An Integrated Grid Interface of Electrode for Sodium-Ion Battery

Sodium-ion batteries (SIBs) attract the research interest of many scientists due to their cost-effectiveness, the abundance of natural sodium resources, and the great potential to replace metal lithium batteries. However, they also encounter substantial issues including sluggish ion kinetics, substantial volume changes, and interfacial instability during cycling. In this study, a GDY/SnO₂/GDY heterostructured anode is fabricated using a grid encapsulation strategy, where SnO₂ nanoparticles are dispersed within a framework of graphdiyne (GDY) nanowalls. The interconnected porous GDY simultaneously enables rapid ion diffusion kinetics and efficient electron transport while providing mechanical compliance to accommodate volume variations of SnO₂. Interestingly, the integrated GDY framework acts as a protective barrier against SnO₂ nanoparticle agglomeration and structural coarsening during electrochemical cycling, thereby substantially improving electrode longevity. SIBs based on the GDY/SnO₂/GDY anode exhibit a stable specific capacity as high as 730 mAh g⁻¹ at 50 mA g⁻¹, remarkable rate capacity, and average specific capacity of 229.5 mAh g⁻¹ with ultralong stability for over 2750 cycles even at 5 A g⁻¹. This work highlights that the rational interface and structure design to realize rapid ion diffusion kinetics and resists volume changes of electrode material for high performance SIBs.