How to improve the performance of low-temperature lithium iron phosphate batteries

The operating temperature range of a lithium battery shows its use characteristics. At very low temperatures, aerospace requires lithium batteries to have a reasonable discharge efficiency at -60°C to -80°C, while the drilling industry requires good performance at temperatures above 100°C. Except for these two market segments, most lithium batteries use a temperature window of -50C to 80C. These windows include household electronics and power tools (-20°C to 60°C), HEV (-30°C to 70°C) and military use (-50°C to 80°C). At present, the solvents of lithium battery electrolytes mostly use carbonate series of high-purity organic solvents, such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). However, the performance of a single solvent is often not able to have the various performances actually required at the same time, and the multi-component mixed solvent obtained by mixing multiple solvents in a certain ratio is often better than a single solvent. To improve the low-temperature performance of the electrolyte by optimizing the organic solvent is to find a low-melting organic solvent that is miscible with the current electrolyte. Use an electrolyte solvent system with better thermal conductivity at low temperatures to increase the body temperature of the battery during charging and discharging at low temperatures, such as the use of solvent system DMC+DEC, etc. Use organic solvents with lower melting point and viscosity to broaden the liquid temperature range of the electrolyte, such as using carboxylate solvents such as ethyl propionate and methyl butyrate. Optimized formula: ECIPC\DMC\EMC\DEC, 2%VC+low temperature additive B)EC\PCEMC\EP\DEC, 2%VC+low temperature additive The most widely used lithium salt at present is LiPF6, the main reason is that it is contained in organic solvents Very good solubility, relatively high conductivity, and relatively low cost. However, because LiPF6 is very sensitive to trace water, its analysis product contains HF, which is easy to corrode the cathode material and current collector, and its lack of temperature stability affects the development of lithium batteries. It is also one of the important ways to improve the low temperature performance of electrolyte by using more stable and better low temperature performance lithium salt. Adding additives to improve the low-temperature energy production of lithium battery organic electrolytes is another research hotspot, and it is also an important development direction in this field in the future. Additives can clearly improve the performance of lithium batteries without basically increasing processing costs and changing processing techniques because they have small dosages and quick effects. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.