Efficient polysulfide trapping in lithium-sulfur batteries using ultrathin and flexible BaTiO3/graphene oxide/carbon nanotube layers.

ABSTRACT

Ultrathin and flexible layers containing BaTiO3 (BTO) nanoparticles, graphene oxide (GO) sheets, and carbon nanotube (CNT) films (BTO/GO@CNT) are used to trap solvated polysulfides and alleviate the shuttle effect in lithium-sulfur (Li-S) batteries. In the functional layers, the CNT films build a conductive framework, and the GO sheets form a support membrane for the uniform dispersion of BTO nanoparticles. BTO nanoparticles without ferroelectricity (nfBTO) can trap polysulfides more effectively by chemical interaction compared to BTO nanoparticles with ferroelectricity (fBTO). A Li-S cell with the nfBTO/GO@CNT functional layer exhibits a reversible capacity of 824.5 mA h g-1 over 100 cycles at 0.2 C. At a high sulfur loading of 5.49 mg cm-2, an electrode with the functional layer shows an areal capacity of 5.15 mA h cm-2 at 0.1 C, demonstrating the nfBTO/GO@CNT functional layer's potential in developing high-performance Li-S batteries.