Carbon-coated MoSe₂/MXene heterostructures as active materials for high-performance Na⁺ batteries

Despiting the technological promise and environmental friendliness of sodium-ion batteries (SIBs), relatively large sizes of Na-ions and moderate oxidation-reduction response slows down their wider-spread industrial implementation. To overcome this obstacle, we developed carbon-coated MoSe₂/MXene heterostructures, in which MXene was covered on the MoSe₂ particles and the loose carbon linked all the coated particles while providing porosity. The density-functional theory was used to understand the electronic structure of the carbon-coated MoSe₂/MXene (MoSe₂/Mo₂CT_x/C) and the mechanism of exchanging charge between MoSe₂ and MXene. MoSe₂/Mo₂CT_x/C as active anode material showed exceptional stability even after 2200 cycles in SIBs. Specifically, the capacities and retention rates observed for the batteries containing MoSe₂/Mo₂CT_x/C and cycled at 0.5, 1, and 2 A g⁻¹ rates were equal to 652.2, 484.4, and 238.4 mAh g⁻¹ and 102.5%, 103.9%, and 86.3%, respectively. Thus, carbon-coated MoSe₂/MXene can be utilized as active SIB anode materials.