Dual carbon confined MoS2 hierarchical microspheres as high-performance anode for sodium-ion batteries with superior cycling stability

Abstract

Due to the growing demand in the energy market, sodium-ion batteries (SIBs) have garnered significant attention as potential energy storage devices for large-scale applications. However, the sluggish kinetics and significant volume expansion during cycling bring about the poor electrochemical behavior of SIBs. In this work, a dual carbon including internal hard carbon core and external N-doped carbon shell confined MoS2 hierarchical microspheres (HC@MoS2@NC) nanocomposites are prepared as anode for SIBs with superior cycling stability and good rate capability. The dual carbon confinement can improve the structural stability of MoS2. The dual carbon with good electronic conductivity ensures well battery rate capability of MoS2 anode. Meanwhile, the larger interlayer spacing of 10.09 Å caused by NC insertion make MoS2 store more Na+. As a consequence, the HC@MoS2@NC nanocomposite delivers a high capacity of 321 mAh g−1 at 0.1 A g−1 after 100 cycles. At large current density of 2 A g−1, a high capacity of 180 mAh g−1 can still be achieved after 1000 cycles. Even at larger current density of 5 A g−1, the capacity can still be kept at 162 mAh g−1 after 100 cycles.