Low temperature lifepo4 lithium battery 48v 100ah, also known as lithium ion battery 48v 100ah, is a rechargeable DC power supply for energy storage, which has low temperature resistance. At present, it is widely used in automotive, household and portable electronic devices and other fields. The new energy storage products represented by lithium-ion batteries have become a hot spot in the current market, with obvious advantages in safety, long life and cycle life. However, its performance at low temperature is not satisfactory. How about the performance of lithium iron battery at low temperature? Let's get to know!
1. Charging process
In the low temperature state of 48v 100ah Lifepo4 Battery, due to the decomposition of the negative active substance, the negative active substance in the battery is separated from the positive active substance and adsorbed, so the internal resistance of the battery increases. At the same time, due to the decomposition of the electrode active substance, the internal resistance of the battery increases, which affects the energy density of the battery. As a result, the current efficiency of the battery decreases during charging and discharging. The internal charging reaction mechanism of the battery is shown in Figure 1. It can be seen from Figure 1 that under low temperature conditions, the battery will not stop charging reaction even if the battery is in a working environment of minus 30 ℃~60 ℃. This phenomenon will aggravate the internal discharge process of the battery at low temperature, and the battery capacity will decrease significantly. This is because the low temperature of the battery at low temperature will lead to the decomposition of active substances inside the battery, resulting in a large amount of oxygen flooding into the battery, and even lead to suffocation inside the battery, causing internal damage to the battery.
2. Low temperature discharge characteristics
At low temperature, the discharge performance of 48v lithium iron battery will also be affected. As shown in Figure 1, at room temperature, the negative electrode surface potential decreases with the increase of temperature, the positive electrode surface potential increases with the increase of temperature, and the negative electrode surface potential decreases with the increase of temperature. At different temperatures, there is a significant positive correlation between the change trend of the positive and negative electrode surface potentials of lithium ion batteries and the negative electrode surface potentials. For the battery with low temperature, the reduction ability of the negative electrode active material is closely related to the temperature because there are oxygen atoms and lithium atoms in the negative electrode material. In addition, the large capacity range of 48v lithium ion battery makes it have better low-temperature discharge characteristics. At room temperature, with the increase of temperature, iron lithium battery has the characteristics of lower current density, larger capacity range, longer discharge time, higher discharge rate and lower cost, which also makes this type of battery have more application value and market prospect at low temperature.
3. Thermal management characteristics
As the polarization of lithium iron battery in low temperature environment leads to a significant increase in energy consumption, attention should be paid to thermal management. During the use of the battery, when the ambient temperature is lower than 30 ℃, the conductivity of the battery becomes worse, and the battery will release more heat, which will increase the probability of overcharging or discharging the battery. The battery reacts to heat very quickly during use, so the lower the temperature, the more likely the battery is to be overcharged or discharged. Therefore, attention must be paid to rapidly reduce the internal temperature of the battery in a short time. However, this process will be related to the internal thermal environment of the battery. If it can be cooled in time, it can greatly improve the thermal management performance of the lifepo4 48v battery.