Why is the low temperature performance of lithium iron phosphate batteries inferior

Lithium iron phosphate battery is a high-tech product with many chemical raw materials and complicated processes. Its processing environment has high requirements on temperature, humidity, and dust. If it is not controlled in place, the quality of the battery will fluctuate. 2. Poor conductivity and slow diffusion of lithium ions. When charging and discharging at a high rate, the actual specific capacity is low. This problem is a difficulty that restricts the development of the lithium iron phosphate battery industry. The reason why lithium iron phosphate has not been widely used so late is an important issue. 3. The influence of materials The lithium iron phosphate positive electrode itself has relatively poor electronic conductivity, and it is more prone to polarization, which reduces the performance of the capacity; the negative electrode is mainly charged at low temperature because it will affect the safety problem; the electrolyte is the one , Maybe the viscosity will increase at low temperature, and the lithium ion migration resistance will increase; the fourth is the binder, which now has a relatively large impact on the low temperature performance of the battery. 4. Cathode material The three-dimensional structure of the cathode material restricts the diffusion rate of lithium iron phosphate batteries, and the effect is particularly obvious at low temperatures. The study found that the discharge performance of lithium iron phosphate batteries and nickel-cobalt-manganese ternary batteries at -20 ℃, and found that the discharge capacity of lithium iron phosphate batteries at -20 ℃ can only reach 67.38% of the capacity at room temperature, while nickel-cobalt-manganese ternary batteries It can reach 70.1%. 5. High melting point solvents Due to the presence of high melting point solvents in the mixed solvents of the lithium battery electrolyte, the viscosity of the lithium battery electrolyte increases in a low temperature environment. When the temperature is too low, the electrolyte solidification phenomenon will occur, resulting in the lithium iron phosphate battery The transmission rate is reduced. 6. In the low temperature environment of SEI film, the SEI film of the negative electrode of lithium iron phosphate battery thickens, and the increase of SEI film impedance causes the conduction rate of lithium ions in the SEI film to decrease. Finally, the lithium battery is charged and discharged in a low temperature environment to form polarization and reduce charge. Discharge efficiency. 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 raw materials produced by lithium battery packs?