Views: 0 Author: Site Editor Publish Time: 2025-09-25 Origin: Site
Compared with air-cooled battery packs, liquid cooled battery packs have smaller temperature differences between battery cells and are increasingly being used in large-scale energy storage systems. In liquid cooled battery packs, the liquid cooled (and heated, the same below) plate usually exchanges heat with the bottom surface of the battery cell, and the lower part of the battery cell can exchange heat with the liquid cooled plate in a timely manner. However, due to the low thermal conductivity of the battery cell body, the upper part of the large battery cell cannot exchange heat with the liquid cooling plate in a timely manner, resulting in a significant temperature difference between the upper and lower parts of the battery cell. This has adverse effects on the performance, cycle life, and safety of the battery. Although multi-faceted liquid cooling technology has also been released, it is still difficult to compete with bottom liquid cooling technology in terms of cost and reliability.
Thermal graphite sheet has been widely used in 3C eletrocnics such as mobile phones. In battery modules, the large surfaces of the battery cells can be used for insulation (to prevent thermal runaway and spread), compression (to prevent excessive expansion of the battery cells), and of course, graphite sheets can also be added for heat dissipation and temperature equalization.
The graphite heat dissipation film pasted on the surface of the battery cell efficiently thickens the aluminum shell of the battery cell from the perspective of temperature equalization (the thermal diffusivity of the graphite film is about 13.5 times that of 3003 aluminum alloy), and has little effect on the energy density of the module. Given that the cost-effectiveness of artificial graphite film is constantly improving, if thicker graphite heat dissipation film is used, the improvement effect of temperature difference between the top and bottom of the battery cell can be better.
