Enhanced Wettability of a PTFE Porous Membrane for a High‐Temperature Stable Lithium‐Ion Battery Separator. Issue 4 (10th March 2022)

• Record Type: Journal Article
• Authors: Guo, Hongxia; Li, Mingye; Li, Fan; Zhu, Qizhen; Zhao, Yao; Wang, Feng; Qin, Zhenping
• Is Part Of: Chemical engineering & technology. Volume 45:Issue 4(2022)
• Page Start: 737
• Page End: 744
• Publication Date: 2022-03-10
• Subjects: Electrochemical performance -- Li‐ion battery separator -- Poly(tetrafluoroethylene) membrane -- Wettability; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.202000218
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: A hydrophobic poly(tetrafluoroethylene) (PTFE) porous membrane was modified into a hydrophilic lithium‐ion battery (LIB) separator with a higher affinity to the electrolyte via the hybrid consisting of a cationic fluorocarbon surfactant (FCS), polyethylenimine (PEI), and tetraethyl orthosilicate (TEOS), which can be in‐situ biomineralized into SiO2 nanoparticles. The obtained PTFE/FCS‐PEI‐SiO2 separator showed a dynamic electrolyte contact angle, which decreased from 50.3° to 0° within 4 s, along with 215 % of electrolyte uptake. The ionic conductivity and the interfacial resistance were 9.12 mS cm −1 and 228.8 Ω, respectively. In addition, the cell equipped with the separator showed a capacity of 163.7 mAh g −1 at a current density of 0.2 C. Notably, the cell with the separator displayed good high‐temperature stability. Abstract : The hydrophobic PTFE porous membrane was modified with fluorocarbon surfactant (FCS), polyethylenimine (PEI), and tetraethyl orthosilicate into a hydrophilic lithium‐ion battery separator. The separator had a negatively charged, superhydrophilic surface and high affinity to the electrolyte. The cell with the PTFE/FCS‐PEI‐SiO2 separator exhibited good high‐temperature endurance and stability.