Ar/NH₃ Radio‐Frequency Plasma Etching and N‐doping to Stabilize Metallic Phase 1T‐MoS₂ for Fast and Durable Sodium‐Ion Storage

Abstract Metallic phase 1T‐MoS₂ is considered a prospective anode material for sodium‐ion batteries (SIBs) due to its remarkable electrical conductivity and unique layered structure. However, 1T‐MoS₂ is thermodynamically unstable and prone to phase transition to the 2H‐MoS₂ phase. Herein, self‐supporting nitrogen‐doped and carbon‐coated 1T/2H mixed‐phase MoS₂ nanosheets with rich sulfur vacancies on carbon cloth (C@N‐MoS₂‐p/CC) are synthesized through a hydrothermal method and Ar/NH₃ radio‐frequency (RF) plasma treatment process. Density‐functional‐theory (DFT) calculations demonstrate that after Ar/NH₃ RF plasma treatment, nitrogen‐doping and etching effects are realized, which combine with carbon‐coating significantly reduce the phase transition energy of 1T‐MoS₂, thus triggering the phase transition and enabling the stable existence of the highly active 1T‐MoS₂. As a result, the C@N‐MoS₂‐p/CC exhibits outstanding sodium storage performance, with initial charge–discharge capacities of 701.0/797.0 mAh g⁻¹ at 1 A g⁻¹, respectively. It also demonstrates exceptional rate capabilities and ultra‐high cyclic stability, maintaining a discharge capacity of 404.2 mAh g⁻¹ after 910 cycles at a high rate of 2 A g⁻¹. In a full cell with Na₃V₂(PO₄)₃/CC cathode, it exhibits excellent initial charge–discharge capacities of 102.3/102.9 mAh g⁻¹ and maintains satisfactory cycling stability after 350 cycles (86.7 mAh g⁻¹) at 0.1 C.