Liu Yulong, Liu Jingru, Sun Qian, Wang Dawei, Adair Keegan R, Liang Jianneng, Zhang Cheng, Zhang Li, Lu Shigang, Huang Huan, Song Xiping, Sun Xueliang
Department of Mechanical and Materials Engineering , The University of Western Ontario , London , Ontario N6A 5B9 , Canada.
State Key Laboratory for Advance Metal and Materials , University of Science and Technology Beijing , Beijing 100083 , China.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27890-27896. doi: 10.1021/acsami.9b08132. Epub 2019 Jul 24.
LiAlTi(PO) (LATP) is a popular solid electrolyte used in solid-state lithium batteries due to its high ionic conductivity. Traditionally, the densification of LATP is achieved by a high-temperature sintering process (about 1000 °C). Herein, we report the compaction of LATP by a newly developed cold sintering process and post-annealing. LATP pellets are first densified at 120 °C and then annealed at 650 °C, yielding an ionic conductivity of 8.04 × 10 S cm at room temperature and a relative density of 93% with a low activation energy of 0.37 eV. High-resolution transmission electron microscopy of the cold sintered pellets is investigated as well, showing that the particles are interconnected with some nanoprecipitates at the grain boundaries. Such nanocrystalline-enriched grain boundaries are beneficial for lithium-ion transportation, which leads to higher ionic conductivity of the cold sintered sample. This new sintering process can direct new horizons for development of all solid-state batteries due to its simplicity.
锂铝钛（磷酸）（LATP）是一种因具有高离子电导率而常用于固态锂电池的固体电解质。传统上，LATP的致密化是通过高温烧结工艺（约1000°C）实现的。在此，我们报道了通过新开发的冷烧结工艺和后续退火对LATP进行压实。LATP颗粒首先在120°C下致密化，然后在650°C下退火，在室温下产生8.04×10 S cm的离子电导率，相对密度为93%，活化能低至0.37 eV。还对冷烧结颗粒进行了高分辨率透射电子显微镜研究，结果表明颗粒相互连接，晶界处有一些纳米析出物。这种富含纳米晶体的晶界有利于锂离子传输，这导致冷烧结样品具有更高的离子电导率。这种新的烧结工艺因其简单性可为全固态电池的开发开辟新的前景。
