Ultrafast Sintering of Dense Li7 La 3 Zr2 O12 Membranes for Li Metal All-Solid-State Batteries

• Published in: Advanced science Vol. 12; no. 2
• Main Authors: Okur, Faruk, Zhang, Huanyu, Baumgärtner, Julian F., Sivavec, Jaka, Klimpel, Matthias, Wasser, Gregor Paul, Dubey, Romain, Jeurgens, Lars P.H., Chernyshov, Dmitry, van Beek, Wouter, Kravchyk, Kostiantyn V., Kovalenko, Maksym V.
• Format: Journal Article
• Language: English
• Published: Wiley Open Access 13.01.2025
• Subjects: Physics
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202412370

Ultrafast sintering (UFS) is a compelling approach for fabricating Li 7 La 3 Zr 2 O 12 (LLZO) solid-state electrolytes (SSEs), paving the way for advancing and commercializing Li-garnet solid-state batteries. Although this method is commonly applied to the sintering of LLZO ceramics, its use for producing dense, phase-pure LLZO SSEs has thus far been primarily limited to millimeter-thick pellets, which are unsuitable for commercial solid-state batteries. This study presents ultrafast sintering as a highly effective approach for fabricating self-standing, dense, 45 µm-thick LLZO membranes. The chemical and structural evolution of LLZO membranes during the UFS process is characterized through in situ synchrotron X-ray diffraction and thermogravimetric analysis-mass spectrometry, complemented by an in-depth investigation of surface chemistry using X-ray photoelectron spectroscopy. The membranes in Li/LLZO/Li symmetrical cell configuration exhibit a high critical current density of up to 12.5 mA cm −2 and maintain superior cycling stability for 250 cycles at a current density of 1 mA cm −2 , with an areal capacity limit of 1 mAh cm −2 . The electrochemical performance of LLZO membranes is also assessed in full cell configuration using a pyrochlore-type iron (III) hydroxy fluoride cathode.