Physical Chemistry

Molecular Engineering of an Alkaline Naphthoquinone Flow Battery

Abstract

Aqueous organic redox flow batteries (AORFBs) have recently gained significant attention as a potential candidate for grid-scale electrical energy storage. Successful implementation of this technology will require redox-active organic molecules with many desired properties. Here we introduce a naphthoquinone dimer, bislawsone, as the redox-active material in a negative potential electrolyte (negolyte) for an AORFB. This novel dimerization strategy substantially improves the performance of the electrolyte vs. that of the lawsone monomer in terms of solubility, stability, reversible capacity, permeability and cell voltage. An AORFB pairing bislawsone with a ferri/ferrocyanide positive electrolyte delivers an open-circuit voltage of 1.05 V and cycles at a current density of 300 mA/cm2 with a negolyte concentration of 2 M electrons in alkaline solution. We determined the degradation mechanism for the naphthoquinone-based electrolyte using chemical analysis, and predict theoretically electrolytes based on naphthoquinones that will be even more stable.

Content

Thumbnail image of bislawsone-manuscript-submit_for_chemrxiv.pdf

Supplementary material

Thumbnail image of bislawsone-SI-submit.pdf
bislawsone-SI-submit
Thumbnail image of 14393894.txt
all molecules b3lyp 6311 gdp pcm
Thumbnail image of submit_stable_moleculess_b3lyp_6311+gdp_pcm.txt
submit stable moleculess b3lyp 6311+gdp pcm