First principles design of anthraquinone derivatives in redox flow batteries

The redox flow battery (RFB), which is famous for its low cost and durability, could improve the utilization of renewable energy. We employed density functional calculations to calculate the intrinsic solubility of 9,10-anthraquinone derivatives and found that -OH groups could theoretically improve the solubility to exceed 5 mol L^-1. Moreover, the reduction potential was calculated for 9,10-anthraquinone derivatives with -OH substitutions at different positions. 1,8-dihydroxyanthraquinone was found to exhibit excellent electrochemical activity, as validated by electrochemical measurements. The diffusion coefficient and kinetic rate constant were faster than those of conventional materials. This is a comparatively integral work that uses first principles calculations to efficiently determine the organic redox flow of battery materials.