Manufacture of a thermoplastic heat exchanger

1 . A method for manufacturing a thermoplastic heat exchanger for a battery module, the method comprising:

extruding a battery interface portion having a battery interface surface and a chamber surface opposite the battery interface surface, the battery interface portion comprising a first thermoplastic composition;

injection molding a base portion having a channeled surface defining a plurality of channels and an outer surface opposite the channeled surface, the base portion comprising a second thermoplastic composition; and

melt-bonding the battery interface portion and the base portion such that the chamber surface cooperates with the plurality of channels of the channeled surface to define a flow chamber for a thermal cooling fluid within the thermoplastic heat exchanger;

wherein the step of melt-bonding the battery interface portion and the base portion comprises the steps of:

contacting a first bonding portion of the chamber surface with a laser beam;

contacting a second bonding portion of the channeled surface with another laser beam; and

subsequently contacting the chamber surface and the channeled surface to weld the battery interface portion and the base portion and form the thermoplastic heat exchanger.

2 . The method of claim 1 wherein the step of contacting the chamber surface and the channeled surface to weld the battery interface portion and the base portion is conducted robotically.

3 . The method of claim 1 wherein the step of melt-bonding the battery interface portion and the base portion comprises:

contacting the battery interface portion and the base portion to form an interface between the chamber surface and the channeled surface; and

contacting the battery interface surface or the outer surface with the laser beam such that the laser beam travels through the battery interface portion or the base portion, respectively, to melt the first and/or the second thermoplastic compositions at the interface and weld the battery interface portion and the base portion together to form the thermoplastic heat exchanger.

4 . The method of claim 3 wherein one of the first and/or the second thermoplastic composition is transparent to the laser beam having a particular wavelength and one of the first and/or the second thermoplastic composition is absorbed by the laser beam having a particular wavelength such that energy from the laser beam is concentrated at the interface allowing both the first and the second thermoplastic compositions to be melted at the interface.

5 . The method of claim 4 wherein the first thermoplastic composition has a greater transparency to laser wavelengths in the infrared and near-infrared spectrum than the second thermoplastic composition.

6 . The method of claim 1 wherein the first and the second thermoplastic composition are the same or different and comprise a polymer selected from polyamide, polycarbonate, and polypropylene.

7 . The method of claim 1 wherein the first and/or the second thermoplastic composition comprises a polyamide selected from polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 6,6, polyamide 6,10, polyamide 6,12, and polyamide PPA.

8 . The method of claim 7 wherein the first and/or the second thermoplastic composition comprises a fibrous filler selected from aramid fibers, carbon fibers, cellulose fibers, acrylic fibers, polyvinyl alcohol fibers, glass fibers, and mineral fibers.

9 . The method of claim 1 wherein the first thermoplastic composition has a greater thermal conductivity than the second thermoplastic composition.

10 . The method of claim 1 wherein:

the battery interface portion has a thickness of from 0.5 to 5 mm; and

the base portion has a thickness of from 2.5 to 10 mm exclusive of the plurality of channels.

11 . The method of claim 1 wherein the flow chamber has a cross sectional area of from 10 to 900 mm 2 .

12 . The method of claim 1 further comprising the step of injection molding an inlet port and an outlet port each having a body and defining a flow channel into the base portion.

13 . The method of claim 1 further comprising the step of injection molding an inlet port comprising a third thermoplastic composition and an outlet port comprising a fourth thermoplastic composition.

14 . The method of claim 13 further comprising the steps of:

drilling and/or molding a first and a second opening into the battery interface portion and/or the base portion, the first and a second opening in fluid communication with the flow chamber;

rotationally contacting the inlet port about a perimeter of the first opening to generate friction sufficient to melt a portion of the third thermoplastic composition;

cooling the melted portion of the third thermoplastic composition to weld the inlet port to the thermoplastic heat exchanger;

rotationally contacting the outlet port about a perimeter of the second opening to generate friction sufficient to melt a portion of the fourth thermoplastic composition; and

cooling the melted portion of the fourth thermoplastic composition to weld the outlet port to the thermoplastic heat exchanger.