What are the factors that affect the polarization of lithium batteries?

(1) The influence of the electrolyte: The low conductivity of the electrolyte is an important reason for the polarization of lithium batteries. In the general temperature range, the conductivity of the electrolyte for lithium batteries is generally only 0.01 to 0.1S/cm, which is one hundredth of the aqueous solution. Therefore, when a lithium battery is discharged at a high current, it is too late to replenish Li+ from the electrolyte, and polarization will occur. Improving the conductivity of the electrolyte is a key factor in improving the high-current discharge capability of lithium batteries. (2) The influence of the positive and negative materials: the channels for the large lithium ions of the positive and negative material particles to diffuse to the surface are lengthened, which is not conducive to high-rate discharge. (3) Conductive agent: The content of conductive agent is an important factor affecting high-rate discharge performance. If the content of the conductive agent in the positive electrode formulation is insufficient, electrons cannot be transferred in time during high current discharge, and the internal polarization resistance increases rapidly, causing the battery voltage to quickly drop to the discharge cut-off voltage. (4) The influence of the pole piece design: the thickness of the pole piece: In the case of high current discharge, the active material reacts quickly, and lithium ions are required to be inserted and extracted quickly in the material. If the pole piece is thick, the lithium ions will diffuse. With the new path, there will be a large lithium ion concentration gradient in the thickness direction of the pole piece. Compaction density: The compaction density of the pole piece is larger, the pore becomes smaller, and the lithium ion movement path in the thickness direction of the pole piece is longer. In addition, if the compaction density is too large, the contact area between the material and the electrolyte will decrease, the electrode reaction site will decrease, and the internal resistance of the battery will increase. (5) The influence of SEI film: The formation of SEI film adds resistance at the electrode/electrolyte interface, causing voltage lag or polarization. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement.