Scalable Design of Zinc-Bromine Flow Battery in 3-Dimensional Honeycomb Lattice for Superior Low-Cost Battery

Abstract

Most of the existing redox flow batteries have adopted 1-dimensionally stacked cells in which electrodes, flow frames, gaskets, and membranes are repeatedly stacked in one direction. However, these stacked cells suffer from system complexity, high cost, and insufficient cell performance. Herein, we suggest an attractive cell configuration with a 3-dimensional ceramic framework by adopting an industrially available cordierite honeycomb structure. We have successfully demonstrated a zinc bromine flow battery (ZBFB) with this 3-dimensional framework. Because the porous ceramic structure shows multi-functional characteristics as membranes and flow channels as well as the cell housing, it does not require expensive membranes or flow frames, thus significantly reducing the stack manufacturing cost by about 64.5%. Furthermore, it shows superior behavior in terms of cell performance such as rate characteristics (> 97% coulombic and > 63% energy efficiencies at 60 mA/cm2), practical energy density (52 Wh/L), and cyclability over 500 cycles, compared to previous studies on ZBFBs. By connecting more channels in serial or parallel mode, flexible scale-up was feasibly demonstrated without any performance degradation.

Keywords: Zinc bromine, Flow battery, Ceramic, Honeycomb, Cell configuration