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

MoS 2 , as a classical 2D material, becomes a capable anode candidate for sodium-ion batteries. However, MoS 2 presents a disparate electrochemical performance in the ether-based and ester-based electrolyte with unclear mechanism. Herein, tiny MoS 2 nanosheets embedded in nitrogen/sulfur-codoped carbon (MoS 2 @NSC) networks are designed and fabricated through an uncomplicated solvothermal method. Thanks to the ether-based electrolyte, the MoS 2 @NSC shows a unique capacity growth in the original stage of cycling. But in the ester-based electrolyte, MoS 2 @NSC shows a usual capacity decay. The increasing capacity puts down to the gradual transformation from MoS 2 to MoS 3 with the structure reconstruction. Based on the above mechanism, MoS 2 @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 MoS 2 @NSC‖Na 3 V 2 (PO 4 ) 3 full cell with ether-based electrolyte is assembled and demonstrates a capacity of 71 mAh g −1 , suggesting the potential application of MoS 2 @NSC. Here the electrochemical conversion mechanism of MoS 2 is revealed in the ether-based electrolyte and significance of the electrolyte design on the promoting Na ion storage behavior is highlighted.