Self-Healing Solid Polymer Electrolyte Facilitated by a Dynamic Cross-Linked Polymer Matrix for Lithium-Ion Batteries

Compared with liquid electrolytes, the solid polymer electrolyte (SPE), which possesses improved thermal and mechanical stability, is believed the broadest potential application for satisfying the safety needs of advanced electrochemical devices. However, some breakable SPEs could lead to catastrophic failure of batteries that triggered by a short circuit. In the present contribution, a new class of SPE containing disulfide bonds and urea groups is reported. The hydrogen bonding between the urea groups and disulfide metathesis reaction endows the SPE with a high level of self-healing without external stimuli at room temperature as well as ultrafast self-healing at elevated temperatures. The completely healed SPE with extreme damage shows a high self-healing efficiency and no changes in the ionic conductivity and cycling performance of the solid-state lithium-metal/LiFePO4 cell compared to the pristine one.