Can the polymer lithium-ion battery pack show its low-temperature starting performance under extreme cold conditions?
Publish Time: 2025-01-20
Polymer lithium-ion battery pack is widely used in electric vehicles, portable electronic devices and other fields due to its high energy density, lightweight, long cycle life and other advantages. However, the performance of lithium-ion batteries will be significantly reduced under low temperature conditions, especially under extreme cold conditions, the starting performance of the battery will be greatly affected.1. The impact of low temperature on lithium-ion batteriesDecrease in electrolyte conductivity: Under low temperature conditions, the viscosity of the electrolyte increases and the ion migration rate decreases, resulting in an increase in the internal resistance of the battery and a decrease in discharge capacity.Reduced activity of electrode materials: Under low temperature, the electrochemical reaction rate of positive and negative electrode materials slows down, the insertion and deinsertion process of lithium ions becomes difficult, and the capacity and power output of the battery are significantly reduced.Increased SEI film impedance: The impedance of the solid electrolyte interface film (SEI film) increases at low temperatures, further hindering the transmission of lithium ions and affecting the charge and discharge performance of the battery.2. Low temperature performance of polymer lithium-ion batteriesAdvantages of polymer electrolytes: Compared with traditional liquid electrolytes, polymer electrolytes have better flexibility and ionic conductivity at low temperatures, and can maintain a certain electrochemical activity at low temperatures.Structural design optimization: The packaging structure of polymer lithium-ion batteries is usually more compact, which can reduce the impact of low temperature on battery performance to a certain extent.3. Starting performance under extremely cold conditionsLimited starting ability: Under extremely cold conditions (such as below -20°C), even polymer lithium-ion batteries will have a significant impact on their starting performance. The battery's discharge capacity and power output will drop significantly, which may cause the device to fail to start normally.Necessity of preheating system: In order to achieve rapid starting under extremely cold conditions, a battery preheating system is usually required. The preheating system can increase the battery temperature and improve its electrochemical performance by external heating or internal self-heating.4. Technical measures to improve low temperature starting performanceElectrolyte modification: By adding low temperature additives or using new electrolytes, the conductivity of the electrolyte at low temperatures can be improved, and the low temperature performance of the battery can be improved.Electrode material optimization: Developing positive and negative electrode materials with high and low temperature activity, such as nanostructured materials and composite materials, can improve the reaction rate of batteries at low temperatures.Battery Management System (BMS): Advanced BMS can monitor the battery status in real time and optimize the performance of the battery at low temperatures through intelligent control strategies (such as preheating, current limiting discharge, etc.).External heating device: Equipment used in extremely cold areas is usually equipped with external heating devices, such as electric heating plates, hot air heating, etc., to ensure that the battery reaches a suitable operating temperature before starting.5. Performance in practical applicationsElectric vehicles: In cold areas, the polymer lithium-ion battery pack of electric vehicles is usually equipped with a battery preheating system to ensure that the vehicle can start and drive normally in low temperature environments.Portable devices: For portable electronic devices, polymer lithium-ion batteries perform relatively well at low temperatures, but they may still be difficult to start under extremely cold conditions.The starting performance of polymer lithium-ion battery packs in low temperature environments is affected by factors such as electrolyte conductivity, electrode material activity, and SEI film impedance. Under extremely cold conditions, the starting performance of the battery will be significantly reduced, making it difficult to achieve rapid starting. However, through technical measures such as electrolyte modification, electrode material optimization, battery management system and external heating device, the starting performance of polymer lithium-ion battery pack in low temperature environment can be effectively improved.
