Se-doped Li6PS5Cl and Li5.5PS4.5Cl1.5 with improved ionic conductivity and interfacial compatibility: a high-throughput DFT study. Issue 48 (2nd December 2022)

• Record Type: Journal Article
• Authors: Jiang, Ming; Chen, Zhi-Wen; Rao, Adwitiya; Chen, Li-Xin; Zu, Xiao-Tao; Singh, Chandra Veer
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 48(2022)
• Page Start: 18294
• Page End: 18302
• Publication Date: 2022-12-02
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc03696g
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Se dopants improved the Li + ionic conductivity of Li6 PS5− x Se x Cl and Li5.5 PS4.5− x Se x Cl1.5 significantly, and Se-doped SSEs showed better interfacial stability with LiCoO2 than sulfides-type SSEs. Abstract : Developing solid-state electrolytes (SSEs) with high Li + ionic conductivity at room temperature and good interfacial compatibility with electrode materials has proven to be challenging. We employed density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations to explore the effects of Se dopant on the performance of Li6 PS5 Cl and Li5.5 PS4.5 Cl1.5 as SSEs. At room temperature, the Li + ionic conductivity of Li6 PS5 Cl was determined to be 2.592 mS cm −1, and a 7-fold increase in Li + ionic conductivity was achieved for the Li6 PSSe4 Cl structure. As for Li5.5 PS4.5− x Se x Cl1.5, the Li + ionic conductivity increased from 8.916 mS cm −1 to 19.286 mS cm −1 . The changes in the static lattice structure and its lattice dynamics provide wider diffusion pathways and more polarizable lattices, which can positively affect the Li + ionic conductivity of Se-doped SSEs. Meanwhile, the Se-doped Li6 PS5 Cl and Li5.5 PS4.5 Cl1.5 materials had better stability with LiCoO2 than sulfide-type SSEs such as Li10 GeP2 S12 and Li3 PS4 . These results provide fundamental insights into the Li + ionic conductivity and interfacial compatibility of Li6 PS5− x Se x Cl and Li5.5 PS4.5− x Se x Cl1.5, and contribute to the rational design of superionic conductors.