High-performance hybrid supercapacitor-immobilized Wells–Dawson polyoxometalates on activated carbon electrodes

Abstract

The nanofabrication of electroactive hybrid materials for next-generation energy storage devices is becoming increasingly significant as supercapacitor (SC) technology develops rapidly. The present study utilizes activated carbon (AC) templates reinforced with Wells–Dawson polyoxotungstates (POMs) to produce nanohybrid electrodes for high-performance supercapacitors. This study analyzes Wells–Dawson polyoxotungstates (P₂W₁₈) for the first time integrated with AC, and its structural and electrochemical performances are discussed. First, the electrochemical performances of symmetric supercapacitors were characterized in an acidic aqueous electrolyte (0.5 M H₂SO₄). It was observed that a supercapacitor cell containing the 5 wt% AC-P₂W₁₈ hybrid symmetric displayed a noteworthy specific capacitance of 289 F g⁻¹ and a remarkable energy density of 40 W h kg⁻¹. Moreover, 5% AC-P₂W₁₈ symmetric supercapacitor cells showed 89% cyclic stability over 4000 cycles. Three LED lights were charged onto the electrode. The LEDs continued to illuminate continuously for red until 160 seconds, yellow until 20 seconds, and blue until 10 seconds after removing the electrode from the electrochemical workstation, demonstrating the device's power and energy density.