Two-dimensional CuO nanosheets-induced MOF composites and derivatives for dendrite -free zinc -ion batteries

Uncontrollable dendrite growth and side reactions resulting in short operating life and low Coulombic efficiency have severely hindered the further development of aqueous zinc -ion batteries (AZIBs). In this work, we designed to grow zeolitic imidazolate framework-8 (ZIF-8) uniformly on Cu nanosheets (NSs) and prepared carbon -coated CuZn alloy NSs (CuZn@C NSs) by calcination under H-2/Ar atmosphere. As reflected by extended X-ray absorption fine structure (EXAFS), density functional theory (DFT), and in-situ Raman, the Cu-Zn and Zn-N bonds present in CuZn@C NSs act as zincophilic sites to uniformly absorb Zn ions and inhibit the formation of Zn dendrites. At the same time, CuZn@C NSs hinder the direct contact between zinc anode and electrolyte, preventing the occurrence of side reactions. More impressively, the symmetric cells constructed with CuZn@C NSs anodes exhibited excellent zinc plating/exfoliation performance and long life cycle at different current densities with low voltage hysteresis. In addition, low polarization, high capacity retention, and long cycle life over 1000 cycles at 5 A -g(-1) were achieved when CuZn@C NSs were used as anodes for CuZn@C/V2O5 full cells.

Automated summary

In this study, zeolitic imidazolate framework-8 (ZIF-8) was grown uniformly on Cu nanosheets, and carbon-coated CuZn alloy nanosheets were prepared by calcination under H-2/Ar atmosphere. The CuZn@C nanosheets acted as zincophilic sites to uniformly absorb Zn ions and inhibit the formation of Zn dendrites. They also prevented the direct contact between zinc anode and electrolyte, preventing side reactions. The CuZn@C nanosheets exhibited excellent zinc plating/exfoliation performance and long cycle life.