摘要
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.