Performance of a vanadium redox flow battery with tubular cell design

We present a vanadium redox flow battery with a tubular cell design which shall lead to a reduction of cell manufacturing costs and the realization of cell stacks with reduced shunt current losses. Charge/discharge cycling and polarization curve measurements are performed to characterize the single test cell performance. A maximum current density of 70 mAcm(-2) and power density of 142 Wl(-1) (per cell volume) is achieved and Ohmic overpotential is identified as the dominant portion of the total cell over potential. Cycling displays Coulomb efficiencies of approximate to 95% and energy efficiencies of approximate to 55%. During 113 h of operation a stable Ohmic cell resistance is observed. (C) 2017 Elsevier B.V. All rights reserved.