2D Metal-Organic Framework Derived Ultra-Thin Nitrogen-doped Oxygen Rich Porous Carbon Nanosheets for Zinc-Ion Hybrid Supercapacitors

Abstract

Zinc-ion hybrid supercapacitors (ZIHSCs) have attracted immense interest owing to their considerable energy density. However, the sluggish Zn²⁺ transfer kinetics on the cathode materials of ZIHSC result in poor rate-capability and low capacity. Herein, we employ a two dimensional (2D) metal-organic framework (MOF) nanosheet precursor to fabricate an ultra-thin N-doped oxygen rich porous carbon nanosheet (A-NOCNS). Owing to the merits of the 2D MOF precursor, the as-prepared A-NOCNS has an atomically thin thickness of only a. 2.5 nm, a high surface area, and a hierarchical porous structure with a microporous pore domain, which provides abundant surface active sites, fast ion diffusion channels, and efficient charge transport paths. Moreover, the uniform doping of N and rich O atoms provides extra redox capacitance, as well as super-hydrophilic properties. Consequently, the ZIHSC based on the A-NOCNS delivers an ultrahigh specific capacity of 176.48 mAh g-1 at 0.2 A g-1, exceptional energy and power densities (162.88 Wh kg-1 and 28.43 kW kg-1, respectively), and long-term cycling stability (90.23% after 20,000 cycles at 10 A g-1). The A-NOCNS demonstrates great potential for advanced ZIHSC applications and will guide the fabrication of low-dimensional carbon cathode materials using MOF precursors in the future. The A-NOCNS demonstrates great potential for advanced ZIHSC applications and may initiate the booming of the research of high-performance 2D carbon cathode materials using MOF precursors in the future.