What is the principle of lithium battery fast charging?

Recently, Xiaomi announced the 200W power fast charging technology, full of 4000mAh battery only 8 minutes.

The fact is that not only in the field of mobile phones, but also in the power battery field, fast charging is also one of the important directions of market attention.

Generally speaking, most electric vehicles are ordinary charging technology. This ordinary charging method charging the tram takes 8-10 hours, while fast charging is fast charging, which only takes one hour to fill the battery.

In terms of simplified concept, in fact, fast charging uses high current and high power DC to charge the battery. The real principle is that in the fast charging state, lithium ions move at high speed, instantly embedded in the poles of the battery.

The realization method is to first charge the battery with a wide charging pulse and raise the lithium battery end voltage. When the charging time limit set by the charging system is reached, the charging system cuts off the battery current, and then intermittently reaches another battery charging point, and then restart the process repeatedly. When all the lithium ions inside the battery gather to the positive and negative electrodes of the battery, the battery is filled quickly.

This fast charging technology has high requirements for the battery itself. The battery itself must have an automatic management system, along with very reliable thermal stability and high pressure and high current resistance.

The above is to realize the battery requirements of fast charging, in order to realize this fast charging, must also have a matching charging system, now many cities provide fast charging pile power as high as 20KW and above, can convert 10KV high voltage AC into hundreds of Ann DC, and through the special cable into the car battery system.

In view of the current battery pack balance technology, transmission and distribution technology, especially heat dissipation technology can not meet the requirements, the real sense of fast charging can not be fully realized, but compared with ordinary charging technology has greatly shortened the charging time, the most important thing is this fast charging technology, it can be seen in principle, fast charging will not be as seriously lose the battery as spread, sacrifice the service life of the battery.