Heterointerface engineering and phosphorus doping dual-regulation enabled P-CoO/Co₉S₈@activated carbon for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitor performance relies heavily on electrode materials.
• Transition metal compounds (TMCs) offer high theoretical capacities but face challenges like poor charge transport and structural degradation.
• These limitations hinder their practical use in energy storage devices.

Purpose of the Study:

• To develop a novel dual-regulation strategy for constructing advanced supercapacitor electrode materials.
• To overcome the inherent limitations of transition metal compounds in energy storage.
• To engineer a P-doped CoO/Co9S8 heterostructure anchored on activated carbon (P-CoO/Co9S8@AC) for improved performance.

Main Methods:

• Fabrication of a P-doped CoO/Co9S8 heterostructure anchored on activated carbon (AC).
• Characterization of the material's structural and electrochemical properties.
• Performance evaluation in a hybrid supercapacitor (HSC) setup.
• Density Functional Theory (DFT) calculations to understand electronic properties and adsorption mechanisms.

Main Results:

• The P-doped CoO/Co9S8@AC heterostructure demonstrated a specific capacity of 1697.3 C g-1 at 1 A g-1.
• Achieved significantly reduced charge-transfer resistance (0.27 Ω) due to heterointerface and P doping.
• The assembled HSC delivered a high energy density of 90.4 Wh kg-1 and retained 86.1% capacity after 20,000 cycles.
• DFT calculations confirmed improved conductivity and OH- adsorption.

Conclusions:

• The dual-regulation strategy effectively enhances supercapacitor electrode performance.
• The P-CoO/Co9S8@AC material offers a promising solution for high-performance energy storage.
• This work provides a viable design pathway for composite electrodes using heterointerface engineering and heteroatom doping.