Abstract: A battery module for use in an electric vehicle includes a housing and a member provided within the housing that contains a plurality of electrochemical cells. The member includes apertures in an outer surface of the member that allow a thermal management fluid to exit the member after passing adjacent outer surfaces of the plurality of the electrochemical cells within the member. The apertures include apertures of a first size near a first end of the member and apertures of a second size larger than the first size near a second opposite end of the member.