Hierarchical core-shell fibers of graphene fiber/radially-aligned molybdenum disulfide nanosheet arrays for highly efficient energy storage

Abstract

Flexible fiber-shaped supercapacitors have broad application prospects in wearable and portable electronics and smart textiles, however, often suffered from their relatively low capacitance and energy density. In this paper, a unique core-shell fiber composed of graphene fiber and radially-aligned molybdenum disulfide nanosheet arrays (GF/MoS2) has been rationally designed and prepared. The morphology and structure of well-designed core-shell fibers were studied by Raman, X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopic (EDX) elemental mapping. All-solid-state, fiber-shaped symmetric supercapacitors were constructed by packaging two parallel GF/MoS2 core-shell fibers with PVA/H2SO4 electrolyte. Owing to the synergistic effects between graphene and MoS2, the fiber-shaped supercapacitor exhibits an enhanced areal capacitance up to 189.73 mF cm−2 and a high energy density of 14.665 μW h cm−2. The fibrous supercapacitors also exhibit good stability and flexibility. This work provides a strategy to design core-shell fibrous electrodes for high performance fiber-shaped supercapacitors, which also holds great potential for future flexible electronic devices.