Wet-Milling Synthesis of Superionic Lithium Argyrodite Electrolytes with Different Concentrations of Lithium Vacancy
Liping Wu, Zhichao Zhang, Zhichao Zhang, Gaozhan Liu, Wei Weng, Zhihua Zhang, Zhihua Zhang, Xiayin Yao
Abstract
The ionic conductivities of argyrodite electrolytes are significantly affected by the concentrations of lithium vacancy. Herein, a facile and rapid synthesis route is proposed to systematically investigate Li6–xPS5–xCl1+x (0 ≤ x ≤ 0.8) with different lithium vacancies by adjusting ratios of S/Cl. The highest ionic conductivity of the wet-milling synthesized Li5.4PS4.4Cl1.6 is 6.18 mS cm–1, which is attributed to higher lithium vacancy concentration and lower electrostatic interaction for ion migration. The Li/Li5.4PS4.4Cl1.6/Li symmetric cell cycles stably for 2000 h at 0.1 mA cm–2, showing excellent dendrite suppression capability. Moreover, the initial discharge capacity of LiCoO2/Li5.4PS4.4Cl1.6/Li all-solid-state battery is 126.0 mAh g–1 at 0.1C and the capacity retention is 83% after 50 cycles. The wet-milling method provides the possibility for rapid exploration and preparation of other argyrodite electrolytes in the future.