Functional BaZrO₃ additive as an anion trap: a new strategy for high-performance PVDF-HFP based solid-state electrolytes

Solid-state electrolytes (SSEs) hold promise for enabling safer and higher-energy-density lithium batteries, yet their practical deployment is hindered by sluggish ion transport and poor interfacial compatibility. To address these challenges, we develop a composite electrolyte by embedding oxygen-deficient BaZrO₃ nanoparticles into a poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix. The intrinsic oxygen vacancies on the BaZrO₃ surface function as effective anion-trapping sites, which simultaneously increases the lithium-ion transference number (from 0.589 to 0.630) a substantial reduction in interfacial charge-transfer resistance (from 71.18 Ω to 39.02 Ω, as determined by electrochemical impedance spectroscopy). These enhancements in ion transport kinetics enable full cells with the composite SSE to retain 88.2% of their initial capacity after 300 cycles, outperforming control cells (81.9% retention). This work establishes a defect-engineering strategy for ceramic fillers as a generalizable route to high-performance solid-state electrolytes.