LiNbO3-Mediated Dielectric Polarization Tailoring at Polymer Electrolyte Interfaces for Dendrite-Free Lithium Metal Batteries

Lithium–metal batteries (LMBs) face critical challenges in interfacial instability and dendritic growth, despite their high theoretical capacity. To address these issues, we designed an interface layer containing LiNbO3 crystals to modify the polymer electrolyte, achieving uniform deposition of lithium ions. This design innovatively integrates electrostatic screening and field-guided ion transport mechanisms─unique to LiNbO3 dielectric polarization materials─achieving unprecedented homogeneous Li+ flux distribution while catalytically mediating the formation of a dual-functional LiF/Li3N-rich solid electrolyte interphase (SEI). Notably, the Li3N component synergistically enhances ion diffusion, while LiF mechanically suppresses dendrites, synergizing physicochemical stabilization where conventional SPEs fail. The optimized LN-SPE demonstrates exceptional ionic conductivity of 4.92 × 10–4 S cm–1 and Li+ transference number of 0.67 at RT, enabling an assembled SSLMB to deliver 138.1 mAh g–1 at 0.5 C with ultrahigh capacity retention of 94.42% after 100 cycles, while maintaining 142.4 mAh g–1 at 1 C. Crucially, the sustained dielectric polarization activity ensures long-term interfacial integrity, positioning this work as a paradigm-shifting approach for electroceramic-polymer hybrids with scalable manufacturing pathways, thus offering transformative solutions for next-generation high-energy-density batteries.