Lithium-ion batteries face increased thermal dissipation challenges during fast charging. Battery thermal management system based on immersion cooling is a novel and promising solution with excellent thermal performance. In this study, an experimental investigation is performed to assess the battery thermal management performance of immersion cooling, utilizing electronic fluoride liquid as the immersion fluid. A battery simulator is designed to replicate the heat generation of a 40 Ah NCM prismatic lithium-ion battery, thereby mitigating technical risks. The results demonstrate that electronic fluoride liquid cooling, equipped with a refrigeration cycle, operates effectively and exhibits excellent thermal control performance. The battery heat is still well dispersed even with heating power as high as 183.75 W. At a charging/discharging rate of 5C/1C, the maximum average temperature is 36.28 ℃ at the end of charging, and the minimum is 21.94 ℃ at the end of discharging, well below the upper limit of 65 ℃. Correspondingly, the maximum and minimum temperature difference is 20.26 ℃ and 1.81 ℃, respectively. Furthermore, the effect of fluid temperature (15, 20, and 25 ℃) and flow rate (0.5, 1, and 1.5 L min-1) is investigated. It is found that increasing the liquid flow rate reduces both the average temperature and temperature difference. In contrast, lower fluid temperature decreases the battery's average temperature but increases the temperature difference.