Synergetic enhancing cycling stability of Li-S battery by hollow SrTiO3 microspheres wrapped by reduced graphene oxide

Abstract

LiPSs shuttle effect and cycling decay are still considered the main bottlenecks towards the practical application of Li-S batteries as commercial batteries. In the paper, we designed hollow SrTiO3 microspheres wrapped by reduced graphene oxide (SrTiO3@rGO) as efficient sulfur host materials with the aim of suppressing LiPSs shuttle and improving cycling stability of Li-S batteries. The hollow SrTiO3 microspheres wrapped by rGO, with appropriate binding energy to LiPSs, provide balancing surface adsorption and diffusion of LiPSs on nonconductive SrTiO3 and then promote its conversion on the interface, thus inhibiting the shuttle effect and greatly minimizing the active material irreversible loss in charge/discharge process. Meanwhile, the conductive rGO tightly wrapped on the surface of SrTiO3 offers an interconnected conductive network to support the fast electron/ion transfer. Profit from these merits, the SrTiO3 @rGO as sulfur host manifested superior cycling stability with a meager capacity decay rate of 0.0398% per cycle after 500 cycles at 0.2 C and an ultralow decay rate of 0.024% per cycle after 600 cycles at 1 C. The superior cycling stability suggested the hollow SrTiO3 @rGO was a potential candidate for the cathode of high-performance Li-S battery.