Heat-pipe based spray-cooling thermal management system for lithium-ion battery: Experimental study and optimization

Today, performance of lithium-ion battery is still limited by its operating temperature. The upper bound is capped by 50 degrees C. However, this limit is easily surpassed if batteries work at a high room temperature. In this article, sintered copper-powder heat pipe combining with water spray at its condensation section is designed to attack this issue-The former is sandwiched among batteries, removing battery heat by air convection under normal thermal conditions. When battery operation deteriorates at a room temperature beyond 40 degrees C, water spray functions for rapid heat dissipation by droplet evaporation. To assess effectiveness of this battery thermal management (BTM) design, discharge of lithium iron phosphate batteries at two large currents, I-d = 12.5 A and 24 A, are performed at 40 degrees C. The cooling performance of the proposed BTM system is examined at different air speeds, air relative humidity, spraying frequencies and duty cycles. It is also compared to other heat-pipe based BTM approaches, and tested in transient cycles. The results demonstrate the proposed BTM system is highly effective. In the case of I-d = 24 A, the maximum temperature and maximum temperature difference of the battery surface are dropped by 29.2 degrees C and 8.0 degrees C in comparison to those without BTM aids. It well protects lithium-ion battery operating at a large discharging current in an adverse thermal environment. (C) 2020 Elsevier Ltd. All rights reserved.