Carbon Cloth-Supported NiSe₂/ZnSe Heterojunction Nanosheet Arrays as Anode Materials for Enhanced Sodium-Ion Storage

Exploiting high-efficiency anode materials with superior rate capability and desirable cycle stability for sustainable sodium-ion storage is significant but remains challenging. Here, NiSe2/ZnSe heterojunction nanosheet arrays vertically grown on carbon cloth (NiSe2/ZnSe@CC) were successfully constructed based on a solvothermal reaction followed by the selenylation process as anode materials to realize effective sodium-ion storage. The unique NiSe2/ZnSe heterojunction can offer an adjustable electronic structure to promote ion-electron transfer efficiency, leading to accelerated surface-internal reaction kinetics. Meanwhile, the uniformly well-aligned nanosheet array morphology and strong interplay between active materials and the collector not only provide a large buffer area but also further amplify charge transfer, both of which effectively improve structural integrity during cycling. Resultantly, the optimized NiSe2/ZnSe@CC as an independent anode manifests rapid rate performance (626.3 mAh g–1 at 0.1 A g–1 and 446.7 mAh g–1 at 5 A g–1) and a long-term cycling stability (393.8 mAh g–1 at 5.0 A g–1 over 2000 cycles), which far exceed those of the comparative NiSe2@CC, ZnSe@CC, and NiSe2/ZnSe powders and are at the forefront of most reported NiZn-based counterparts. Notably, the full-cell equipped with a NiSe2/ZnSe@CC anode and a Na3V2(PO4)3 cathode can harvest a remarkable cycle lifespan with a reversible capacity of 264.5 mAh g–1 after 300 cycles at 0.5 A g–1. This research can afford valuable insights for the targeted design of heterostructures in self-supporting anode materials aimed at improving the efficiency of sodium-ion storage.