Hierarchical MoSe₂ yolk-shell microspheres with superior Na-ion storage properties

Yolk-shell-structured MoSe₂ microspheres were prepared via a simple selenization process of MoO₃ microspheres. The yolk-shell-structured MoSe₂ and MoO₃ microspheres delivered initial discharge capacities of 527 and 465 mA h g(-1) in the voltage range of 0.001-3 V vs. Na/Na(+) at a current density of 0.2 A g(-1), respectively, and their discharge capacities after 50 cycles were 433 and 141 mA h g(-1), respectively. The yolk-shell-structured MoSe₂ microspheres also exhibited outstanding high rate capabilities. The hierarchical yolk-shell structure comprised of wrinkled nanosheets facilitated fast Na-ion and electron kinetics, and buffered the large volume changes encountered during cycling.

Superior electrochemical properties of MoS2 powders with a MoS2@void@MoS2 configuration

Yolk-shell MoS2 powders with a distinct configuration of MoS2@void@MoS2 were prepared for the first time by applying spray pyrolysis. The yolk-shell MoO3 powders prepared by spray pyrolysis were converted into MoS2 powders by a simple sulfidation process at 400 °C without altering the morphology. Dense structured MoS2 powders were also prepared by a similar process. The respective initial discharge capacities of the yolk-shell and dense structured MoS2 powders at a current density of 1000 mA g(-1) were 651 and 490 mA h g(-1), and the corresponding capacity retentions after 100 cycles measured from the second cycle were 100 and 72%.