The impact of bulk electrolysis cycling conditions on the perceived stability of redox active materials

Abstract

© 2019 The Authors Emerging grid storage needs are motivating the discovery and development of new, potentially inexpensive redox couples for use in flow batteries. Long-term stability in electrochemical environments remains a key challenge and charge/discharge cycling in a bulk electrolysis cell is a common initial approach. However, as cycling protocols are not yet standardized, comparison between different materials is difficult. Here, using a well-studied, substituted dialkoxybenzene as a model compound, we examine the impact of cycling conditions on perceived stability. Specifically, we show that cycle time is a better measure of stability than cycle number and, for materials that are unstable in their charged state, the fractional capacity accessed is inversely related to cycle time until failure.