Why not charge lithium batteries at low temperatures?

In winter, users of electric vehicles have a clear feeling that the battery use time has become shorter! Why is that?

For lithium batteries, there is no clear theory in the industry to support the internal resistance, discharge platform, life span, capacity and other necessary links under each temperature performance, and the relevant calculation formulas and mathematical models are still groping for the stage. In general, lithium batteries are not sensitive to the temperature of the 0-40 °C range, but once the temperature exceeds this range, the life and capacity will be reduced.

There is no way to specifically quantify it, because lithium-ion batteries are too active and consistency is the biggest problem. Even products of the same batch, the same material, and the same process will have very different performance.

Many experiments have been done. The low-temperature properties of lithium batteries of different materials are also different. Now the hottest lithium iron phosphate has the worst low-temperature performance. Our product emits 89 % of its maximum capacity at -10 °C. Should already be relatively high in the industry; The emission capacity can reach 95 % at 55 °C, and the relative low temperature attenuation is still relatively small. This is still to send inspection products, you know, quality relative to the normal pipeline products are much higher.

Relatively speaking, lithium manganate, lithium cobalt acid and ternary products have better low temperature performance, but they are also limited; The sacrifice is high temperature performance. At present, the safety performance of lithium iron phosphate blowing in the industry is high, and the high temperature performance is good. In fact, the battery activity is not the above three high, and it is relatively safe. The overall performance is still not as good as manganese lithium or ternary.

Therefore, some people report that lithium batteries can not be charged in the winter. Some of the batteries with the battery management system are due to product protection, and others are due to quality problems. Lithium batteries are necessarily shorter in winter than summer. In this reminder, lithium-ion batteries are best not to be charged in winter. Due to the low temperature, lithium ions nested on the negative pole will produce ion crystals and directly pierce the diaphragm. In general, a micro-short circuit will affect the life and performance, and a serious explosion may occur!

The page contains the contents of the machine translation.