TY  - JOUR
AU  - Korshunov, Aleksandr
AU  - Milner, Matthew James
AU  - Grünebaum, Mariano
AU  - Studer, Armido
AU  - Winter, Martin
AU  - Cekic-Laskovic, Isidora
TI  - An oxo-verdazyl radical for a symmetrical nonaqueous redox flow battery
JO  - Journal of materials chemistry / A
VL  - 8
SN  - 2050-7488
CY  - London ˜[u.a.]œ
PB  - RSC
M1  - FZJ-2023-05474
SP  - 22280–22291
PY  - 2020
AB  - Verdazyl free radical compounds are promising candidates for symmetrical all-organic redox flow batteries(RFBs) due to their redox stability, the ease with which their chemical structure can be varied, and theirunique bipolar nature. The present work reports a preliminary screening of a selection of oxo-verdazylcompounds for key redox electrolyte parameters. Of the considered candidates, the 1,5-diphenyl-3-isopropyl-6-oxo-verdazyl radical performed best and is investigated in extensive RFB experiments tocompare its electrochemical behavior in cyclic voltammetry (CV) to that within an actual battery. Thesymmetrical oxo-verdazyl non-aqueous electrolyte RFB provides a mean voltage of 1.42 V anddemonstrates good stability as well as high coulombic (>97%) and energy efficiencies over more than100 charge/discharge cycles. The redox electrolyte is characterized at different stages within a singlecycle (‘state of charge’ experiments) independently for each half-cell. To address the specifics of theelectrolyte transition to RFB cell setup an ‘in-cell’ CV flow-enabled electrochemical study has beenconducted, introduced here as a new step towards standardization of the electrochemical description ofRFB electrolytes. The electrochemical performance results highlight oxo-verdazyls as versatile materialsfor energy applications and indicate great promise for their further development and optimization in thefield of RFBs.
LB  - PUB:(DE-HGF)16
UR  - https://juser.fz-juelich.de/record/1019527
ER  -