Analysis of important components of lithium battery electrolyte

Lithium battery pack electrolyte is mainly composed of components. Lithium battery electrolyte is the carrier of ion transmission in the battery. Its purpose is the same as blood transporting oxygen, which is very important. A good electrolyte can improve the conductivity, stability and charge-discharge capacity of lithium battery packs. Lithium battery electrolyte composition (1) Solvent: cyclic carbonate (PC, EC); chain carbonate (DEC, DMC, EMC); carboxylic acid esters (MF, MA, EA, MA, MP, etc.); (used for Dissolved lithium salt) (2) Lithium: LiPF6, LiClO4, LiBF4, LiAsF6, etc. (3) Additives: film-forming additives, conductive additives, flame retardant additives, overcharge protection additives, additives for controlling the content of H2O and HF in the electrolyte, additives for improving low-temperature functions, and multifunctional additives. Analyzed the common solvent carbonate of lithium battery electrolyte: ethylene carbonate (EC) is a functional organic solvent that can dissolve many polymers. It can irritate the eyes, affect the respiratory system, and damage the skin. This product should be stored in a cool, ventilated, dry place, and stored and transported in accordance with general chemical requirements. Carboxylic acid esters: There are many varieties, low cost, simple, and high purity. It is chemically stable, that is, it is not easy to be oxidized (except formates), and it is not easy to be reduced. Most of it is liquid at room temperature. Carbonate and carboxylate ester: The mixed solvent of the two can make the charging process of the lithium battery pack, the negative electrode forms a high SEI film potential, prevents solvent reduction, ensures the safety of the battery, improves the low-temperature battery capacity retention rate and high-rate charging Discharge capacity. Lithium salt analysis LiBF4 commonly used in lithium battery electrolyte: mild Lewis acid for Diels-Alder reaction; ethylene oxide ammonolysis catalyst. The low temperature function is better, but the price is expensive and the solubility is low. LiPF6: LiPF6 is a white granular or powdery solid with different forms and different fluidity and solubility. It is easy to distinguish at high temperatures, starting to distinguish in dry nitrogen (N2) at 160°C, and distinguishing in air at 70°C. LiPF6 is very corrosive to the skin, so acid and alkali resistant gloves are required. The overall performance is better, but the disadvantage is that it is easy to hydrolyze and absorb water. LiClO4: Lithium perchlorate, also known as lithium perchlorate, is a colorless crystal with delirium. Explosive mixtures can be mixed with reducing agents, organic substances, flammable substances such as sulfur, phosphorus or metal powder. The comprehensive function is good, but strong oxidation leads to low safety. Lithium borate: also known as lithium diethyl borate, with a purity of 99% and a white powder in appearance. The high temperature function is good, especially it can simulate the insertion damage of the negative electrode to the solvent, but the solubility is too low. Analysis of additives commonly used in lithium battery electrolytes. Conductive additives. Solid electrolyte membranes are incompatible with organic solvents, allowing lithium ions to enter and exit freely. The electrodes and solvent molecules cannot cross, thereby preventing the damage of solvent molecules co-inserted on the electrodes and improving the battery’s cycle power and reversibility. Ability and other functions. It is mainly divided into inorganic film-forming additives and organic film-forming additives. The research of film-forming additives to improve electrolyte conductivity mainly focuses on improving the dissolution and ionization of conductive lithium salt, and preventing the damage of the co-insertion of the solvent into the electrode. According to the effect type, it can be divided into cation effect type, anion effect type and electrolyte ion effect type. Flame retardant additives Adding flame retardant additives is an effective way to improve the stability of electrolyte and the safety of lithium batteries. It is mainly divided into organophosphorus compounds, organofluorine compounds and halogenated alkyl phosphates. Lithium batteries are mainly composed of electrolyte, separator material, positive electrode material and negative electrode material. Among these components, the electrolyte is an extremely important component of lithium battery materials, so it is very useful to know the electrolyte material. I hope that the lithium battery pack electrolyte materials analyzed above can be helpful to us. 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: Opportunities and Challenges of Lithium Battery Technology in the Future