Zinc Slurry Electrodes for Double Flow Zinc-Nickel Batteries

Abstract

Lithium-based systems are still the major storage technology especially in mobile applications like electromobility and consumer electronics. However, in the field of stationary energy storage devices, redox-flow batteries exhibit significant advantages because energy and power can be scaled independently and the device can be discharged up to 20 h, in contrast to lithium-ion batteries.[1] In the field of redox-flow batteries, the main focus is placed on vanadium-based systems. However, vanadium-based systems have some drawbacks due to the low gravimetric energy densities, the toxicity [2] and the high price of vanadium [3], as well as the short life span of the membrane separating the half-cells.[4] In our research project NiZi-Flow², a new concept of flow cells based on nickel and zinc is investigated, in which slurries of zinc and nickel-hydroxide particles are pumped through the flow battery, respectively. Our part in the project is the examination of the electrodeposition and dissolution of zinc under idealized conditions to obtain the influence of flow and current density parameters on the zinc surface morphology. To study the zinc half-cell, a stirred electrochemical cell was designed and cycling experiments with the zinc slurry were performed. M. Skyllas-Kazacos, M.H. Chakrabarti, S.A. Hajimolana, F.S. Mjalli, M. Saleem, J. Electrochem. Soc. , 158 (2011) R55. A. Ciotola, M. Fuss, S. Colombo, W.-R. Poganietz, J. Energy Storage , 33 (2021) 102094. T. Nguyen, R.F. Savinell, Electrochem. Soc. Interface , 19 (2010) 54–56. A.Z. Weber, M.M. Mench, J.P. Meyers, P.N. Ross, J.T. Gostick, Q. Liu, J. Appl. Electrochem. , 41 (2011) 1137–1164.