Why can't a lithium ion battery in low temperature environments

　　Author ：Iflowpower – Dostawca przenośnych stacji zasilania

Why can't I charge a lithium ion battery in a low temperature environment? Lithium-ion battery cannot be in too low temperature. At the low temperature, lithium in the battery causes internal short circuits. Simply put, in a low temperature environment, it is not a lithium battery really no power, but there is electricity but not normal release.

Ordinary lithium battery When zero degrees Celsius, its capacity will be reduced by 20%, and when it reaches 10 degrees Celsius, the capacity may only be about half. Low temperature charging battery three yuan, lithium iron phosphate system - 20 ¡ã C low temperature 0.5C charging, and charge and discharge cycle 300 weeks; -40 ¡ã C low temperature 0.

2C charging, and charge and discharge cycle for 300 weeks. Lithogenic discharge battery triple, lithium iron phosphate system -40 ¡ã C high magnification 5C continuous discharge, 80% or more capacity retention rate; -50 ¡ã C low temperature discharge, 75% capacity retention ratio. Why can't I charge a lithium ion battery in a low temperature environment? Most of the materials such as diaphragm, electrolyte, etc.

are all organic materials, and the amount of melting point is low. If the temperature is too negative chemical reaction, it is severely affecting battery life or even safety performance. The electrical conductivity of the key material of the lithium ion battery under low temperature conditions is lowered, resulting in a decrease in conductivity, which will seriously affect lithium battery life.

For lithium batteries, there is currently no clear theory that has no clear theory to support the internal resistance, discharge platform, life, capacity, etc. at each temperature performance, and the relevant calculation formula and mathematical model are still exploiting. In general, the temperature of the lithium battery is not sensitive to the temperature of 0-40 ¡ã C, however, once the temperature exceeds this, life and capacity will be discounted.

After making a lot of experiments, the low temperature performance of different material lithium batteries is also different. Now the hottest lithium iron phosphate is the worst low temperature performance, and our products are more than 89% of the maximum capacity at -10 ¡ã C, and should have been in the industry It is relatively high; the release capacity at 55 ¡ã C can reach 95%, relatively low temperature attenuation is still relatively small. This is still a product, everyone understands, quality relative to the normal product is much higher.

Low temperature protection is that the metal lithium in the lithium-ion battery will produce deposition phenomena in the case of too low temperature, and the case where the substance is chemically reacted, thereby generating a short circuit in the battery. Since the working principle of the lithium ion battery is the internal electrolyte by chemical reaction, the potential difference occurs at the positive and negative electrode. The electrolyte movement in a low temperature environment is relatively slow, which affects the transfer activity between the lithium ions between the positive and negative electrodes, resulting in a decrease in battery charge and discharge performance.

Some people reflect the winter lithium-ion battery charging charge, and some of the lithium battery management system is due to product protection, and there is still because of quality problems. Lithium battery is in winter, it is inevitably shorter than summer. Alert everyone, the lithium battery is best not to charge in winter.

Due to low temperature, nesting lithium ions on the negative electrode produce ionic crystals, directly piercing the diaphragm, in general, the micro-short circuit affects life and performance, and severe possible explosion! Effect of lithium battery in low temperature environment, low temperature, the positive and negative electrode, electrolyte and adhesive, etc. of phosphate, electrolyte, and adhesive. For example, the lithium iron phosphate positive electrode itself is poor, it is easy to generate polarization in a low temperature environment, thereby reducing battery capacity; due to low temperature, graphite is lowered, easy to precipitate metal lithium in the negative surface, if charging is insufficient after charging In addition, metal lithium cannot be embedded inside the graphite, and some metal lithium continues to have a negative surface, which is very likely to form a lithium delegated crystal, affecting battery safety; low temperature, the viscosity of the electrolyte increases, the lithium ion migration impedance will also In addition, in the production process of lithium iron phosphate, the adhesive is also a very critical factor, and the performance of the low temperature to the adhesive also has a large effect.

In low temperature environments, battery charging has certain risks. Because of the decrease in temperature, the kinetic characteristics of the graphite negative electrode is changed. During the charging process, the electrochemical polarization of the negative electrode is significantly agly, and the precipitated metal lithium is easily formed to form a lithium delegated crystal, wear the diaphragm and lead to a positive and negative short circuit.

Summary: In low temperature environments, there is a battery charging risk, and it should be avoided to charge a lithium-ion battery at low temperatures. With the further development of the technology, the lithium battery will have further breakthroughs in a low temperature envir.