Regulating Proton Activity of Quinone‐Based Electrodes for Aqueous All‐Organic Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 21; no. 27; pp. e2502591 - n/a
• Main Authors: Sun, Tao, Yang, Jiaxu, Peng, Haian, Kang, Fangyuan, Zhang, Jianming, Zhang, Qichun
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.07.2025
• Subjects: aqueous rechargeable batteries; Benzoquinone; Electrochemical analysis; Electrodes; Electrolytes; organic electrode; Protons; quinone; Quinones; reaction mechanism; Solvation; Zn‐organic batteries; organic electrode; Zn‐organic batteries; aqueous rechargeable batteries; reaction mechanism; quinone
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202502591

Aqueous Zn‐organic batteries (ZOBs) have emerged as a focal point due to their eco‐sustainability and versatility. However, the origins of protons and their impact on electrochemical performance remain poorly understood and are subject to considerable debate. To address this gap, it is proposed to investigate model quinone‐based electrodes, 3,5‐Di‐tert‐butyl‐o‐benzoquinone (DBBQ), in mild‐to‐strong acidic conditions. The electrochemical features of DBBQ in Zn2+‐based mild electrolyte are elaborated, proving its preferential coordination with protons over Zn2+ cations. Notably, proton‐driven electrochemical reactivity exhibits superior stability and higher operating voltage, whereas the reactivity region of Zn2+ leads to significant capacity loss. To highlight the unique aspects of protons, an aqueous all‐quinone proton battery is fabricated under acidic conditions. As a proof‐of‐concept demonstration, the proton rocking‐chair cell exhibits satisfactory electrochemical performance, illustrating the feasibility of metal‐free sustainable batteries. With an emphasis on the fundamental impacts of electrolyte composition and pH, the findings reveal that the manners of proton storage can be regulated via the regulation of solvation character of the anions, which provides new perspective to understand the mechanistic charge storage of organic electrodes in aqueous batteries. In this study, 3,5‐Di‐tert‐butyl‐o‐benzoquinone (DBBQ) serves as a model quinone‐based cathode in various zinc salt electrolytes. The comprehensive investigation reveals that enhancing the proton reaction priority can be achieved by regulating the water structuring capability of anions. This finding provides insight into the mechanistic charge storage processes of organic electrodes in aqueous batteries.