Electrode Materials with High Performance of Nickel Sulfide/Titanium Nitride@Co-Based Metal–Organic Frameworks/Nickel Foam for Supercapacitors

Abstract

The metal–organic framework (MOF) materials with significant steadiness and a large specific surface area have been popular with supercapacitor material in recent years. However, its application in supercapacitors is restricted due to the low specific capacitance and poor conductivity. Herein, sulfur compounds with a high theoretical specific capacitance and highly conductive titanium nitride (TiN) were introduced into Co-based metal–organic frameworks/nickel foam (Co-MOF/NF) through a two-step hydrothermal technique (nickel sulfide/titanium nitride@ Co-based metal–organic frameworks/nickel foam). In detail, the fabricated nickel sulfide/titanium nitride@Co-based metal–organic frameworks/nickel foam (Ni3S2/TiN@Co-MOF/NF) electrode material exhibits a markedly high specific capacitance (2648.8 F g−1) at 1 A g−1, compared with that (770 F g−1) of the precursor Co-MOF/NF. And its mass specific capacitance is retained 88.3% (8 A g−1) after 5000 cycles. Furthermore, a non-symmetrical supercapacitor (ASC) composed of Ni3S2/TiN@Co-MOF/NF and AC exhibits excellent power density (801.8 W kg−1) and energy density (97.8 W h kg−1). Therefore, Ni3S2/TiN@Co-MOF/NF with excellent electrochemical properties and stability provides new ideas for the development of excellent supercapacitor electrode materials.

Keywords

• metal–organic framework materials
• power density
• two-step hydrothermal method
• energy density
• supercapacitor
• specific capacitance