Constructing fast ion/electron migration multichannels and aliovalent doping co-regulated MoSe₂ for high energy density Na⁺ storage

Constructing structures suitable for sodium ion deintercalation is of great significance for the innovation of sodium-ion batteries (SIBs) materials. In this work, multi-channel carbon nanofibers (MCFs) supported sulfurdoped MoSe2 (S-MoSe2) nanosheets are fabricated via modified electrospinning followed by in situ selenation process and sulfur deposition. The integrated S-MoSe2/MCFs can effectively buffer the volume stress caused by sodium ion (de)intercalation and provide abundant ion/electron migration transportations. As anode for SIBs, the S-MoSe2/MCFs demonstrates good rate capability, delivering 308.3 mAh g-1 at 10 A g-1. Additionally, it exhibits cycling stability, maintaining 336.2 mAh g-1 after enduring 1000 cycles at 5 A g-1. These attributes are direct result of the S-MoSe2/MCFs' structural stability and better electronic conductivity, as confirmed by diffusion analysis. When paired with Na3V2(PO4)2O2F cathode, the full cell also achieves a high energy density of 102.2 Wh kg-1. The detailed theoretical calculation of the different surface sites of S-MoSe2 confirming the high performance SIBs is due to the enhanced adsorption and diffusion performance of Na ion bought by the S doping. The study has provided substantial evidence supporting the creation of a network of rapid ion and electron migration pathways. This network effectively facilitates sodium-ion storage and paves the way for exploring the high-performance transition metal dichalcogenides (TMDs)-based electrodes in SIBs.