A material of hierarchical interlayer-expanded MoS₂nanosheets/hollow N-doped carbon nanofibers as a promising Li⁺/Mg²⁺co-intercalation host

Combining the high operational security of magnesium-ion batteries (MIBs) and the fast Li intercalation mechanism of lithium-ion batteries (LIBs), Li+/Mg2+ hybrid-ion batteries (LMIBs) have been developed and are regarded as a promising source of stored power for applications. However, pristine MoS2 with an interplanar distance of 0.62 nm only allows Li+ intercalation, leading to limited energy densities and mediocre electrochemical performance. Herein, we designed and prepared a material consisting of hierarchical interlayer-expanded MoS2 nanosheets/hollow N-doped carbon nanofibers (O-MoS2/HN-CNFs) with interplanar expanded O-MoS2 (0.94 nm). HN-CNFs adequately conduct electrons, and the expanded interlayer spacing of O-MoS2 ensures that Mg2+ and Li+ simultaneously intercalate into the host, even at 1000 mA g-1. Additionally, O-MoS2/HN-CNFs can significantly reduce the ion diffusion barrier and increase the number of intercalated active sites. As a result, O-MoS2/HN-CNFs exhibited superior rate capabilities, good cycling performance, and long-term cycling stability, with a reversible capacity of 134.4 mA h g-1 at 1000 mA g-1 after 2000 cycles.