What does high-rate lithium battery mean, and what is the principle of fast charging of lithium battery?

Recently, Xiaomi mobile phones announced the 200W power fast charging technology, which takes only 8 minutes to charge a 4000mAh battery.

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

Generally speaking, most electric vehicles use ordinary charging technology. This ordinary charging method takes 8-10 hours to charge the electric car. Fast charging means fast charging, and it only takes 1 hour to fully charge the battery. .

To simplify the concept, in fact, fast charging uses high-current and high-power direct current to charge the  high-rate lithium battery. The true principle is that in the fast charging state, the lithium ions in the lithium battery move at a high speed and are instantly embedded in the two poles of the battery.

The realization method is to first charge the battery with a wider charging pulse to increase the terminal voltage of the lithium battery. When the charging time limit set by the charging system is reached, the charging system cuts off the power supply current to suspend the charging of the battery, and then when the intermittent reaches At another charging point, restart the charging and repeat this process. When the lithium ions inside the battery are all collected to the positive and negative electrodes of the battery, the battery is quickly fully charged.

This fast charging technology has very high requirements on the battery itself. The  high-rate lithium battery itself must have an automatic management system, and at the same time, it must have very reliable thermal stability and withstand high voltage and high current.

The above are the battery requirements for fast charging. To achieve this fast charging, you must also have a matching charging system. Now many cities provide fast charging charging piles with a power of up to 20KW and above, which can convert 10KV high-voltage AC power. Hundreds of amps of direct current is continuously fed into the car battery system through a dedicated cable.

In view of the fact that the current battery pack equalization technology, power transmission and distribution technology, especially the heat dissipation technology, do not meet the requirements, fast charging in the true sense cannot be fully realized. Compared with ordinary charging technology, the charging time has been greatly shortened. The important thing is this fast charging technology. It can be seen from the principle that fast charging will not consume the  high-rate lithium battery  as severely as it has been spread, and sacrifice the battery life.