Construction of an In-BDC MOF Artificial Interface Layer on Zinc Metal Anode for Ultra-Long Stability Zinc-Ion Capacitors

Abstract

Zinc anodes offer several compelling advantages, including elevated theoretical capacity, favorable redox potential, and plentiful natural reserves, which have made aqueous zinc-ion hybrid capacitors a focal point of intensive research. However, uncontrolled dendrite growth and hydrogen evolution reactions remain critical issues limiting their stability and reliability. In this study, an indium-based In-BDC MOF was constructed as protective layer on the surface of zinc foil. Benefiting from the zincophilic nature of In3+, the abundant porous channels in the MOF structure, and the physical shielding effect of the artificial protective coating, this interfacial layer exhibited excellent cycling stability. The In-BDC@Zn symmetric cell exhibited exceptional cycling durability, operating steadily for 1200 h under conditions of 2 mA cm-2 and 1 mAh cm-2, while maintaining stability beyond 1000 h at an elevated current density of 20 mA cm-2. When paired with activated carbon in a full zinc-ion hybrid capacitor, the device retained 40.8 mAh g-1 after 15,000 cycles at 1 A g-1, corresponding to 93.93% capacity retention.