WO3 Nanoparticle/Biomass Derived N-Doped Activated Carbon Decorated with Polyaniline Nanofibers Ternary Nanocomposite for High-Performance Symmetric and Asymmetric Supercapacitor

Supercapacitors have captured the curiosity of researchers due to their extremely high energy storage capacity. Hybrid supercapacitors deliver high specific capacitance values compared to the exciting (electrical double layer capacitor) EDLC and pseudocapacitors. This work presents a simple and scalable synthetic method to design a hybrid ternary composite as electrode material. In this work, the combination of EDLC-type behaviour material, i. e., sustainable biomass-derived Nitrogen-doped activated carbon (NAC) and pseudocapacitive behaviour electrode materials, i. e., metal oxides (tungsten oxide) and conductive polymer (polyaniline) are selected to achieve a high gravimetric capacity. The PANi/WO3/NAC (PWNAC) ternary composite is tested for symmetric and asymmetric supercapacitor (ASC). In a symmetric capacitor, PWNAC acts as both the positive and negative electrode, whereas in ASC, PWNAC acts as the positive electrode and NAC as the negative electrode. It is observed that the ASC shows a better capacitance value than symmetric. ASC operates at a potential range of 1.4 V in 1 M H2SO4 aqueous electrolyte, shows a maximum capacitance of 608.2 F/g at 0.5 A/g, and has long capacitance retention of 98.32 % of its initial capacitance after 2000 charge-discharge cycles.