Analysis of factors affecting low temperature performance of lithium batteries

Lithium batteries are mainly composed of positive electrode materials, negative electrode materials, separators, and electrolytes. Lithium batteries in a low temperature environment have the characteristics of reduced discharge voltage plateau, low discharge capacity, fast capacity decay, and poor rate performance. The factors that restrict the low-temperature performance of lithium batteries are as follows: 1. Cathode material: The three-dimensional structure of the cathode material restricts the diffusion rate of lithium ions, and the effect is particularly clear at low temperatures. 2. Electrolyte: The material and physical and chemical parameters of the electrolyte have a major impact on the low-temperature performance of the battery. The viscosity of the electrolyte increases, the ion conduction speed becomes slower, the electron migration speed does not match with the external circuit, and the charge and discharge capacity decreases sharply. Especially in the case of low-temperature charging, lithium ions can easily form lithium dendrites on the surface of the negative electrode, leading to battery failure. 3. Lithium ion diffusion rate: The decrease of the diffusion rate of lithium ions in the graphite anode under low temperature environment, and the increase of the charge transfer resistance of the lithium battery leads to the decrease of the diffusion rate of lithium ions in the graphite anode. This is an important reason that affects the low temperature performance of the lithium battery. 4. SEI film: The SEI film of the negative electrode of the lithium battery is thickened in a low temperature environment. The increase in the impedance of the SEI film causes the conduction rate of lithium ions in the SEI film to decrease, and finally the lithium battery is charged and discharged in a low temperature environment to form polarization and reduce the charge and 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 post: What are the correct charging and discharging methods for lithium batteries