Synergistic regulation of sodium storage in porous nanocubic metal selenide anode materials via dual-component collaboration for improving performance

Transition metal selenides (TMSs) possess low cost, high safety and excellent mechanical properties, but their low conductivity, high volume expansion, and poor cycle stability and rate properties severely limit their commercial development. This study proposes a simple hydrothermal synthesis strategy to successfully synthesize porous nanocubic bimetallic selenide (CoSe₂/FeSe₂) with heterogeneous interfaces. Excellent sodium storage characteristics are demonstrated by the CoSe₂/FeSe₂-based anode: at a large current density of 5 A g⁻¹ , the specific capacity can reach 546.88 mAh g⁻¹ , with exceptional rate performance; even when the current density is 10 A g⁻¹ for 3300 rounds, the specific capacity still remains at 318 mAh g⁻¹ , demonstrating excellent cycling stability. Experiments confirm that the porous nanocube structure of this material reduces volume expansion and enhances the efficiency of ion/electron transmission, while the heterointerface further improves diffusion kinetics, realizes high-speed transmission of sodium ions and inhibits detachment of nanoparticles, significantly enhancing cycle stability; It is a very interesting choice for anodes in sodium-ion batteries (SIBs) because of its high theoretical specific capacity and the combined effect of the two components.