Triple‐Shelled Manganese–Cobalt Oxide Hollow Dodecahedra with Highly Enhanced Performance for Rechargeable Alkaline Batteries

• Published in: Angewandte Chemie International Edition 2019-01, Vol.58 (4), p.996-1001
• Main Authors: Jiao, Chuangwei, Wang, Zumin, Zhao, Xiaoxian, Wang, Huan, Wang, Jing, Yu, Ranbo, Wang, Dan
• Format: Article
• Language: English
• Subjects: Alkaline batteries; Cobalt; Cobalt oxides; Electrochemical analysis; Electrochemistry; Manganese; manganese-cobalt oxide; Metal-organic frameworks; multi-shelled structures; Performance enhancement; rechargeable alkaline batteries; Rechargeable batteries; Structural stability; zeolitic imidazolate frameworks (ZIFs)
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201811683

Precisely carving of multi‐shelled manganese–cobalt oxide hollow dodecahedra (Co/Mn‐HD) with shell number up to three is achieved by a controlled calcination of the Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor (Co/Mn‐ZIF). The unique multi‐shelled and polycrystalline structure not only provides a very large electrochemically active surface area (EASA), but also enhances the structural stability of the material. The residual C and N in the final structures might aid stability and increase their conductivity. When used in alkaline rechargeable battery, the triple‐shelled Co/Mn‐HD exhibits high electrochemical performance, reversible capacity (331.94 mAh g−1 at 1 Ag−1), rate performance (88 % of the capacity can be retained with a 20‐fold increase in current density), and cycling stability (96 % retention over 2000 cycles). Me, my shell, and I: A controlled continuous two‐step calcination of the Mn‐doped zeolitic imidazolate framework ZIF‐67 precursor (Co/Mn‐ZIF) gives triple‐shelled manganese–cobalt oxide hollow dodecahedra (Co/Mn‐HD). Co/Mn‐HD has promising electrochemical performance for rechargeable alkaline batteries.