Challenges and recent progress in thermal management with heat pipes for lithium-ion power batteries in electric vehicles

Electric vehicles (EVs) are globally undergoing rapid developments, and have great potentials to replace the traditional vehicles based on fossil fuels. Power-type lithium-ion batteries (LIBs) have been widely used for EVs, owing to high power densities, good charge/discharge stability, and long cycle life. The driving ranges and acceleration performances are gaining increasing concerns from customers, which depend highly on the power level of LIBs. With the increase in power outputs, rising heat generation significantly affects the battery performances, and in particular operation safety. Meanwhile, the cold-start performance is still an intractable problem under extreme conditions. These challenges put forward higher requirements for a dedicated battery thermal management system (BTMS). Compared to traditional BTMSs in EVs, the heat pipe-based BTMS has great application prospects owing to its compact structure, flexibility, low cost, and especially high thermal conductivity. Encompassing this topic, this review first introduces heat generation phenomena and temperature characteristics of LIBs. Multiple abuse conditions and thermal runaway issues are described afterward. Typical cooling and preheating methods for designing a BTMS are also discussed. More emphasis on this review is put on the use of various heat pipes for BTMSs to enhance the thermal performances of LIBs. For lack of wide application in actual EVs, more efforts should be made to extend the use of heat pipes for constructing an energy-efficient, cost-effective, and reliable BTMS to improve the performances and safety of EVs.