Naphthalene diimides (NDI) in highly stable pH-neutral aqueous organic redox flow batteries
Artikel i vetenskaplig tidskrift, 2021

In the pursuit of environmentally friendly energy storage, aqueous organic redox flow batteries (AORFBs) that use naphthalene diimide hold promise for successful application. In the present article, two different naphthalene diimides (NDI) are studied as negative electrolyte materials for pH-neutral aqueous organic/organometallic redox flow batteries. The two molecules, one core-unsubstituted NDI (2H-NDI) and one core-dimethylamino substituted NDI (2DMA-NDI) are coupled with a solubilized ferrocene (BTMAP-Fc) at a concentration of 50 mM in phosphate buffered potassium chloride. High energy efficiencies and coulombic efficiencies were obtained for both batteries, but a gradual capacity fade was observed while cycling. However, when changing the cation of the supporting electrolyte from potassium to ammonium, similar energy and coulombic efficiencies were obtained, but with undetectable capacity losses over 320 cycles. Finally, 2H-NDI and BTMAP-Fc at 500 mM were tested in the ammonium-based electrolyte, and while obtaining high coulombic efficiency, the energy efficiency and cycling stability decreased compared to the same system at lower concentration. It is concluded that loss of activity is mainly due to formation of electrochemically inactive compounds and that the electrolyte cation is of great importance for the outcome. Important design strategies for AORFB molecules include using supporting salts that prevent self-association and introducing sterically hindering substituents to the structures.

DFT

Capacity utilization

Electrochemistry

Self-association

Energy efficiency

Författare

Cedrik Wiberg

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Lars Evenäs Group

Lars Evenäs

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Lars Evenäs Group

Michael Busch

Aalto-Yliopisto

Elisabet Ahlberg

Göteborgs universitet

Journal of Electroanalytical Chemistry

1572-6657 (ISSN)

Vol. 896 115224

Grön Bearbetade Polymer: Polymer Solceller på förnybara Biomaterial

Formas (942-2015-411), 2016-01-01 -- 2018-12-31.

Muliblockpolymerer för organiska solceller

Vetenskapsrådet (VR) (2015-04853), 2016-01-01 -- 2019-12-31.

Ämneskategorier

Materialkemi

Annan kemi

Energisystem

DOI

10.1016/j.jelechem.2021.115224

Mer information

Senast uppdaterat

2021-09-13