IMPROVEMENT OF COOLING PERFORMANCE AND MITIGATION OF FIRE PROPAGATION IN LITHIUM-ION BATTERIES USING A NOVEL GAS-COOLED THERMAL MANAGEMENT SYSTEM

Abstract

Development of battery thermal management systems has become significant because an inappropriate operating temperature is the primary cause of battery deterioration, fires, and explosions. The current work proposes a revolutionary battery thermal management system that uses an inert gas instead of air as a coolant to increase cooling performance and avoid battery thermal runaway and fire propagation. The thermal behavior of 18650 cylindrical lithium-ion battery modules was assessed using a test station. The cooling performance of this battery thermal management system was investigated using Ansys Fluent, while the fire dynamics simulator assessed fire propagation when the battery was surrounded by various inert gas coolants. Inert gases can be more effective coolants than air. They were successful in lowering the maximum temperature and enhancing the convective heat transfer coefficient. Increased turbulent flow contributed in enhancement of heat transfer, as assessed by the Nusselt number. Although all gas coolants in this investigation effectively kept the cell temperature below 60°C, which is the starting temperature of thermal runaway, a high Reynolds number was necessary. Otherwise, helium is the best coolant for transferring heat from a battery, even at extremely low Reynolds numbers. When the battery was surrounded by inert gas, fire propagation in the battery can be minimized. Use of an air-cooling system can initiate fires and explosions when battery thermal runaway occurs.