Electroless chemical aging of carbon felt electrodes for the all-vanadium redox flow battery (VRFB) investigated by Electrochemical Impedance and X-ray Photoelectron Spectroscopy

In this paper, thiourea was successfully grafted onto the surface of acid preprocessed graphite felts [sulfuric acid-treated graphite felt (SA-GFs)] by thiol-carboxylic acid esterification. The thiourea-grafted graphite felts (TG-GFs) were investigated as the positive electrode for vanadium redox flow battery (VRFB). X-ray photoelectron spectroscopy results suggested that thiourea was grafted into the surface of graphite felts. The cyclic voltammetry showed that the peak potential separation decreased by 0.2 V, and peak currents were greatly enhanced on TG-GF electrode compared with SA-GF electrode, implying improved electro-catalytic activity and reversibility of TG-GF electrode toward VO2+/VO2+ redox reaction. The initial capacity of TG-GF-based cell reached 55.6 mA h at 100 mA cm−2, 22.6 mA h larger than that of SA-GF-based cell. The voltage and energy efficiency for TG-GF-based cell increased by 4.9% and 4.4% compared with those of SA-GF-based cell at 100 mA cm−2, respectively.

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The influence of compressed carbon felt electrodes on the performance of a vanadium redox flow battery

Electrochimica Acta ◽

10.1016/j.electacta.2013.11.073 ◽

2014 ◽

Vol 116 ◽

pp. 447-452 ◽

Cited By ~ 57

Author(s):

Se-Kook Park ◽

Joonmok Shim ◽

Jung Hoon Yang ◽

Chang-Soo Jin ◽

Bum Suk Lee ◽

...

Keyword(s):

Vanadium Redox Flow Battery ◽

Redox Flow Battery ◽

Carbon Felt ◽

Flow Battery ◽

Vanadium Redox ◽

Felt Electrodes

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Asymmetric Performance Testing of Carbon Felt Electrodes to Identify the Limiting Electrode in Vanadium Redox Flow Battery

ECS Meeting Abstracts ◽

10.1149/ma2013-01/9/488 ◽

2013 ◽

Keyword(s):

Performance Testing ◽

Vanadium Redox Flow Battery ◽

Redox Flow Battery ◽

Carbon Felt ◽

Flow Battery ◽

Vanadium Redox ◽

Felt Electrodes

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Asymmetric Performance Testing of Carbon Felt Electrodes to Identify the Limiting Electrode in Vanadium Redox Flow Battery

ECS Transactions ◽

10.1149/05307.0069ecst ◽

2013 ◽

Vol 53 (7) ◽

pp. 69-73 ◽

Cited By ~ 1

Author(s):

E. Agar ◽

C. R. Dennison ◽

K. W. Knehr ◽

E. C. Kumbur

Keyword(s):

Performance Testing ◽

Vanadium Redox Flow Battery ◽

Redox Flow Battery ◽

Carbon Felt ◽

Flow Battery ◽

Vanadium Redox ◽

Felt Electrodes

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Highly Hydroxylated Graphite Felts Used as Electrodes for a Vanadium Redox Flow Battery

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.471 ◽

2014 ◽

Vol 936 ◽

pp. 471-475 ◽

Cited By ~ 4

Author(s):

Wen Wen Li ◽

You Qun Chu ◽

Chun An Ma

Keyword(s):

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Vanadium Redox Flow Battery ◽

Electrochemical Characteristics ◽

Redox Flow Battery ◽

Flow Battery ◽

Oh Groups ◽

Average Current ◽

Vanadium Redox ◽

Mixed Acids

The highly hydroxylated graphite felts (GFs) were obtained by treating in mixed acids (V(HNO3)/V(H3PO4)=3:1) for different time at 80°C, and used as the electrodes for all vanadium redox flow battery (VRB). The physical, chemical and electrochemical characteristics of these GFs are characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, cyclic voltametry, electrochemical impedance spectroscopy and charge/discharge test. The excellent electrochemical properties of the treated GFs to VRB electrode reactions can be ascribed to the enhancement of the interaction between vanadium ions with –OH groups introduced by acid treatment. Using GFs treated in the mixed acids for 8 h as electrodes, the VRB exhibits excellent performance under a current density of 20 mA/cm2. The average current efficiency, voltage efficiency and energy efficiency are about 97%, 83.3% and 78%, respectively.

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