Uniform In Situ Grown ZIF-L Layer for Suppressing Hydrogen Evolution and Homogenizing Zn Deposition in Aqueous Zn-Ion Batteries

The hydrogen evolution and dendrite of Zn anode are the major troubles hindering the commercialization of aqueous Zn-ion batteries (AZIBs). ZIF-Ls, a typical metal–organic framework (MOF) with a highly ordered structure and abundant functional groups, seem to be the answer for the above bottlenecks. In this paper, a uniform ZIF-L layer was obtained on the Zn surface (Zn@ZIF-L) via an in situ synthesis method to moderate the solvation structure of solid–liquid interface electrolyte reducing the contact between water and Zn, thereby relieving the hydrogen evolution and corrosion. Furthermore, density functional theory (DFT) analysis reveals the binding energy of H (−4.01 eV) and Zn (−0.82 eV) for ZIF-L is superior to that of pure Zn (H (−1.49 eV) and Zn (−0.68 eV)). Due to the multifunctional ZIF-L layer, the Zn@ZIF-L can regulate Zn deposition to overcome the dendrite for obtaining a long-life Zn anode. Consequently, the modified Zn@ZIF-L anode can cycle for 800 h at 0.25 mA cm–2 for 0.25 mAh cm–2, while the bare Zn anode is only maintained for 422 h. Finally, a designed V2O5 grown on carbon cloth (V2O5@CC) was used as the cathode and coupled with the Zn@ZIF-L anode to assemble the full-cell. The Zn@ZIF-L//V2O5@CC full-cell possesses a capacity retention rate of 84.9% after 250 cycles at 0.5 C, prominently higher than Zn//V2O5@CC (40.7%).