In Situ Self-Healing of Gel Polymer Electrolytes Enhancing the Cycling Stability of Lithium Ion Batteries

• Published in: ACS sustainable chemistry & engineering Vol. 12; no. 20; pp. 7894 - 7902
• Main Authors: Tsai, Wan-Tzu, Lu, Yu-Hsuan, Liu, Ying-Ling
• Format: Journal Article
• Language: English
• Published: American Chemical Society 20.05.2024
• Subjects: gel polymer electrolytes; Diels−Alder reaction; lithium ion battery; cycling stability; self-healing
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.4c01368

Gel polymer electrolytes (GPEs) for lithium ion batteries (LiB) have received massive research attention. One critical issue for GPEs is damage of GPEs and GPE/electrode interfaces in charging/discharging cycles. To address this issue, dissociative covalent adaptable networks (CANs) are incorporated to GPEs to bring dynamic features and self-healing ability to the GPEs. Based on the thermally reversible property of Diels–Alder adducts of furan and maleimide groups, dissociative CANs were prepared by employing a trifunctional furan (TF) and a trifunctional maleimide (TMI) as monomers. The GPE was prepared through an in situ cross-linking reaction of TF and TMI in the presence of liquid electrolytes. The dissociative CANs possess amine and hydroxyl groups to enhance the compatibility between the cross-linked polymer matrix and liquid electrolytes as well as the liquid electrolyte content of the GPE. In the cycling charging/discharging operation, autonomous recovery of capacity loss was observed with the LiB cells. Moreover, the cells also demonstrated long-term stability of 500 cycles at 2 C without a significant capacity decay. The self-healing ability of the GPE, performed with the de-cross-linking and re-cross-linking behavior of TF/TMI dissociative CANs, contributes to the above-mentioned performance of the LiB cells.