Super tough, electrochemical stability and puncture resistant electrolyte for lithium‐metal batteries

Abstract

Polymer electrolytes (PEs) are widely used in the field of flexible energy storage due to their high safety, good flexibility, and ease of processing. Developing PEs with both high mechanical properties, high ionic conductivity and wide electrochemical stability window (ESW) for lithium‐metal batteries (LMBs) is an urgent issue to be addressed. In this work, we designed and synthesized the poly (vinyl alcohol) (PVA)‐polyacrylic acid (PAA)‐LiCl electrolyte for LMBs with a high ionic conductivity, wide ESW, high modulus and puncture resistance simultaneously. Through the construction of dual cross‐linking networks, the PVA‐PAA‐LiCl exhibits a wide ESW (6.2 V), achieves a notable ionic conductivity (1.08 × 10−4 S cm−1) at room temperature and can realize a high cycle stability of Li symmetric battery more than 300 h at 1 mA cm−2/1 mA h cm−2. Furthermore, it demonstrates exceptional puncture resistance, capable of withstanding pressures up to 5.73 × 108 Pa exerted by a steel nail, while simultaneously exhibites a commendable tensile strength of 4.9 MPa. Hence, this conceptual framework featuring dual‐crosslink network structure offers profound implications for the progression of next‐generation flexible energy storage.