Enhanced electrochemical performance of W₁₈O₄₉/TiN binary composite electrodes for asymmetric supercapacitors

To develop high-performance supercapacitors, this study produced and thoroughly characterized a TiN-W₁₈O₄₉ nanocomposite electrode. The successful production of the TiN-W₁₈O₄₉ nanocomposite, which combines the high electrical conductivity of TiN with the pseudocapacitive behavior of W₁₈O₄₉, was validated by structural and morphological investigations (XRD, SEM, and EDX). The results of the electrochemical tests showed that the composite outperformed the materials used individually. Low solution resistance (R _s = 0.54 Ω) and a significantly reduced charge-transfer resistance (R _ct = 1.38 Ω) were observed by electrochemical impedance spectroscopy, suggesting effective electron transport and enhanced interfacial kinetics. Redox peaks were clearly visible in the potential window of 0.0-0.5 V at a scan rate of 50 mV s^-1 in cyclic voltammetry, and a high specific capacitance of 1482 F g^-1 at 1 A g^-1 was obtained in galvanostatic charge-discharge analysis. The asymmetric supercapacitor (ASC) operated in the potential range of 1.3 V retained 91.1% of its initial capacitance after 10 000 cycles, demonstrating exceptional cycling stability. Furthermore, the TiN-W₁₈O₄₉//AC asymmetric supercapacitor achieved a maximum power density of 4564.9 W kg^-1 and an impressive energy density of 58.91 Wh kg^-1. Based on these findings, the TiN-W₁₈O₄₉ heterostructure is a potential electrode material for next-generation supercapacitors due to the synergistic effect of the two materials.