Free-standing and flexible air electrodes with long-lasting bifunctional activities for both the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER)are crucial to the development of wearable Zn-air rechargeable batteries.In this work,we synthesize a flexible air electrode consisting of 3D nanoporous N-doped graphene with trimodal shells and Ni particles through repeated chemical vapor deposition(CVD)and acidic etching processes.Our results indicate that such trimodal graphene morphology significantly enhances the active N-dopant sites and graphene-coated Ni surface,which con-sequentially boosts both the ORR and OER activities,as well as catalytic durability.First-principles den-sity functional theory(DFT)calculations reveal the synergetic effects between the Ni and the N-doped graphene;namely,the Ni nanoparticles boost the bifunctional activities of the coated N-doped graphene,and in turn the graphene-covering layers enhance the stability of Ni.Thanks to the better protection from the triple graphene shells,our trimodal N-doped graphene/Ni-based Zn-air battery can be stably dis-charged/recharged beyond 2500 h with low overpotentials.It is reasonable to expect that such free-standing trimodal graphene/Ni would be promising in many flexible energy conversion/storage devices.

School of Materials Science and Engineering,Harbin Institute of Technology,Shenzhen 518055,Guangdong,China;Shenzhen R&D Center for Al-based Hydrogen Hydrolysis Materials,Shenzhen 518055,Guangdong,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China;Blockchain Development and Research Institute,Harbin Institute of Technology,Shenzhen 518055,Guangdong,China;Institute of Applied Physics,Graduate School of Pure and Applied Sciences,University of Tsukuba,Tsukuba 305-8573,Japan

[1]Yanyi Zhang;Xiang-Peng Kong;Xiaorong Lin;Kailong Hu;Weiwei Zhao;Guoqiang Xie;Xi Lin;Xingjun Liu;Yoshikazu Ito;Hua-Jun Qiu-.Enhanced bifunctional catalytic activities of N-doped graphene by Ni in a 3D trimodal nanoporous nanotubular network and its ultralong cycling performance in Zn-air batteries)[J].能源化学,2022(03):466-473

Enhanced,bifunctional,catalytic,activities,doped,graphene,by,trimodal,nanoporous,nanotubular,network,its,ultralong,cycling,performance,air,batteries,Free,standing,flexible,electrodes,lasting,both,oxygen,reduction,reaction,ORR,evolution,OER,are,crucial,development,wearable,rechargeable,In,this,synthesize,consisting,shells,through,repeated,chemical,vapor,deposition,CVD,acidic,etching,processes,Our,results,indicate,that,such,morphology,significantly,enhances,active,dopant,sites,coated,surface,which,sequentially,boosts,well,durability,First,principles,den,sity,theory,DFT,calculations,reveal,synergetic,effects,between,namely,nanoparticles,turn,covering,layers,stability,Thanks,better,protection,from,triple,our,battery,stably,dis,recharged,beyond,low,overpotentials,It,reasonable,expect,free,would,promising,many,energy,conversion,storage,devices

0.564393