Will the temperature change affect the performance of the lithium battery of the electric vehicle?

Date:Nov 11, 2019

Will temperature changes affect the performance of lithium batteries in electric vehicles? How much influence does temperature have on lithium battery capacity? For electric vehicle lithium batteries, our focus is often on capacity and energy density. These data can usually reflect the cruising range intuitively. length. But what we have to pay attention to is that most lithium batteries are electrochemical products. Since they are related to chemistry, their performance has a great relationship with temperature.

Will the temperature change affect the performance of the lithium battery of the electric vehicle?

The change of temperature will directly affect the charging and discharging performance of lithium batteries for electric vehicles, but many electric vehicle users will not pay attention to this when using electric vehicles. From the current test results of lithium battery manufacturers, the ambient temperature is too high or too low, which has a significant impact on the characteristics of lithium batteries. It is reflected in the voltage drop and the capacity is insufficient. It is better to control the temperature between 10-50 degrees. There are insulation measures. In fact, the lithium battery of the electric vehicle will undergo a chemical reaction during charging and discharging, and this reaction will cause the activity of the active substance on the battery to increase or decrease, and the lower the discharge temperature, the less the discharged capacitance, the charging temperature. The higher the acceptance, the higher the charging voltage, so the charging voltage is fixed so that it can be fully charged.

The effect of temperature on the lithium battery of electric vehicles will still be more or less, and the focus is on daily maintenance. High temperature will make electric vehicles self-ignite. This is wrong, but there is no direct relationship between high temperature in summer and spontaneous combustion of electric vehicles. Why do you say this, starting from the cause of self-ignition of electric vehicles. When we talk about the spontaneous combustion of electric vehicles, we will think of it because of the battery. Because the battery will generate a large amount of heat during charging and discharging, if the internal temperature of the lithium battery of the electric vehicle is continuously increased or the temperature between the cells is not uniform, there is a risk of overheating and explosion. According to the information provided by the experts, the charging time at an ambient temperature of -25 °C is 63% slower than the charging time at 25 °C under the condition of a charging current of 5 A. The effect of low temperature on the charging time of battery lithium battery can not be ignored, too long charging time will seriously hinder the promotion of electric vehicles. Although the low temperature environment has little effect on the discharge performance of the lithium battery, it will seriously affect the charging performance of the battery and greatly shorten the life of the battery.

The effect of temperature on discharge performance is directly reflected to the discharge capacity and discharge voltage. The temperature is lowered, the internal resistance of the lithium battery is increased, the electrochemical reaction speed is slowed down, the internal resistance of the polarization is rapidly increased, the discharge capacity of the battery and the discharge platform are lowered, and the output of the power and energy of the electric vehicle battery is affected.

At present, the lithium battery technology of electric vehicles sold in the market is mainly divided into two types, namely a ternary polymer lithium battery and a lithium iron phosphate battery. Regardless of the battery technology, there is a degradation in battery performance in the face of low temperature environments.

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