The technology of fast charging technology -Lithium - Ion Battery Equipment

Material requirements for fast charging technology -Lithium - Ion Battery Equipment

The requirements of fast charging technology for lithium-ion battery materials and structures

Answers to some popular science questions about fast charging

First, the concept of C in battery charging is introduced. This concept is very important and is the most commonly used term in battery discussions and analysis. is an abbreviation for current ratio The rate of a battery C rate is a measure of the rate at which A' is discharged relative to its maximum capacity. A rate of 1c means that the discharge current will discharge in 1 hour - the battery. 1C represents the current required to drain the battery in one hour. 2C represents the amount of current required to discharge in 0.5 hours. The higher the multiplier, the higher the current.(Lithium - Ion Battery Equipment)

It is the meaning of fast charging: literally, fast charging is the process of charging and discharging fast secondary rechargeable, in fact, the speed is fast, the speed is not too fast is not a particularly strict meaning, but it can generally be simplified to understand the charging of the system in less than 1 hours (ie, the charging rate is greater than 1c). Zhihu is often consulted by authors on various fast-charging issues. Here, the author will first emphasize a few concepts for scientific use:

1) Battery charging is generally determined by measuring its voltage to determine the degree of charge and discharge. There are not many coulomb meters used. In this case, the charge and discharge power of the battery is actually only a real-time battery voltage conversion relationship. Fast charging and slow filling will bring a large amount of voltage, current, U=IR, and the internal resistance of the battery will supply a larger overvoltage), and the dispersion chemical reaction will also keep up, although the battery can be charged at this time on the surface. High power is high, not actually flooded with so much electricity, an example is shown below:

Fast charging technology to ensure battery safety

In the figure, the same material in different optimization processes, the multiplier performance is different (the left is bad), in the 5 degree high multiplier charging and discharging system, although they all charge 4.5v (reflecting the complete), but There is actually a big difference in the available capacity, one is 75mah/g and the other is 108mah/g.

2) So, in fact, any battery can be quickly charged. In this case, full only adds voltage, which is inconsistent with the linear ratio of charge/energy. Time, high current charging will lead to the increase of Joule heating effect (Q=I2Rt), and cause adverse reactions of materials to decompose in cells, natural gas and a series of problems, sudden new risks, not to mention the case of battery life , The life of non-power lithium batteries will inevitably be greatly shortened, so it is actually the safest and most reliable manufacturer. Consider that the circuit planned by the manufacturer should limit the charging current limit of the battery, and do not let people use fast charging.

3) If you want to charge the battery quickly, the performance requirements related to power are higher, and lower internal resistance is an important article (Q=I2Rt, small resistance R can reduce Joule heating), in this case, use high Conductive electrode materials (carbon coating modified lithium to improve dispersion coefficient, reduce particle size and shorten scattering paths), use more conductive agents, coatings and thinner electrodes (to make mass transfer and dispersion distances shorter) are typical for batteries The power to quickly fill planning ideas. The idea of ​​these plans will of course conflict with the energy density approach, and you can't have it both ways.

Fast charging technology to ensure battery safety

4) It meets the characteristics of the power lithium battery described in 3), and is more suitable for fast charging than energy type batteries, which means that it has small internal resistance, low charging calorific value, less side uses, and better safety performance than most Energy type/those are not suitable for fast charging batteries, voltage and filling power/energy is better at high current fast charging, the popular saying is: less heat appears, safer, can really drown out that much electricity, not only Can be displayed as fill.

5) There is an old saying that is very simple, if someone is bragging about their fast charging technology, you must calculate the charging power, and then look at the thickness corresponding to the charging power requirements. This criterion alone is enough to screen out 90% of unreliable fast-charging fake news.



Contact Us

24 hours online service