Pea-like MoS₂@NiS_1.03–carbon heterostructured hollow nanofibers for high-performance sodium storage

The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices. Here, we designed pea-like MoS₂@NiS_1.03–carbon hollow nanofibers using a simple electrospinning and thermal treatment method. The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_1.03 tube wall, in which pea-like uniformly discrete MoS₂ nanoparticles are enclosed. As a sodium-ion battery electrode material, the MoS₂@NiS_1.03–carbon hollow nanofibers have abundant diphasic heterointerfaces, a conductive network, and appropriate volume variation-buffering spaces, which can facilitate ion diffusion kinetics, shorten the diffusion path of electrons/ion, and buffer volume expansion during Na⁺ insertion/extraction. It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery. This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.