Water-soluble pH-switchable cobalt complexes for aqueous symmetric redox flow batteries

2020 ◽  
Vol 56 (25) ◽  
pp. 3605-3608 ◽  
Author(s):  
Hao Wang ◽  
Sayed Youssef Sayed ◽  
Yuqiao Zhou ◽  
Brian C. Olsen ◽  
Erik J. Luber ◽  
...  
Keyword(s):  
Water Splitting ◽  
Cobalt Complex ◽  
Cobalt Complexes ◽  
Water Soluble ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Redox Flow Batteries ◽  
Redox Couples ◽  
Flow Batteries

A water soluble cobalt complex with two redox couples that fall within the water splitting window can be applied as both the posolyte and negolyte in an aqueous symmetric redox flow battery.

Aqueous Symmetrical Redox Flow Batteries Based Upon a pH-Responsive Cobalt Complex

2019 ◽  
Author(s):  
Hao Wang ◽  
Sayed Youssef Sayed ◽  
Yuqiao Zhou ◽  
Brian Olsen ◽  
Erik J. Luber ◽  
...  
Keyword(s):  
Cobalt Complex ◽  
Redox Properties ◽  
Water Soluble ◽  
Cobalt Metal ◽  
Ph Responsive ◽  
Fast Kinetics ◽  
Redox Flow Batteries ◽  
Redox Couples ◽  
Flow Batteries ◽  
Carboxylic Groups

<div>Aqueous symmetric redox flow batteries (RFB) are of great interest due to the non-flammability and high conductivity of the solvent, and avoidance of irreversible anolyte crossover seen in asymmetric cells. In this work, we introduce a simple octahedral Co(II) complex, termed BCPIP-Co(II), that has 4 appended carboxylic groups on the ligand periphery that render it both water-soluble and pH-sensitive in the range of pH 1.5 - 5.5. The complex has reversible BCPIP-Co(II-III) and BCPIP-Co(II-I) redox couples within the water splitting window, as well as fast kinetics. The overall charge of the complex varies from +3 to -3, resulting from the level of deprotonation of the carboxylic acid moieties and the oxidation state of the cobalt metal center, both of which affect the resulting redox properties. BCPIP-Co(II) was then incorporated, as both the posolyte and negolyte, into a symmetric aqueous RFB, demonstrating Coulombic efficiencies >99% for up to 100 cycles.</div>

Aqueous Symmetrical Redox Flow Batteries Based Upon a pH-Responsive Cobalt Complex

2019 ◽  
Author(s):  
Hao Wang ◽  
Sayed Youssef Sayed ◽  
Yuqiao Zhou ◽  
Brian Olsen ◽  
Erik J. Luber ◽  
...  
Keyword(s):  
Cobalt Complex ◽  
Redox Properties ◽  
Water Soluble ◽  
Cobalt Metal ◽  
Ph Responsive ◽  
Fast Kinetics ◽  
Redox Flow Batteries ◽  
Redox Couples ◽  
Flow Batteries ◽  
Carboxylic Groups

<div>Aqueous symmetric redox flow batteries (RFB) are of great interest due to the non-flammability and high conductivity of the solvent, and avoidance of irreversible anolyte crossover seen in asymmetric cells. In this work, we introduce a simple octahedral Co(II) complex, termed BCPIP-Co(II), that has 4 appended carboxylic groups on the ligand periphery that render it both water-soluble and pH-sensitive in the range of pH 1.5 - 5.5. The complex has reversible BCPIP-Co(II-III) and BCPIP-Co(II-I) redox couples within the water splitting window, as well as fast kinetics. The overall charge of the complex varies from +3 to -3, resulting from the level of deprotonation of the carboxylic acid moieties and the oxidation state of the cobalt metal center, both of which affect the resulting redox properties. BCPIP-Co(II) was then incorporated, as both the posolyte and negolyte, into a symmetric aqueous RFB, demonstrating Coulombic efficiencies >99% for up to 100 cycles.</div>

Synthesis and investigation of imidazolium functionalized poly(arylene ether sulfone)s as anion exchange membranes for all-vanadium redox flow batteries

RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6029-6037 ◽  
Author(s):  
Di Lu ◽  
Lele Wen ◽  
Feng Nie ◽  
Lixin Xue
Keyword(s):  
Anion Exchange ◽  
Vanadium Redox Flow Battery ◽  
Anion Exchange Membranes ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Redox Flow Batteries ◽  
Arylene Ether ◽  
Flow Batteries ◽  
Vanadium Redox

A serials of imidazolium functionalized poly(arylene ether sulfone) as anion exchange membranes (AEMs) for all-vanadium redox flow battery (VRB) application are synthesized successfully in this study.

scholarly journals Electrochemical Studies on Alizarin Red S as Negolyte for Redox Flow Battery: a Preliminary Study

2018 ◽  
Vol 7 (4.35) ◽  
pp. 375
Author(s):  
C. Khor ◽  
M. R. Mohamed ◽  
C. K. Feng ◽  
P. K. Leung
Keyword(s):  
Diffusion Coefficient ◽  
Negative Electrode ◽  
Operating Conditions ◽  
Alizarin Red S ◽  
Fast Diffusion ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Alizarin Red ◽  
Redox Flow Batteries ◽  
Flow Batteries

Redox flow battery (RFB) has received tremendous attention as energy storage system coupled with renewable energy sources. In this paper, a low-cost alizarin red S (ARS) organic dye is proposed to serve as the active material for the negative electrode reaction for organic redox flow batteries. Cyclic voltammetry has been conducted under a number of operating conditions to reveal the electrochemical performance of this molecule. The results suggest that ARS is highly reversible at low electrode potential (c.a. 0.082 V vs. standard hydrogen electrode), indicating that ARS is a promising negative electrode material for organic redox flow batteries. The diffusion coefficient of ARS is calculated in the range of 6.424 x 10-4 cm2 s-1, This has indicated fast diffusion rate and electrochemical kinetics for oxidation and reduction in higher concentration of ARS. It has been found out that the higher concentration of ARS in base electrolyte cause lowest diffusion coefficient due to solubility issue of ARS.

Improved radical stability of viologen anolytes in aqueous organic redox flow batteries

2018 ◽  
Vol 54 (50) ◽  
pp. 6871-6874 ◽  
Author(s):  
Bo Hu ◽  
Yijie Tang ◽  
Jian Luo ◽  
Grant Grove ◽  
Yisong Guo ◽  
...  
Keyword(s):  
Power Density ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Capacity Retention ◽  
Redox Flow Batteries ◽  
Flow Batteries

A 1.38 V aqueous organic redox flow battery demonstrated 97.48% capacity retention for 500 cycles and 128 mW cm−2 power density.

Functionalised carbazole as a cathode for high voltage non-aqueous organic redox flow batteries

2020 ◽  
Vol 44 (34) ◽  
pp. 14401-14410
Author(s):  
Chinmaya R. Mirle ◽  
Raja M. ◽  
Vasudevarao P. ◽  
Sankararaman S. ◽  
Kothandaraman R.
Keyword(s):  
High Voltage ◽  
Cathode Materials ◽  
Reduction Potential ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
High Reduction

Prospective high reduction potential cathode materials have been proposed that can be used in non-aqueous redox flow battery applications.

An Energy Dense, Robust, Powerful Bipolar Zinc-Ferrocene Redox Flow Battery

2020 ◽  
Author(s):  
Jian Luo ◽  
Bo Hu ◽  
Wenda Wu ◽  
Maowei Hu ◽  
Leo Liu
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Low Cost ◽  
High Energy ◽  
High Energy Density ◽  
Redox Flow Battery ◽  
Power Performance ◽  
Flow Battery ◽  
Redox Flow Batteries ◽  
Flow Batteries

Redox flow batteries (RFBs) have been recognized as a promising option for scalable and dispatchable renewable energy storage (e.g. solar and wind energy). Zinc metal represents a low cost, high capacity anode material to develop high energy density aqueous redox flow batteries. However, the energy storage applications of traditional inorganic Zn halide flow batteries are primarily plagued by the material challenges of traditional halide cathode electrolytes (e.g. bromine) including corrosion, toxicity, and severe crossover. As reported here, we have developed a bipolar Zinc-ferrocene salt compound, Zinc 1,1’-bis(3-sulfonatopropyl)ferrocene, Zn[Fc(SPr)2] (1.80 M solubility or 48.2 Ah/L charge storage capacity) – a robust, energy-dense, bipolar redox-active electrolyte material for high performance Zn organic RFBs. Using a low-cost porous Daramic membrane, the Zn[Fc(SPr)2] aqueous organic redox flow battery (AORFB) has worked in dual-flow and single-flow modes. It has manifested outstanding current, energy, and power performance, specifically, operating at high current densities of up to 200 mA/cm2 and delivering an energy efficiency of up to 81.5% and a power density of up to 270.5 mW/cm2. A Zn[Fc(SPr)2] AORFB demonstrated an energy density of 20.2 Wh/L and displayed 100% capacity retention for 2000 cycles (1284 hr or 53.5 days). The Zn[Fc(SPr)2] ionic bipolar electrolyte not only offers record-setting, highly-stable, energy-dense, and the most powerful Zn-organic AORFBs to date, but it also provides a new paradigm to develop even more advanced redox materials for scalable energy storage.

scholarly journals Segmented Printed Circuit Board Electrode for Locally-resolved Current Density Measurements in All-Vanadium Redox Flow Batteries

Batteries ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 38 ◽  
Author(s):  
Gerber ◽  
Fischer ◽  
Pinkwart ◽  
Tübke
Keyword(s):  
Current Density ◽  
Printed Circuit Board ◽  
Current Density Distribution ◽  
Circuit Board ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Printed Circuit ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Vanadium Redox

One of the most important parameters for the design of redox flow batteries is a uniform distribution of the electrolyte solution over the complete electrode area. The performance of redox flow batteries is usually investigated by general measurements of the cell in systematic experimental studies such as galvanostatic charge-discharge cycling. Local inhomogeneity within the electrode cannot be locally-resolved. In this study a printed circuit board (PCB) with a segmented current collector was integrated into a 40 cm2 all-vanadium redox flow battery to analyze the locally-resolved current density distribution of the graphite felt electrode. Current density distribution during charging and discharging of the redox flow battery indicated different limiting influences. The local current density in redox flow batteries mainly depends on the transport of the electrolyte solution. Due to this correlation, the electrolyte flow in the porous electrode can be visualized. A PCB electrode can easily be integrated into the flow battery and can be scaled to nearly any size of the electrode area. The carbon coating of the PCB enables direct contact to the corrosive electrolyte, whereby the sensitivity of the measurement method is increased compared to state-of-the-art methods.

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