Heterointerface engineering driven FeS₂/MoS₂ hollow porous nanofibers enable high-rate and ultra-long cycle sodium-ion batteries

Given the extensive potential of sodium-ion batteries (SIBs) for renewable energy storage and electric vehicles, it is crucial to develop anode materials that are of both affordable cost and long-term cycle stability to facilitate large-scale energy storage. However, existing anode materials face significant challenges regarding rate capability and cycle stability. To address this issue, we designed a bamboo-sprout-structured FeS₂/MoS₂ heterogeneous hollow porous nanofibers for SIBs anode. The heterogeneous components forms abundant highly Na-adsorbent heterointerface, which significantly lowers the migration energy barrier for Na-ions and speeds up redox kinetics, resulting in high capacity at elevated rates. The unique hierarchical hollow structure effectively mitigates volume expansion, encourages complete electrolyte penetration, and improves ion transport efficiency. This design also prevents the aggregation of FeS₂ and MoS₂, ensuring the structural stability over cycles. The FeS₂/MoS₂ hollow nanofibers anode demonstrates high specific capacity (671.3 mAh g⁻¹ at 0.5 A g⁻¹, 387.5 mAh g⁻¹ at 5.0 A g⁻¹) and maintains a stable capacity of 228.9 mAh g⁻¹ after 6700 cycles, showcasing remarkable ultra-long stability. This designing provides new insights for developing high-performance anodes for both SIBs and widespread implementation of secondary battery technology.