Engineering a Glass-Ceramic Solid Electrolyte Membrane for Reliable and Scalable Electrochemical Lithium Recycling Systems > Publication | UNIST YK RESEARCH

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Publication

Engineering a Glass-Ceramic Solid Electrolyte Membrane for Reliable and Scalable Electrochemical Lithium Recycling Systems
Author
Hyungjun Lee, Jongwoo Kim, Seungwoo Lee, Minsung Kim, Shun Myung Shin, Yong-Yeon Joo, Dong Ju Shin, Dongseok Lee, Bogeum Choi, Youngsik Kim, Ungyu Paik, Taeseup Song
Journal
ACS Applied Energy Materials
Year
2025
Lithium recycling technology has become increasingly important to address the growing demand for lithium-ion batteries (LIBs) and the limited availability of natural lithium resources. Among various approaches, the electrochemical lithium recycling system has emerged as a promising candidate due to its mild operating conditions and environmental compatibility. In this system, the solid electrolyte (SE) membrane plays a critical role by enabling selective lithium-ion transport while physically separating the electrode compartments. Therefore, SE membranes should possess high ionic conductivity and sufficient density to ensure a stable system operation. However, conventional sol–gel-derived SE membranes often suffer from incomplete densification, undermining the function of the membrane as a physical barrier. In this work, a high-density, high-conductivity lithium aluminum titanium phosphate (LATP)-based glass-ceramic SE membrane is developed via a melt-quenching approach. Optimization of quenching and crystallization conditions yields a SE membrane with a high relative density of 97.1% and an ionic conductivity of 5.06 × 10–4 S cm–1. The optimized SE membrane exhibits a dense microstructure that effectively suppresses liquid leakage and enables a stable electrochemical operation over 100 cycles. Additionally, a scalable bottom-up fabrication strategy based on glass powder processing is established. An integrated prismatic lithium recycling module, constructed by scaling up the SE membrane arrangement from a 1 × 1 to a 3 × 3 configuration and stacking multiple unit cells, yields an approximately 100-fold increase in the available current compared to the single-cell configuration, thereby enhancing the lithium recycling rate per unit time by 2 orders of magnitude.