Metal–Organic Framework-Derived NiS₂/C Nanocomposite for High-Performance Rechargeable Magnesium Batteries

Rechargeable magnesium batteries (RMBs) have become a research hotspot due to their high energy density, low cost, and safety. However, due to the high polarization and slow diffusion kinetics of Mg²⁺ in the cathode material, the development of a suitable cathode material is critical. NiS₂ is regarded as a promising cathode material for RMBs owing to its high theoretical specific capacity and weaker Ni–S bond. Nevertheless, the low conductivity of the discharge product and large volume change during cycling limits the application potential of the NiS₂ cathode. Hence, this work explored a metal–organic framework (MOF) derivative strategy to prepare a NiS₂/C nanocomposite via simultaneous carbonization and sulfurization. When employed as cathode material for RMBs, the as-prepared NiS₂/C nanocomposite with high NiS₂ content exhibited maximum discharge capacity of 379 mAh g⁻¹ at a current density of 200 mA g⁻¹, with specific capacity maintained at 213 mAh g⁻¹ after 100 cycles. The superior electrochemical performance benefits from both the nanosized NiS₂ and porous carbon skeleton, which may accelerate the electrochemical reaction kinetics and provide a buffer space for volume change during repeated charge and discharge.