All Transition Metal Selenide Composed High-Energy Solid-State Hybrid Supercapacitor

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Transition metal selenides (TMSs) offer excellent conductivity and redox activity for electrochemical devices.
• Current synthesis methods for TMSs are complex, hindering practical applications.
• Developing efficient TMSs is crucial for next-generation energy storage.

Purpose of the Study:

• To demonstrate a versatile in situ approach for synthesizing nanostructured TMSs.
• To design high-energy solid-state hybrid supercapacitors (HSCs) using these TMSs.
• To overcome the challenges associated with TMSs synthesis and improve their utility.

Main Methods:

• An in situ conversion reaction was used to anchor NiSe@Cu2Se (NiCuSe) and FeSe nanoparticles onto Cu foam.
• Nanostructured NiCuSe and FeSe electrodes were synthesized for positive and negative applications, respectively.
• Solid-state HSCs were assembled using the prepared electrodes.

Main Results:

• The NiCuSe and FeSe electrodes exhibited complementary potential windows and excellent electrical conductivity.
• The fabricated solid-state HSCs operated at a high voltage of 0-1.6 V.
• The HSCs achieved a specific energy density of 87.6 Wh kg−1 at 914.3 W kg−1 and retained 91.3% capacity over 10,000 cycles.

Conclusions:

• The in situ synthesis approach provides a feasible route for developing high-energy battery-type electrodes.
• The designed nanostructured TMSs offer superior electrochemical performance for hybrid supercapacitors.
• This work inspires new material synthesis strategies for advanced energy storage systems.