High-loading polysulfide/cement cathode for the manufacture of dynamically and statically stable lean-electrolyte lithium–sulfur batteries

Abstract

In order to design lithium-sulfur cells for practical viability in the high-density energy storage, the exploitation of the effective contribution of the large amount of active-material mass to the high specific capacity at a lean-electrolyte condition must be considered. However, this is limited by the insulating nature of solid-state sulfur/sulfide, and the diffusion loss of the liquid-state polysulfides. In this study, Portland cement is adopted as a reinforcement material to design a high-loading polysulfide/cement cathode with sulfur loading and content of 8.64 mg cm−2 and 60 wt%, respectively. The nonporous cement exhibits a high polysulfide-trapping capability and low electrolyte consumption, which enable the high-sulfur-loading cathode to achieve record low electrolyte-to-sulfur ratios of 7–3 μL mg−1, with high gravimetric capacity and areal capacity of the cathode (i.e., 768 mA h g−1 and 11.06 mA h cm−2, respectively) and dynamically/statically electrochemical stability with 90% capacity retention after 100 cycles and a 1-month rest.