A self-healing solid polymer electrolyte enabled by synergistic dynamic bonds for high-performance lithium metal batteries

Solid polymer electrolytes (SPEs) offer enhanced safety for lithium metal batteries (LMBs) but suffer from mechanical damage and interfacial instability during cycling. Herein, we report a novel self-healing SPE (PATE-1:3) fabricated by incorporating multiple dynamic bonds into a polymer matrix. The synergistic interplay of dynamic disulfide bonds, hydrogen bonds, and thiourea groups creates a hierarchical reversible network that endows PATE-1:3 with excellent autonomous self-healing capability at room temperature, enabling a fractured membrane to recover mechanical integrity within 1 h without external stimulus. The electrolyte exhibits a high ionic conductivity of 1.18 × 10⁻⁴ S cm⁻¹ at 30 °C, a broad electrochemical stability window of 5.0 V, and an enhanced lithium-ion transference number of 0.4. Benefiting from these attributes, Li/PATE-1:3/Li symmetric cells demonstrate stable cycling for over 1200 h at 0.05 mA cm⁻² with a low polarization voltage of 0.1 V. Furthermore, all-solid-state LiFePO₄/PATE-1:3/Li cells deliver excellent cycling performance with a capacity retention of 93.5% after 100 cycles at 0.1 C and outstanding rate capability. This work presents a promising strategy for designing high-performance, self-healing solid polymer electrolytes toward safe and long-life LMBs.