Zero-Dimensional Methylammonium Bismuth Iodide-Based Lead-Free Perovskite Capacitor

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Symmetrical electrochemical capacitors are crucial for energy storage due to their rapid charge-discharge capabilities, high energy density, and cost-effectiveness.
• Research focuses on identifying new, affordable electrode materials to enhance energy and power densities in these devices.

Purpose of the Study:

• To fabricate and evaluate an electrochemical double-layer capacitor utilizing a lead-free, zero-dimensional hybrid perovskite material, methylammonium bismuth iodide ((CH3NH3)3Bi2I9).
• To assess the electrochemical performance, including capacitance and cycle stability, of the developed device.

Main Methods:

• Fabrication of an electrochemical double-layer capacitor device.
• Electrochemical characterization including cyclic voltammetry and galvanostatic charge-discharge cycling.
• Impedance spectroscopy to analyze charge transport properties.

Main Results:

• The fabricated device achieved a maximum areal capacitance of 5.5 mF/cm².
• The capacitor demonstrated remarkable stability, retaining 84.8% of its initial capacitance after 10,000 charge-discharge cycles.
• Impedance spectroscopy indicated a high surface area of the active layer, facilitating electrolyte access and resulting in low charge transport resistance.

Conclusions:

• Methylammonium bismuth iodide is a promising lead-free material for high-performance electrochemical capacitors.
• The developed device exhibits excellent capacitance and long-term cycling stability, suitable for energy storage applications.
• The material's properties contribute to efficient charge transport, underpinning the device's superior performance.