Phase change composite apparatus for battery packs and methods of making

A method for making a phase change composite for a battery pack of a plurality of electrochemical cells, the method comprising:

• impregnating a sheet of a matrix material with a phase change material by soaking a sheet of the matrix material in a bath of the phase change material, wherein the sheet of matrix material comprises an expanded graphite sheet;
• fragmenting the sheet of matrix material into impregnated matrix material pieces;
• mixing the impregnated matrix material pieces with binder material particles to form a composite mix, wherein the binder material particles form 2% to 5% of the composite mix;
• placing the composite mix into a screw extruder;
• screw extruding the fragmented and impregnated matrix material within the screw extruder into a shaped composite corresponding to an extruder shape, wherein the shaped composite is a spacer having at least two battery seats on each of two opposing sides of the spacer, each of the battery seats of the spacer is an open face seat that does not fully surround a corresponding cell of the battery pack, and
• the spacer retains the extruder shape for use with the battery pack;
• coating the spacer with a polymer coating material selected from a polyurethane, an epoxy, a silicone, a rubber, and combinations thereof.