Spherical NiS decorated on Ti3C2 as cathode materials in Mg - S batteries

Magnesium‑sulfur batteries are regarded as a highly promising alternative to lithium‑sulfur batteries, offering notable benefits in cost-efficiency and environmental sustainability. The development of high-performance cathode materials is crucial for advancing rechargeable magnesium‑sulfur batteries. In this study, we fabricated Ti₃C₂@NiS/S composites as cathode materials using a straightforward hydrothermal method. The integration of Ti₃C₂ and NiS not only enhances the overall conductivity of the composites but also provides abundant active sites, leading to superior discharge performance and cycling stability. Compared to pure NiS/S, the Ti₃C₂@NiS/S-2 composite demonstrates exceptional cycling durability and rate capability, achieving a maximum specific capacity of 1385 mAh g⁻¹ at 0.1C. After 100 cycles, the capacity retention rate remains at 72.9 %, with a minimal capacity decay rate of approximately 0.0081 % per cycle. Furthermore, the Ti₃C₂@NiS/S-2 composite exhibits reversible capacities of 1344, 1199.8, 1076, 904, 674, and 322.5 mAh g⁻¹ at rates of 0.1, 0.2, 0.5, 1, 2, and 5C, respectively. When the current density is restored to 0.1C, the reversible specific capacity quickly recovers to 1280.7 mAh g⁻¹. The outstanding discharge performance of Ti₃C₂@NiS/S-2 is attributed to the optimized reversible reaction kinetics and the structural stability of the Ti₃C₂@NiS/S catalyst.