Controlling Diffusion Dynamics Through Additive Electrolyte Chemistry in Flexible Free-Standing Electrode With...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors (SCs) require electrodes with high electronic conductivity and specific capacitance, especially for neutral electrolyte applications.
• Free-standing electrodes face challenges in mechanical strength, flexibility, and charge transport.
• Developing advanced materials is crucial for next-generation energy storage devices.

Purpose of the Study:

• To develop a 1D/2D heterostructure electrode (rGO/PANI/Ce-MOF) for enhanced supercapacitor performance.
• To improve charge transport and ion mobility in neutral electrolytes.
• To investigate the impact of electrolyte additives on electrochemical properties.

Main Methods:

• Fabrication of a 1D/2D rGO/PANI/Ce-MOF heterostructure electrode.
• Engineering hydrogen bond interactions using propanol, 1,2-propanediol, and glycerol (Gly) as electrolyte additives.
• Electrochemical characterization including specific capacitance, energy density, and power density measurements.
• Density Functional Theory (DFT) calculations and Distribution of Relaxation Time (DRT) analysis.

Main Results:

• The rGO/PANI/Ce-MOF electrode exhibited improved mechanical strength, flexibility, and electrical conductivity.
• Specific capacitance reached 1180 F g^{- 1} in Na₂SO₄ and 1346 F g^{- 1} in a Gly-modified electrolyte.
• An asymmetric supercapacitor demonstrated an energy density of 113 Wh kg^{- 1} at 1.1 kW kg^{- 1} with 98% capacitance retention.
• DFT and DRT analyses confirmed enhanced ion interactions and electrode kinetics.

Conclusions:

• The 1D/2D rGO/PANI/Ce-MOF heterostructure is a promising material for high-performance flexible supercapacitors.
• Tailored electrolytes with additives can significantly enhance ion mobility and device performance.
• This approach offers a viable strategy for advanced energy storage in neutral electrolytes.