Which factors will affect the internal resistance of lithium batteries?

What factors affect the internal resistance of lithium batteries? 1. Temperature The internal resistance of a lithium iron phosphate battery is an important parameter to measure the difficulty of the internal conductive ions and electrons of the battery, which directly determines the power characteristics of the battery, and therefore has an important impact on the power of the electric vehicle. The actual operating environment temperature range of electric vehicles is wide, and the internal resistance of the battery is different under different temperatures and working conditions. Grasp the internal relationship between battery internal resistance and temperature, SOC, charge and discharge rate, etc. As the temperature rises, the ohmic internal resistance and the polarization internal resistance of the lithium iron phosphate battery during the charging and discharging process decrease, and the ohmic internal resistance change rate at different temperatures is higher than the polarization internal resistance change rate, and the ohmic internal resistance change rate at low temperature is greater than high Down rate of change. 2. The influence of the diaphragm on the ion resistance. The important factors affecting the ion resistance of the diaphragm are: electrolyte distribution in the diaphragm, diaphragm area, thickness, pore size, porosity, and tortuosity coefficient. Regarding ceramic diaphragms, it is also necessary to prevent ceramic particles from blocking the pores of the diaphragm, which is not conducive to the passage of ions. While ensuring that the electrolyte is fully infiltrated into the diaphragm, there should be no excess electrolyte remaining in it, which reduces the efficiency of the electrolyte. 3. Structure design influence In the battery structure design, in addition to the riveting and welding of the battery structure itself, the number, size, and location of the battery tabs directly affect the internal resistance of the lithium iron phosphate battery. To a certain extent, the number of new tabs can effectively reduce the internal resistance of the battery. The position of the tab also affects the internal resistance of the battery. The internal resistance of the wound battery with the tab position at the head of the positive and negative pole pieces is the largest. Compared with the wound battery, the laminated battery is equivalent to dozens of small batteries in parallel. , Its internal resistance is smaller. Statement: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: What are the test methods for UPS battery capacity?