Revisiting Zinc-Side Electrochemistry

Abstract

On the basis of a reasonable understanding of Zn/Br redox flow battery systems obtained from the previous chapter, it is possible to formulate a sound strategy to carry out in-depth studies of each Zn/Br half-cell (i.e. the zinc and bromine sides). The knowledge obtained from such investigations would in turn enable researchers to test and identify methods of individually optimizing each half-cell to achieve significantly better overall performance. This chapter presents a deeper understanding of zinc-side electrochemical processes occurring in the Zn/Br during charge/discharge cycling, collating and reviewing relevant literature pertaining to this area from the field of flow batteries and others, such as studies on industrial electroplating. The problems faced by earlier generations of Zn/Br systems due to the utilization of metallic electrodes are highlighted, followed by a description of the attractiveness and viability of employing carbon-based electrode stacks instead. Finally, a detailed look is taken at zinc-side redox mechanisms and the kinetics of related reactions, leading into methods of catalytically enhancing electrode performance.