Scalable synthesis of mesoporous FeS₂ nanorods as high-performance anode materials for sodium-ion batteries

Sodium-ion batteries (SIBs), as highly promising alternatives to lithium-ion batteries (LIBs), can be widely used in a variety of next-generation energy storage systems. However, the current commercial graphite anodes of LIBs could not intercalate sodium ions to appreciable extent, and the electrochemical irreversibility hinders further application. Searching for a suitable anode material is a critical issue for the successful development of SIBs. Herein, we report a convenient, fast, and large-scale preparation method of mesoporous FeS₂ nanorods. Our specially designed one-dimensional mesoporous structure of FeS₂ takes full advantage of ultra-high strain relaxation as well as fast Na⁺ transport rate arising from microstructural characteristics. As a result, the mesoporous FeS₂ nanorods exhibited excellent sodium storage performance. The discharge capacity was retained at 711.1 mAh·g⁻¹ after 450 cycles at a current density of 1000 mA·g⁻¹. The special microstructure and superior performance of mesoporous FeS₂ nanorods represent a critical step for transition metal sulfides electrode materials toward practical SIBs application.