Explain the composition analysis and advantages of lithium battery electrolyte

1. Lithium battery electrolyte composition analysis 1. Ethylene carbonate: molecular formula C3H4O3 transparent colorless liquid (>35°C), crystalline solid at room temperature. Boiling point: 248°C/760mmHg, 243-244°C/740mmHg; Flash point: 160 ℃; Density: 1.3218; Refractive index: 1.4158 (50℃); Melting point: 35-38℃; This product is a good solvent for polyacrylonitrile and polyvinyl chloride. It can be used as a spinning fluid in textiles; it can also be directly used as a solvent for removing acid gases and an additive in concrete; it can be used as a pharmaceutical component and raw material in medicine; it can also be used as a plastic foaming agent and a synthetic lubricant The stabilizer; in the battery industry, it can be used as an excellent solvent for lithium battery electrolyte. 2. Propylene carbonate: molecular formula C4H6O3 is colorless, odorless, or light yellow transparent liquid, soluble in water and carbon tetrachloride, and miscible with ether, acetone, benzene, etc. It is an excellent polar solvent. This product is mainly used in polymer operations, gas separation processes and electrochemistry. It is especially used to absorb carbon dioxide from natural gas and synthetic ammonia raw materials in petrochemical plants. It can also be used as a plasticizer, spinning solvent, olefin and aromatic extractant, etc. This product should be stored in a cool, ventilated, dry place, away from fire, and stored and transported in accordance with the regulations of general low-toxic chemicals. 3. Diethyl carbonate: colorless liquid with molecular formula CH3OCOOCH3, slightly odor; vapor pressure 1.33kPa/23.8°C; flash point 25°C (flammable liquid can volatilize into vapor and run into the air. The temperature rises, the volatilization speeds up. When the mixture of volatilized vapor and air contacts the fire source, it can flash sparks. This short combustion process is called flash burning, and the lowest temperature at which flash burning occurs is called flash point. The lower the flash point, the risk of fire. The larger.); Melting point -43°C; Boiling point 125.8°C; Solubility: insoluble in water, miscible in most organic solvents such as alcohol, ketone, ester, etc.; Density: relative density (water u003d 1) 1.0; relative density (air u003d1) 4.07; stability: stable; hazard mark 7 (flammable liquid); important use: used as a solvent and used in organic synthesis. 2. Advantages of lithium battery electrolyte The electrolyte plays a role of conducting electrons between the positive and negative electrodes of the lithium battery, which guarantees that the lithium battery obtains the advantages of high voltage and high specific energy. Electrolyte is generally prepared from raw materials such as high-purity organic solvents, electrolyte lithium salts, and necessary additives under certain conditions and in certain proportions. The important electrolytes used in lithium batteries are lithium perchlorate, lithium hexafluorophosphate and so on. However, batteries made of lithium perchlorate are not effective at low temperatures and may explode. Japan and the United States have banned their use. The battery made of fluorine-containing lithium salt has good performance, no explosion hazard, and strong applicability. In particular, the battery made of lithium hexafluorophosphate, in addition to the above advantages, the future disposal of waste batteries is relatively simple and ecologically friendly, so The market prospect of this type of electrolyte is very broad. 3. Lithium battery electrolyte is mainly composed of three parts: (1) Solvent: cyclic carbonate (PC, EC); chain carbonate (DEC, DMC, EMC); carboxylic acid esters (MF, MA, EA, MA, MP, etc.); (used to dissolve lithium salts) (2) Lithium salts: LiPF6, LiClO4, LiBF4, LiAsF6, etc.; (3) Additives: film-forming additives, conductive additives, flame retardant additives, overcharge protection additives, Additives that control the content of H2O and HF in the electrolyte, additives that improve low-temperature performance, and multifunctional additives. 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: What are the performance requirements for lithium battery separators?