High-performance electrochemical supercapacitors based on polyoxometalate integrated into polyaniline and activated carbon nanohybrid

Abstract

Polyaniline (PANI) and carbonaceous materials and metallic compounds have played a significant role in energy storage and conversion devices. PANI has demonstrated tremendous potential in the supercapacitor industry due to its high specific capacitance, high flexibility, and economical price. The CPs damage the hierarchical structure during the charging and discharging process and start swelling. Thus, incorporating polyoxometalates (POMs) into the conducting polymer matrix increases the stability of the electrode material. Here, we have demonstrated a comparative study of two newly synthesized composite materials consisting of K<inf>5</inf>H<inf>2</inf>[PV<inf>4</inf>W<inf>8</inf>O<inf>40</inf>] ·11H<inf>2</inf>O, (PV<inf>4</inf>W<inf>8</inf>) POM incorporated into two different supports, such as pseudocapacitive polyaniline (PANI) and EDLC activated carbon (AC) matrix. It was observed that the PANI-PV<inf>4</inf>W<inf>8</inf> composite exhibited excellent capacitance nature at 0.5 M H<inf>2</inf>SO<inf>4</inf> electrolyte solution than AC-PV<inf>4</inf>W<inf>8</inf>. The PANI-PV<inf>4</inf>W<inf>8</inf> composite demonstrated the specific capacitance of 584 F g−1 at 0.8 A g−1. The composite also exhibited energy and power density of 81Wh kg−1 and 1598 W kg−1, respectively. Besides, the composite shows 93.13% capacity retention after 4500 cycles by cyclic voltammetry measurement at a 500 mV s−1 scan rate. Furthermore, the AC-PV<inf>4</inf>W<inf>8</inf> showed a specific capacitance of 62 F g−1 at the current density of 0.6 A g−1. Interestingly, The PANI-PV<inf>4</inf>W<inf>8</inf> composite could glow up the red and yellow LED bulb for more than a minute, suggesting a promising electrode material for practical supercapacitor purposes. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.