A Superionic Conductor Lithium Argyrodite Sulfide of Li<sub>7–<i>x</i></sub>(GeSi)<sub>(1–<i>x</i>)/2</sub>Sb<sub><i>x</i></sub>S<sub>5</sub>I toward All-Solid-State Lithium-Ion Batteries
Yuxin Ma, Daokuan Jin, Haodong Shi, Rui Li, Yutao Niu, Yunyun Xu, Cong Dong, Yangyang Liu, Rui Yang, Guiming Zhong, Chunyang Wang, Zhizhen Zhang, Zhangquan Peng, Zhong‐Shuai Wu
Abstract
Li 6 PS 5 I based solid-state electrolytes (SSEs) show promising interface compatibility for all-solid-state batteries (ASSBs), but they still suffer from limited ionic conductivity. Herein, a superionic conductor lithium argyrodite sulfide, Li 7– x (GeSi) (1– x )/2 Sb x S 5 I, was developed through multi-cation substitution of Ge, Si, and Sb for P, increasing configurational entropy of the Li 6 PS 5 I. This approach enhanced Li + content and anion site disorder, leading to a low activation energy of 0.17 eV for Li + migration, and consequently a high cold-pressed ionic conductivity of 12.7 mS cm –1, and a record value of 32.2 mS cm –1 after hot-pressing. When incorporating Li 3 InCl 6 as the catholyte and interlayer, the LiNi 0.8 Co 0.1 Mn 0.1 O 2 @Li 3 InCl 6 |Li 3 InCl 6 |Li 20/3 (GeSiSb) 1/3 S 5 I|Li-In ASSBs exhibited a high capacity of 219 mAh g –1 at 0.1 C, and a notable capacity of 135 mAh g –1 with 84.4% retention at 1 C after 550 cycles. Our ASSBs demonstrated stable cycling across −20 to 60 °C and operated well at an ultrahigh cathode loading of 100 mg cm –2 . These findings advance sulfide SSEs for high-performance and wide-temperature ASSBs.