What factors affect the polarization of lithium batteries?

What are the factors that affect the polarization of lithium batteries? Lithium battery is essentially a kind of lithium ion concentration difference battery. The charging and discharging process of lithium battery is the process of insertion and extraction of lithium ions in the positive and negative electrodes. The factors that affect the polarization of lithium batteries include: 1. The influence of electrolyte: the low conductivity of electrolyte is an important reason for the occurrence of 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 that of an aqueous solution. Therefore, when the 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 very quickly, and lithium ions are required to be inserted and extracted quickly in the material. If the pole piece is thick, the path of lithium ion diffusion Newly added, 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. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: What are the differences between wet and dry diaphragms for power lithium batteries?