TRACTION BATTERY PACK THERMAL BARRIER

A traction battery pack assembly includes a cell stack within an interior of an enclosure. The cell stack has a plurality of battery cells disposed along a cell stack axis and at least one thermal barrier disposed along the cell stack axis. The at least one thermal barrier has a plurality of more compressible pieces secured to a plurality of less compressible pieces to establish at least one channel that is configured to communicate a liquid coolant though the cell stack.