Ni-Doped MoS₂/N-Doped Carbon Hollow Nanostructures for Sodium-Ion Half and Full Batteries

Sodium-ion batteries (SIBs) are restricted in their energy storage capacity primarily because the considerable size of Na⁺ and inherently slow redox processes limit efficient charge transfer. Transition metal chalcogenides with layered structures have considerable promise as advanced materials of SIBs. Herein, the Ni-doped hollow MoS₂/NC spheres with nitrogen-doped carbon are fabricated by a simple water/ethanol system combined with thermal annealing. Nickel doping effectively modifies the electronic properties of MoS₂, leading to a substantial improvement in electrical conductivity and an increase in the density of electrochemically active sites. The addition of nitrogen-doped carbon within the composite helps to improve redox kinetics, ensuring improved structural integrity. Consequently, the Ni-MoS₂/NC anode demonstrates excellent cycling stability, delivering a capacity of 176 mAh g^-1 at 5.0 A g^-1 for 10,000 cycles. Moreover, a full battery paired with a Na₃V₂(PO₄)₃/C cathode exhibits impressive rate performance, when the current is restored to 0.1 A g^-1, and it showed a high specific capacity of 326 mAh g^-1, which indicates that the Ni-MoS₂/NC||Na₃V₂(PO₄)₃/C full battery exhibits robust performance across varying current densities, maintaining high electrochemical reversibility. This effective approach ensures improved electrochemical performance, prolonged cycling life, and higher efficiency, making hollow nanostructures a promising design for next-generation energy storage systems.