Insights into Molecular Oxidation Mechanism to Achieve Highly Stable Aqueous Organic Flow Batteries DOI
Xiaoxuan Xu,

Fengke Sun,

Wenming Tian

et al.

Small Methods, Journal Year: 2025, Volume and Issue: unknown

Published: May 22, 2025

Abstract Aqueous organic redox flow batteries (AOFBs) have emerged as promising candidates for large‐scale energy storage systems. However, due to the high sensitivity of molecules O 2 , most AOFBs be operated in glove boxes, which limits their practical applications. In this study, reversible and irreversible oxidation behaviors 7,8‐dihydroxyphenazine‐2‐sulfonic acid (DHPS) are investigated through situ UV–vis ex transient absorption spectra. It turned out that alkaline concentrations can effectively reduce auto‐oxidation rate, however, it would also accelerate reaction triggered by photoexcited singlet oxygen ( 1 ) when under irradiation. As a result, combining reducing agents employing light‐proof tanks improve cycle life effectively. Batteries encapsulated outside box achieve stable operation with Coulombic efficiency over 99% capacity decay rate 0.0054%/cycle 2500 cycles. The work proves ambient conditions possible, further enabling application

Language: Английский

Boosting the Activity and Stability of 3‐Hydroxyphenothiazine Derivatives for Aqueous Organic Flow Batteries DOI Open Access
Mengqi Zhang, Cuicui Mu, Tianyu Li

et al.

Advanced Energy Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 24, 2025

Abstract Aqueous organic flow batteries (AOFBs) represent one of the most promising technologies for stationary energy storage due to their features abundant resources and high tunability. Phenothiazines have stable conjugated structures are considered potential catholytes AOFBs. However, highly structure phenothiazines is always hydrophobic reduces molecular polarity, which makes it challenging achieve capacity efficiency. Herein, a new class 3‐hydroxyphenothiazine derivatives with solubility 1.8 m fast redox kinetics by introducing hydrophilic tertiary ammonium groups. The designed 7‐bromo‐2,4‐dimethylaminemethylene‐3‐hydroxyphenothiazine (BDAHP) based cell not only exhibited an ultra‐stable cycling (over 10 000 cycles fade rate 0.00048% per cycle symmetric cell) but also achieved efficiency 82.3% (80 mA cm −2 at 0.5 ). Furthermore, displayed reversible catholyte 82 Ah L −1 concentration 1.7 wide temperature adaptability (−15–60 °C). Combining volumetric capacity, reaction, stability, hydroxyl‐substituted PTZ demonstrates great large‐scale storage.

Language: Английский

Citations

0
Insights into Molecular Oxidation Mechanism to Achieve Highly Stable Aqueous Organic Flow Batteries DOI
Xiaoxuan Xu,

Fengke Sun,

Wenming Tian

et al.

Small Methods, Journal Year: 2025, Volume and Issue: unknown

Published: May 22, 2025

Abstract Aqueous organic redox flow batteries (AOFBs) have emerged as promising candidates for large‐scale energy storage systems. However, due to the high sensitivity of molecules O 2 , most AOFBs be operated in glove boxes, which limits their practical applications. In this study, reversible and irreversible oxidation behaviors 7,8‐dihydroxyphenazine‐2‐sulfonic acid (DHPS) are investigated through situ UV–vis ex transient absorption spectra. It turned out that alkaline concentrations can effectively reduce auto‐oxidation rate, however, it would also accelerate reaction triggered by photoexcited singlet oxygen ( 1 ) when under irradiation. As a result, combining reducing agents employing light‐proof tanks improve cycle life effectively. Batteries encapsulated outside box achieve stable operation with Coulombic efficiency over 99% capacity decay rate 0.0054%/cycle 2500 cycles. The work proves ambient conditions possible, further enabling application

Language: Английский

Citations

0