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

Nanomaterials

Shuang Lian¹  Xiongwei Qu¹  Haifeng Ji¹  Yu Wang¹  Yi Feng¹  Xiaojie Zhang¹  Jingjing Shi² 

[1] Hebei Key Laboratory of Functional Polymers, Department of Polymer Materials and Engineering, Hebei University of Technology, 8 Guangrong Street, Tianjin 300130, China;School of Science, Nantong University, Nantong 226019, Jiangsu, China;

关键词: solid-state electrolyte;    cyclopropenium cationic-based polymer;    polyethylene oxide;    Li⁺ conductivity;    lithium sulfur battery;   

DOI  :  10.3390/nano11102562

来源: DOAJ

【 摘 要 】

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%.

【 授权许可】

Unknown