Chem. J. Chinese Universities ›› 2020, Vol. 41 ›› Issue (5): 1035.doi: 10.7503/cjcu20190722

• Physical Chemistry • Previous Articles     Next Articles

Two-Electron Storage Viologen for Aqueous Organic Redox Flow Batteries

HAN Juntian,CUI Yaoxing,SU Zhijun,WU Yi,CHEN Liuping(),XU Junhui()   

  1. Jiangsu Engineering Research Center for Comprehensive Utilization of Well and Rock Salt,China Salt Jintan Co., Ltd., Jintan 213200, China
  • Received:2019-12-31 Online:2020-05-10 Published:2020-02-21
  • Contact: Liuping CHEN,Junhui XU E-mail:jsb@chinasalt-jt.com;jhxu@chinasalt-jt.com

Abstract:

A two-electron storage, 1,1'-bis(2,3-dihydroxypropyl)-(4,4'-bipyridine)-1,1'-diium chloride(DHPV2+Cl2-), was synthesized by simply one-step reaction of 3-chloro-1,2-propanediol with 4,4'-bipyridine. The theoretical specific capacity of the viologen anolyte is up to 142.56 mA·h/g in NaCl solution(1.5 mol/L) and the reduction potential is as low as -0.807 V(vs. Ag/AgCl). In full battery testing, with the two-electron storage viologen as anolyte, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl(4-OH-TEMPO) as catholyte in NaCl supporting electrolyte, the full battery voltage is up to 1.562 V. At the same time, the charge and discharge curves exhibit two-electron storage characteristics of DHPV2+Cl2-. Furthermore, the full battery performance showed that the battery could operate stably at the current density from 10 mA/cm2 to 100 mA/cm2. The effective utilization rate of the active material is 70.90% at the current density of 25 mA/cm2. After 100 cycles, the capacity retention rate of the battery and the capacity average retention rate per cycle are 98.09% and 99.93%, respectively. The DHPV2+Cl2-/4-OH-TEMPO AORFB showed attractive cycle performance. These AORFB materials are built from earth-abundant elements and are environmentally friendly, thus representing a promising choice for safe and sustainable energy storage.

Key words: Aqueous organic flow battery(AORFB), Viologen, Electrochemistry

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