The three elements of a general battery: positive electrode, negative electrode and electrolyte. The so-called lithium polymer battery refers to a battery system in which at least one or more of the three elements adopts polymer materials. In lithium polymer battery system, polymer materials are mostly used in cathode and electrolyte. The positive electrode materials are conductive polymer or inorganic compounds used in general lithium-ion batteries. The negative electrode is often lithium metal or lithium carbon interlayer compound, and the electrolyte is solid or colloidal polymer electrolyte or organic electrolyte. Since there is no excess electrolyte in the lithium polymer, it is more reliable and stable
Lithium polymer battery uses file alloy as positive electrode, polymer conductive material, polyacetylene, polyaniline or poly-p-phenol as negative electrode, and organic solvent as electrolyte. The specific energy of lithium polyaniline battery can reach 350W H / kg, but the specific power is only 50-60w / kg, the service temperature is - 40-70 degrees, and the service life is about 330 times.
Compared with lithium-ion batteries, lithium polymer batteries have the following characteristics:
1. The problem of battery leakage is relatively improved, but it has not been completely improved.
2. It can be made into thin battery: with a capacity of 3.6V 250mah, its thickness can be as thin as 0.5mm.
3. Batteries can be designed in a variety of shapes.
4. It can be made into a single high voltage: the battery with liquid electrolyte can only obtain high voltage by connecting several batteries in series, while the polymer battery can be made into multi-layer combination in a single battery to achieve high voltage because it has no liquid.
5. The discharge capacity is theoretically 10% higher than that of lithium-ion batteries of the same size.
Lithium polymer battery (Li polymer, also known as polymer lithium-ion battery) has many advantages such as high specific energy, miniaturization, ultra-thin, lightweight and high safety. Based on such advantages, lithium polymer batteries can be made into batteries of any shape and capacity, so as to meet the needs of various products; And it uses aluminum-plastic packaging, internal problems can be immediately shown through the outer packaging, even if there are potential safety hazards, it will not explode, but will swell. In polymer battery, electrolyte plays the dual functions of diaphragm and electrolyte: on the one hand, it separates the positive and negative electrode materials like diaphragm, so that there is no self discharge and short circuit in the battery; on the other hand, it conducts lithium ions between the positive and negative electrodes like electrolyte. Polymer electrolyte not only has good conductivity, but also has the characteristics of light weight, good elasticity and easy film formation of polymer materials. It also conforms to the development trend of light weight, safety, high efficiency and environmental protection of chemical power supply