TY - JOUR

T1 - Planar carbenium ions for robust symmetrical all organic redox flow batteries

AU - Moutet, Jules

AU - Nowack, Marko H.

AU - Mills, David D.

AU - Lozier, Diego L.

AU - Laursen, Bo W.

AU - Gianetti, Thomas L.

N1 - Funding Information: We are grateful to the University of Arizona, Salt River Project (Phoenix, AZ), Research Corporation for Science Advancement Cottrell Scholarship 2021 (Award #27536) and by Novo Nordic Foundation award number NNF20OC0062176 for financially supporting this work. All NMR data were collected in the NMR facility of the Department of Chemistry and Biochemistry at the University of Arizona, RRID:SCR_012716. The purchase of the Bruker NEO 500 MHz spectrometer was supported by the National Science Foundation under Grant Number 1920234 and the University of Arizona. All SEM images and data were collected in the W.M. Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona, RRID:SCR_022884, with funding from the W.M. Keck Foundation Grant. Publisher Copyright: © 2023 The Royal Society of Chemistry.

PY - 2023

Y1 - 2023

N2 - Grid-scale energy storage can benefit from the potential of non-aqueous full organic redox flow batteries (NAORFBs). However, the majority of current NAORFBs rely on the utilization of distinct anolytes and catholytes, separated by a membrane or porous separator. Unfortunately, this setup can lead to crossover of redox active material from one side of the battery to the other, resulting in electrolyte mixing and irreversible fading in energy density and capacity. An attractive solution to tackle this crossover problem is the adoption of symmetric flow batteries, wherein a single bipolar molecule serves as both an anolyte and a catholyte. Herein, we report the use of of a diazatriangulenium ion, a heterocyclic fused carbenium ion, as a bipolar redox active material in such symmetric flow batteries. This redox active molecule exhibits promising characteristics, including a straightforward synthesis, high tunability, non-toxicity, and availability. Evaluation of this molecule through 3-electrode cell testing reveals excellent electrokinetic parameters suitable for NAORFB deployment. The performance is further demonstrated in a prototype of a fully organic symmetrical redox flow battery, exhibiting an large Egap of 2.36 V, energy density exceeding 6 W h L−1, and 99.93% capacity retention over 300 cycles, despite a moderate energetic efficiency.

AB - Grid-scale energy storage can benefit from the potential of non-aqueous full organic redox flow batteries (NAORFBs). However, the majority of current NAORFBs rely on the utilization of distinct anolytes and catholytes, separated by a membrane or porous separator. Unfortunately, this setup can lead to crossover of redox active material from one side of the battery to the other, resulting in electrolyte mixing and irreversible fading in energy density and capacity. An attractive solution to tackle this crossover problem is the adoption of symmetric flow batteries, wherein a single bipolar molecule serves as both an anolyte and a catholyte. Herein, we report the use of of a diazatriangulenium ion, a heterocyclic fused carbenium ion, as a bipolar redox active material in such symmetric flow batteries. This redox active molecule exhibits promising characteristics, including a straightforward synthesis, high tunability, non-toxicity, and availability. Evaluation of this molecule through 3-electrode cell testing reveals excellent electrokinetic parameters suitable for NAORFB deployment. The performance is further demonstrated in a prototype of a fully organic symmetrical redox flow battery, exhibiting an large Egap of 2.36 V, energy density exceeding 6 W h L−1, and 99.93% capacity retention over 300 cycles, despite a moderate energetic efficiency.

U2 - 10.1039/d3ma00417a

DO - 10.1039/d3ma00417a

M3 - Journal article

AN - SCOPUS:85172810676

VL - 4

SP - 4598

EP - 4606

JO - Materials Advances

JF - Materials Advances

SN - 2633-5409

IS - 19

ER -