Nano-wired polyaniline/VS2 composite materials for quasi-solid-state supercapacitor and zinc-ion battery applications

Abstract

Electrochemical energy storage devices, including supercapacitors and metal-ion batteries, are some of the most sustainable energy technologies. The advancement of layered materials constantly improves the charge storage capacity of these devices by facilitating the intercalation/de-intercalation mechanism. In the present study, we have prepared a PANI/VS₂ composite material using a facile method and used it to fabricate quasi-solid-state supercapacitors (QSSCs) and zinc ion batteries (ZIBs). In situ growth of PANI on the layered VS₂ improved the conductivity and charge acceptor sites during the cycling process. The PANI/VS₂ composite showed an specific capacitance of 822 F g⁻¹ at 2 A g⁻¹ discharge current density due to the pseudocapacitance contribution from PANI. In addition, the observed nanowire network of PANI over the VS₂ surface facilitated the electrolyte accessibility. The assembled ZIB, with PANI/VS₂ as the cathode, showed a charge storage capacity of 219 mA h g⁻¹ at a discharge rate of 0.1 A g⁻¹ with a coulombic efficiency of ∼100% after 750 continuous cycles at 3 A g⁻¹. The observed higher charge storage capacity and the cycling reversibility of the devices are attributed to the robustness of the prepared PANI/VS₂ composite material.