Are Janus MoSSe/Ti3C2-MXene heterostructures excellent anode materials for Na-ion batteries? A computational insight combined experiment

The heterostructures composed of transition-metal dichalcogenides and MXene show excellent performance as Na-ion batteries anodes. Herein, the electrochemical performance of MoSe2/MXene is verified to be better than that of MoS2/MXene through experiments. Thereafter, first-principles calculations on electronic properties and electrochemical performances of MoSSe/MXene, MoSeS/MXene, MoSe2/MXene and MoS2/MXene are all per-formed to investigate Janus heterostructures' feasibility as anodes. Diffusion barrier of MoSSe/MXene is slightly higher than that of MoSe2/MXene. Moreover, calculations of electronic properties reveal that the conductivity of the heterostructures is mainly provided by MXenes. Especially when the Se is connected with MXene, the con-ductivities of corresponding heterostructures are better as shown by MoSSe/MXene, followed by MoSe2/MXene. Then from crystal orbital Hamilton population, the strength of O-Na is proportional to that of S/Se-Na. Finally, MoSSe/Ti3C2-MXene possesses lower open circuit voltage (1.538 V) and higher theoretical capacity (593.3 mAh/ g) than MoSe2/Ti3C2-MXene according to calculation results, which is more suitable for Na-ion batteries anodes. While overall performance tests show that MoSeS/MXene does not perform well. This work provides evidence to realize potential of Janus heterostructures as anodes for Na-ion batteries.

Automated summary

Heterostructures composed of transition-metal dichalcogenides and MXene exhibit excellent performance as Na-ion batteries anodes. MoSe2/MXene is shown to have better electrochemical performance than MoS2/MXene. However, MoSeS/MXene performs poorly in overall performance tests.