Atomically dispersed NiN4Cl-NC nanoreactors catalyze high-efficiency MoSe2 conversion for remarkable sodium storage

Sodium-ion batteries based on two-dimensional (2D) lamellar structural MoSe 2 anode have emerged as a promising candidate thanks to its high theoretical capacity and favorable band gap structure. Yet, its intrinsic limitations involving poor conductivity, limited reaction reversibility, and unavoidable volumetric fluctuations upon cycling trigger severe structural degradation and capacity fading, ultimately resulting in inferior rate kinetics and unsatisfactory cycling durability. Herein, an innovative atomic-level interfacial coupling engineering is applied for fabricating a 2D hierarchical nanoarchitecture with ultrathin MoSe 2 nanosheet grafting on graphene-like nitrogen-doped carbon-supported atomically dispersed NiN 4 Cl active sites (MoSe 2 @NiN 4 Cl-NC). Collaborative electrochemical analyses and computational modeling reveal that the NiN 4 Cl-NC architecture as an efficient nanoreactor can significantly optimize electronic conductivity and charge transfer efficiency while enhancing Na + -ion adsorption and migration capability, as well as reduce thermodynamic barriers for Na 2 Se/Na x MoSe 2 decomposition, thereby achieving superior spatial confinement and reaction reversibility of active species. In-situ/ex-situ electrochemical analysis showcases high phase-transformation reversibility of MoSe 2 during the sodiation and desodiation processes. Consequently, as-fabricated composites deliver an attractive rate capability and cyclic lifespan, that is, a capacity of 230 mAh g -1 at 20.0 A g -1 over 4600 cycles. Remarkably, the fabricated sodium-ion full cells and capacitors based on MoSe 2 @NiN 4 Cl-NC anode demonstrate excellent performance metrics and remarkable energy/power density, collectively validating its potential proof-of-feasibility in practical use. An innovative atomic-level interfacial coupling engineering is applied for fabricating a 2D hierarchical nanoarchitecture with ultrathin MoSe 2 nanosheet grafting on graphene-like nitrogen-doped carbon-supported atomically dispersed NiN 4 Cl active sites (MoSe 2 @NiN 4 Cl-NC). Based on the remarkable advantages of ingenious nanoarchitectures, the MoSe 2 @NiN 4 Cl-NC presents significantly improved reaction reversibility and admirable electrochemical performance.