Experimental investigation on thermal performance of a battery liquid cooling structure coupled with heat pipe

Thermal management is critical in electric vehicles to maintain cell longevity and guarantee auto safety. A battery liquid cooling structure composed of cold plate and heat pipe is proposed under the premise that the heat pipe does not immersed in coolant directly. The effects of different evaporation part and condensation part length of the proposed HP-CP structure is studied. Influence factors such as flow rate of coolant water, ambient and inlet coolant water temperature, and battery discharging rate are investigated experimentally in detail. The results show that the coolant water flow needs to be selected comprehensively considering temperature rising and uniformity. Battery cooling system needs to pay attention to different indicators under diverse ambient and inlet water temperature. The HP-CP structure has the potential for battery cooling in fast charging rate. Finally, thermal performance of the battery operated under three discharging-charging cycles is investigated. Temperature rising and uniformity reach equilibrium state after the second cycle, so the HP-CP structure can meet cooling needs of battery continuous working. The weight of heat pipe-cooper plate structure used in experiments is only 253 g, accounting for a very small part of the whole cooling system. The proposed HP-CP structure provides a new idea and a feasible method for application of heat pipe coupling cold plate in battery thermal management.