Reliable, High-Performance Electrochromic Supercapacitors Based on Metal-Doped Nickel Oxide

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Electrochromic supercapacitors (ECSs) integrate energy storage and display functionalities.
• Developing stable and high-performance materials is crucial for advancing ECS technology.

Purpose of the Study:

• To fabricate high-performance and reliable electrochromic supercapacitors (ECSs).
• To optimize device performance by controlling material stoichiometry and doping.
• To investigate the visual indication of energy storage status.

Main Methods:

• Fabrication of tungsten trioxide (WO3) and nickel oxide (NiO) films for ECSs.
• Controlled adjustment of NiO film thickness and WO3 film thickness (∼660 nm).
• Copper (Cu) doping of NiO films (≤10 mol %) to enhance conductivity and electrochemical activity.

Main Results:

• Optimized ECS with 7 mol % Cu doping achieved high areal capacitance (∼14.9 mF/cm²) and excellent coulombic efficiency (∼99%).
• Demonstrated wide operating temperature range (0-80 °C) and superior cyclic stability (>10,000 cycles).
• Achieved synchronized transmittance changes with galvanostatic charging/discharging for real-time visual energy status indication.

Conclusions:

• The developed copper-doped NiO/WO3 ECS exhibits promising potential for energy storage applications.
• The device offers a visually intuitive method for monitoring energy storage status.
• These findings suggest a viable platform for future electronic components requiring integrated energy storage and display.