NiSe nanoparticles anchored on hollow carbon nanofibers with enhanced rate capability and prolonged cycling durability for sodium-ion batteries

Nickel selenides have been studied as potential anode materials for sodium-ion batteries due to their high theoretical capacity. However, the low electrical conductivity and the large volumetric variation during the charging/discharging process greatly reduce the specific capacity and cycling lifespan of the batteries. In this paper, a simple strategy to fabricate NiSe nanoparticles enclosed in carbon hollow nanofibers (NiSe/C@CNF) is proposed, involving the preparation of Ni-precursor nanofibers by electrospinning, the coating of polydopamine and the formation of NiSe/C@CNF by calcination and selenization. The combination of NiSe nanoparticles and porous carbon hollow nanofibers creates a strong conductive environment, which enhances the dynamic ability of sodium-ion transport and improves charge storage capacity. The fabricated NiSe/C@CNF material exhibits excellent performance. It demonstrates a high rate capability, with specific capacities of 406.8 and 300.1 mAh·g⁻¹ at 0.1 and 5.0 A·g⁻¹, respectively. These results highlight the potential of NiSe/C@CNF as an anode material for sodium-ion batteries, offering a large capacity and long life.