A prismatic-cell battery pack is provided with integral coolant passages including an intake plenum, an exhaust plenum, and a distributed array of coolant channels coupled between the intake plenum and the exhaust plenum. Coolant medium forced into the intake plenum enters the coolant channels in parallel, draws heat away from the battery cells, and then enters the exhaust plenum for expulsion into the atmosphere. The battery pack is configured as a set of stackable interlocking battery cell modules including at least one battery cell in thermal proximity to an array of coolant channels distributed over the profile of the battery cell, and a pair of peripheral chambers joined to opposite ends of the coolant channels to form the intake and exhaust plenums when the modules are arranged and interlocked in a lineal stack.