Cross-Linking of Sugar-Derived Polyethers and Boronic Acids for Renewable, Self-Healing, and Single-Ion Conducting Organogel Polymer Electrolytes

• Published in: ACS applied energy materials 2023-03, Vol.6 (5), p.2924-2935
• Main Authors: Daniels, Emma L., Runge, James R., Oshinowo, Matthew, Leese, Hannah S., Buchard, Antoine
• Format: Article
• Language: English
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.2c03937

This report describes the synthesis and characterization of organogels by reaction of a diol-containing polyether, derived from the sugar d-xylose, with 1,4-phenylenediboronic acid (PDBA). The cross-linked materials were analyzed by infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (FE-SEM), and rheology. The rheological material properties could be tuned: gel or viscoelastic behavior depended on the concentration of polymer, and mechanical stiffness increased with the amount of PDBA cross-linker. Organogels demonstrated self-healing capabilities and recovered their storage and loss moduli instantaneously after application and subsequent strain release. Lithiated organogels were synthesized through incorporation of lithium bis­(trifluoromethanesulfonyl)­imide (LiTFSI) into the cross-linked matrix. These lithium–borate polymer gels showed a high ionic conductivity value of up to 3.71 × 10–3 S cm–1 at 25 °C, high lithium transference numbers (t + = 0.88–0.92), and electrochemical stability (4.51 V). The gels were compatible with lithium-metal electrodes, showing stable polarization profiles in plating/stripping tests. This system provides a promising platform for the production of self-healing gel polymer electrolytes (GPEs) derived from renewable feedstocks for battery applications.