A MoS2 and Graphene Alternately Stacking van der Waals Heterostructure for Li+/Mg2+ Co-Intercalation

Owing to the low-cost, dendrite-free formation, and high volumetric capacity, rechargeable Li + /Mg 2+ hybrid-ion batteries (LMIBs) have attracted great attention and are regarded as promising energy storage devices. However, due to the strong Coulombic interaction of Mg 2+ with host materials, the traditional “Daniell Type” LMIBs with only Li + intercalation usually cannot ensure a satisfactory energy density. Herein, graphene monolayers are arranged intercalating into MoS 2 interlamination to construct van der Waals heterostructures (MoS 2 /G VH). This operation transforms the construction of ion channels from pristine interlamination of two MoS 2 monolayers to the interlamination of MoS 2 monolayer with graphene monolayer, thereby greatly reducing ion diffusion energy barriers. Compared with pristine MoS 2 , the MoS 2 /G VH can obviously reduce the migration energy barriers of Li + (from 0.67 to 0.09 eV) and Mg 2+ (from 1.01 to 0.21 eV). Moreover, it is also demonstrated that MoS 2 /G VHs realize Li + /Mg 2+ co-intercalation even at a rate current of 1000 mA g −1 . As expected, the MoS 2 /G VH exhibits superior electrochemical performance with a reversible capacity of 145.8 mAh g −1 at 1000 mA g −1 after 2200 cycles, suggesting the feasibility of potential applications for high-performance energy storage devices.