2023/09/26 by Hiroaki Ito, Yuki Nakahira, Naoki Ishimatsu +14
Chemistry · Engineering · #Advanced Battery Materials and Technologies #Advancements in Battery Materials #Inorganic Chemistry and Materials
paper · doi:10.1246/bcsj.20230132
openalex publication_date 2023/09/26 · crossref created 2023/09/26 · crossref issued 2023/09/27 · crossref published 2023/09/27 · crossref published-online 2023/09/27 · crossref published-print 2023/11/15 · crossref deposited 2024/01/16 · openalex created_date 2025/10/10 · crossref indexed 2026/07/30 · openalex updated_date 2026/07/30
Abstract Metastable solid electrolytes exhibit superior conductivity compared to stable ones, making them a subject of considerable interest. However, synthesis of the metastable phase is affected by multiple thermodynamic and kinetic parameters, leading to ambiguity in the organization of stability and metastability. In this study, we organized remnant and intermediate metastability based on temperature. The intermediate metastable phase, which is less stable than the temperature-independent stable phase, typically transforms into the stable phase(s) at high temperatures. In contrast, the remnant metastable phase is formed by first obtaining most stable phase at specific temperatures and then “trapping” it by rapidly changing the temperature. By investigating Li+ conducting chlorides, Li3MCl6 (M = Y and Ho), we demonstrated that heating starting materials to approximately 600 K produced low-temperature Li3MCl6 phase with one formula unit while further heating resulted in high-temperature Li3MCl6 phase with three formula units. Annealing quenched Li3MCl6 at 573 K resulted in a phase transition from the high-temperature to low-temperature phase, indicating that the high-temperature phase was remnant metastable at low temperatures.