What are the important reasons for the excessive internal resistance of lithium-ion batteries?

1. There are too few conductive agents in the positive electrode ingredients (the conductivity between the material and the material is not good, because the conductivity of lithium cobalt itself is very poor) 2. There are too many binders in the positive electrode ingredients (the binders are generally polymer materials, Strong insulation function) 3. Too much binder for negative electrode ingredients (binders are generally high-molecular materials with strong insulation function) 4. Ingredients are not symmetrically separated 5. The binder solvent is not complete during the ingredients 6. Coating The drawing surface density is too large 7. The compaction density is too large, and the roll is too compact. 8. The positive electrode lug is not welded firmly, showing a virtual welding. 9. The battery storage is not fair. Material 1. The lithium ion battery positive electrode material has a large resistance (conductive Poor performance, such as lithium iron phosphate) 2. The influence of the barrier material (the thickness of the barrier, small porosity, and the small pore size) 3. The influence of the electrolyte material (small electrical conductivity, high viscosity) 4. The influence of the positive electrode PVDF material (a large amount may have a large molecular weight) ) 5. The influence of the material of the positive electrode conductive agent (poor conductivity, high resistance) 6. The influence of the material of the positive and negative pole ears (the thickness is thin, the conductivity is poor, the thickness is uneven, and the purity of the material is poor) 7. The copper foil and aluminum foil have poor conductivity or appearance Oxide 8. The internal resistance of the cover pole is too large for riveting. 9. The negative material resistance is one of the important indicators for evaluating the performance of lithium-ion batteries. The internal resistance test of lithium-ion batteries includes exchange internal resistance and DC internal resistance. Regarding the single battery, the evaluation is generally based on the exchange of internal resistance, which is usually called ohmic internal resistance. However, for large-scale lithium-ion battery pack applications, such as power supply systems for electric vehicles, due to the limitations of test equipment, it is impossible or unfavorable to directly conduct exchange internal resistance tests. Generally, DC internal resistance is used to evaluate the characteristics of the battery pack. Disclaimer: 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: Explanation of the reasons for the deterioration of lithium-ion batteries