Nickel Nanoparticles Embedded in MoO2/NC Hollow Spheres for Enhanced Durability and Stability of Sodium-Ion Batteries

Transition metal oxides demonstrate exceptional promise as advanced electrode materials for sodium-ion batteries (SIBs) due to their high theoretical capacity and tunable structure enabling efficient Na[Formula: see text] intercalation. In this study, nickel nanoparticle-embedded hollow MoO 2 /NC spheres integrated with nitrogen-doped carbon (Ni-MoO 2 /NC) are synthesized via a facile solvothermal method followed by thermal treatment. This novel morphology is achieved by dispersing nickel nanoparticles in a spherical structure. The nitrogen-doped carbon matrix further facilitates ion/electron transport and stabilizes the composite structure during cycling. The Ni-MoO 2 /NC can maintain a capacity of 106 mAh g[Formula: see text] after 10,000 cycles at 5.0 A g[Formula: see text]. The full cell exhibits remarkable rate adaptability, delivering a high specific capacity of 281 mAh g[Formula: see text] upon returning to 0.1 A g[Formula: see text], confirming robust electrochemical reversibility across varying current densities. This innovative design synergistically improves energy storage efficiency and structural durability, positioning it as a viable candidate for next-generation SIBs.