Molecular redox species for next-generation batteries

This Tutorial Review describes how the development of dissolved redox-active molecules is beginning to unlock the potential of three of the most promising 'next-generation' battery technologies - lithium-air, lithium-sulfur and redox-flow batteries. Redox-active molecules act as mediators in lithium-air and lithium-sulfur batteries, shuttling charge between electrodes and substrate systems and improving cell performance. In contrast, they act as the charge-storing components in flow batteries. However, in each case the performance of the molecular species is strongly linked to their solubility, electrochemical and chemical stability, and redox potentials. Herein we describe key examples of the use of redox-active molecules in each of these battery technologies and discuss the challenges and opportunities presented by the development and use of redox-active molecules in these applications. We conclude by issuing a call to arms to our colleagues within the wider chemical community, whose synthetic, computational, and analytical skills can potentially make invaluable contributions to the development of next-generation batteries and help to unlock of world of potential energy-storage applications.

Automated summary

This Tutorial Review highlights the importance of redox-active molecules in unlocking the potential of lithium-air, lithium-sulfur, and redox-flow batteries. The role of these molecules varies depending on the type of battery, but their solubility, electrochemical and chemical stability, and redox potentials are crucial factors influencing their performance. Collaborations within the chemical community are essential for the development and utilization of redox-active molecules in next-generation batteries.