| Autor: |
ShakeriHosseinabad F; Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada., Frost B; Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K., Said S; Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K., Xu C; Department Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4, Canada., Behnoudfar D; School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331, United States., Amini K; Harvard John A. Paulson School of Engineering and Applied Sciences, 29 Oxford Street, Cambridge, Massachusetts 02138, United States., Momodu D; Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada., Mahinpey N; Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada., Egberts P; Department Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4, Canada., Miller TS; Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K., Roberts EPL; Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada. |
| Abstrakt: |
Aqueous redox flow battery systems that use a zinc negative electrode have a relatively high energy density. However, high current densities can lead to zinc dendrite growth and electrode polarization, which limit the battery's high power density and cyclability. In this study, a perforated copper foil with a high electrical conductivity was used on the negative side, combined with an electrocatalyst on the positive electrode in a zinc iodide flow battery. A significant improvement in the energy efficiency (ca. 10% vs using graphite felt on both sides) and cycling stability at a high current density of 40 mA cm -2 was observed. A long cycling stability with a high areal capacity of 222 mA h cm -2 is obtained in this study, which is the highest reported areal capacity for zinc-iodide aqueous flow batteries operating at high current density, in comparison to previous studies. Additionally, the use of a perforated copper foil anode in combination with a novel flow mode was discovered to achieve consistent cycling at exceedingly high current densities of >100 mA cm -2 . In situ and ex situ characterization techniques, including in situ atomic force microscopy coupled with in situ optical microscopy and X-ray diffraction, are applied to clarify the relationship between zinc deposition morphology on the perforated copper foil and battery performance in two different flow field conditions. With a portion of the flow going through the perforations, a significantly more uniform and compact zinc deposition was observed compared to the case where all of the flow passed over the surface of the electrode. Results from modeling and simulation support the conclusion that the flow of a fraction of electrolyte through the electrode enhances mass transport, enabling a more compact deposit. |
