Abstract Lithium lanthanum titanate (LLTO) is one of the most promising solid electrolytes for next generation batteries owing to its high ionic conductivity of ∼1 × 10 − 3 S/cm at room temperature. To comprehensively understand the microstructure and ion diffusion mechanism of LLTO, recent research in diffraction and spectroscopy techniques as well as computational study have been reviewed in this paper. The extremely low ionic conductivity at grain boundary as well as the increased electronic conductivity related to the direct contact with metallic lithium has impeded the practical application of LLTO for the solid-state batteries. Various studies including substitution, the introduction of grain boundary layer modifier, high temperature sintering, and synthesis of amorphous LLTO have been applied to solve these major challenges and their effectiveness are discussed in this review. Moreover, different types of synthesis methodologies of LLTO thin films are reviewed and compared in detail. In the end, the recent reports of solid-state battery system are reviewed and discussed.

中文翻译：

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钛酸镧锂电解液向全固态锂离子二次电池的最新进展

摘要 钛酸镧锂（LLTO）是下一代电池最有前途的固体电解质之一，因为它在室温下具有~1 × 10 - 3 S/cm 的高离子电导率。为了全面了解LLTO的微观结构和离子扩散机制，本文综述了近年来在衍射和光谱技术以及计算研究方面的研究。晶界处极低的离子电导率以及与金属锂直接接触相关的电子电导率增加阻碍了 LLTO 在固态电池中的实际应用。各种研究，包括取代、引入晶界层改性剂、高温烧结、和非晶态 LLTO 的合成已被应用于解决这些主要挑战，本综述讨论了它们的有效性。此外，还详细回顾和比较了不同类型的 LLTO 薄膜的合成方法。最后，回顾和讨论了近期关于固态电池系统的报道。