Thermal management of an electrochemical cell by a combination of heat transfer fluid and phase change material

The invention is directed at devices systems and processes for managing the temperature of an electrochemical cali including a device (10) comprising an inlet for receiving a heat transfer fluid; one or more electrochemical cell compartments (12) for receiving one or more electrochemical calls (20); one or more thermal energy storage material compartments (14) containing one or more thermal energy storage materials (18); and one or more heat transfer fluid compartments (16) for flowing the heat transfer fluid through the device; wherein the space between the one or more heat transfer fluid compartments (16) and the one or more electrochemical cell compartments (12) preferably includes one or more first regions (22) (i.e. portion) that are substantially free of the thermal energy storage materia! (18): and the space between the one or more heat transfer fluid compartments (18) and the one or more thermal energy storage material compartments (14) preferably includes one or more second regions (24) (i.e. portion) that are substantially free of an electrochemical ceil (20); so that the heat transfer fluid compartment (16) is in direct thermal communication with both the thermal energy storage material compartment (14) and the electrochemical cell compartment (12).