Problems in thermal management of power battery for new energy vehicles
Although the thermal management of power batteries for new energy vehicles has achieved certain development, there are also some urgent problems to be solved, such as imperfect thermal management design of single cells, the need to optimize the heat dissipation structure of the battery system, and the low intelligence level of the control strategy of the thermal management system. To this end, it is necessary to optimize the thermal design of the battery, the system heat dissipation structure and control strategy to achieve more efficient thermal management and ensure that the battery operates within the optimal temperature range.
1. Imperfect thermal management design of single cells
The design of the thermal management system of power batteries for new energy vehicles is crucial, but there are still some problems, especially in the thermal management of single cells.
First, there is a problem of insufficient temperature uniformity in the thermal management design of single cells. Since the battery pack is composed of a number of single cells, these single cells will generate heat during the charging and discharging process. If the heat cannot be dispersed in time and evenly, it will cause the local temperature of the battery to rise and form hot spots. This hot spot effect will not only affect the working efficiency of the battery, but may also accelerate battery aging and even cause safety hazards. At the same time, the complexity of the internal structure of the battery and the change in the gap between the single cells will cause uneven heat distribution. It is difficult for the current thermal management design to completely solve this problem, especially under high load or extreme environments.
Second, the matching problem of thermal response speed and thermal capacity of single cells is also a major challenge in thermal management design. An ideal thermal management system for power batteries of new energy vehicles should be able to respond quickly to changes in the heat generated by the battery and have sufficient thermal capacity to absorb or release thermal energy to ensure the stability of the battery temperature. However, when the power battery works in an environment with rapid charging and discharging, high-rate discharge or large temperature fluctuations, the thermal management system is often difficult to respond quickly and manage effectively. Especially when the battery design pursues high energy density, the thermal response performance and thermal capacity configuration of the thermal management system are particularly important, but it is difficult for existing designs to find a perfect balance between lightweight and high efficiency. This may affect the cycle life and safety performance of the power battery.
2. The heat dissipation structure of the battery system needs to be optimized
There is a problem in the thermal management of power batteries of new energy vehicles that the heat dissipation structure of the battery system needs to be optimized. At present, the heat dissipation structure of the power battery system has challenges in dealing with high temperature environments and rapid charging and discharging. It is easily damaged in high temperature environments, and excessive temperature will accelerate the aging of the battery and reduce its performance. At the same time, rapid charging and discharging will generate a lot of heat, and traditional heat dissipation systems often cannot effectively dissipate heat in this case, resulting in excessively fast temperature rise of the battery. In addition, the heat dissipation structure of the battery system is insufficient in terms of the heat dissipation effect and heat dissipation uniformity of large-capacity battery packs. With the development of new energy vehicles, the battery capacity continues to increase, and the heat dissipation problem of large-capacity battery packs has become more and more prominent. The traditional heat dissipation structure often cannot fully cover the entire battery pack, resulting in excessively high temperatures in some areas and too low temperatures in other areas, resulting in uneven heat dissipation. This uneven heat dissipation will cause the temperature difference of the single cells inside the battery pack to be too large, affecting the battery's charging and discharging performance and service life.
3. The control strategy of the thermal management system is low in intelligence
First, the control strategy has certain limitations. At present, the thermal management system of the power battery of new energy vehicles mainly adopts the traditional temperature threshold control strategy, that is, triggering heat dissipation or cooling measures by setting static upper and lower temperature limits. However, this static control strategy cannot fully adapt to the battery thermal management requirements under different working conditions and environmental conditions. For example, in a high temperature environment, the traditional temperature threshold control strategy may be too conservative, resulting in frequent triggering of heat dissipation measures, affecting the energy utilization efficiency of the battery. In a low temperature environment, the traditional control strategy may not be able to start the heating measures in time, affecting the performance and service life of the battery.
Second, the degree of intelligence in data processing and decision making is limited. Although some power battery thermal management systems use sensors and control units for data monitoring and adjustment, there are still limitations in data processing and decision-making. For example, in thermal management systems, for complex battery thermal characteristics and environmental conditions, such as battery internal temperature distribution, charging rate, ambient temperature, etc., the data processing capabilities of existing systems are limited, and it is impossible to fully mine and utilize these data to optimize thermal management strategies. In addition, the decision-making capabilities of existing thermal management systems are relatively limited, and they cannot be comprehensively optimized based on multiple parameters and conditions, resulting in limited accuracy and adaptability of control strategies.
