Lithium-ion transport in inorganic active fillers used in PEO-based composite solid electrolyte sheets

In this study, we evaluated the properties exhibited by a composite solid electrolyte (CSE) prepared via tailoring the particle size of an active filler, Li6.4La3Zr1.4Ta0.6O12 (LLZTO). The average particle size was reduced to 2.53 mu m via ball milling and exhibited a specific surface area of 3.013 m(2) g(-1). Various CSEs were prepared by combining PEO and LLZTO/BM-LLZTO. The calculated lithium ionic conductivity of the BM-LLZTO CSE was 6.0 x 10(-5) S cm(-1), which was higher than that exhibited by the LLZTO CSE (4.6 x 10(-5) S cm(-1)). This result was confirmed via(7)Li nuclear magnetic resonance (NMR) analysis, during which lithium-ion transport pathways varied as a function of the particle size. NMR analysis showed that when BM-LLZTO was used, the migration of Li ions through the interface occurred at a fast rate owing to the small size of the constituent particles. During the Li/CSEs/Li symmetric cell experiment, the BM-LLZTO CSE exhibited lower overvoltage characteristics than the LLZTO CSE. A comparison of the characteristics exhibited by the LFP/CSEs/Li cells confirmed that the cells using BM-LLZTO exhibited high discharge capacity, rate performance, and cycling stability irrespective of the CSE thickness.

Automated summary

This study evaluated the properties of a composite solid electrolyte (CSE) prepared by adjusting the particle size of an active filler, Li6.4La3Zr1.4Ta0.6O12 (LLZTO), which resulted in higher lithium ionic conductivity when compared to the original LLZTO CSE. The use of small particle size in the BM-LLZTO CSE allowed for fast lithium-ion transport pathways, as confirmed by NMR analysis. The BM-LLZTO CSE showed lower overvoltage and better performance in Li-ion cells compared to the LLZTO CSE.