Electrochimica Acta, Vol.191, 695-704, 2016
Broad temperature adaptability of vanadium redox flow battery-Part 2: Cell research
The operating temperature of vanadium redox flow battery (VRFB) will change with seasons and places. Hence, the broad temperature adaptability of VRFB is one of the key issues which affect its large-scale practical application. In our previous work, we have reported the impact of temperature (-35 degrees C-50 degrees C) on the static stability, physicochemical and electrochemical properties of five typical vanadium electrolytes (Electrochim. Acta, 2016, 187, 525). As a follow-up study, VRFB single cells are evaluated in this paper at a broad temperature range under current density of 40-200 mA cm (2). The results show that VRFB can operate from 20 degrees C to 50 degrees C with acceptable energy efficiency under appropriate current densities (e.g. 65%-78% at 100 mA cm (2)). Ohmic and polarization resistances of VRFB decrease with temperature while the voltage efficiency and electrolyte utilization present the opposite tendency. The fast crossover of the vanadium ions at high temperatures aggravates the capacity fading of the cell. Notably, VRFB suffers much more damage during alternate temperatures operation between moderate temperature and high temperature, which should be given special attention. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:Vanadium redox flow battery;Temperature adaptability;Efficiency;Cycling stability;Capacity fading