A Self‐Healing and Nonflammable Cross‐Linked Network Polymer Electrolyte with the Combination of Hydrogen Bonds and Dynamic Disulfide Bonds for Lithium Metal Batteries

The self‐healing solid polymer electrolytes (SHSPEs) can spontaneously eliminate mechanical damages or micro‐cracks generated during the assembly or operation of lithium‐ion batteries (LIBs), significantly improving cycling performance and extending service life of LIBs. Here, we report a novel cross‐linked network SHSPE (PDDP) containing hydrogen bonds and dynamic disulfide bonds with excellent self‐healing properties and non‐flammability. The combination of hydrogen bonding between urea groups and the metathesis reaction of dynamic disulfide bonds endows PDDP with rapid self‐healing capacity at 28 °C without external stimulation. Furthermore, the addition of 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) improves the ionic conductivity (1.13 × 10 −4 S cm −1 at 28 °C) and non‐flammability of PDDP. The assembled Li/PDDP/LiFePO 4 cell exhibits excellent cycling performance with a discharge capacity of 137 mA h g −1 after 300 cycles at 0.2 C. More importantly, the self‐healed PDDP can recover almost the same ionic conductivity and cycling performance as the original PDDP.