Novel Synergistic Strategy for Developing High-Performance Lithium Sulfur Batteries of Large Areal Sulfur Loading by SEI Modified Separator

As a crucial energy density determining factor, the areal sulfur loading is still low nowadays for practical applications of Li–S batteries. To address this issue, intensive research efforts have been devoted to development of sulfur-hosting materials with ultrahigh specific surface area. However, design and manufacturing processes for these materials are complicated. Herein, we report a novel and facile strategy for developing a high-performance cathode with high areal sulfur content using conventional sulfur hosts without ultrahigh specific area. This strategy features a dense blocking layer of solid electrolyte interface (SEI) on the separator to ensure cycle stability of the cathode with a high areal sulfur loading. Meanwhile, a nanoarray cathode structure (CNT array on carbon cloth) is adopted to guarantee high sulfur utilization and rate performance. With the synergistic effect of a dense blocking layer and CNT array structure, the cathode with 10 mg/cm2 sulfur (90.9% in CNT/S composite) shows good rate and cycle performance. Our strategy may open up a new avenue for the design and construction of superior Li–S batteries with large sulfur loading without complex materials synthesis.