Boosting lithium polysulfide conversion via TiO2-supported niobium catalyst for lithium sulfur battery

Lithium sulfur (Li-S) batteries demonstrate enormous promise as a high-performance high-capacity energy storage solution but are severely limited by a low cycle life which stems from rapid capacity decay due to the low conductivity of lithium polysulfides and the poor kinetics of the lithium sulfur reduction reaction, which com-bined lead to the loss of active cathodic material. In this work, titanium oxide (TiO2) nanostructures are used as a host for a niobium catalyst which accelerates the conversion of polysulfides. Cells containing the TiO2-supported niobium catalyst demonstrated a very high level of stability, with a specific capacity decay rate of 0.045 % per cycle over 350 cycles. Li-S cells using this cathode host material also demonstrated high initial specific capac-ities, with initial capacities as high as 961 mAh g-1 at 0.2 C and 629 mAh g-1 at 3.0 C.