Crosslinked network solid polymer electrolyte with self‐healing ability and high stability for lithium metal battery

Abstract All‐solid polymer electrolytes with good self‐healing ability and high stability were designed based on polyoxyethylenebis(amine) (H 2 N‐PEG‐NH 2 ) and 1,3,5‐benzenetricarboxaldehyde through the Schiff base reaction. The effects of H 2 N‐PEG‐NH 2 of various molecule weights on thermal and electrochemical properties were studied. It was found that shCLSPE‐3400 electrolyte with appropriate PEG chain simultaneously exhibited good thermal stability, excellent self‐healing ability and high mechanical strength, which is due to the introduction of crosslinked network structure and dynamic reversible bonds in the electrolyte. It also showed a high ionic conductivity of 4.8 × 10 −4 S cm −1 , wide electrochemical stability window (5.1 V) and good lithium ion transfer number ( t Li+ = 0.31) with an ethylene oxide/Li + ratio of 20:1 at 25 °C. In addition, a Li|shCLSPE‐3400|LiFePO 4 battery with shCLSPE‐3400 as electrolyte was studied, and it showed good reversible specific capacity. Such electrolyte has potential for application in solid‐state batteries, which will facilitate improvement in the safety performance of lithium metal batteries. © 2022 Society of Industrial Chemistry.