Naphthalene diimide as a two-electron anolyte for aqueous and neutral pH redox flow batteries

2020 ◽  
Vol 8 (22) ◽  
pp. 11218-11223
Author(s):  
Veerababu Medabalmi ◽  
Mahesh Sundararajan ◽  
Vikram Singh ◽  
Mu-Hyun Baik ◽  
Hye Ryung Byon
Keyword(s):  
Potassium Salt ◽  
Redox Reactions ◽  
Ion Pairing ◽  
Redox Flow Batteries ◽  
Neutral Ph ◽  
Naphthalene Diimide ◽  
Flow Batteries

The potassium salt of N,N′-bis(glycinyl)naphthalene diimide [K2-BNDI] showed stable two-electron redox reactions accompanied by ion-pairing in aqueous redox-flow batteries.

scholarly journals Concurrent nanoscale surface etching and SnO2 loading of carbon fibers for vanadium ion redox enhancement

2019 ◽  
Vol 10 ◽  
pp. 985-992 ◽  
Author(s):  
Jun Maruyama ◽  
Shohei Maruyama ◽  
Tomoko Fukuhara ◽  
Toru Nagaoka ◽  
Kei Hanafusa
Keyword(s):  
Carbon Fiber ◽  
Redox Reactions ◽  
Negative Electrode ◽  
Fiber Surface ◽  
Electrode Reaction ◽  
Redox Flow Batteries ◽  
Surface Etching ◽  
Flow Batteries ◽  
Carbon Fiber Surface ◽  
Vanadium Redox

Facile and efficient methods to prepare active electrodes for redox reactions of electrolyte ions are required to produce efficient and low-cost redox flow batteries (RFBs). Carbon-fiber electrodes are widely used in various types of RFBs and surface oxidation is commonly performed to enhance the redox reactions, although it is not necessarily efficient. Quite recently, a technique for nanoscale and uniform surface etching of the carbon fiber surface was developed and a significant enhancement of the negative electrode reaction of vanadium redox flow batteries was attained, although the enhancement was limited to the positive electrode reaction. In this study, we attempted to obtain an additional enhancement effect of metal-oxide nanoparticles without the need for further processing steps. A coating with carbonaceous thin films was obtained coating by sublimation, deposition, and pyrolysis of tin(II) phthalocyanine (SnPc) on a carbon fiber surface in a single heat-treatment step. The subsequent thermal oxidation concurrently achieved nanoscale surface etching and loading with SnO2 nanoparticles. The nanoscale-etched and SnO2-loaded surface was characterized by field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The activity for the vanadium ion redox reactions was evaluated by cyclic voltammetry (CV) to demonstrate the enhancement of both the positive and negative electrode reactions. A full cell test of the vanadium redox flow battery (VRFB) showed a significant decrease of the overpotential and a stable cycling performance. A facile and efficient technique based on the nanoscale processing of the carbon fiber surface was presented to substantially enhance the activity for the redox reactions in redox flow batteries.

scholarly journals Sulfonated tryptanthrin anolyte increases performance in pH neutral aqueous redox flow batteries

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Daniela Pinheiro ◽  
Marta Pineiro ◽  
J. Sérgio Seixas de Melo
Keyword(s):  
Alternative Energy ◽  
Active Material ◽  
High Energy ◽  
Disodium Salt ◽  
Water Soluble ◽  
Great Promise ◽  
Safe Alternative ◽  
Redox Flow Batteries ◽  
Neutral Ph ◽  
Flow Batteries

AbstractAqueous organic redox flow batteries (AORFBs) hold great promise as low-cost, environmentally friendly and safe alternative energy storage media. Here we present aqueous organometallic and all-organic active materials for RFBs with a water-soluble active material, sulfonated tryptanthrin (TRYP-SO3H), working at a neutral pH and showing long-term stability. Electrochemical measurements show that TRYP-SO3H displays reversible peaks at neutral pH values, allowing its use as an anolyte combined with potassium ferrocyanide or 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt monohydrate as catholytes. Single cell tests show reproducible charge-discharge cycles for both catholytes, with significantly improved results for the aqueous all-organic RFB reaching high cell voltage (0.94 V) and high energy efficiencies, stabilized during at least 50 working cycles.

Neutral pH aqueous redox flow batteries using an anthraquinone-ferrocyanide redox couple

2020 ◽  
Vol 8 (17) ◽  
pp. 5727-5731 ◽  
Author(s):  
Wonmi Lee ◽  
Agnesia Permatasari ◽  
Yongchai Kwon
Keyword(s):  
Redox Couple ◽  
Disulfonic Acid ◽  
Sodium Salts ◽  
Redox Flow Batteries ◽  
Neutral Ph ◽  
Flow Batteries

Anthraquinone-2,7-disulfonic acid (2,7-AQDS) and ferrocyanide including potassium and sodium salts are used as a redox couple for neutral aqueous redox flow batteries (ARFBs).

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