A potent assistor of firm MoO2/MoS2 heterojunction dominating high-rate and ultralong-life lithium/sodium storage

It is imperative to design the suitable anode materials of both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) with high-rate performance and ultralong cycling life. Herein, we fabricate a MoO2/MoS2 heterostructure that is homogeneously distributed in N,S-doped carbon nanofiber (MoO2/MoS2@NSC) by electrospinning technique and sulfuration engineering. The one-dimensional carbon skeleton serves as a conductive frame to decrease the diffusion pathway of Li+/Na+. The doping of N/S heteroatoms in carbon fiber creates abundant active sites and significantly enhances ion diffusion kinetics. Moreover, the in situ formation of MoS2 nanosheets on the MoO2 phase bulk intensifies the heterointerface, and the construction of heterointerface between MoO2 and MoS2 enables the fast Li+/Na+ transport, which is crucial for achieving the high efficiency energy storage. Consequently, as anode for LIBs, MoO2/MoS2@NSC delivers fantabulous cyclability of 640 mAh g-1 upon 2000 cycles under 5.0 A g-1 with an ultralow average capacity drop rate of 0.002 % per cycle and exceptional rate property of 614 mAh g-1 at 10.0 A g-1. For SIBs, it still renders the significantly enhanced electrochemical performance (reversible capacity of 242 mAh g-1 under 2.0 A g-1 upon 2000 loops and 261 mAh g-1 under 5.0 A g-1). The current work exploits a novel interface manipulation strategy to rationally develop anode materials, implementing rapid Li+/Na+ storage kinetics and durable cycling performance.