Sourcing the merits of 3D integrated air cathodes for highperformance Zn-air batteries by bubble pump consumption chronoamperometry  

作　　者：Mengxuan Li Linfeng Yu Hai Liu Chuanyi Zhang Jiazhan Li Liang Luo Xiaoming Sun 

机构地区：[1]State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China

出　　处：《Nano Research》2024年第8期6951-6959,共9页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21935001 and 22379005);the Beijing Natural Science Foundation(No.Z210016);the National Key Research and Development Program of China(No.2018YFA0702002);Xinjiang Youth Science and Technology Top Talent Project(No.2022TSYCCX0053);Xinjiang Key Research and Development Project(No.2022B01003-2);the Fundamental Research Funds for the Central Universities,and the long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of PRC.

摘　　要：Zn-air batteries(ZABs)as a potential energy conversion system suffer from low power density(typically≤200 mW·cm^(−2)).Recently,three-dimensional(3D)integrated air cathodes have demonstrated promising performance over traditional twodimensional(2D)plane ones,which is ascribed to enriched active sites and enhanced diffusion,but without experimental evidence.Herein,we applied a bubble pump consumption chronoamperometry(BPCC)method to quantitatively identify the gas diffusion coefficient(D)and effective catalytic sites density(ρEC)of the integrated air cathodes for ZABs.Furthermore,the D andρEC values can instruct consequent optimization on the growth of Co embedded N-doped carbon nanotubes(CoNCNTs)on carbon fiber paper(CFP)and aerophilicity tuning,giving 4 times D and 1.3 timesρEC over the conventional 2D Pt/C-CFP counterparts.As a result,using the CoNCNTs with half-wave potential of merely 0.78 V vs.RHE(Pt/C:0.89 V vs.RHE),the superaerophilic CoNCNTs-CFP cathode-based ZABs exhibited a superior peak power density of 245 mW·cm^(−2) over traditional 2D Pt/C-CFP counterparts,breaking the threshold of 200 mW·cm^(−2).This work reveals the intrinsic feature of the 3D integrated air cathodes by yielding exact D andρEC values,and demonstrates the feasibility of BPCC method for the optimization of integrated electrodes,bypassing trial-and-error strategy.

关 键 词：Zn-air batteries three-dimensional(3D)integrated air cathodes superaerophilic gas diffusion coefficient effective catalytic sites density 

分 类 号：TM911.41[电气工程—电力电子与电力传动]