Highly Stable Poly(o-methoxyaniline)/WO₃-Nanoflower Composite-Based Electrochromic Supercapacitors with Real-Time Charge Indication

Polymer-based electrochromic supercapacitors (ECSs) arestate-of-the-artinnovations that use a color change to visually convey stored energystatus in real time. However, the electrochemical instability of thepolymers utilized in such devices limits their commercialization dueto the difficulties in solution processability and short charge-dischargecyclic life. Herein, a simple and cost-effective chemical oxidativepolymerization method is proposed for developing a highly stable andelectrochromically active nanocomposite comprising poly-(o-methoxyaniline) (PMOANI) and WO3 nanoflowers. The nanocompositeshows areal and specific capacitances of 83 mF/cm(2) and133.16 F/g, respectively. Moreover, the practical multifunctionalityof the nanocomposite is demonstrated by developing an ECS device (5x 5 cm(2)), which shows an energy density of 370 mWh/kgand power density of 4 W/kg with stable and prolonged charge-dischargecycles (>5000). Further, the ECS device is utilized to power atimerdisplay (1.2 V) for >20 min using the energy stored in the chargedstate (blue color), which changes its color during discharge, demonstratingits capability as a power source with a real-time energy level indicator.It is expected that the polymer/metal oxide nanocomposite will certainlybe a promising candidate to replace the traditional polymers in ECStechnologies to achieve prolonged stability for their applicationin modern electronic gadgets and infrastructures.