Thermal performance analysis of L-shaped ultra-thin vapor chamber for lithium battery thermal management considering tilt angle and vibration

Ultra-thin vapor chamber utilizing phase change technology have shown promise in improving the temperature uniformity of battery packs. This study developed a new type of bent ultra-thin vapor chamber and experimentally investigated its performance under various operating conditions such as different tilts, vibrations, and different water temperatures. A battery thermal management system was also constructed to analyze its performance in a pack configuration. The results indicate that thermal resistance gradually increases as the tilt angle increases from 0 to 45 degrees and gradually decreases as the angle increases from 45 to 90 degrees, with 45 degrees being the angle of maximum thermal resistance. Under vibration conditions, thermal resistance decreases when the tilt angle is between 0 and 30 degrees and increases when the angle is between 45 and 90 degrees. Regardless of vibration, the thermal resistance is the greatest at a tilt of 45 degrees. Additionally, when the coolant temperature is 10 degrees and 25 degrees, the temperature can be maintained below 40 degrees even at a 3C discharge rate. After forming a battery pack, regardless of how the coolant temperature varies between 10 degrees C and 40 degrees C, the temperature difference within the battery pack can be controlled within 5 degrees C.