Creating Unidirectional Fast Ion Diffusion Channels in G/NiS2‐MoS2 Heterostructures for High‐Performance Sodium‐Ion Batteries

Exploring novel electrode composites and their unique interface physics plays a significant role in tuning electrochemical properties for boosting the performance of sodium‐ion batteries (SIBs). Herein, mixed‐dimensional G/NiS2‐MoS2 heterostructures are synthesized in a low‐cost meteorological vulcanization process. The stable graphene supporting layer and nanowire heterostructure guarantee an outstanding structural stability to tolerate certain volume changes during the charge/discharge process. The rational construction of NiS2‐MoS2 heterostructures induces abundant interfaces and unique ion diffusion channels, which render fast electrochemical kinetics and superior reversible capacities for high‐performance SIBs. Interestingly, theoretical studies reveal that the anisotropic diffusion barriers create unidirectional “high‐speed” channels, which can lead to ordered and fast Na+ insertion/extraction in designed heterostructures. G/NiS2‐MoS2 anode exhibits a high capacity of 509.6 mA h g−1 after 500 cycles and a coulombic efficiency >99% at 0.5 A g−1, which also displays excellent cycling performance with the capacity of 383.8 mA h g−1 after the 1000 cycles at 5 A g−1. Furthermore, full cells are constructed exhibiting a high capacity of 70 mA h g−1 at 0.1 A g−1 after 150 cycles and applied to light LEDs. This study provides a feasible strategy of constructing mixed‐dimensional heterostructures for SIBs with excellent performance and a long service lifetime.