Chemical-dealloying to fabricate nonconductive interlayers for high-loading lithium sulfur batteries

Abstract Lithium sulfur batteries have been recognized as a promising on-board energy-storage technology. One of the challenges in this system is the efficient inhibition of polysulfides shuttle with the low-cost sulfur hosts. In this work, we report the fabrication of nanoporous CeO2 and TiO2 by a novel chemical dealloying approach as a thin nonconductive interlayer to confine polysulfides in the cathodes. The abundant pores provide channels for the transportation of electrolyte, whereas the dissolved polysulfide species are chemically interacted with the metal oxides. Between the two interlayers, CeO2 demonstrates superior performance over TiO2, which is attributed to the appropriate redox window of the Ce3+/Ce4+ couple to in-situ catalyse the polysulfides. The cells with such a configuration exhibit significantly enhanced capacities and long-term stability. Even at a high sulfur loading of 6 mg cm−2, it is demonstrated stable capacities of ∼600 mAh g−1 over 120 cycles. These results suggest chemical dealloying is an efficient approach to prepare desired nanoporous interlayers to achieve practical cycling performance with a commercial sulfur host.