A Polymer Network Layer Containing Dually Anchored Ionic Liquids for Stable Lithium-Sulfur Batteries

Authors：Dai, Shuqi; Wang, Chaozhi; Huang, Chongyang; Li, Shurong; Xu, Yongsheng; Song, Yaohao; Zeng, Guangjian; Zhu, Jie; Sun, Taoling; Huang, Mingjun^*

Source：Macromolecular Rapid Communications, 2023, 44(1): 2200246.

DOI：10.1002/marc.202200246

• ionic liquids
• lithium-sulfur batteries
• polymer network
• separator function layer

Lithium-sulfur (Li-S) batteries with high sulfur utilization, long-cycle life, and dendrite-free features hold great promise for the development of next-generation energy storage devices of high energy density. Considerable efforts have been committed to solving the polysulfide shuttle problem toward highly stable Li-S batteries. Here, a unique polymer network containing dually anchored ionic liquids (DA-PIL) is devolped to improve the cycling performance and coulombic efficiency of Li-S batteries. This DA-PIL electrolyte incorporates the amphiphilicity of both the polysulfides anion and lithium cation, creating an ionic function layer on polypropylene separator. Noteworthily, the DA-PIL network is "clean" in the sense that no free ionic specifies are introduced to the electrolyte system. The DA-PIL layer not only enables strong supression against polysulfide shuttling but simultaneously allows fast lithium transportation owing to cooperate electrostatic interaction among anchored cations and anions. The DA-PIL layer functionalized on a polypropylene separator can boost excellent stability of Li-S battery with >1600 h cycling test at 0.25 mA cm(-2). The Li-S cell with DA-PIL layer delivers a higher discharge capacity of 827.4 mAh g(-1) at 1C. A discharge capacity of 630.6 mAh g(-1) is retained after 1000 cycles.

• Institution
  天津大学; 厦门大学