Lithium-sulfur batteries have high theoretical energy density while their practical application is trapped because of severe shuttle effect and sluggish conversion kinetics of polysulfides. Here, a nitrogen, oxygen, and sulfur co-doped porous carbon (NOSAKC) is prepared by one-step pyrolysis of acesulfame potassium, which is employed as an efficient component on polypropylene separators to restrict the shuttle of polysulfides based on Lewis acid-base theory. The NOSAKC exhibits a hierarchical porous structure with high specific surface area and abundant adsorption/catalytic sites. The substantial mesoporous channels are conducive to rapid ion transfer, and the micropores minimize the polysulfide shuttle. The abundant heteroatoms doped in NOSAKC can achieve synergistic constraint and conversion of lithium polysulfides. So the Li-S battery with the NOSAKC separator displays distinguished electrochemical performance with a high discharge capacity of 1598 mAh g-1 at 0.2C and 1012 mAh g-1 at 1C. It maintains 84% of the initial capacity after 500 cycles with a stable coulombic efficiency of 99.8%. Moreover, the Li-S battery achieves a capacity retention of 67% after 200 cycles for a high sulfur loading of 4.33mgcm-2. This work reports a one-step preparation of hierarchical porous carbon with tri-doped heteroatoms for synergistic polysulfide adsorption and conversion.
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