Feasibility of a Supporting-Salt-Free Nonaqueous Redox Flow Battery Utilizing Ionic Active Materials.
Nonaqueous redox flow batteries (NAqRFBs) are promising devices for grid-scale energy storage, but high projected prices could limit commercial prospects. One route to reduced prices is to minimize or eliminate the expensive supporting salts typically employed in NAqRFBs. Herein, the feasibility of a flow cell operating in the absence of supporting salt by utilizing ionic active species is demonstrated. These ionic species have high conductivities in acetonitrile (12-19 mS cm-1) and cycle at 20 mA cm-2with energy efficiencies (>75 %) comparable to those of state-of-the-art NAqRFBs employing high concentrations of supporting salt. A chemistry-agnostic techno-economic analysis highlights the possible cost savings of minimizing salt content in a NAqRFB. This work offers the first demonstration of a NAqRFB operating without supporting salt. The associated design principles can guide the development of future active species and could make NAqRFBs competitive with their aqueous counterparts.
Joint Center for Energy Storage Research, USA.|Department of Materials Science and Engineering, Massachusetts Institute of Technology, USA.
Jarrod D
0000-0001-8322-5106
JD
Milshtein
Joint Center for Energy Storage Research, USA.|Department of Chemical Engineering, University of Michigan, 2300 Hayward St, Ann Arbor, MI, 48109, USA.
Sydney L
SL
Fisher
Joint Center for Energy Storage Research, USA.|Department of Chemical Engineering, University of Michigan, 2300 Hayward St, Ann Arbor, MI, 48109, USA.
Tanya M
TM
Breault
Joint Center for Energy Storage Research, USA.|Department of Chemical Engineering, University of Michigan, 2300 Hayward St, Ann Arbor, MI, 48109, USA.
Levi T
LT
Thompson
Joint Center for Energy Storage Research, USA.|Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Fikile R
0000-0002-7361-6637
FR
Brushett
D000097:Acetonitriles; D001881:Borates; D001888:Boric Acids / Q000737:chemistry; D004467:Economics; D011211:Electric Power Supplies / Q000191:economics; D004573:Electrolytes; D004867:Equipment Design; D005240:Feasibility Studies; D007477:Ions; D010084:Oxidation-Reduction
D000097:Acetonitriles; D001881:Borates; D001888:Boric Acids; D004573:Electrolytes; D007477:Ions; C098759:fluoroboric acid; C032159:acetonitrile
electrochemistry; energy storage; nonaqueous flow batteries; redox chemistry; techno-economic analysis