Zhu Yuntong, Chon Michael, Thompson Carl V, Rupp Jennifer L M
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Department of Chemistry, Technical University Munich, Garching, 85748, Germany.
Angew Chem Int Ed Engl. 2023 Nov 6;62(45):e202304581. doi: 10.1002/anie.202304581. Epub 2023 Oct 2.
Efficient and affordable synthesis of Li functional ceramics is crucial for the scalable production of solid electrolytes for batteries. Li-garnet Li La Zr O (LLZO), especially its cubic phase (cLLZO), attracts attention due to its high Li conductivity and wide electrochemical stability window. However, high sintering temperatures raise concerns about the cathode interface stability, production costs, and energy consumption for scalable manufacture. We show an alternative "sinter-free" route to stabilize cLLZO as films at half of its sinter temperature. Specifically, we establish a time-temperature-transformation (TTT) diagram which captures the amorphous-to-crystalline LLZO transformation based on crystallization enthalpy analysis and confirm stabilization of thin-film cLLZO at record low temperatures of 500 °C. Our findings pave the way for low-temperature processing via TTT diagrams, which can be used for battery cell design targeting reduced carbon footprints in manufacturing.
高效且经济地合成锂功能陶瓷对于电池固体电解质的规模化生产至关重要。锂石榴石LiLaZrO（LLZO），尤其是其立方相（cLLZO），因其高锂电导率和宽电化学稳定窗口而备受关注。然而，高烧结温度引发了人们对阴极界面稳定性、生产成本以及规模化制造过程中的能源消耗等问题的担忧。我们展示了一种替代的“无烧结”途径，可在其烧结温度的一半时将cLLZO稳定成薄膜。具体而言，我们建立了一个时间 - 温度 - 转变（TTT）图，该图基于结晶焓分析捕捉非晶态到晶态的LLZO转变，并证实了在500°C的创纪录低温下薄膜cLLZO的稳定性。我们的研究结果为通过TTT图进行低温加工铺平了道路，该图可用于电池单元设计，目标是在制造过程中减少碳足迹。
