Self-Structured\nBinder Confinement of Sulfur for Highly\nDurable Lithium-Sulfur Batteries

Abstract

The lithium-sulfur battery (LSB)\nis a promising candidate for high-performance\nenergy storage applications due to its high theoretical energy density\nand low cost. However, developing a highly durable sulfur cathode\nfor LSBs has been challenging due to the known polysulfide shuttling\nand volume variation of sulfur that leads to chemical and mechanical\ndegradation of the cathode during cycling. Sulfur confinement has\nbecome a promising solution to both issues. However, confining sulfur\ntypically requires a complex and expensive process. Herein, we present\na simple electrode processing method for producing highly durable\nsulfur cathodes with self-structured binder confinement for sulfur\nparticles using only commercially available sulfur, carbon black,\nand binder, with no additional components. The dissolution of the\nbinder is controlled during the slurry preparation step to form a\nporous binder/carbon shell structure around the sulfur particles that\ncan entrap the soluble polysulfides and slow down the shuttling mechanism.\nThe sulfur cathodes achieved through this method offer an outstanding\ncapacity retention of 74% over 1000 cycles, a considerable reduction\nin the lithium-polysulfide shuttling and active material loss. Electrodes\nwith a high areal loading of 7.37 mAh/cm² (4.4 mg/cm²) also showed excellent cyclability as well as a high capacity\nof 800 mAh/g. The simplicity and cost-effectiveness of the presented\nmethod make it promising for the large-scale manufacturing of low-cost\nand durable sulfur cathodes, which pave the path to the commercialization\nof LSBs.