Core-shell-structured Co@Co4N nanoparticles encapsulated into MnO-modified porous N-doping carbon nanocubes as bifunctional catalysts for rechargeable Zn-air batteries

• 作者: Bin Li Fengmei Wang Huimin Zhao Lei Wang Yiru Ma Yu Yang Yuanyuan Cui Ziyang Guo
• 来源期刊: 能源化学
• 年，卷（期）: 2020,（11）
• 页码范围: 52-62
• 页数: 11页
• 语种: 英文

摘要

Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction (ORR/OER) is paramount for metal-air batteries.Metal-organic frameworks (MOFs)-based materials have attracted a great deal of attention as the potential candidate for effectively catalyzing ORR/OER due to their adjustable composition and porous structure.Herein,we first introduce the Mn species into zeolitic-imidazole frameworks (ZIFs) and then further pyrolyze the Mn-containing bimetallic ZIFs to synthesize core-shell-structured Co@Co4N nanoparticles embedded into MnO-modified porous N-doped carbon nanocubes (Co@Co4N/MnO-NC).Co@Co4N/MnO-NC exhibits the outstanding catalytic activity toward ORR and OER which is attributed to its abundant pyridinic/graphitic N and Co4N,the optimized content of MnO species,highly dispersed catalytic sites and porous carbon matrix.As a result,the Co@Co4N/MnO-NC-based Zn-air battery exhibits enhanced performances,including the high discharge capacity (762 mAh gzn-1),large power density (200.5 mW cm-2),stable potential profile over 72 h,low overpotential (＜1.0 V) and superior cycling life (2800 cycles).Moreover,the belt-shaped Co@Co4N/MnO-NC cathode-based Zn-air batteries are also designed which exhibit the superb electrochemical properties at different bending/twisting conditions.