title: Towards high-energy-density pseudocapacitive flowable electrodes by the incorporation of hydroquinone.
abstract: This study reports an investigation of hydroquinone (HQ) as a multielectron organic redox molecule to enhance the performance of flowable electrodes. Two different methods to produce high-performance pseudocapacitive flowable electrodes were investigated for electrochemical flow capacitors. First, HQ molecules were deposited on carbon spheres (CSs) by a self-assembly approach using various HQ loadings. In the second approach, HQ was used as a redox-mediating agent in the electrolyte. Flowable electrodes composed of HQ showed a capacitance of 342 F g(-1), which is >200 % higher than that of flowable electrodes based on nontreated CSs (160 F g(-1)), and outperformed (in gravimetric performance) many reported film electrodes. A similar trend in capacitance was observed if HQ was used as a redox agent in the electrolyte; however, its poor cycle life restricted further consideration. In addition, a twofold increase in capacitance was observed under flow conditions compared to that of previous studies.
authors: A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (USA).
authors: M
authors: M
authors: Boota
authors: K B
authors: KB
authors: Hatzell
authors: E C
authors: EC
authors: Kumbur
authors: Y
authors: Y
authors: Gogotsi
mesh_terms: D025802:Electric Capacitance; D004563:Electrochemistry; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006873:Hydroquinones / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: D004573:Electrolytes; D006873:Hydroquinones; C031927:hydroquinone
keywords: carbon; electrochemistry; energy transfer; redox chemistry; surface analysis