Composite Assembling of Oxide-Based Optically Transparent Electrodes for High-Performance Asymmetric Supercapacitors.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Achieving transparent and high-energy density supercapacitors is challenging due to material trade-offs.
• Existing transparent energy storage solutions often compromise on performance or optical clarity.

Purpose of the Study:

• To develop an optically transparent asymmetric supercapacitor (Trans-ASC) with high energy density.
• To investigate the electrochemical performance and transparency of novel composite thin-film electrodes.

Main Methods:

• Fabrication of ZnO-SnO2 and TiO2-SnO2 composite thin-film electrodes on indium-doped tin oxide substrates using reactive DC magnetron cosputtering.
• Electrochemical characterization of the electrodes in 0.5 M KOH electrolyte.
• Assembly and testing of the TiO2-SnO2//ZnO-SnO2 Trans-ASC device.

Main Results:

• The composite thin films exhibited high optical transmittance (68% for ZnO-SnO2, 64% for TiO2-SnO2).
• The Trans-ASC operated at +1.2 V, achieving an areal capacitance of 44.6 mF cm-2 at 2 mA cm-2.
• The device demonstrated a maximum areal energy density of 8.75 μW h cm-2 and power density of 570 μW cm-2.
• Excellent cycling stability with 81.6% capacitance retention after 10,000 cycles, maintaining significant transparency.

Conclusions:

• The developed Trans-ASC successfully balances high energy density with optical transparency.
• The novel composite electrodes exhibit robust electrochemical performance and cycling stability.
• This Trans-ASC is a promising candidate for integrated transparent electronic devices and energy storage applications.