Battery thermal management (BTM) is essential to ensure the safety of the battery pack of electric vehicles. For a variety of BTM technologies, the battery's internal resistance always plays a critical role in the he. Lithium-ion battery (LIB), with the features of high specific energy, high power, long life-cycle, low s. 2.1. Experiment platformThe experimental platform (Fig. 1) consists of an environment chamber for environment control, batteries, an electronic load (ITECH IT8511), a charge. 3.1. The construction of MF-DIRMThe internal resistance R of battery discharge is affected by temperature T, SOC and discharge rate C. The function relation of interna. 4.1. Effect of the temperature and SOC on internal resistanceWhen the discharge rate is 0.25C and the temperature varies from 5 °C to 45 °C, the change curves o. In this study, the synergistic effect of three factors (temperature, SOC and discharge rate C) on the battery's internal resistance was explored and an innovative method MF-DIRM was co.