Hydrophobic Metal-Organic Framework-Based Ion-Conductive Interfaces Toward Stabilizing Zn Metal for High-Performance
Mingzheng Ge1, Jing Shang1, Yanrui Zhao1
1School of Textile and Clothing, Nantong University, Nantong, P. R. China.
None:
Aqueous zinc-ion batteries (AZIBs) have received numerous attention due to their high safety, low cost, and environmental friendliness. However, Zn metal suffers from uncontrollable dendritic Zn growth, H2 generation and Zn corrosion, etc., which seriously reduce the lifetime of aqueous zinc-metal batteries. To overcome these challenges, an artificial hydrophobic metal-organic framework (MOF)-based ion-conductive protective coating is constructed to stabilize the Zn metal anode for high-performance AZIBs. The hydrophobic pores in zeolitic imidazolate framework (ZIF-8) provide channels for rapid Zn-ions migration, reduce the desolvation activation energy of Zn-ions, and facilitate Zn uniform deposition, inhibiting dendrite growth. Meanwhile, the outer layer polydimethylsiloxane (PDMS) around ZIF-8 prevents Zn metal from contacting water molecules, which suppresses H2 generation, Zn corrosion, and by-products formation. Thus, the lifetime of PDMS@ZIF-8-modified Zn anode extends over 1100 h at the current density/areal capacity of 2 mA cm-2/1 mAh cm-2, significantly longer than that of bare Zn (80 h). Meanwhile, the full cells paired with a VO2 cathode exhibit excellent long-term cycling stability, maintaining 82.3% capacity retention after 870 cycles at 3A g-1, which is much higher than that of bare Zn (61.3%). This facile strategy is applicable to other aqueous metallic batteries toward practical applications.
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