Dual‐Functional Phosphorus‐Doped Iron Single‐Atom Catalyst on Reduced Graphene Oxide for Efficient Lithium–Sulfur Batteries: Simultaneous Polysulfides Trapping/Catalysis and Lithium Deposition Regulation
Abdul Hameed Pato, Longtao Ren, Imran Ali Chandio, Qiaoli Zhang, Yaxian Li, Jinrui Liang, Mengchao Li, Safdar Abbas, Elhussein Desoki Helal, Wen Liu
Abstract
The development of high-performance lithium-sulfur (Li-S) batteries is hindered by the complex interplay of lithium polysulfides (LiPSs) shuttle effects and uncontrolled lithium dendrite growth. Herein, we introduce a dual-functional-phosphorus-doped iron single-atom catalysts on reduced graphene oxide (Fe-NPC@rGO)-to address both issues. Density functional theory (DFT) and experiments reveal that Fe-NPC@rGO enhances sulfur redox kinetics and regulates lithium deposition. The Fe-NPC high charge density and enhanced electron transfer (vs. Fe-N4) enable Fe-NPC@rGO to trap polysulfides (LiPSs) and boost their conversion, reducing shuttle effects. Simultaneously, its lithiophilic properties enable uniform Li plating, inhibiting dendrites. Li-S cells with Fe-NPC@GO modified separators deliver a high discharge capacity of 1156 mAh g-1 at 1 C, with an exceptionally low-capacity decay of 0.032% per cycle over 1000 cycles. Moreover, full Li-S battery configuration (Fe-NPC@rGO-Li||Fe-NPC@rGO-PP||ROCNT-S) achieves high areal capacity of 4.9 mAh cm-2 at 5 mg cm-2 sulfur loading, low electrolyte to sulfur (E/S) ratio of 6 µL mg-1, and an ultralow negative to positive (N/P) ratio of 1.2. These findings provide valuable insights into the structural optimization of electrocatalysts and underscore the significant potential of Fe-NPC@rGO in advancing the electrochemical performance of next-generation Li-S batteries.