2D Confined Alloying‐Type SnS Anode Enabled by van der Waals Interaction for Fast and Long‐Life Sodium Storage

Abstract Sodium ion batteries (SIBs) are facing a shortage of anode materials with high‐capacity, durable, and high‐rate performance. SnS is a promising alloying‐type anode with high theoretical capacity, but still faces serious problems such as large volume expansion and sluggish ion transport kinetics. Herein, a van der Waals interaction strategy is proposed by atomically disperse SnS into interlayers of 2D 2D NbS 2 frameworks to form (SnS) 1.18 NbS 2 . In situ and ex situ analyses reveal the multistep reversible reaction processes during the charging (formation of layered structure NbS 2 confining amorphous SnS, (SnS) Amorphous NbS 2 ) and discharging (precipitation of fracture‐resistant Na 9 Sn 4 in the ionic‐conductive Na 0.67 NbS 2 /Na 2 S matrix) processes. Consequently, the (SnS) 1.18 NbS 2 anode exhibits a capacity of 943 mAh cm −3 at 0.44 C after 150 cycles, and retains 667 mAh cm −3 at 11 C after 2500 cycles with 100% capacity retention. The assembled (SnS) 1.18 NbS 2 || Na 3 V 2 (PO 4 ) 3 full cell maintains ≈100% capacity retention over 1000 cycles at 15 C. The full cell also exhibits good low‐temperature performance at −20 °C with a capacity retention of 100% after 1200 cycles at 1 C. The proposed van der Waals interaction strategy for stabilizing fast and high‐capacity Na + storage offers a viable pathway for practical SIBs.