What impact does temperature have on lithium-ion battery packs? When searching for the operating temperature of lithium-ion battery packs on Baidu, the answer given is that the commonly used operating temperature for lithium-ion batteries is 20°C. However, below 0°C, the performance of lithium-ion battery packs will typically decrease, leading to reduced discharge. Therefore, the typical operating temperature range for lithium-ion batteries to function fully is 0-40°C. Some special environments require lithium-ion battery packs to operate at temperatures that vary greatly, with some even capable of operating at hundreds of degrees Celsius.
Temperature. JPG
As can be seen from the above, lithium-ion battery packs can operate in both high and low temperatures, meeting the requirements of most ambient environments. However, the operating power of lithium-ion battery packs is still affected by temperature. For example, if the temperature is too low, the capacitance of the lithium-ion battery pack decreases more rapidly, and the internal resistance also increases.
Causes of temperature changes in lithium-ion battery packs
Regarding lithium-ion battery packs, the internal heat of the battery consists of reaction heat, polarization heat, and Joule heat. One of the important reasons for the temperature rise of lithium-ion battery packs is the temperature rise caused by the internal resistance of the battery. In addition, due to the dense arrangement of the heated battery cells, more heat must be collected in the central area and less in the peripheral area, which adds to the temperature imbalance between individual cells in the lithium-ion battery package.
The problem. JPG
The effect of different temperatures on the performance of lithium-ion battery packs
The internal resistance of a 150Ah lithium-ion battery pack doubles when the temperature drops from 18°C to 0°C. Below 0°C, the discharge capacity of the lithium-ion battery pack decreases rapidly. When the temperature drops to -10°C, the resistance of the lithium-ion battery pack doubles.
Lithium-ion battery packs exhibit varying heat dissipation rates at different temperatures because the chemical reactions within the battery are closely temperature-dependent. At lower ambient temperatures, lithium-ion battery packs generate more heat during operation.
The operating temperature of lithium-ion battery packs has a certain impact on the battery's internal resistance, heat dissipation rate, discharge capacity, cycle life, and state consistency.
Temperature scheduling method
Internal scheduling
Temperature sensors will be placed at the most representative locations with the greatest temperature fluctuations, especially at the highest and lowest temperatures, as well as in the area where heat is more intensely stored in the center of the lithium-ion battery pack.
External scheduling
Cooling management: Considering the complexity of the battery pack structure, shorter air-cooling methods are often used. To ensure uniform heat dissipation, parallel ventilation is frequently employed.
Heating scheduling: The simplest heating method is to add upper and lower heating plates to heat the lithium-ion battery pack, and surround each lithium-ion battery pack before and after the heating wire, or perhaps use a heating film to cover the entire lithium-ion battery pack during heating.
