Self-healing polyurethane-based polymer electrolyte with high strength for all-solid-state lithium metal batteries

Polyethylene oxide, as one of the most common polymers, has been extensively studied for solid-state polymer electrolytes. However, its poor mechanical properties and low ionic conductivity severely limit its application. Herein, a series of double dynamic self-healing polyurethane polymer electrolyte (PUSPE-X) with hydrogen bonds and dynamic urea bonds was prepared by a simple polycondensation reaction. The constructed network exhibits excellent mechanical properties, strong self-healing and good shape memory properties. Benefiting from the oxygens in the PEG segment and the nitrogen atom in the imide (-NH-) group simultaneously act as electron donor to form coordination bonds with lithium ions by coulombic interaction, further promoting the anion and cation of the lithium salt to dissociate, the PUSPE-6000 demonstrates good ion conductivity of 0.127 m S cm- 1 and satisfactory lithium-ion transference number (tLi+=0.55) at 60 degrees C. The Li|PUSPE-6000|Li symmetric cell works stable for 1200 h at 0.1 mA cm-2 and the LFP|PUSPE-6000|Li cell also achieves excellent cycling stability. The flexible battery based on PUSPE-6000 can continue to work under a variety of harsh conditions, which expand the choice for the all solid-state electrolyte in the flexible wearable electronic device.