SEPARATOR STRUCTURES FOR MITIGATING THE TRANSFER OF THERMAL ENERGY INSIDE TRACTION BATTERY PACKS

Battery systems are provided for traction battery packs. An exemplary battery system may include a first cell stack, a second cell stack, and a separator arranged between the first and second cell stacks. The separator may be configured to mitigate the transfer of thermal energy from cell stack-to-cell stack, structurally integrate the battery system to perimeter structures, inhibit cell displacement due to external forces, resist cell expansion forces, etc.