Interface stability of LiCl-rich argyrodite Li6PS5Cl with propylene carbonate boosts high-performance lithium batteries. (10th December 2020)

• Record Type: Journal Article
• Authors: Li, Yang; Arnold, William; Jasinski, Jacek B.; Thapa, Arjun; Sumanasekera, Gamini; Sunkara, Mahendra; Narayanan, Badri; Druffel, Thad; Wang, Hui
• Is Part Of: Electrochimica acta. Volume 363(2020)
• Publication Date: 2020-12-10
• Subjects: Li6PS5Cl -- Argyrodite electrolyte -- LiCl-rich -- Interface -- Lithium battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.137128
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: LiCl-rich argyrodite SE (Li6 PS5 Cl-LiCl) is synthesized by solvent-based method. PC and excess LiCl in SE facilitates to form stable SEI layer at interface. Improved interface stability significantly boosts battery cycling performance. Abstract: In solid-state lithium (Li)-metal batteries (SSLMBs), sulfide-based Li-ion conductors represent one of the most popular solid electrolytes (SEs). However, the development of sulfide-based SSLMBs is significantly hampered by interfacial issues including large solid-solid contact resistance and serious side reactions at the SE/electrode interface. To address these issues, here, we demonstrated a simple and efficient strategy by using LiCl-rich argyrodite Li6 PS5 Cl (Li6 PS5 Cl-LiCl) SE and trace amount of propylene carbonate (PC) at the SE/electrode interface to facilitate the formation of stable and robust solid electrolyte interphase (SEI). The formed SEI not only serves as a buffer layer to passivate the interfacial reactions and suppress Li dendrite growth, but also acts as a bridge for Li-ion conduction to reduce the contact resistance. As a result, the Li||Li symmetric cell exhibited long-term electrochemical cycling stability over 1000 h at a current density of 0.2 mA cm −2 . Furthermore, the assembled Li||Li4 Ti5 O12 (LTO) batteries delivered a specific capacity of 175 mAh g –1 at 0.2 C, and remained an excellent specific capacity of 116 mAh g –1 after 200 cycles at a high current rate of 1 C. These features indicate a feasible strategy to enhance the interfacial property of high-performance SSLMBs. Graphical abstract: An effective and feasible strategy is demonstrated to address the interfacial issues faced by sulfide-based solid-state Li batteries by the combination of Li6 PS5 Cl LiCl argyrodite SE with a wetting interface. The excess LiCl in SEs could facilitate the formation of stable SEI at SE/Li interface, which boosts outstanding electrochemical performance. Image, graphical abstract