The polymer lithium battery is a chemical battery. Compared with previous batteries, it has the characteristics of high energy, miniaturization and light weight.
The so-called lithium polymer battery refers to a battery system that uses polymer materials for at least one or more of the three elements. In lithium polymer battery systems, most polymer materials are used for the positive electrode and electrolyte. The positive electrode material adopts the conductive polymer or inorganic compound used in general lithium ion batteries, the negative electrode mostly adopts metal lithium or lithium carbon intercalation compound, and the electrolyte adopts solid or colloidal polymer electrolyte or organic electrolyte. Since there is no excess electrolyte in the lithium polymer, it is more reliable and stable.
The working principle of polymer lithium battery
There are two types of lithium ion batteries: liquid lithium ion batteries and lithium polymer batteries. Among them, the liquid lithium ion battery refers to a secondary battery with Li+ intercalation compound as the positive and negative electrodes. The positive electrode adopts lithium compound LiCoO2, LiNiO2 or LiMn2O4, and the negative electrode adopts lithium carbon intercalation compound LixC6. A typical battery system is:(-) C | LiPF6—EC+DEC | LiCoO2 (+)
Positive electrode reaction: LiCoO2 = Li1-xCoO2 + xLi+ + xe-
Negative reaction: 6C + xLi+ + xe- = LixC6
Total battery reaction: LiCoO2 + 6C = Li1-xCoO2 + LixC6
The principle of lithium polymer battery is the same as that of liquid lithium, but the main difference is that the electrolyte is different from liquid lithium. The main structure of the battery includes three elements: positive electrode, negative electrode and electrolyte. The so-called lithium polymer battery refers to the use of polymer materials as the main battery system in at least one or more of these three main structures. In the lithium polymer battery system developed, polymer materials are mainly used for the positive electrode and electrolyte.
Cathode materials include conductive polymers or inorganic compounds commonly used in lithium-ion batteries. The electrolyte may use a solid or gel polymer electrolyte or an organic electrolyte. Generally, lithium ion technology uses liquid or gel electrolyte, so it needs high strength. The secondary packaging contains flammable active ingredients, which increase weight and limit size flexibility.
The shape of the new generation of lithium polymer battery is theoretically achievable, and the shape is diversified, which improves the flexibility of battery shape design, so that it can meet product needs, and make some shape and capacity batteries for application equipment developers. Provide a high degree of design flexibility and adaptability in the power supply solution to maximize its product performance. At the same time, the unit energy of lithium polymer batteries is 10% higher than that of general lithium ion batteries. Compared with lithium-ion batteries, its capacity and cycle life have been greatly improved.