Spartina anglica-Derived Carbon-Coated PE Separator for Physically Restraining Polysulfide Migration in Lithium-Sulfur Batteries

• Published in: The Korean journal of chemical engineering 2024, 41(4), 289, pp.1187-1196
• Main Authors: Jeon, Ye Jin, Ha, Yuna, Kim, Jang Kyun, Kim, Youn-Jung, Yim, Taeeun
• Format: Article
• Language: English
• Subjects: Biotechnology; Carbon; Catalysis; Chemistry; Chemistry and Materials Science; Confining; Contact angle; Cycles; Electrochemical analysis; Electrolytes; Industrial Chemistry/Chemical Engineering; Interface stability; Lithium; Lithium sulfur batteries; Lithium-ion batteries; Materials Science; Original Article; Polyethylenes; Polysulfides; Rechargeable batteries; Separators; Sulfur; 화학공학
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-024-00060-1

Lithium–sulfur batteries (LSBs) have received substantial interest because their theoretical energy density is considerably higher than that of conventional lithium-ion batteries. However, the difficulty in confining the soluble intermediate polysulfide (PS) species of LSBs hinders the prolonged cycling of the cell. In this study, a Spartina anglica -derived carbon-coated polyethylene (PE) separator (SC-coated PE separator), which can confine the PS species on the cathode side, is developed to improve the cycling retention of LSBs. Spartina anglica , which is considered a predominant marine waste, is converted to task-specific carbon materials via size-controlled milling and carbonization, and is embedded on a PE separator through a simple casting process. The SC-coated PE separator improves the electrolyte affinity, which is characterized by measuring the contact angle, electrolyte uptake, and transference number of Li + ; consequently, the migration of Li + is undisturbed in the cell, even if an additional layer is formed on the PE separator. Based on the electrochemical performance, the SC-coated PE separator exhibits a higher initial specific capacity than the PE separator, in addition to a remarkably increased cycling retention (65.3% vs. 27.7%) after 100 cycles. The SC-coated PE separator effectively inhibits the PS species through physical absorption, thereby increasing the utilization of the active sulfur species. Moreover, the SC-coated PE separator presents a relatively stable interfacial morphology of the cycled Li anode, revealing that the comprehensive interfacial stability of the Li–S cell is enhanced by effectively confining the PS species in the cell. Graphical Abstract