PRESSURE AND FLOW RELIEF STRATEGIES FOR TRACTION BATTERY THERMAL MANAGEMENT COOLANT CIRCUITS

Thermal management systems are provided for managing the thermal energy levels of a traction battery pack of an electrified vehicle. An exemplary thermal management system may include a coolant circuit for circulating a coolant through the traction battery pack. A pressure relief valve may be arranged to control a flow of a fluid through an auxiliary fluid path of the coolant circuit. For example, the pressure relief valve may control the flow of a vent byproduct released by a battery cell of the traction battery pack into the auxiliary fluid path during a battery thermal event of the traction battery pack. The vent byproduct may then be directed from the auxiliary fluid path to either atmosphere or a coolant reservoir. The system may additionally include a gas separator. The gas separator may remove entrained gases (air, vent byproducts, etc.) from the coolant during both normal operating conditions and during battery thermal events. The removed gases can be expelled to atmosphere from within the coolant reservoir.