Hierarchical MoS2 /Carbon Composite Microspheres as Advanced Anodes for Lithium/Sodium-Ion Batteries.

Abstract

It is crucial to design advanced electrodes with large Li/Na-ion storage capacities for the development of next-generation battery systems. Herein, hierarchical MoS2 /C composite microspheres were constructed by facile template-free self-assembly sulfurization plus post-carbonization. Cross-linked MoS2 nanosheets and outer carbon layer are organically combined together to form composite microspheres with diameters of 400-500 nm. Due to enhanced electrical conductivity and good structural stability, the MoS2 /C composite microspheres exhibit substantially improved Li/Na-ion storage performance. Compared to unmodified MoS2 , MoS2 /C composite microspheres deliver higher Li/Na-ion storage capacity (Li+ : 1017 mA h g-1 at 100 mA g-1 and Na+ : 531 mA h g-1 at 100 mA g-1 ), as well as better rate capability (Li+ : 434 mA h g-1 at 1 Ag-1 and Na+ : 102 mA h g-1 at 1 Ag-1 ) and capacity retention (Li+ : 902 mA h g-1 after 200 cycles and Na+ : 342 mA h g-1 over 100 cycles). The superior Li/Na-ion storage performance is mainly attributed to the unique porous microsphere architecture with increased electrode/electrolyte interfaces and more diffusion paths for Li/Na ion insertion. Additionally, the carbon coating can not only improve the electronic conductivity, but also suppress the shuttle effect of polysulfides.