Effectively Modulating Oxygen Vacancies in Flower-Like δ-MnO2 Nanostructures for Large Capacity and High-Rate Zinc-Ion Storage

• DOI: 10.1007/s40820-023-01194-3
• Publication Date: 2023-10-07T10:02:50Z
• Authors: Yiwei Wang; Yuxiao Zhang; Ge Gao; Yawen Fan; Ruoxin Wang; Jie Feng; Lina Yang; Alan Meng; Jian Zhao; Zhenjiang Li
• Keywords: Oxygen vacancy modulation; Technology; T; Large specific capacity; Znic-ion battery; High-rate capability; δ-MnO2 cathode materials; 0210 nano-technology; Article; 0104 chemical sciences

In recent years, manganese-based oxides as an advanced class of cathode materials for zinc-ion batteries (ZIBs) have attracted a great deal attentions from numerous researchers. However, their slow reaction kinetics, limited active sites and poor electrical conductivity inevitably give rise to the severe performance degradation. To solve these problems, herein, we introduce abundant oxygen vacancies into flower-like δ-MnO2 nanostructure effectively modulate vacancy defects reach optimal level (δ-MnO2-x-2.0). The smart design intrinsically tunes electronic structure, guarantees ion chemisorption-desorption equilibrium increases electroactive sites, which not only accelerates charge transfer rate during processes, but also endows more redox reactions, verified by first-principle calculations. These merits can help fabricated δ-MnO2-x-2.0 present large specific capacity 551.8 mAh g-1 at 0.5 A g-1, high-rate capability 262.2 10 excellent cycle lifespan (83% retention after 1500 cycles), is far superior those other metal compound cathodes. addition, charge/discharge mechanism has been elaborated through ex situ techniques. This work opens up new pathway constructing next-generation high-performance ZIBs materials.