Electrolyte Design for Improving Mechanical Stability of Solid Electrolyte Interphase in Lithium–Sulfur Batteries

• Published in: Angewandte Chemie International Edition Vol. 62; no. 32; pp. e202305466 - n/a
• Main Authors: Hou, Li‐Peng, Li, Yuan, Li, Zheng, Zhang, Qian‐Kui, Li, Bo‐Quan, Bi, Chen‐Xi, Chen, Zi‐Xian, Su, Li‐Ling, Huang, Jia‐Qi, Wen, Rui, Zhang, Xue‐Qiang, Zhang, Qiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 07.08.2023
• Edition: International ed. in English
• Subjects: 1,3,5-Trioxane; Cathodes; Electrolytes; Interphase; Life span; Lithium; Lithium sulfur batteries; Mechanical Stability; Pouch Cells; Solid Electrolyte Interphase; Solid electrolytes; Specific capacity; Stability; Sulfur; Solid Electrolyte Interphase; 1,3,5-Trioxane; Pouch Cells; Lithium-Sulfur Batteries; Mechanical Stability
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202305466

Practical lithium–sulfur (Li−S) batteries are severely plagued by the instability of solid electrolyte interphase (SEI) formed in routine ether electrolytes. Herein, an electrolyte with 1,3,5‐trioxane (TO) and 1,2‐dimethoxyethane (DME) as co‐solvents is proposed to construct a high‐mechanical‐stability SEI by enriching organic components in Li−S batteries. The high‐mechanical‐stability SEI works compatibly in Li−S batteries. TO with high polymerization capability can preferentially decompose and form organic‐rich SEI, strengthening mechanical stability of SEI, which mitigates crack and regeneration of SEI and reduces the consumption rate of active Li, Li polysulfides, and electrolytes. Meanwhile, DME ensures high specific capacity of S cathodes. Accordingly, the lifespan of Li−S batteries increases from 75 cycles in routine ether electrolyte to 216 cycles in TO‐based electrolyte. Furthermore, a 417 Wh kg−1 Li−S pouch cell undergoes 20 cycles. This work provides an emerging electrolyte design for practical Li−S batteries. An emerging electrolyte design, which can construct high‐mechanical‐stability solid electrolyte interphase (SEI) on lithium metal anodes, is proposed for practical lithium–sulfur batteries. High‐mechanical‐stability SEI effectively restricts its fracture and ongoing reactions of electrolytes on lithium metal anodes, which notably improves the stability of practical lithium–sulfur coin and pouch cells.