Steric hindrance shielding viologen against alkali attack in realizing ultrastable aqueous flow batteries  

作　　者：Liwen Wang Kai Wan Xianzhi Yuan Zhipeng Xiang Zhiyong Fu Zhenxing Liang 

机构地区：[1]Guangdong Provincial Key Laboratory of Fuel Cell Technology,School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510641,Guangdong,China [2]State Key Laboratory of Pulp and Paper Engineering,South China University of Technology,Guangzhou 510641,Guangdong,China [3]Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center,Jieyang 522000,Guangdong,China

出　　处：《Journal of Energy Chemistry》2024年第10期529-534,I0011,共7页能源化学（英文版）

基　　金：jointly supported by the Guangdong Major Project of Basic and Applied Basic Research (2023B0303000002);National Natural Science Foundation of China (22178126,22325802,U22A20417,22208110);Guangdong Basic and Applied Basic Research Foundation (2023B1515120005);Science and Technology Program of Guangzhou (2023B03J1281,2023A04J1357);China Postdoctoral Science Foundation (2023T160223);the State Key Laboratory of Pulp and Paper Engineering (2023ZD03)。

摘　　要：Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).

关 键 词：Aqueous organic flow batteries VIOLOGEN Stability Steric hindrance Alkali resistance 

分 类 号：TB34[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]