The meaning, characteristics and classification of lithium polymer batteries

The meaning, characteristics and classification of lithium polymer batteries Lithium ion batteries as a green energy source were developed in the middle of the 20th century. Traditional lead, cadmium, nickel, and nickel-metal hydride secondary batteries have the following advantages: high voltage (working voltage greater than 3.6V, higher than Lead-acid battery 2.0V, nickel-metal hydride, nickel-cadmium battery 1.2V), high specific energy (energy volume to energy and mass ratio), wide operating temperature range, long cycle life, environmental protection, no memory effect, low self-discharge rate, large The advantages of current charging and discharging [1]. Lithium ion battery (free), also known as lithium ion battery, consists of a positive electrode (lithium cobalt oxide, lithium manganate oxide, iron oxide, oxide, lithium iron phosphate, etc.) and a negative electrode ( Hard and soft graphite, carbon, carbon, etc.), electrolytes, polymer separation membranes and protection circuits for rechargeable batteries. In practical applications, from small power sources such as mobile phones and MP3/MP4 to large battery packs for electric vehicles, the superior performance of lithium-ion batteries is undoubtedly the wisest choice. 1. The meaning of lithium polymer battery The three elements of a general battery: positive, negative, and electrolyte. Lithium polymer battery is a battery system that uses at least one or more than three polymer materials. In current lithium polymer battery systems, polymer materials are mostly used for positive electrodes and electrolytes. The negative electrode material uses conductive polymers or inorganic compounds commonly used in lithium ion batteries. The cathode is usually composed of lithium metal or lithium-carbon intercalation compound. The electrolyte can be solid, colloidal polymer electrolyte, or organic electrolyte. Because there is no excess electrolyte in lithium polymer, it is more reliable and stable. 2. The characteristics of lithium polymer batteries Lithium polymer batteries (also known as polymer lithium ion batteries) have the advantages of high specific energy, small size, ultra-thin, light weight, and high safety. Based on this advantage, the lithium polymer battery can be used in any shape and capacity to meet the needs of various products; and it uses aluminum-plastic packaging, and internal problems can be immediately manifested through the external packaging. Even if there is a safety hazard, it will not explode. Will bulge. In polymer batteries, the electrolyte is both a separator and an electrolyte: on the one hand, it separates the positive and negative materials like a separator to prevent battery self-discharge and short circuit; on the other hand, it conducts between the positive and negative electrodes like an electrolyte lithium ion. Polymer electrolyte not only has good electrical 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 chemical power, that is, light, safe, efficient, and environmentally friendly. 3. Classification of lithium polymer batteries Lithium polymer batteries can be divided into three categories according to the electrolyte: (1) Gel polymer electrolyte [11] Lithium ion batteries, that is, adding additives to solid polymer electrolytes to improve ion conductivity, The battery can be used at room temperature; (2) solid polymer electrolyte lithium ion battery, the electrolyte is a mixture of polymer and salt, its ionic conductivity is low at room temperature, suitable for high temperature use; (3) composite gel polymer The negative electrode material of the lithium ion battery uses a conductive polymer as the negative electrode material, and its specific energy is three times that of the existing lithium ion battery, which is the latest generation of lithium ion battery. Due to various reasons, such as technology, lithium polymer batteries are now focused on the research of low-current charge and discharge characteristics, small-capacity batteries and large-capacity. The high-power lithium-ion battery charging protection circuit is immature [20]. Battery charging, balancing and protection circuit problems, and then polymer lithium-ion batteries will be better used in electric mopeds. Therefore, increasing the research on lithium polymer has significant social and economic benefits, as well as other potential significance. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Introduction to Ni-MH rechargeable batteries