Design of interfacial cobalt oxide on titanium boride hybrid nanocomposites for enhanced electrochemical performance

Abstract

We developed an interfacial cobalt oxide (Co3O4) and exfoliated titanium diboride (TB) hybrid composite (TBC HC) electrode material using a precipitation-assisted hydrothermal method to evaluate its electrochemical energy storage performance. Different TBC HCs were synthesized by varying the weight ratio of Co3O4 to TB (85: 15, 75:25 & 50:50). Structural characterization of the TBC HCs was performed using FTIR, XPS, XRD, FE-SEM, EDS, and FE-TEM. The resulting TBC HC electrode materials exhibited a hierarchical morphology with uniformly distributed Co3O4 nanoparticles at the TB interface. Electrochemical performance was studied using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Among the composites, the TBC2 HC (75:25) displayed a superior specific capacitance (Cs) of 1152.2 F/g at 0.5 A/g, outperforming pristine TB (189.2 F/g) and Co3O4 (629.6 F/g) in a three-electrode configurations using 1 M KOH electrolyte. Furthermore, a symmetric solid-state device (SSD) constructed with TBC2 HC (75:25)//TBC2 HC (75:25) delivered a specific capacitance of 256.1 F/g at 0.5 A/g, achievening a maximum energy density of 10.4 Wh/kg and a power density of 540.4 W/kg. The device maintained 87 % of its initial capacity after 10,000 charge-discharge cycles, demonstrating strong potential for energy-storage applications. © 2025 Elsevier Ltd