Self‐Activated Formation of Hierarchical Co3O4 Nanoflakes with High Valence‐State Conversion Capability for Ultrahigh‐Capacity Zn–Co Batteries. Issue 12 (27th January 2022)

• Record Type: Journal Article
• Authors: Shang, Wenxu; Yu, Wentao; Xiao, Xu; Ma, Yanyi; He, Yi; Zhao, Zhongxi; Tan, Peng
• Is Part Of: Small. Volume 18:Issue 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-27
• Subjects: Co‐based materials -- secondary structures -- ultrahigh capacity -- valence‐state conversion -- Zn batteries; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202107149
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Cobalt‐based materials are attracting increasing interest in alkaline Zn batteries due to the high theoretical capacity. However, the practical utilization is restricted by the poor microstructure and insufficient valence‐state conversion. Herein, a self‐activated formation of hierarchical Co3 O4 nanoflakes with high valence‐state conversion capability is designed. This electrode not only exhibits the optimized microstructure with large reaction surfaces, but also shows excellent valence‐state conversion capability. Consequently, this battery delivers an ultrahigh capacity of 481.4 mAh g −1 and an energy density of 818.3 Wh kg −1 based on the active material, which shines among reported Co‐based materials. Besides, the capacity can retain 41.9% with even 20× current density increases, and it can operate with a capacity decay of 20% after the 1000th cycle. This strategy greatly enhances the performance and durability of integrated air electrodes, raising the attention of boundary design for other electrochemical energy conversion and storage devices. Abstract : Cobalt‐based materials are attracting increasing interest in alkaline Zn batteries while restricted by the poor microstructure and insufficient valence‐state conversion. This work designs a self‐activated formation of hierarchical Co3 O4 nanoflakes with high valence‐state conversion capability, obtaining ultrahigh capacity.