How to improve the fast charging performance of lithium batteries?

　　The essence of rapid charging and discharging of lithium batteries is that lithium ions can be quickly deintercalated between the positive and negative materials. Battery material properties, process design, and charging and discharging systems will all have an impact on the high-current charging performance.

　　The essence of rapid charging and discharging of lithium batteries is that lithium ions can be quickly deintercalated between the positive and negative materials. Battery material properties, process design, and charging and discharging systems will all have an impact on the high-current charging performance.

　　For example of 6C charging and 1C discharging of lithium cobalt oxide battery, you can take a look:

　　(3)Pole piece coating consistency

　　A friend asked before, does the inconsistent surface density of the poles affect the battery? By the way, for fast charging performance, it is mainly the consistency of the negative pole piece. If the surface density of the negative electrode is inconsistent, after rolling, the internal porosity of the active material will be quite different. The difference in porosity will cause the difference in internal current distribution, affect the formation and performance of SEI in the battery formation stage, and ultimately affect the fast charging performance of the battery.

　　(4)Pole piece compaction density

　　Why do 　　 pole pieces need to be compacted? One is to increase the specific energy of the battery, and the other is to improve the battery performance. The optimal compaction density is different for different electrode materials. Increasing the compaction density, the smaller the porosity of the electrode pole piece, the tighter the connection between the particles, and the smaller the thickness of the pole piece under the same areal density, so the migration path of lithium ions can be reduced.

　　When the compaction density is too high, the electrolyte infiltration effect is not good, which may damage the material structure and conductive agent distribution, and winding problems will occur later. The same is the 6C charge and 1C discharge of the lithium cobalt oxide battery, the effect of compaction density on the discharge specific capacity is as follows:

　　05 Formation aging and others

　　For carbon anode batteries, formation-aging is the key process of lithium batteries, and this process will affect the quality of SEI. The uneven thickness or unstable structure of the SEI will affect the fast charging capacity and cycle life of the battery.

　　In addition to the above several important factors, cell production and charging and discharging systems will have a greater impact on the performance of lithium batteries. As the use time is prolonged, the battery charging rate should be appropriately reduced, otherwise the polarization will be aggravated.