图3. a通过在线（蓝色）和原位（红色）实验测得的自由基分数。b 醌/铁液流电池电化学循环负极醌电解液原位伪二维在线H谱^[44]。c醌/铁液流电池电化学循环正极铁氰根电解液原位伪二维在线H谱^[45]。d-e 不同电压下的电化学原位NMR测试谱图。f 不同醌离子物种的质子标签^[46]。 g电池运行过程中的原位伪二维核磁 ¹H谱。h MB-V液流电池在10 mA cm^-2 电流密度下恒流充放电的电压和电流循环曲线。i MB的氧化态（蓝色）、自由基态（黄色）和还原态（红色）的结构式^[26]。

Fig.3. a In situ pseudo-2D 1H NMR spectra of anolyte acquired during the ferrocyanide(ii)/anthraquinone (AQ) flow battery cycling. b Experimentally determined fraction of DHAQ?3- radicals as a function of SOC determined via the on-line (blue triangles) and operando (purple squares) detection methods. c In situ pseudo-2D 1H NMR spectra of catholyte acquired during electrochemical cycling.^[44]. d and e In situ NMR spectra acquired during several potentiostatic cycling. f Proton labels of the several anthraquinone anions^[46]. g In situ pseudo-2D 1H NMR spectra of MB acquired during the MB/V flow battery cycling h Current and potential profiles MB-V full cell with a current density of 10 mA cm-2. i Molecular structures of oxidation (red), radical (yellow) and reduction (blue)^[26].