The rational design of hierarchical MoS2 nanosheet hollow spheres sandwiched between carbon and TiO2@graphite as an improved anode for lithium-ion batteries

Abstract

Molybdenum disulfide (MoS2) shows high capacity but suffers from poor rate capability and rapid capacity decay, which greatly limit its practical applications in lithium-ion batteries. Herein, we successfully prepared MoS2 nanosheet hollow spheres encapsulated into carbon and titanium dioxide@graphite, denoted as TiO2@G@MoS2@C, via hydrothermal and polymerization approaches. In this hierarchical architecture, the MoS2 hollow sphere was sandwiched by graphite and an amorphous carbon shell; thus, TiO2@G@MoS2@C exhibited effectively enhanced electrical conductivity and withstood the volume changes; moreover, the aggregation and diffusion of the MoS2 nanosheets were restricted; this advanced TiO2@G@MoS2@C fully combined the advantages of a three-dimensional architecture, hollow structure, carbon coating, and a mechanically robust TiO2@graphite support, achieving improved specific capacity and long-term cycling stability. In addition, it exhibited the high reversible specific capacity of 823 mA h g-1 at the current density of 0.1 A g-1 after 100 cycles, retaining almost 88% of the initial reversible capacity with the high coulombic efficiency of 99%.