Tailoring Mesoporous MoSeS Nanosheets/Carbon Hybrids via Heterointerface and Structural Engineering for Rapid Lithium...

Lamellar MoSe₂-based materials are considered promising anodes for lithium/sodium storage. However, their further applications are impeded by the sluggish transport dynamics, the intrinsically low conductivity, and the unavoidable volume variation. Herein, a sulfur-doped MoSe₂ nanosheet/carbon mesoporous composite (MoSeS/C) was synthesized via a heterointerface and structural engineering strategy for rapid lithium/sodium storage. The engineered MoSeS/C mesoporous composite precisely tailors its electronic structure while effectively accommodating volume fluctuations of the electrode. Specifically, the open pore structure and large surface area of MoSeS/C provide abundant active sites, promote efficient electrolyte penetration, and accelerate ion/electron diffusion. Notably, sulfur atom doping effectively enlarges the interlayer spacing of lamellar MoSe₂ nanosheets, further generating enough active sites for Li⁺/Na⁺ storage. The mesoporous carbon framework concurrently improves both the conductivity and structural integrity of the electrode. By virtue of the above merits, the MoSeS/C electrode displays a substantial capacity of 815 mAh g^-1 at 0.5 A g^-1 for lithium storage and 363 mAh g^-1 at 0.1 A g^-1 for sodium storage after 100 cycles. Additionally, to deepen the understanding of the reaction mechanism and the origins of the outstanding electrochemical properties of the MoSeS/C electrode, the transfer kinetics, morphology, and chemical states of MoSeS/C at different states are further investigated via a series of ex situ characterizations.