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

Abstract

AbstractMoS2, 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‖Na3V2(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.