Stabilizing a Reversible Sodiation Pathway Through a Partial Conversion and Vacancy‐Rich Host in Graphene‐Confined Te‐Rich MoSeTe Anodes for High‐Performance Sodium‐Ion Batteries

Abstract Transition metal dichalcogenide (TMD) anodes for sodium‐ion batteries (SIBs) are hindered by poor conductivity and destructive conversion reactions. Herein, the sodiation pathway in MoSe 2 is re‐engineered via synergistic design. Heavy tellurium doping induces a partial conversion reaction, creating a stable, vacancy‐rich Na x MoSeTe intermediate for reversible Na + storage. This engineered host is confined within a robust reduced graphene oxide framework, which acts as a conductive scaffold and mechanical buffer. This unique sodiation mechanism leverages an initial partial conversion to create a stable, vacancy‐rich host, which then facilitates highly reversible sodium storage. Consequently, the resulting MoSeTe@rGO anode demonstrates exceptional performance: a high reversible capacity of 512 mAh g −1 at 1 A g −1 , outstanding rate capability, and remarkable long‐term stability, retaining over 97.99% of its capacity after 1000 cycles at 5 A g −1 . Ex situ studies and DFT calculations confirm this vacancy‐mediated, reversible sodiation pathway. Furthermore, a full cell constructed with a Na 3 V 2 (PO 4 ) 3 @C cathode delivers a stable capacity of 368 mAh g −1 after 800 cycles at 5 A g −1 , showcasing its practical potential. This work presents a new paradigm for designing high‐performance TMD anodes, shifting the focus from merely mitigating conversion reaction issues to proactively engineering more stable and efficient electrochemical pathways.