Electrical and Mechanical Characterisation of Poly(ethylene)oxide-Polysulfone Blend for Composite Structural Lithium Batteries

• Published in: Polymers 2023-06, Vol.15 (11), p.2581
• Main Authors: Gucci, Francesco, Grasso, Marzio, Russo, Stefano, Leighton, Glenn J T, Shaw, Christopher, Brighton, James
• Format: Article
• Language: English
• Subjects: Composite materials; Electric vehicles; Electrical properties; Electrochemical impedance spectroscopy; Electrodes; Electrolytes; Ethylene oxide; Graphene; Ion currents; Lithium; Lithium batteries; Mechanical properties; Modulus of elasticity; Molecular weight; Polyethylene; Polymers; Polysulfone resins; Room temperature; Temperature; Tensile strength; Tensile tests
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym15112581

In this work, a blend of PEO, polysulfone (PSF), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSi) was prepared at different PEO-PSf weight ratios (70-30, 80-20, and 90-10) and ethylene oxide to lithium (EO/Li) ratios (16/1, 20/1, 30/1, and 50/1). The samples were characterised using FT-IR, DSC, and XRD. Young's modulus and tensile strength were evaluated at room temperature with micro-tensile testing. The ionic conductivity was measured between 5 °C and 45 °C through electrochemical impedance spectroscopy (EIS). The samples with a ratio of PEO and PSf equal to 70-30 and EO/Li ratio equal to 16/1 have the highest conductivity (1.91 × 10 S/cm) at 25 °C, while the PEO-PSf 80-20 EO/Li = 50/1 have the highest averaged Young's modulus of about 1.5 GPa at 25 °C. The configuration with a good balance between electrical and mechanical properties is the PEO-PSf 70-30 EO/Li = 30/1, which has a conductivity of 1.17 × 10 S/cm and a Young's modulus of 800 MPa, both measured at 25 °C. It was also found that increasing the EO/Li ratio to 16/1 dramatically affects the mechanical properties of the samples with them showing extreme embrittlement.