Redox-Targeting-Based Flow Batteries for Large-Scale Energy Storage

Redox-targeting reactions of battery materials by redox molecules are extensively studied for energy storage since the first report in 2006. Implementation of the "redox-targeting" concept in redox flow batteries presents not only an innovative idea of battery design that considerably boosts the energy density of flow-battery system, but also an intriguing research platform applied to a wide variety of chemistries for different applications. Here, a critical overview of the recent progress in redox-targeting-based flow batteries is presented and the development of the technology in the various aspects from mechanistic understanding of the reaction kinetics to system optimization is highlighted. The limitations presently lying ahead for the widespread applications of "redox targeting" are also identified and recommendations for addressing the constraints are given. The adequate development of the redox-targeting concept should provide a credible solution for advanced large-scale energy storage in the near future.