An exemplary battery thermal management assembly includes a first structure having a first material composition, and a second structure having a different, second material composition. The second structure is configured to exchange thermal energy between a battery array and a fluid communicated through a fluid channel that is bounded by the first and second structures. An exemplary battery thermal management method includes securing a first structure of a first material composition relative to a second structure of a different, second material composition to provide a fluid channel. The method further includes using the second structure to pass thermal energy between a battery and a fluid within the fluid channel.