Solid Hybrid Electrolyte Featuring a Vertically Aligned Li6.4La3.0Zr1.4Ta0.6O12 Membrane for All-Solid-State Lithium Batteries

All-solid-statelithium batteries (ASSLBs) with enhanced safetyare considered one of the most promising substitutes for liquid electrolyte-basedLi-ion batteries. However, many properties of solid electrolytes,such as ionic conductivity, film formability, and electrochemical,mechanical, thermal, and interfacial stability need to be improvedfor their practical application. In this study, a vertically alignedLi(6.4)La(3.0)Zr(1.4)Ta(0.6)O(12) (LLZO) membrane with finger-like microvoids was preparedusing processes involving phase inversion and sintering. A hybridelectrolyte was then obtained by infusing the LLZO membrane with asolid polymer electrolyte based on poly(& epsilon;-caprolactone). Thesolid hybrid electrolyte (SHE) was a flexible thin film with highionic conductivity, superior electrochemical stability, high Li+ transference number, enhanced thermal stability, and improvedLi metal electrode-solid electrolyte interfacial stability.A solid-state Li/LiNi0.78Co0.10Mn0.12O2 cell assembled with the hybrid electrolyte exhibitedgood cycling performance, in terms of discharge capacity, cyclingstability, and rate capability. Accordingly, the SHE using a verticallyaligned LLZO membrane is a promising solid electrolyte for realizingsafe, high-performance ASSLBs.

Automated summary

A vertically aligned LLZO membrane with finger-like microvoids was prepared and used as a solid electrolyte for a hybrid electrolyte. The resulting solid hybrid electrolyte exhibited high ionic conductivity, superior electrochemical stability, and improved Li metal electrode-solid electrolyte interfacial stability. A solid-state Li/LiNi0.78Co0.10Mn0.12O2 cell assembled with this hybrid electrolyte showed excellent cycling performance. Therefore, the vertically aligned LLZO membrane-based hybrid electrolyte is a promising solid electrolyte for safe and high-performance all-solid-state lithium batteries.