Metal sulfides are promising anode candidates for sodium-ion batteries (SIBs) due to their high theoretical capacities. However, their practical application is limited by significant volume extension and sluggish Na+ diffusion during cycling, which lead to rapid capacity degradation and poor long-term stability. In this work, we report the rational design of a hollow triple-shelled high-entropy sulfide (NaFeZnCoNiMn)9S8, synthesized through sequential templating method under hydrothermal conditions. Transmission electron microscopy confirms its well-defined three-shelled architecture. The inter-shell voids effectively buffer Na+ insertion/desertion-induced volume extension, while the tailored high-entropy matrix enhances electronic conductivity and accelerates Na+ transport. This synergistic design yields outstanding performance, including a high initial Coulombic efficiency (ICE) of 94.1% at 0.1 A g-1, low charge-transfer resistance (0.32~2.54 Ω), fast Na+ diffusion efficiency (10-8.5-10-10.5 cm2 s-1), and reversible capacity of 582.6 mAh g-1 after 1600 cycles at 1 A g-1 with 91.2% capacity retention. These results demonstrate the potential of high-entropy, multi-shelled architectures as a robust platform for next-generation durable SIB anodes.
Keywords: high-entropy materials; hollow multi-shelled structures; sodium–ion batteries; transition metal sulfides.