Self-template synthesis of hollow nano-spherical nickel silicate/nickel sulfide composite and its application for lithium-sulfur battery

A new strategy of using hollow nano-spherical nickel silicate/nickel sulfide composite to stabilize sulfur for lithium-sulfur (Li-S) battery was introduced for the first time. The hollow composite with an accessible mesoporous shell obtained by self-template synthesis can encapsulate ca. 75 wt% sulfur which displays a specific capacity of 640 mAh g−1 after 500 cycles at 0.5 C rate. Furthermore, even at a very high current density of 2.0 C, the discharge capacity remains at a high value of 466 mAh g−1. The long cycling stability and prominent rate performance in Li-S battery can be due to the expedient structure of hollow cavity and mesoporous shell for physisorption and the nickel silicate/nickel sulfide composite for chemisorption of polysulfide.