Self-healing solid-state polymer electrolytes for high-safety and long-cycle lithium-ion batteries

Current lithium-ion batteries (LIBs) with lightweight, rechargeable, and powerful characteristics have revolutionized our lives. However, commercialized battery technology is far from meeting the demands of high energy density and high safety, especially under mechanical abuse, latent defect abuse, and thermal abuse circumstances. Self-healing solid-state polymer electrolytes (SHSSPEs), which are precisely capable of meeting the demands for mechanically repairing damage, have garnered significant attention. This review comprehensively elaborates and highlights the various self-healing mechanisms closely linked to the physical and chemical approaches and, consequently, to develop advanced functional polymer electrolyte (PE) materials for LIBs. These mechanisms include polymer interchain diffusion, capsule-based self-healing, vascular-based self-healing, reversible covalent chemistry, and supramolecular dynamic chemistry. Furthermore, to improve the safety and cycle life of LIBs, the progress of composite functional self-healing PEs is summarized. We also highlight the significant role of advanced characterization techniques and theoretical calculation simulations in analyzing and predicting the performance of PEs. To develop novel self-healing PE materials, we emphasize effective self-healing mechanisms and provide relevant perspectives based on the self-healing polymer electrolyte genome project and machine learning. This evaluation is expected to influence the development of high-safety, long-cycle energy storage devices.