title: The lightest organic radical cation for charge storage in redox flow batteries.
abstract: In advanced electrical grids of the future, electrochemically rechargeable fluids of high energy density will capture the power generated from intermittent sources like solar and wind. To meet this outstanding technological demand there is a need to understand the fundamental limits and interplay of electrochemical potential, stability, and solubility in low-weight redox-active molecules. By generating a combinatorial set of 1,4-dimethoxybenzene derivatives with different arrangements of substituents, we discovered a minimalistic structure that combines exceptional long-term stability in its oxidized form and a record-breaking intrinsic capacity of 161 mAh/g. The nonaqueous redox flow battery has been demonstrated that uses this molecule as a catholyte material and operated stably for 100 charge/discharge cycles. The observed stability trends are rationalized by mechanistic considerations of the reaction pathways.
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Jinhua
authors: J
authors: Huang
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Baofei
authors: B
authors: Pan
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Energy &Environmental Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors: Wentao
authors: W
authors: Duan
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Energy &Environmental Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors: Xiaoliang
authors: X
authors: Wei
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Materials Science Division; Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Rajeev S
authors: RS
authors: Assary
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Liang
authors: L
authors: Su
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Fikile R
authors: FR
authors: Brushett
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Materials Science Division; Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Lei
authors: L
authors: Cheng
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Chen
authors: C
authors: Liao
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Magali S
authors: MS
authors: Ferrandon
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Energy &Environmental Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors: Wei
authors: W
authors: Wang
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Zhengcheng
authors: Z
authors: Zhang
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Anthony K
authors: AK
authors: Burrell
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Materials Science Division; Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Larry A
authors: LA
authors: Curtiss
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Ilya A
authors: IA
authors: Shkrob
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors: Jeffrey S
authors: JS
authors: Moore
authors: Joint Center for Energy Storage Research, Argonne National Laboratory, Argonne, IL 60439, USA.|Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors: Lu
authors: L
authors: Zhang