TEMPERATURE CONTROL APPARATUS

A temperature-control apparatus has individual battery cells combined to form a module and arranged within a flow duct through which a temperature-control fluid flows in a main flow direction. Temperature regulation of a temperature-control apparatus is improved with a constant packing density of the battery cells despite small amounts of temperature-control fluid, with a flow guiding surface provided for each battery cell of a group. The flow guiding surface is spaced apart from a lateral section of the battery cell and has in each case an inlet section and an outlet section that are both substantially parallel to the lateral section. A diffuser section is arranged between the inlet section and the outlet section, the diffuser section-being set back with respect to the inlet section and the outlet section and with respect to the lateral section.