关键词: 锌离子混合电容器, 锌负极改性, 界面修饰, ZIF-8-In(Ⅲ), 循环稳定性

Aqueous zinc-ion hybrid capacitors (AZHCs) rationally combine the inherent merits of supercapacitors and secondary batteries, featuring superior power density, low manufacturing cost and excellent intrinsic safety, thereby emerging as one of the most promising advanced electrochemical energy storage devices. Nevertheless, their large-scale commercial applications are severely hindered by unavoidable inherent defects of zinc anodes, including uncontrollable dendrite growth, severe surface corrosion and parasitic hydrogen evolution reaction. Metal-organic framework (MOF) materials with high porosity, large specific surface area and favorable conductivity have been widely utilized for rational zinc anode interface modification. Herein, a functional composite modification layer integrating physical confinement and chemical ion-regulation capability is successfully fabricated by introducing In³⁺ into ZIF-8 via a facile one-step low-temperature hydrothermal method (35 °C, 24 h). The intrinsic three-dimensional ordered pores of ZIF-8 serve as oriented ion transport channels to guide directional Zn migration and physically isolate the zinc foil from corrosive electrolyte, effectively restraining adverse interfacial side reactions. Moreover, the doped In³⁺ significantly optimizes pore surface charge distribution and enhances surface positivity, which prevents excessive Zn²⁺ accumulation inside pores and drives migrating ions toward the zinc substrate to eliminate undesirable zinc aggregation. Electrochemical measurements and in-situ optical observations distinctly verify that the ZIF-8-In(III) interfacial layer realizes homogeneous zinc deposition and effectively strengthens the anode anticorrosion capability. Compared with bare Zn and ZIF-8@Zn electrodes, the optimized ZIF-8-In(III)@Zn symmetric coin cell delivers remarkably low polarization and maintains an ultralong cycling lifespan of 900 h at 2 mA cm^-2. Furthermore, the assembled AZHC with an activated carbon cathode achieves a specific capacity of 39.05 mAh g at 1 A g^-1, retaining nearly 100% capacity after 20000 long-term cycles. Besides, it possesses a maximum energy density of 36.96 Wh kg^-1 at a power density of 90 W kg^-1. This work provides an innovative and feasible route for high-efficiency zinc anode stabilization via ex-situ artificial interface engineering.

Key words: Zinc-ion hybrid capacitors, zinc anode modification, interface modification, ZIF-8-In(Ⅲ), cycling stability