Spin‐State and Clustering Effects in Fe‐Complex Negolytes for Near‐Neutral Aqueous Redox Flow Batteries

Author:

Ko Donghwi1ORCID,Kwon Seongyeon12,Nedsaengtip Jantakan1,Kim Yohan1,Choi Yunseop3,Kim Dongwook12,Lyu Xingyi4,Dixit Ruchi12,Zhang Yugang5,Li Tao4ORCID,Seo Jongcheol3ORCID,Baik Mu‐Hyun12ORCID,Byon Hye Ryung1ORCID

Affiliation:

1. Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea

2. Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea

3. Department of Chemistry Pohang University of Science and Technology Pohang 37673 Republic of Korea

4. Department of Chemistry and Biochemistry Northern Illinois University DeKalb IL 60115 USA

5. Center for Functional Nanomaterials Brookhaven National Laboratories Upton New York 11973 USA

Abstract

AbstractCost‐effective redox‐active materials are essential for advancing redox flow batteries (RFBs). Iron, with its abundance and suitability as a redox couple, is a promising candidate; however, achieving stable and fast redox reactions in aqueous RFBs remains a challenge. This study presents an Fe‐based negolyte stabilized by a hexadentate ligand, where Fe–ligand bonds are enhanced through intermolecular interactions. The sulfonate‐substituted Fe complex exhibits a formal potential of −0.44 V versus Ag/AgCl and an exceptionally high rate constant of 0.69 cm s−1. Near‐neutral RFBs incorporating 0.5 M Fe complex show excellent cycling stability, with no discernible capacity fading over 300 cycles. This performance is attributed to intermolecular hydrogen bonds that reinforce Fe–ligand coordination and promote the formation of stable trimeric clusters. Operando electrochemical Raman spectroscopy and density functional theory reveal that π‐backdonation from Fe(II) to the imino‐phenolate moiety further stabilizes the complex after reduction. In contrast, the hydroxyl‐substituted complex exhibits inferior stability due to weaker hydrogen bonding and less pronounced π‐backdonation. These findings underscore the importance of ligand design and intermolecular interactions in developing cost‐effective, high‐performance redox‐active materials for aqueous RFBs.

Publisher

Wiley

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.7亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2025 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3