A Porous Nano-Micro-Composite as a High-Performance Bi-Functional Air Electrode with Remarkable Stability for Rechargeable Zinc-Air Batteries  

作　　者：Yasir Arafat Muhammad Rizwan Azhar Yijun Zhong Xiaomin Xu Moses OTadé Zongping Shao 

机构地区：[1]WA School of Mines:Minerals,Energy and Chemical Engineering(WASM‑MECE),Curtin University,Perth,WA 6845,Australia [2]School of Engineering,Edith Cowan University,Perth,WA 6027,Australia [3]State Key Laboratory of Materials‑Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 210009,Jiangsu,People’s Republic of China

出　　处：《Nano-Micro Letters》2020年第10期87-102,共16页纳微快报（英文版）

基　　金：the support provided by the“Australian Government Research Training Program(RTP)Scholarship”at Curtin University,Perth,Australia。

摘　　要：The development of bi-functional electrocatalyst with high catalytic activity and stable performance for both oxygen evolution/reduction reactions(OER/ORR)in aqueous alkaline solution is key to realize practical application of zinc-air batteries(ZABs).In this study,we reported a new porous nano-micro-composite as a bifunctional electrocatalyst for ZABs,devised by the in situ growth of metal-organic framework(MOF)nanocrystals onto the micrometersized Ba0.5Sr0.5Co0.8Fe0.2O3(BSCF)perovskite oxide.Upon carbonization,MOF was converted to porous nitrogen-doped carbon nanocages and ultrafine cobalt oxides and CoN4 nanoparticles dispersing inside the carbon nanocages,which further anchored on the surface of BSCF oxide.We homogeneously dispersed BSCF perovskite particles in the surfactant;subsequently,ZIF-67 nanocrystals were grown onto the BSCF particles.In this way,leaching of metallic or organic species in MOFs and the aggregation of BSCF were effectively suppressed,thus maximizing the number of active sites for improving OER.The BSCF in turn acted as catalyst to promote the graphitization of carbon during pyrolysis,as well as to optimize the transition metal-tocarbon ratio,thus enhancing the ORR catalytic activity.A ZAB fabricated from such air electrode showed outstanding performance with a potential gap of only 0.83 V at 5 mA cm-2 for OER/ORR.Notably,no obvious performance degradation was observed for the continuous charge-discharge operation for 1800 cycles over an extended period of 300 h.

关 键 词：BSCF perovskites ZIF-67 Porous carbon Zn-air batteries Oxygen evolution reaction Oxygen reduction reaction 

分 类 号：TB33[一般工业技术—材料科学与工程] TM911.41[电气工程—电力电子与电力传动]