Solvent Induced Activation Reaction of MoS₂ Nanosheets within Nitrogen/Sulfur-Codoped Carbon Network Boosting Sodium...

MoS₂ , as a classical 2D material, becomes a capable anode candidate for sodium-ion batteries. However, MoS₂ presents a disparate electrochemical performance in the ether-based and ester-based electrolyte with unclear mechanism. Herein, tiny MoS₂ nanosheets embedded in nitrogen/sulfur-codoped carbon (MoS₂ @NSC) networks are designed and fabricated through an uncomplicated solvothermal method. Thanks to the ether-based electrolyte, the MoS₂ @NSC shows a unique capacity growth in the original stage of cycling. But in the ester-based electrolyte, MoS₂ @NSC shows a usual capacity decay. The increasing capacity puts down to the gradual transformation from MoS₂ to MoS₃ with the structure reconstruction. Based on the above mechanism, MoS₂ @NSC demonstrates an excellent recyclability and the specific capacity keeps around 286 mAh g^-1 at 5 A g^-1 after 5000 cycles with an ultralow capacity fading rate of only 0.0034% per cycle. In addition, a MoS₂ @NSC‖Na₃ V₂ (PO₄ )₃ full cell with ether-based electrolyte is assembled and demonstrates a capacity of 71 mAh g^-1 , suggesting the potential application of MoS₂ @NSC. Here the electrochemical conversion mechanism of MoS₂ is revealed in the ether-based electrolyte and significance of the electrolyte design on the promoting Na ion storage behavior is highlighted.