Heterostructured Nanocube‐Shaped Binary Sulfide (SnCo)S2 Interlaced with S‐Doped Graphene as a High‐Performance Anode for Advanced Na+ Batteries

Abstract Heterostructuring electrodes with multiple electroactive and inactive supporting components to simultaneously satisfy electrochemical and structural requirements has recently been identified as a viable pathway to achieve high‐capacity and durable sodium‐ion batteries (SIBs). Here, a new design of heterostructured SIB anode is reported consisting of double metal‐sulfide (SnCo)S 2 nanocubes interlaced with 2D sulfur‐doped graphene (SG) nanosheets. The heterostructured (SnCo)S 2 /SG nanocubes exhibit an excellent rate capability (469 mAh g −1 at 10.0 A g −1 ) and durability (5000 cycles, 487 mAh g −1 at 5.0 A g −1 , 92.6% capacity retention). In situ X‐ray diffraction reveals that the (SnCo)S 2 /SG anode undergoes a six‐stage Na + storage mechanism of combined intercalation, conversion, and alloying reactions. The first‐principle density functional theory calculations suggest high concentration of p–n heterojunctions at SnS 2 /CoS 2 interfaces responsible for the high rate performance, while in situ transmission electron microscopy unveils that the interlacing and elastic SG nanosheets play a key role in extending the cycle life.