A redox-flow battery with an alloxazine-based organic electrolyte

作者：Lin, Kaixiang; Gomez-Bombarelli, Rafael; Beh, Eugene S.; Tong, Liuchuan; Chen, Qing; Valle, Alvaro; Aspuru-Guzik, Alan; Aziz, Michael J.^*; Gordon, Roy G.^*

来源：Nature Energy, 2016, 1(9): 16102.

DOI：10.1038/NENERGY.2016.102

Redox-flow batteries (RFBs) can store large amounts of electrical energy from variable sources, such as solar and wind. Recently, redox-active organic molecules in aqueous RFBs have drawn substantial attention due to their rapid kinetics and low membrane crossover rates. Drawing inspiration from nature, here we report a high-performance aqueous RFB utilizing an organic redox compound, alloxazine, which is a tautomer of the isoalloxazine backbone of vitamin B-2. It can be synthesized in high yield at room temperature by single-step coupling of inexpensive o-phenylenediamine derivatives and alloxan. The highly alkaline-soluble alloxazine 7/8-carboxylic acid produces a RFB exhibiting open-circuit voltage approaching 1.2V and current effciency and capacity retention exceeding 99.7% and 99.98% per cycle, respectively. Theoretical studies indicate that structural modification of alloxazine with electron-donating groups should allow further increases in battery voltage. As an aza-aromatic molecule that undergoes reversible redox cycling in aqueous electrolyte, alloxazine represents a class of radical-free redox-active organics for use in large-scale energy storage.

• 出版日期2016-7-18