Stability of molecular radicals in organic non-aqueous redox flow batteries: A mini review

• Published in: Electrochemistry communications Vol. 91; pp. 19 - 24
• Main Authors: Armstrong, Craig G., Toghill, Kathryn E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2018
• Subjects: Molecular radicals; Non-aqueous electrolyte; Redox active organics; Redox flow batteries; Redox flow batteries; Non-aqueous electrolyte; Redox active organics; Molecular radicals
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2018.04.017

The application of novel organic redox materials is a plausible pathway towards techno-economic energy storage targets due to their low cost and sustainable design. Their operation in non-aqueous redox flow batteries affords researchers the opportunity to innovate, design and optimise these new chemistries towards practical energy densities. Despite this, the identification of high capacity organics which also display long-term stability is inherently challenging due to the high reactivity of molecular radicals. •Redox-active organic molecules are promising new energy storage materials.•The stability of molecular free radicals is concisely reviewed.•Decomposition of radical states results in irreversible battery capacity loss.•Radical half-life depends on chemical structure and electrolyte conditions.•Neutral, anionic and cationic radicals are distinct chemical species.