Enhanced rate capability due to highly active Ta2O5 catalysts for lithium sulfur batteries

Abstract The heterogeneous catalysis is widely recognized to promote polysulfide fragmentations can play a key role for the rate capability enhancement of lithium sulfur batteries (LSB). In this study, we report the most active catalysts (Ta 2 O 5 ) for LSB which showed an enhanced rate capability (914 mAh g −1 at 5 C) in comparison with the previously reported catalysts, TiN (865 mAh g −1 at 5 C). The addition of Ta 2 O 5 into the carbon-coated separator facilitates the chemical disproportionation of reaction intermeditates, Li 2 S 4 into Li 2 S 8 and Li 2 S effectively, which leads to the greatly lengthened second plateau in discharge profile. The heterogeneous catalysis of Ta 2 O 5 is clearly verified with the UV–Vis spectra directly showing the change of Li 2 S 4 concentration and the battery performance tests without any active elemental sulfur.