Acoustic cavitation engineering of LLZTO-coated separators for moisture-resistant lithium metal batteries
Journal
Journal of Materials Chemistry A
ISSN
2050-7488
2050-7496
Date Issued
2026
Author(s)
Abstract
Acoustic cavitation is an effective surface reconstruction strategy to overcome the intrinsic moisture sensitivity, carbonate contamination, and dispersion limitations of garnet-type LLZTO nanoparticles used in separator engineering for lithium–metal batteries. Through microbubble collapse-induced shock waves and microjets, cavitation partially removes the Li2CO3 shell to produce a thin, Li-deficient passivation layer while reducing particle agglomeration and enhancing surface charge. These physicochemical improvements enable the formation of a uniform, conformal LLZTO coating on polypropylene (PP) separators via a scalable, water-based process. The resulting PP-S-LLZTO separator exhibits markedly improved wettability, porosity, electrolyte uptake, and ionic transport and achieves an ionic conductivity of 1.43 mS cm−1, a widened electrochemical stability window of 5.6 V, and a Li+ transference number of 0.56. When implemented in Li‖Li symmetric cells, PP-S-LLZTO enables stable cycling for 800 h with suppressed polarization. By contrast, full cells exhibit high-rate capability and 92.7% capacity retention after 100 cycles at 1C. Mechanistic analysis reveals that the reconstructed LLZTO establishes homogeneous Li-ion flux pathways, mitigates interfacial impedance growth, and promotes uniform lithium nucleation. These results demonstrate that acoustic cavitation engineering provides a robust, scalable approach for separator modification and offers a practical route toward durable, high-performance lithium–metal batteries.
Publisher
Royal Society of Chemistry (RSC)
Type
journal article