Introduction：
Since entering the market, lithium batteries have been widely used for their advantages such as long life, large specific capacity, and no memory effect. When used at low temperatures, lithium-ion batteries have problems such as low capacity, severe attenuation, poor cycle rate performance, obvious lithium precipitation, and unbalanced lithium insertion and extraction. However, as the application field continues to expand, the constraints brought by the poor low-temperature performance of lithium-ion batteries are becoming more and more obvious. Let's explore the reasons and explain how to treat lithium batteries correctly in winter?
Discussion on factors affecting low temperature performance of lithium batteries
1. Electrolyte influence
The electrolyte has the greatest impact on the low-temperature performance of lithium batteries. The composition and physicochemical properties of the electrolyte have an important impact on the low-temperature performance of the battery. The problem faced by the battery cycle at low temperature is that the viscosity of the electrolyte will increase, the ion conduction speed will slow down, resulting in a mismatch in the electron migration speed of the external circuit, so the battery will be severely polarized and the charge and discharge capacity will drop sharply. Especially when charging at low temperature, lithium ions can easily form lithium dendrites on the surface of the negative electrode, causing battery failure.
2. Influence of negative electrode materials
- Battery polarization is serious during low-temperature high-rate charging and discharging, and a large amount of metallic lithium is deposited on the surface of the negative electrode. The reaction product of metallic lithium and electrolyte is generally not conductive;
- From a thermodynamic point of view, the electrolyte contains a large number of polar groups such as C-O and C-N, which can react with the negative electrode material, and the SEI film formed is more susceptible to low temperature;
- It is difficult for carbon negative electrodes to embed lithium at low temperatures, and there is asymmetry in charging and discharging.
How to treat lithium batteries correctly in winter?
1. Do not use lithium batteries in low temperature environments
Temperature has a great impact on lithium batteries. The lower the temperature, the lower the activity of lithium batteries, which directly leads to a significant reduction in charging and discharging efficiency. Generally speaking, the operating temperature of lithium batteries is between -20 degrees and 60 degrees.
When the temperature is below 0℃, be careful not to charge outdoors. We can take the battery indoors for charging (note, be sure to stay away from flammable materials!!!). When the temperature is below -20℃, the battery will automatically enter a dormant state and cannot be used normally.
Therefore, it is especially for users in cold areas in the north, if there is really no indoor charging condition, make full use of the residual heat when the battery is discharged, and charge it in the sun immediately after parking to increase the charging amount and avoid lithium precipitation.
2. Develop the habit of charging as you use it
In winter, when the battery power is too low, we must charge it in time and develop a good habit of charging as you use it. Remember, never estimate the battery power in winter according to the normal battery life.
In winter, the activity of lithium batteries decreases, which can easily cause over-discharge and over-charge, which may affect the battery life or even cause combustion accidents. Therefore, in winter, you should pay more attention to charging in a small discharge and small charge manner. In particular, do not park the vehicle for a long time while charging to avoid overcharging.
3. Do not stay away when charging. Remember not to charge for a long time.
Do not charge the vehicle for a long time for the sake of convenience. Just unplug it when it is fully charged. The charging environment in winter should not be lower than 0℃. When charging, do not leave too far away to prevent emergencies and deal with them in time.
4. Use a dedicated charger for lithium batteries when charging.
The market is full of low-quality chargers. Using low-quality chargers will cause battery damage and even cause fires. Do not buy low-priced and unsecured products for cheapness, let alone use lead-acid battery chargers; if your charger cannot be used normally, stop using it immediately, and do not lose the big picture for the small.
5. Pay attention to the battery life and replace it in time
Lithium batteries have a lifespan. Different specifications and models have different lifespans. In addition, due to improper daily use, the battery life ranges from a few months to three years. If the car loses power or the battery life is abnormally short, please contact the lithium battery maintenance personnel in time to handle it.
6. Leave some power for the winter
In order to use the vehicle normally in the spring of next year, if the battery is not used for a long time, remember to charge it to 50%-80%, remove it from the car for storage, and charge it regularly, about once a month. Note: The battery must be stored in a dry environment.
7. Place the battery correctly
Do not immerse the battery in water or make it wet; do not stack the battery more than 7 layers, or invert the direction of the battery.
Conclusion
At -20℃, the discharge capacity of lithium-ion batteries is only about 31.5% of that at room temperature. The operating temperature of traditional lithium-ion batteries is between -20 and +55℃. However, in the fields of aerospace, military industry, electric vehicles, etc., batteries are required to work normally at -40℃. Therefore, improving the low-temperature properties of lithium-ion batteries is of great significance. Of course, the lithium battery industry is constantly developing, and scientists continue to study lithium batteries that can be used at low temperatures to solve problems for customers.
Heltec Energy is your trusted partner in battery pack manufacturing. With our relentless focus on research and development, coupled with our comprehensive range of battery accessories, we offer one-stop solutions to meet the evolving needs of the industry. We can customize lithium batteries for various scenarios for customers. If you need to upgrade your lithium battery or configure a protection board, please contact us.
If you have any questions or would like to learn more, please don't hesitate to reach out to us.
Request for Quotation:
Jacqueline: jacqueline@heltec-bms.com / +86 185 8375 6538
Sucre: sucre@heltec-bms.com / +86 136 8844 2313
Nancy: nancy@heltec-bms.com / +86 184 8223 7713
Post time: Oct-09-2024