Battery module

Battery module (1) for a propulsion battery system of an electrical vehicle, comprising

• a) a plurality of battery cells (50), arranged in a cooling volume for containing a cooling fluid for cooling the battery cells, each battery cell comprising an anode, a cathode and an electrolyte, and
• b) a plurality of wall elements (10, 20, 30, 31, 33, 40), attached to each other such as to define the cooling volume, wherein one of the wall elements is a structured wall element (30, 31, 33) which comprises
• an inner surface (110), oriented towards one of the battery cells (50), for contacting the cooling fluid, and
• an outer surface (120) forming an exterior surface of the battery module,
• characterized in that the inner surface is shaped to define a plurality of grooves (130) or a plurality of ridges (180) for increasing the contact surface between the structured wall element (30, 31, 33) and the cooling fluid, and for directing the flow of the cooling fluid in the cooling volume.