What is the principle of lithium battery fast charging?

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

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

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

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

Implementation method is, the first use of wide charging pulse for charging battery, lithium battery voltage, when the charging system set charging time limit, charging system cut off the power supply current makes the battery suspended, and then when intermittent to another charging point, then restart charging, the process repeatedly, when the lithium ion all gathered inside the battery inside the positive and negative electrodes, the battery is quickly full.

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

Above is to realize the fast charging battery requirements, in order to realize this fast charging, must also have the 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 dc, and through the special cable into the car battery system.

In view of the current battery equilibrium technology, transmission and distribution technology, especially heat dissipation technology can not meet the requirements, the real sense of fast charge is not fully realized, but compared to ordinary charging technology has greatly shortened the charging time, the most important is the fast charging technology, can be seen in principle, fast charge is not like the serious loss of battery, sacrifice the service life of the battery.