The Construction of Nanoflower-like MoO₂@C Composites via Crystal Engineering for Ultrastable Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) offer advantages such as low cost, high safety, and environmental friendliness. However, the crystal structure design of cathode materials such as molybdenum oxide is of vital importance for AZIBs. Herein, a novel nanoflower-structured molybdenum dioxide (MoO2@C) is synthesized by using MnMoO4 nanoflower-like precursor. The presence of manganese and reduction process play a crucial role in the formation of nanoflower structure, which enhances the electrochemical performance when it is used as cathode for AZIBs. As a result, the MoO2@C cathode exhibits high initial coulombic efficiency, excellent cycling stability, and outstanding rate capability. Moreover, in situ/ex situ analysis (ex situ X-Ray diffraction/in situ Raman spectroscopy) is used to reveal Zn-ion storage mechanism of reversible intercalation and ultrastable structural framework.