Hierarchical porous yolk-shell Co-N-C nanocatalysts encaged in graphene nanopockets for high-performance Zn-air battery  

作　　者：Yisi Liu Zongxu Li Shizhu Wang Jinnan Xuan Dongbin Xiong Lina Zhou Jianqing Zhou Jun Wang Yahui Yang Yue Du 

机构地区：[1]Institute for Advanced Materials,Hubei Normal University,Huangshi 435002,China [2]Jiangsu Key Laboratory of Materials and Technology for Energy Conversion,College of Material Science and Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China [3]National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources,College of Chemistry and Chemical Engineering,Hunan Normal University,Changsha 410081,China

出　　处：《Nano Research》2023年第7期8893-8901,共9页纳米研究（英文版）

基　　金：This study was supported by the National Natural Science Foundation of China(Nos.22008058 and 52074119);the Joint Funds of National Natural Science Foundation of China(No.U20A20280);the program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(No.T2021010);the Joint supported by Hubei Provincial Natural Science Foundation and Huangshi of China(No.2022CFD039);the Postgraduate Innovative Research Project of Hubei Normal University(Nos.20220512 and 20220552);College Students innovation and entrepreneurship training program of Hubei Province(No.S202210513055).

摘　　要：The rational design and preparation of promising cathode electrocatalysts with excellent activity and strong stability for metal-air batteries is a huge challenge.In this work,we innovate an approach of combining solvothermal with high-temperature pyrolysis utilizing zeolitic imidazolate framework(ZIF)-8 and ZIF-67 as the template to synthesize a novel hybrid material of hierarchical porous yolk-shell Co-N-C polyhedron nanocatalysts engaged in graphene nanopocket(yolk-shell Co-N-C@GNP).The obtained catalyst exhibits prominent bifunctional electrocatalytic performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)in the alkaline condition,in which the half-wave potential is 0.86 V for ORR,and the over-potential for OER is 0.42 V at 10 mA·cm^(-2).The rechargeable aqueous Zn-air battery fabricated with yolk-shell Co-N-C@GNP cathode deliveries an open circuit voltage(OCV)of 1.60 V,a peak power density of 236.2 mW·cm^(-2),and excellent cycling stability over 94 h at 5 mA·cm^(-2).The quasi-solid-state Zn-air battery(ZAB)using yolk-shell Co-N-C@GNP displays a high OCV of 1.40 V and a small voltage gap of 0.88 V in continuous cycling tests at 2 mA·cm^(-2).This work provides a valuable thought to focus attention on the design of high-efficient bifunctional catalysts with hierarchical porous yolk-shell framework and high-density metal active sites for metal-air battery technologies.

关 键 词：zeolitic imidazolate framework(ZIF)-67@ZIF-8 yolk-shell graphene nanopocket Bi-functional catalysts Zn-air battery 

分 类 号：O64[理学—物理化学]