Synergistic interface engineering of tungsten disulfide (WS2) with iron-cobalt-tellurium-zirconium (FeCoTeZr) for supercapattery devices

The increasing reliance on renewable energy sources has intensified the need for advanced energy storage technologies. Hybrid energy storage devices (HESDs) present a promising approach, combining both power and energy density. In this study, the energy storage performance of tungsten disulfide $\left({\text{WS}}_2\right)$ is enhanced by introducing an iron-cobalt-tellurium-zirconium (FeCoTeZr) alloy as an interfacial layer. This layer, deposited using a binder-free magnetron sputtering method, resolves the conductivity mismatch between the nickel foam (NF) substrate and ${\text{WS}}_2$, significantly improving device performance. The structural characteristics (SEM, XRD, Raman, and EDX) and electrochemical activities (CV, GCD, and EIS) of the prepared samples were acquired. The electrodes were subsequently used as a faradaic-dominated electrode in conjunction with activated carbon as electrochemical double-layer capacitor (EDLC) electrode in a real device. The high-efficiency WS₂/FeCoTeZr device achieved an energy density of 55 Wh/kg and a power density of 4250 W/kg, while retaining 97.9 % of its capacity after 3000 GCD cycles. Additionally, the device's capacitive and diffusive behaviors were analyzed using two modeling techniques. This novel strategy emphasizes the significant potential of interfacial-layer-enhanced HESDs as a cutting-edge solution for future energy storage systems.