Intrinsic nitrogen-doped graphdiyne boosts sodium storage via fast ion desolvation kinetics

Sodium-ion batteries (SIBs) have emerged as promising alternatives to lithium-ion batteries. However, the development of SIBs is severely constrained by the limited capacity and inferior rate performance of the current anode materials. Herein, we focus on the molecular engineering of carbon materials to simultaneously enhance the Na storage capacity and charge-discharge kinetics. Specifically, intrinsic nitrogen doping was introduced to fabricate triazine-graphdiyne (TA-GDY), which not only created additional storage sites but also accelerated the Na⁺ diffusion process, thereby significantly improving the rate performance of SIBs. TA-GDY-based half-cell delivered a high reversible specific capacity of 580 mAh g⁻¹ at 100 mA g⁻¹. Even at 5000 mA g⁻¹, it still maintained a stable average specific capacity of 205 mAh g⁻¹ over 6000 cycles with a capacity retention of 95%, showcasing exceptional Na storage capacity and rate capability. Further study revealed the Na⁺ desolvation can be accelerated by the TA-GDY network. A pouch SIB constructed with the TA-GDY anode and NaNi_1/3Fe_1/3Mn_1/3O₂ cathode achieved an active-material-based impressive energy density of 361 Wh kg⁻¹, highlighting the great application potential of TA-GDY and providing a novel method for developing high-performance SIBs.