Ni_0.85Se@MoSe₂ Nanosheet Arrays as the Electrode for High-Performance Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors are crucial for energy storage.
• Developing high-performance electrode materials is essential for improving supercapacitor efficiency.
• Nickel selenide (NiSe) and molybdenum diselenide (MoSe2) are promising but require optimized structures.

Purpose of the Study:

• To synthesize novel Ni0.85Se@MoSe2 nanosheet arrays.
• To evaluate their performance as electrode materials for supercapacitors.
• To fabricate and test an asymmetric supercapacitor (ASC) using these arrays.

Main Methods:

• A facile one-step hydrothermal method was employed.
• Nickel foam was used as the nickel precursor.
• MoSe2 was integrated to form hierarchical nanosheet arrays.

Main Results:

• Ni0.85Se@MoSe2 nanosheet arrays exhibited a high specific capacitance of 774 F g-1.
• Performance significantly surpassed Ni0.85Se and MoSe2 nanoparticles.
• An ASC device (Ni0.85Se@MoSe2//Graphene Nanosheets) showed 1.6 V output, 25.5 Wh kg-1 energy density, and 88% retention after 5000 cycles.

Conclusions:

• Ni0.85Se@MoSe2 nanosheet arrays are highly effective electrode materials for supercapacitors.
• The hierarchical architecture enhances electrochemical performance.
• The developed ASC demonstrates excellent energy density and cycling stability.