LLZTO (Li6.4La3Zr1.4Ta0.6O12) and Alumina Coated PE Roll as Solid-State Battery Separator, CSSBSPELLZTO

LLZTO (Li6.4La3Zr1.4Ta0.6O12 (LLZTO) is a Tantalum-doped garnet-type oxide known for its high ionic conductivity and excellent electrochemical stability. In the architecture of a Solid-State Battery (SSB), a LLZTO-coated PE separator serves as a "quasi-solid-state" bridge. It combines the safety and stability of a solid ceramic electrolyte with the low cost and flexibility of traditional polyethylene (PE).

Traditional ceramic coatings (like Alumina) are just "safety blankets" to prevent shrinking. LLZTO adds functional performance: (1) Dendrite Suppression: LLZTO has a high shear modulus (G ~60 GPa). This makes it physically difficult for lithium dendrites to pierce through the separator and cause a short circuit. (2) Enhanced Ion Flux: Unlike inert coatings that can block pores, LLZTO provides additional Li+$pathways. This leads to a more uniform "ion flux," reducing the local hot spots where dendrites typically start to grow. (3) Electrolyte Wettability: LLZTO has a high surface energy, which helps liquid or gel electrolytes spread more evenly across the separator, lowering interfacial resistance. (4) High Voltage Stability: LLZTO is stable up to ~6.0 V, allowing the use of high-energy cathodes (like NCM811) without the separator degrading.