Heterostructure of 2D MoSe₂ nanosheets vertically grown on bowl-like carbon for high-performance sodium storage

Transition metal dichalcogenides are attractive anode materials for sodium ion batteries (SIBs) due to their high theoretical capacity and large interlayer spacing. However, its practical application is hampered by the sluggish kinetics of Na⁺ insertion and structure collapse caused by Na⁺ insertion/deinsertion. Herein, the heterostructures of MoSe₂ nanosheets vertically growing on bowl-like carbon (MoSe₂@C) are designed and prepared by a template method coupled with selenization treatment to boost storage sodium performance. The hollow and collapse could provide enough storage space for Na⁺ and alleviate the volume expansion during the charge/discharge processes. MoSe₂ nanosheets vertically grown on carbon could expose more active sites for adsorbing Na⁺ to enhance the utilization rate of electrode materials. Moreover, building heterostructures by combining different phase components could facilitate Na⁺ diffusion and advance reaction kinetics. Benefiting from these merits, the bowl-like MoSe₂@C shows outstanding reversible capacity (356.8 mAh·g⁻¹ after 1500 cycles at 1 A·g⁻¹) and remarkable rate performance (249.9 mAh·g⁻¹ 10 A·g⁻¹).