Polymer–Ceramic Framework Stabilized Solid Electrolyte for Advanced Lithium-Ion Energy Storage

Abstract Advancing lithium-metal solid-state batteries (LSSBs) demands innovative composite solid electrolytes with superior safety, energy density, and cycle life. Here, we report a high-performance polymer-ceramic composite solid electrolyte (PCCSE) engineered by integrating lithium perborate (LiBO₃) and surface-functionalized lithium lanthanum zirconium oxide (LLZO) nanofibers into a polyethylene oxide/polyvinylidene fluoride (PEO/PVDF) matrix using an optimized Stokes’ solution casting method. The synergistic interplay of LiBO₃ and LLZO disrupts polymer crystallinity, enhances amorphization, and facilitates ionic transport through robust polymer–ceramic interfacial interactions. Advanced characterization via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis), and electrochemical impedance spectroscopy (EIS) confirms reduced crystallinity, improved segmental chain mobility, and optimized ionic pathways. The resulting PCCSE achieves a remarkable ionic conductivity of 4.25 × 10⁻ ⁵ S cm⁻¹ at room temperature and a wide electrochemical stability window of 5.33 V, enabling compatibility with high-voltage cathodes. Full-cell tests with a lithium metal anode and LiCoO₂ cathode demonstrate high specific capacity, exceptional rate capability, and 95% capacity retention after 100 cycles. The PCCSE effectively mitigates lithium dendrite growth through uniform ion conduction and enhanced interfacial stability. These findings position PCCSE as a promising, safe, and high-performance electrolyte for next-generation all-solid-state lithium-metal batteries, paving the way for scalable, high-energy-density energy storage solutions.