Mechanically Strong and Electrochemically Stable Single-Ion Conducting Polymer Electrolytes Constructed from Hydrogen Bonding

• Published in: Langmuir 2021-07, Vol.37 (27), p.8270-8280
• Main Authors: Gan, Huihui, Li, Shaoqiao, Zhang, Yong, Yu, Liping, Wang, Jirong, Xue, Zhigang
• Format: Article
• Language: English
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.1c01035

Herein, composite membranes based on a single-ion conducting polymer electrolyte (SIPE) and poly­(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) were prepared by an electrospinning technology. The SIPE with hydrogen bonding was obtained via reversible addition–fragmentation chain transfer (RAFT) copolymerization of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)­ureido)­ethyl methacrylate (UPyMA), poly­(ethylene glycol) methyl ether methacrylate (PEGMA), and lithium 4-styrenesulfonyl (phenylsulfonyl) imide (SSPSILi). The obtained composite membrane exhibited a highly porous network structure, superior thermal stability (>300 °C), and high mechanical strength (17.3 MPa). The fabricated SIPE/PVDF-HFP composite membrane without lithium salts possessed a high ionic conductivity of 2.78 × 10–5 S cm–1 at 30 °C, excellent compatibility with the lithium metal electrode, and high lithium-ion transference number (0.89). The symmetric Li//Li cell exhibited a superior cycle performance without short circuit, indicating the generation of a stable interface between SIPE and the lithium metal electrode during the process of lithium plating/stripping, which could inhibit lithium dendrite growth in lithium metal batteries (LMBs). The Li//LiFePO4 cell also exhibited superior cycle life and excellent rate capability at 60 or 25 °C. In consequence, the composite membrane exhibits a considerable future prospect for advanced LMBs.