Reducing graphene oxide carbon skeleton supported P-N heterostructure of bimetallic sulfide CoS-MoS nanorods for high-performance lithium storage.

Constructing bimetallic sulfide components are considered to be a promising and efficient lithium storage materials. Nonetheless, preparation routes of rational structures that have abundant hierarchical interfaces or phase boundaries bimetallic sulfide are still a problem to over come. In this work, a novel hierarchical nanostructure of bimetal sulfide CoS-MoS nanorods are synthesized successfully by in-situ self-growth means at the hydrothermal conditions. Subsequently, we loaded it to the carbon matrix (CoS-MoS@rGO) forming a three-dimensional structures with the help of freeze drying technology. This well-designed hierarchical structure could created a stable heterogeneous contact surface, which guarantees rapid Li ions diffusion and facilitates charge transfer at the heterointerface. Which can maintain capacity of 776 mAh/g over 800 cycles at 1 A/g. On the other hand, it shows an excellent rate capability of 464 mAg h at 5 A/g. From the perspective of electrochemical kinetics, we analyze and explore the reason about the improved lithium storage performance. Furthermore, to insight into the relationship between matter and phase conversion, the in-situ X-ray diffraction characterization is executed. The strategy of rationally designing hierarchical heterostructures will shed light on outstanding electrochemical performance in energy storage applications.