Tubular cell designs offer several potential advantages over planar cell designs and might lead to a reduction of manufacturing costs, shunt current losses, sealing length, while allowing for a greater flexibility in system design. A reduction of power specific costs might be achieved by an in-line production of entire tubular cells with an extrusion-based fabrication process. By replacing the positive VFB half-cell (V4+/5+) with a bifunctional gas diffusion electrode (GDE) a vanadium/air flow battery (VAFB) with an increased energy density and reduced energy specific costs shall be created.