Construction of MnS/MoS2 heterostructure on two-dimensional MoS2 surface to regulate the reaction pathways for high-performance Li-O2 batteries

The inherent catalytic anisotropy of two-dimensional (2D) materials has limited the enhancement of Li-O2 batteries (LOBs) performance due to the significantly different adsorption energies on 2D and edge surfaces. Tuning the adsorption strength in 2D materials to the reaction intermediates is essential for achieving high-performance LOBs. Herein, a MnS/MoS2 heterostructure is designed as a cathode catalyst by adjusting the adsorption behavior at the surface. Different from the toroidal-like discharge products on the MoS2 cathode, the MnS/MoS2 surface displays an improved adsorption energy to reaction species, thereby promoting the growth of the film-like discharge products. MnS can disturb the layer growth of MoS2, in which the stack edge plane features a strong interaction with the intermediates and limits the growth of the discharge products. Experimental and theoretical results confirm that the MnS/MoS2 heterostructure possesses improved electron transfer kinetics at the interface and plays an important role in the adsorption process for reaction species, which finally affects the morphology of Li2O2. In consequence, the MnS/MoS2 heterostructure exhibits a high specific capacity of 11696.0 mA h g-1 and good cycle stability over 1800 h with a fixed specific capacity of 600 mA h g-1 at current density of 100 mA g−1. This work provides a novel interfacial engineering strategy to enhance the performance of LOBs by tuning the adsorption properties of 2D materials.