How is the internal resistance of a lithium-ion battery composed

The internal resistance of lithium-ion batteries mainly includes two parts. The ohmic resistance and the polarization internal resistance are basically stable under the condition of constant temperature, and the polarization resistance will change with the factors that affect the polarization level. The ohmic internal resistance mainly refers to the composition of electrode material, electrolyte, diaphragm resistance and contact resistance of various parts, and is related to the size, structure, and assembly of the battery. When current passes through the electrodes, the phenomenon that the electrode potential deviates from the equilibrium electrode potential is called electrode polarization. Polarization resistance refers to the internal resistance caused by the polarization of the positive electrode and the negative electrode of the battery during the electrochemical reaction. The internal resistance of the battery is not constant. It changes with time during the charge and discharge process. This is because the composition of the active material, the concentration of the electrolyte and the temperature are constantly changing. The ohmic internal resistance obeys Ohm's law, and the polarization internal resistance increases with the increase in current density, but it is not a linear relationship. It is often added linearly as the logarithm of the current density increases. Different types of batteries have different internal resistances. The same type of battery has different internal resistance due to the inconsistency of internal chemical characteristics. The internal resistance of the battery is very small, we generally use the unit of milliohm to mean it. Internal resistance is an important technical indicator to measure battery performance. Under normal circumstances, a battery with a small internal resistance has a strong high-current discharge capacity, and a battery with a large internal resistance has a weak discharge capacity. The internal resistance of the battery is very small, we generally use the unit of microohm or milliohm to mean it. In general measurement occasions, we require that the internal resistance measurement accuracy error of the battery must be controlled within plus or minus 5%. Such small resistance and such accurate requirements must be measured with special instruments. 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: Types of lithium ion battery separators and the three major competitive characteristics of the industry