The construction of interlayer based on Ti2O(PO4)2 to hinder the shuttle effect of lithium polysulfides

Abstract

The soluble lithium polysulfides' shuttle effect impedes the practical application of Li–S batteries with high theoretical energy density. To confine the active S species in the cathode region, in this work, an artificial interlayer based on the composition of TiO(PO) (TOPO) and N-doped carbon nanotube (NCNT) is introduced to hinder the lithium polysulfides’ shuttle effect and enhance the reaction kinetics of active S species. The TOPO provides sufficient chemical bonding to soluble lithium polysulfides and fast Li migration, while the NCNT ensures fast electron transport to the transformation of absorbed lithium polysulfides. Thanks to the synergistic combination of TOPO and NCNT, at 0.1 C, the initial discharge specific capacity of corresponding Li–S batteries is 1483.55 mAh g, while at 1 C, a capacity decay of 0.14 % per cycle is achieved for 400 cycles.