Cationic Cyclopropenium-Based Hyper-Crosslinked Polymer Enhanced Polyethylene Oxide Composite Electrolyte for All-Solid-State Li-S Battery

Autor: Shuang Lian, Yu Wang, Haifeng Ji, Xiaojie Zhang, Jingjing Shi, Yi Feng, Xiongwei Qu
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Nanomaterials, Vol 11, Iss 10, p 2562 (2021)
Druh dokumentu: article
ISSN: 2079-4991
DOI: 10.3390/nano11102562
Popis: The development of solid-state polymer electrolytes is an effective way to overcome the notorious shuttle effect of polysulfides in traditional liquid lithium sulfur batteries. In this paper, cationic cyclopropenium based cross-linked polymer was firstly prepared with the one pot method, and then the counter ion was replaced by TFSI− anion using simple ion replacement. Cationic cyclopropenium hyper-crosslinked polymer (HP) was introduced into a polyethylene oxide (PEO) matrix with the solution casting method to prepare a composite polymer electrolyte membrane. By adding HP@TFSI to the PEO-based electrolyte, the mechanical and electrochemical properties of the solid-state lithium-sulfur batteries were significantly improved. The PEO-20%HP@TFSI electrolyte shows the highest Li+ ionic conductivity at 60 °C (4.0 × 10−4 S·cm−1) and the highest mechanical strength. In the PEO matrix, uniform distribution of HP@TFSI inhibits crystallization and weakens the interaction between each PEO chain. Compared with pure PEO/LiTFSI electrolyte, the PEO-20%HP@TFSI electrolyte shows lower interface resistance and higher interface stability with lithium anode. The lithium sulfur battery based on the PEO-20%HP@TFSI electrolyte shows excellent electrochemical performance, high Coulombic efficiency and high cycle stability. After 500 cycles, the capacity of the lithium-sulfur battery based on PEO-20%HP@TFSI electrolytes keeps approximately 410 mAh·g−1 at 1 C, the Coulomb efficiency is close to 100%, and the cycle capacity decay rate is 0.082%.
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