Achieving high-performance parameters in NASICON-polymer composite electrolyte-based solid-state supercapacitors by...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state supercapacitors offer safer energy storage alternatives.
• Optimizing the electrode-electrolyte interface is crucial for enhancing supercapacitor performance.
• Activated carbon and solid polymer electrolytes are key components in supercapacitor design.

Purpose of the Study:

• To develop a strategy for enhancing solid-state supercapacitor performance.
• To optimize the electrode-electrolyte interface using a novel solvent layer approach.
• To investigate the impact of solvent incorporation on device characteristics and stability.

Main Methods:

• Utilized activated carbon electrodes with high surface area (1800 m² g⁻¹).
• Employed a Na₃Zr₂Si₂PO₁2 (NZSP) dispersed fast ionic solid polymer electrolyte.
• Introduced a small amount of acetonitrile organic solvent at the electrode-electrolyte interface.
• Performed galvanostatic charge-discharge cycles to assess performance and stability.

Main Results:

• Achieved a specific capacitance of ~260 F g⁻¹ and a high specific power of 4780 W kg⁻¹ at 3 V/5 mA.
• Demonstrated ~99% coulombic efficiency and ~90% capacitance retention after 10,000 cycles.
• Showcased the ability of five stacked cells to power an 8 V LED circuit for over 30 minutes.
• Observed enhanced utilization of activated carbon surface area and faster charge transfer.

Conclusions:

• The solvent layer approach effectively enhances solid-state supercapacitor performance.
• Solvent incorporation creates a local 'gel-like' layer, improving electrode-electrolyte coupling and charge movement.
• This strategy presents a promising pathway for developing high-performance, stable solid-state energy storage devices.