Highly transparent supercapacitors based on ZnO/MnO₂ nanostructures

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Transparent electronics demand high-performance, transparent energy storage solutions.
• Existing carbon-based transparent supercapacitors have limited transparency (around 50%).
• ZnO/MnO2 nanostructured electrodes offer a promising alternative for transparent energy storage.

Purpose of the Study:

• To fabricate highly transparent supercapacitors using ZnO/MnO2 nanostructured electrodes.
• To investigate the effect of different MnO2 synthesis routes on supercapacitor performance.
• To evaluate the transparency and capacitance of the developed devices.

Main Methods:

• Fabrication of ZnO/MnO2 nanostructured electrodes via two MnO2 synthesis routes (KMnO4 with Mn(Ac)2 and PAH).
• Characterization of electrode materials and supercapacitor performance (capacitance, transparency).
• Testing of supercapacitors with a non-acidic LiCl gel electrolyte.

Main Results:

• Achieved high capacitances of 2.6 mF cm⁻² and 1.6 mF cm⁻² at 1 mV s⁻¹.
• Demonstrated significant capacitances of 104 μF cm⁻² and 204 μF cm⁻² at a high scan rate of 1 V s⁻¹.
• Attained a very high transparency of 86% (vs. air) for Mn(Ac)2-based devices, outperforming existing transparent energy storage devices.

Conclusions:

• ZnO/MnO2 nanostructured electrodes enable the fabrication of highly transparent and high-performance supercapacitors.
• The chosen synthesis route significantly impacts device performance and transparency.
• The use of a non-acidic gel electrolyte enhances safety and broadens application possibilities for transparent wearable devices.