Multiple-dimensioned defect engineering for graphite felt electrode of vanadium redox flow battery  

作　　者：Yingqiao Jiang Yinhui Wang Gang Cheng Yuehua Li Lei Dai Jing Zhu Wei Meng Jingyu Xi Ling Wang Zhangxing He 

机构地区：[1]School of Chemical Engineering,North China University of Science and Technology,Tangshan,China [2]Tsinghua Shenzhen International Graduate School,Institute of Materials Research,Tsinghua University,Shenzhen,China

出　　处：《Carbon Energy》2024年第2期143-153,共11页碳能源（英文）

基　　金：supported by the National Natural Science Foundation of China(No.51872090);Natural Science Foundation of Hebei Province(No.E2019209433,E2022209158);Colleges and Universities in Hebei Province Science and Technology Research Project(No.JZX2024026).

摘　　要：The scarcity of wettability,insufficient active sites,and low surface area of graphite felt(GF)have long been suppressing the performance of vanadium redox flow batteries(VRFBs).Herein,an ultra-homogeneous multipledimensioned defect,including nano-scale etching and atomic-scale N,O codoping,was used to modify GF by the molten salt system.NH_(4)Cl and KClO_(3) were added simultaneously to the system to obtain porous N/O co-doped electrode(GF/ON),where KClO_(3) was used to ultra-homogeneously etch,and O-functionalize electrode,and NH4Cl was used as N dopant,respectively.GF/ON presents better electrochemical catalysis for VO_(2)+/VO_(2)+ and V3+/V2+ reactions than only O-functionalized electrodes(GF/O)and GF.The enhanced electrochemical properties are attributed to an increase in active sites,surface area,and wettability,as well as the synergistic effect of N and O,which is also supported by the density functional theory calculations.Further,the cell using GF/ON shows higher discharge capacity,energy efficiency,and stability for cycling performance than the pristine cell at 140 mA cm^(−2) for 200 cycles.Moreover,the energy efficiency of the modified cell is increased by 9.7% from 55.2% for the pristine cell at 260 mA cm^(−2).Such an ultra-homogeneous etching with N and O co-doping through“boiling”molten salt medium provides an effective and practical application potential way to prepare superior electrodes for VRFB.

关 键 词：graphite felt molten salt N O co-doping ultra-homogeneous etching vanadium redox flow battery 

分 类 号：TM912[电气工程—电力电子与电力传动]