Efficient Flexible All-Solid Supercapacitors with Direct Sputter-Grown Needle-Like Mn/MnO@Graphite-Foil Electrodes...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Next-generation energy storage demands cost-effective, lightweight, safe, and flexible supercapacitors with high performance.
• Current research focuses on advanced electrode materials and solid electrolytes for improved capacitance, stability, flexibility, and safety.

Purpose of the Study:

• To develop novel flexible pseudocapacitive supercapacitor components using binder-free, nanostructured Mn/MnO2 layers on graphite foil and polymer gel electrolytes.
• To fabricate and characterize a flexible, lightweight, symmetric, solid-state supercapacitor device.

Main Methods:

• Fabrication of Mn/MnO2@Graphite-foil electrodes using reactive sputtering.
• Preparation of a polymer gel electrolyte with ionic liquid ethyl-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM)(TFSI).
• Characterization using X-ray diffractometry (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS).

Main Results:

• The fabricated supercapacitor exhibited a wide stable electrochemical potential window (up to 2.2 V) and long cycle stability.
• Achieved a maximum areal capacitance of 11.71 mF/cm2 at 0.03 mA/cm2.
• Demonstrated high areal energy density (7.87 mWh/cm2) and areal power density (1099.64 mW/cm2) with low resistance and good flexibility.

Conclusions:

• The developed flexible symmetric all-solid-state supercapacitors are promising candidates for integrated renewable energy storage.
• The materials and device design offer a safe, environmentally friendly, and high-performance energy storage solution.
• The supercapacitor shows potential for wide potential window operation without significant capacitance degradation.