AUTHOR=Wang Shuo , Wu Xinbin , Liang Yuhan , Xu Yushuai , Guan Shundong , Wen Kaihua , Miao Xiang , Liang Ying , He Hongcai , Lin Yuanhua , Shen Yang , Nan Ce-Wen 

TITLE=Facile synthesis of lithium argyrodite Li5.5PS4.5Br1.5 with high ionic conductivity for all-solid-state batteries

JOURNAL=Frontiers in Chemical Engineering

VOLUME=4

YEAR=2022

URL=https://www.frontiersin.org/journals/chemical-engineering/articles/10.3389/fceng.2022.883502

DOI=10.3389/fceng.2022.883502

ISSN=2673-2718

ABSTRACT=<p>Bromine-rich lithium argyrodite electrolytes with high ionic conductivity and low cost are promising for the replacement of flammable liquid electrolytes and separators in lithium-ion batteries. However, the synthesis process of argyrodite electrolytes is usually complex and time-consuming. We use a facile solid-state reaction method to obtain a highly Li-ion conductive Li<sub>5.5</sub>PS<sub>4.5</sub>Br<sub>1.5</sub> (LPSB). The influence of annealing temperature on the phase and ionic conductivity of the LPSB was investigated for the first time. High ionic conductivity of 5.21 × 10<sup>−3</sup> S cm<sup>−1</sup> at room temperature for the LPSB with minor LiBr impurity was achieved by direct annealing at 430°C for 8 h. The In/InLi | LPSB | LiCoO<sub>2</sub>@ LiNb<sub>0.5</sub>Ta<sub>0.5</sub>O<sub>3</sub> (LCO(coated))-LPSB cell with 8.53 mg cm<sup>−2</sup> LCO loading shows a discharge capacity of 102 mAh g<sup>−1</sup> with high-capacity retention of 93% after 70 cycles at 0.5 mA cm<sup>−2</sup> at 30°C.</p>