A fluorinated branched polyether for PEO-based polymer electrolyte via thiol-Michael addition click reaction

• Published in: Solid state ionics 2024-09, Vol.412, p.116602, Article 116602
• Main Authors: Tian, Jianling, Li, Ruiyang, Yang, Xueying, Lai, Pengbin, Liu, Jiaxiang, Ye, Ruilai, Deng, Yi, Chen, Qichen, Zhang, Peng, Zhao, Jinbao
• Format: Article
• Language: English
• Subjects: lithium-ion transference number; PEO; Solid polymer electrolyte; Thiol-Michael addition click reaction
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2024.116602

Polyethylene oxide (PEO) is considered as the most promising and widely studies polymer matrix. However, its practical application is limited for its low ionic conductivity at room temperature. Here, a novel fluorinated branched (2,2,2-Trifluoroethyl methacrylate (TFEMA)) ether polymer (PFP) was synthesized through thiol-Michael addition click reaction and blended with PEO to obtained PEO-based polymer electrolyte. The introduction of PFP could reduce the crystallinity and hinder the migration of anions, resulting in a double increase in ionic conductivity and lithium-ion transference number. More importantly, the symmetric Li/Li employing blended polymer shows stable cycle more than 1700 h and the Li/LiFePO4 cell shows the superior performance of both cycling and rating at 60 °C. Even at lower temperature (28 °C), the Li/LiFePO4 cell exhibits encouraging cycling performance with 88.6% capacity retention at 0.2C after 100 cycles. This study provides a novel strategy for structural design and synthesis progress of solid polymer electrolyte. •PFP is synthesized by thiol-Michael addition click reaction, without any specialized energy required.•Branched structure reduced crystallinity of PEO and δ = 3.16 × 10−5 S cm−1 at 30 °C, which is an order of magnitude higher.•The polar groups in PFP optimal ionic conduction, resulting in the increase of lithium-ion transference number.•δ = 1.66 × 10−4 S cm−1 and tLi+ = 0.30 at 45 °C, which can benefit for the stable cycle of solid-state battery.