Sandwiched ReS₂ nanocables with dual carbon coating for efficient K⁺/Na⁺ storage performance

In this work, the nanocables of few-layered ReS₂ nanosheets sandwiched between carbon nanotubes (CNTs) and nitrogen-doped amorphous carbon (NC) coating (i.e., CNT@ReS₂@NC) are synthesized as high-performance anodes of both potassium-ion batteries (PIBs) and sodium-ion batteries (SIBs). The CNT@ReS₂@NC nanocables with dual carbon modifications have the several advantages for efficient K⁺/Na⁺ storage. The few-layered ReS₂ nanosheets with a wide interlayer spacing of 0.64 nm contribute to accelerated reaction kinetics for fast K⁺/Na⁺ intercalation/extraction. The carbon nanotube skeleton with a hollow interior can effectively relieve the volume change and serve as a robust conductive network to boost structural stability. The NC layer provides rich defects as active sites and suppresses the shuttle effect of polysulfides produced in discharge/charge processes. Consequently, the CNT@ReS₂@NC nanocables possess outstanding electrochemical performance in both PIBs and SIBs owing to the synergistic effect from the different components. A long cycling lifespan of 3500 cycles with a maintained discharge capacity of 125 mAh/g is achieved for CNT@ReS₂@NC at 1 A/g in PIBs. In SIBs, it can keep a high capacity of 202 mAh/g over 3000 cycles at 5 A/g. Moreover, the CNT@ReS₂@NC||Na₃V₂(PO₄)₃ full cell can exhibit remarkable cycling performance, yielding a low capacity decay rate of 0.019 % per cycle over 1000 cycles at 2C.