High Magnetic Field-Engineered Bunched Zn-Co-S Yolk-Shell Balls Intercalated within S, N Codoped CNT/Graphene Films...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Faradaic redox reactions in supercapacitors depend heavily on material microstructure, including surface area, porosity, composition, and conductivity.
• Tuning these properties is key to developing superior electrode materials for enhanced energy storage.

Purpose of the Study:

• To investigate the use of high magnetic fields (HMF) to control the microstructure of bimetallic sulfides for supercapacitor applications.
• To develop a novel HMF-controlled synthesis method for one-dimensional (1D) bunched Zn-Co-S yolk-shell balls (ZCS^6T BYSBs).

Main Methods:

• A novel HMF-controlled anion-exchange methodology was employed to synthesize ZCS^6T BYSBs.
• Flexible films of ZCS^6T BYSBs embedded in S, N codoped carbon nanotubes/graphene (CZS^6T/CNTs/SNGS) were fabricated via vacuum filtration.
• Asymmetric supercapacitors were assembled using the fabricated electrodes.

Main Results:

• HMF induced directional growth and 1D assembly of Zn_0.76Co_0.24S, resulting in ZCS^6T BYSBs with enhanced surface area, pore volume, crystallinity, and electrical conductivity.
• The CZS^6T/CNTs/SNGS electrode demonstrated significantly improved specific capacitance and rate capability, retaining 78.7% capacitance at 30 A g^-1.
• The asymmetric supercapacitor achieved a high energy density of 41.1 W h kg^-1 at a power density of 9022 W kg^-1 with remarkable cycling stability.

Conclusions:

• HMF is an effective tool for tailoring the microstructure of bimetallic sulfides, leading to superior supercapacitor electrode performance.
• The developed ZCS^6T BYSBs and their integration into flexible films offer a promising pathway for high-performance energy storage devices.
• The study highlights the potential of HMF-assisted synthesis for next-generation electrochemical energy storage systems.