Thermal management of battery systems

A battery system comprising:

• a plurality of battery cells including a first battery cell and a second battery cell, each battery cell comprising a casing enclosing an anode and a cathode;
• a first fluid circulation system comprising a plurality of fluid conduits including a first fluid conduit that is adjacent to the first battery cell and a second fluid conduit that is adjacent to the second battery cell, wherein the first fluid circulation system is configured to circulate a first fluid through the battery system in a first direction;
• and
• a second fluid circulation system comprising a plurality of fluid conduits including a first fluid conduit that is adjacent to the first fluid conduit of the first fluid circulation and is interposed between the first fluid conduit of the first fluid circulation system and the second fluid conduit of the first fluid circulation system, wherein the second fluid circulation system is configured to circulate a second fluid through the battery system in a second direction that is opposite the first direction.