Self-healing and high stretchable polymer electrolytes based on ionic bonds with high conductivity for lithium batteries

Flexible solid-state lithium batteries based on self-healing electrolytes are promising alternatives to resolve battery breakage issues in wearable electronic devices. However, self-healing electrolytes for lithium batteries are far from wide applications for their low ionic conductivity and limited self-healing capability. Now, a new kind of composite self-healing electrolyte is fabricated based on dicationic polymerized ionic liquids (PILs) as a backbone filled in an ionic liquid within interspaces among chain segments. The self-healing function is realized through reversible ionic bonds constructed by abundant cations and anions existing in polymer chains and ionic liquids in the interspaces. Moreover, the polymer backbone incorporated with the ionic liquid forms a sea-island system that works as interlaced channels for Li⁺ transfer, boosting the ionic conductivity of the electrolytes. As a result, the composite electrolytes exhibit efficient self-healing performance, good flexibility and high ionic conductivity. This work provides a brand new vision and considerable potential for developing self-healing lithium batteries.