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Abstract The development of practical lithium–sulfur (Li–S) batteries with prolonged cycle life and high Coulombic efficiency is limited by both parasitic reactions from dissolved polysulfides and mossy lithium deposition. To address these challenges, here lithium trithiocarbonate (Li2CS3)‐coated lithium sulfide (Li2S) is employed as a dual‐function cathode material to improve the cycling performance of Li–S batteries. Interestingly, at the cathode, Li2CS3forms an oligomer‐structured layer on the surface to suppress polysulfide shuttle. The presence of Li2CS3alters the conventional sulfur reaction pathway, which is supported by material characterization and density functional theory calculation. At the anode, a stable in situ solid electrolyte interphase layer with a lower Li‐ion diffusion barrier is formed on the Li‐metal surface to engender enhanced lithium plating/stripping performance upon cycling. Consequently, the obtained anode‐free full cells with Li2CS3exhibit a superior capacity retention of 51% over 125 cycles, whereas conventional Li2S cells retain only 26%. This study demonstrates that Li2CS3inclusion is an efficient strategy for designing high‐energy‐density Li–S batteries with extended cycle life.
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Ferromagnetic Nanoparticle–Assisted Polysulfide Trapping for Enhanced Lithium–Sulfur Batteries
Abstract The lithium–sulfur (Li–S) battery is a promising candidate for next‐generation high‐density energy storage devices because of its ultrahigh theoretical energy density and the natural abundance of sulfur. However, the practical performance of the sulfur cathode is plagued by fast capacity decay and poor cycle life, both of which can be attributed to the intrinsic dissolution/shuttling of lithium polysulfides. Here, a new built‐in magnetic field–enhanced polysulfide trapping mechanism is discovered by introducing ferromagnetic iron/iron carbide (Fe/Fe3C) nanoparticles with a graphene shell (Fe/Fe3C/graphene) onto a flexible activated cotton textile (ACT) fiber to prepare the ACT@Fe/Fe3C/graphene sulfur host. The novel trapping mechanism is demonstrated by significant differences in the diffusion behavior of polysulfides in a custom‐designed liquid cell compared to a pure ACT/S cathode. Furthermore, a cell assembled using the ACT@Fe/Fe3C/S cathode exhibits a high initial discharge capacity of ≈764 mAh g−1, excellent rate performance, and a remarkably long lifespan of 600 cycles using ACT@Fe/Fe3C/S (whereas only 100 cycles can be achieved using pure ACT/S). The new magnetic field–enhanced trapping mechanism provides not only novel insight but unveils new possibilities for mitigating the “shuttle effect” of polysulfides thereby promoting the practical applications of Li–S batteries.
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- Award ID(s):
- 1728042
- PAR ID:
- 10056281
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 28
- Issue:
- 20
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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