MoS₂/graphene heterostructure with facilitated Mg-diffusion kinetics for high-performance rechargeable magnesium batteries

Mg ions exhibit sluggish kinetics when migrating in most of traditional two-dimensional (2D) layered materials, leading to the dissatisfactory Mg-storage capabilities. Lattice engineering can settle this issue by constructing van der Waals’ heterostructures (vdWHs) comprising heterogeneous monolayers, which establish specific ionic diffusion path with lower energy barriers. Herein, MoS₂ monolayer and graphene (GR) are alternately overlapped with each other to construct a vdWH with a reduced Mg-diffusion barrier of 0.4 eV, and this brings the diffusion rate 11 orders of magnitude faster than that of pristine MoS₂. The facilitated diffusion kinetics delivers a desirable Mg-storage capacity of 210 mAh g⁻¹ at 20 mA g⁻¹, and outstanding rate performance (90 mAh g⁻¹ at 500 mA g⁻¹). Moreover, enhanced structure durability of MoS₂/GR allows the chemical reversibility for the repeated intercalation/deintercalation of Mg²⁺, thus 87% of initial remains after 300 cycles.