Experimental investigation of thermal performance of large-sized battery module using hybrid PCM and bottom liquid cooling configuration

Highlights: • Hybrid PCM and bottom liquid cooling of large battery module were experimentally studied. • Hybrid cooling significantly reduces maximum temperature and temperature nonuniformity. • Battery temperature levels off after melting point C in hybrid cooling instead of ramp-up for PCM cooling. • Hybrid cooling maintains T_bmax below 50 °C and ΔT_b below 3.5 °C in cyclic discharge rate over 5C. • Non-uniformity temperature factor is lower in comparison with others' work. -- Abstract: A hybrid thermal management system (TMS) using phase change material (PCM) and bottom liquid cooling techniques for a large-sized power battery module was experimentally investigated. The system consisted of 106 test batteries in 18650 format, connected with a heat spreading plate, adjacent thermal columns and a cold plate populated with mini-channels installed beneath the module for liquid cooling to form the interconnected thermal structure. The experiment was conducted by heating the test batteries and monitoring representative battery temperatures. Three different heat dissipation options were studied with the same test bench, including the PCM cooling, liquid cooling and the hybrid cooling. Comparing with the liquid cooling, the hybrid cooling reduced the maximum battery temperature and temperature difference at steady-state. A temperature nonuniformity factor is introduced to evaluate the temperature difference across the module of different sizes. In addition, the test with the hybrid cooling for battery module under the cyclic working conditions exhibited sustaining temperature control, which is favorable for the battery module in continuous operation.