Design and Analysis of a Hybrid Double‐End Flat Heat Pipe‐Fins Battery Thermal Management System at High‐Rate Discharge

ABSTRACT Flat heat pipe (FHP) has been paid significant attention due to its exceptional thermal conductivity in the battery thermal management system (BTMS). However, only heat pipe cooling cannot meet battery cooling requirements at high discharge rates. In this study, a hybrid double‐end FHP‐fins (HDE‐FHP‐F) BTMS is designed, and its thermal dissipation performances are investigated. Then, the influences of l 1 – l 2 ( l 1 and l 2 are, respectively, the left and right condensing length of the double‐end FHP) and the fin spacing on the FHP1 and FHP6 upon the thermal performances are, respectively, discussed. Finally, the auxiliary heating of the battery pack is carried out at low temperature. Numerical results show that the designed HDE‐FHP‐F BTMS (Design 1) has better thermal dissipation performance than the original one. The reduction of local fin number (Design 2) makes the maximum temperature ( T b,max ) and the maximum temperature difference (Δ T b,max ) of the battery pack meet the safety threshold at 8 C discharge rate (C‐rate is the measurement of the charge and discharge current with respect to its nominal capacity) and, respectively, achieve a 2.62% and 42.20% reduction. Design 4 with auxiliary heating exhibits better temperature uniformity and consistency, and its T b,min and Δ T b,max are successfully maintained within the safety threshold at low temperature. The proposed design provides valuable guidance for the battery thermal management scheme at high discharge rates.