Transition metal sulfides demonstrate attractive potential for sodium storage owing to their high theoretical specific capacity and high reserve. However, the low conductivity and volume expansion deteriorate their high-rate performance and cycling stability. In this work, we construct NiS₂/FeS heterostructure by growing Ni-based layered double hydroxide nanosheets on Fe-based Prussian Blue nanocrystals followed by gaseous sulfurization, giving rise to flower-like NiS₂/FeS nanoparticles. The as-prepared nanocomposite exhibits good rate performance of 156 mAh g⁻¹ at 50 A g⁻¹ and long cycle life of 606 mAh g⁻¹ at 5 A g⁻¹ after 1,000 cycles, which are superior to the heterostructure-free counterpart of NiS₂ and FeS. Density functional theory calculation further verifies that the enhanced electrochemical performance of NiS₂/FeS is due to the existence of interface derived from the heterostructure.

Li₄Ti₅O₁₂ is considered as a safe and stable anode material for high-power lithium-ion batteries due to its “zero-strain” characteristic during the charge/discharge. However, the intrinsically low electronic conductivity leads to a deterioration in high-rate performance, impeding its intensive application. Herein, the Li₄Ti₅O₁₂/rutile TiO₂ (LTO/RT) heterostructured nanorods with tunable oxide phases have been in-situ fabricated by annealing the electrospun nanofiber precursor. By constructing such a heterostructured interface, the as-prepared sample delivers a high capacity of 160.3 mAh·g^–1 at 1 C after 200 cycles, 125.5 mAh·g^–1 at 10 C after 500 cycles and a superior capacity retention of 90.3% after 1,000 cycles at 30 C, outperforming the heterostructure-free counterparts of pure LTO, RT and the commercial LTO product. Density Functional Theory calculation suggests a possible synergistic effect of the LTO/RT interface that would improve the electronic conductivity and Li-ion diffusion.