Encapsulation of zinc hexacyanoferrate nanocubes with manganese oxide nanosheets for high-performance rechargeable zinc ion batteries

Abstract

With the rapid development of rechargeable zinc ion (Zn-ion) batteries, it is essential to understand and modulate the energy storage process of the active component to maximize the battery performance. In this research, manganese oxide (MnO₂) wrapped zinc hexacyanoferrate (ZnHCF) nanocubes (ZnHCF@MnO₂) were prepared using an in situ co-precipitation method. The resulting composite with a unique structure was able to modulate the Zn-ion storage because of the incorporation of capacitive and intercalative properties of both components together with the redox reactions, benefiting from the synergistic effects. Thus, the encapsulation of ZnHCF nanocubes with MnO₂ nanosheets gives a high discharge capability for Zn-ion storage with an operation voltage as high as ∼1.7 V. Impressively, the flexible quasi-solid-state Zn-ion battery was assembled using a neutral polymer gel electrolyte, and this resulted in a battery which had potential applications for specific wearable electronics.