Introduction to the composition and formula of the electrolyte for lithium iron batteries

1. Ethylene carbonate: The molecular formula C3H4O3 is a clear and colorless liquid (u003e35℃), it is a crystalline solid at room temperature. Boiling point: 248℃/760mmHg, 243-244℃/740mmHg; flash point: 160℃; density: 1.3218; refractive index: 1.4158 (50℃); melting point: 35-38℃; this product is polyacrylonitrile , Good solvent for PVC. It can be used as a spinning fluid in textiles; it can also be used as a solvent for removing acid gas 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, colorless, odorless, or light yellow translucent 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. In particular, it is 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 extraction agent, etc. Toxicological data: No poisoning was found in animal tests by oral or skin contact. Rat oral LD50u003d2,9000mg/kg. 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 evaporate into vapor and run into the air. The temperature rises and the volatilization speeds up When the mixture of volatilized steam and air comes into contact with a fire source, sparks can be flashed. 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 greater the resistance.); melting point -43°C; boiling point 125.8°C; solubility: insoluble in water, miscible in most organic solvents such as alcohols, ketones, esters, etc.; density: relative density (water u003d 1) 1.0 ; Relative density (air u003d 1) 4.07; Stability: stable; Danger mark 7 (flammable liquid); critical use: used as a solvent and used in organic synthesis. 4. Dimethyl carbonate: Molecular formula C3H6O3 Dimethyl carbonate is a non-toxic, environmentally friendly, and versatile chemical raw material. It is an important organic synthesis intermediate. Its molecular structure contains carbonyl, methyl and methyl. Functional groups such as oxy groups have a variety of reaction properties and are safe to use, convenient, less polluting, and easy to transport in processing. Due to its low toxicity, dimethyl carbonate is a green chemical product with development prospects. DMC has excellent solubility, its melting and boiling point range is narrow, the surface tension is large, the viscosity is low, the dielectric constant of the medium is small, and it has a higher evaporation temperature and a faster evaporation speed, so it can be used as a low-toxic solvent for coatings. Industrial and pharmaceutical industries. It can be seen from Table 1 that DMC not only has low toxicity, but also has the characteristics of high flash point, low vapor pressure and high lower explosion limit in the air, so it is a green solvent that combines cleanliness and safety. Lithium iron battery electrolyte formulation: 1. Chlorinated ethylene carbonate with chlorine gas to synthesize chloroethylene carbonate, and then use triethylamine as an acid binding agent to remove hydrogen chloride to obtain vinylene carbonate. The chlorination reaction is carried out under solvent-free conditions, and the elimination reaction uses dimethyl carbonate, which is commonly used as a solvent in the electrolyte, as a solvent, which can prevent the residual solvent from causing adverse effects on additives. At the same time, choose 2,3,4-tri-tert-butyl Phenol is used as polymerization inhibitor, and the yield of the two-step reaction is 75.0%, which is higher than the literature value. 2. Using anhydrous KF and chloroethylene carbonate to prepare fluoroethylene carbonate, the safety cost is reduced, the processing technology is easy to control, and PEG. 800 is a catalyst, and the single-step yield is 82.5%. 3. 1,3-propane sultone is chlorinated with chlorine gas to synthesize 2-chloro-1,3-propane sultone, and then triethylamine is used as an acid binding agent to remove hydrogen chloride to obtain 1,3-propane Compared with the literature, the reaction route of sultone is greatly shortened, and the yield of the two-step reaction is 72.7%. 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 post: What kind of lithium battery separator is good?