Battery-cell tab direct cooling using a multi-material cooling module

A battery module comprising:

• a battery pack including a plurality of battery pouches;
• a plurality of battery cell tabs, each of the battery pouches including a respective battery cell tab extending from an end thereof, the plurality of battery cell tabs defining a common plane;
• and a cooling module configured to directly cool the plurality of battery cell tabs, the cooling module including:
• an isolation sheet being generally prismatic with a first planar surface opposite a second planar surface, the first planar surface contacting the plurality of battery cell tabs along the common plane;
• and a heat exchanger configured to promote turbulent mixing of a cooling fluid and having a longitudinal axis and first and second opposing walls arranged along the longitudinal axis, the heat exchanger including:
• a cooling fluid inlet nozzle and a cooling fluid outlet nozzle disposed perpendicular to the longitudinal axis;
• a metallic portion defining an open cavity, the metallic portion having surface imperfections and including an outer planar surface engaging the second planar surface, and a lightweight portion having a first edge and a second edge spaced opposite from the first edge, wherein the lightweight portion is joined to the metallic portion to define a unitary flow assembly, the lightweight portion being formed from a thermally conductive plastic material selected from the group consisting of a polyamide, a polycarbonate, and a polyphenylene sulfide, the lightweight portion including a plurality of baffles extending therefrom, the plurality of baffles being integrally formed with the lightweight portion, the plurality of baffles spaced apart from each other across the longitudinal axis and engaging an interior surface of the metallic portion to thereby define a serpentine path for the cooling fluid;
• wherein a first of the plurality of baffles abuts the first wall of the heat exchanger and extends laterally toward, but does not contact, the second wall of the heat exchanger opposite the first wall, while at least one of the plurality of baffles adjacent to the first baffle abuts the second wall and extends laterally toward, but does not contact, the first wall;
• wherein the metallic portion and the lightweight portion are directly bonded together at a lap joint in which the thermally conductive plastic material is disposed within the surface imperfections such that the heat exchanger is unitary and the lap joint is free from melted metal;
• wherein the heat exchanger is free from an adhesive disposed between the metallic portion and the lightweight portion;
• wherein respective ends of two or more of the plurality of baffles adjacent to the cooling fluid outlet nozzle are non-abutting such that a first mean residence time of the cooling fluid in the heat exchanger near the cooling fluid outlet nozzle is greater than a second mean residence time of the cooling fluid in the heat exchanger through the serpentine path;
• and respective ends of remaining ones of the plurality of baffles that are not adjacent to the cooling fluid outlet nozzle abut at least one of the first edge and the second edge of the lightweight portion such that the first mean residence time is greater than the second mean residence time.