Correlation between structural properties and electrochemical performances of h-BN/AC/NiO/Poly(ANI-co-Py) electrodes for supercapacitors

In this study, a hybrid electrode material composed of hexagonal boron nitride (h-BN), activated carbon (AC), nickel (II) oxide (NiO) and poly(aniline-co-pyrrole) (Poly(ANI-co-Py) was developed for high-performance supercapacitor applications. The AC was derived from wheat straw, a sustainable and low-cost biomass source abundantly cultivated in the Thrace Region of Turkiye. Structural optimization focused on enhancing electrical conductivity, pore size distribution, and surface area to achieve superior electrochemical performance. Although h-BN offers excellent chemical and thermal stability, its low-conductivity was compansated by the incorporation of NiO nanoparticles, which improved electron transport through redox activity. Additionally, the copolymerization of aniline and pyrrole provided extented pi-conjugation, further increasing the conductivity of the hybrid system. As a result, the low electrical serial resistance (ESR) and higher power density were obtained in the supercapacitor. Comprehensive characterization was conducted using FTIR-ATR, SEM-EDX, XRD, BET, AFM, TEM, TGA-DTA, CV, GCD and EIS analyses. The optimized electrode composition ([ANI]o/[Py]o=1:2) exhibited the highest specific capacitance of 261 F/g at a scan rate of 2 mV/s. The findings demonstrate a strong correlation between structural parameters and electrochemical behavior, providing a promising route toward cost-effective and sustainable symmetric supercapacitor materials.