to customer needs, and new cell models can be developed. They are inexpensive and have a short mold opening cycle.
The biggest difference between lithium-ion battery packs and polymer lithium-ion batteries lies in their application size and direction. Polymer lithium-ion batteries prioritize thinness and small size, and are mainly used for the daily power storage needs of smaller electronic devices such as mobile phones.
