Electrochemical Intercalation of Fluoride-Ions into Oxyfluorosulfide Via Electrolyte Solution for Liquid-Based Fluoride-Ion Battery

作者：Shicong Zhang, Ken-ichi Okazaki, Chengchao Zhong, Keiji Shimoda, Yuki Orikasa · 发表于：ECS Meeting Abstracts · 年份：2024 · DOI：10.1149/ma2024-02674652mtgabs

Rechargeable batteries with high energy density have been required for recent applications such as battery electric vehicles. Fluoride ion batteries (FIBs) can achieve high energy density by using monovalent fluoride ions as charge carriers and multi-electron reactions of electrode active materials, and have attracted much attention as a candidate to surpass the performance of the current lithium-ion battery (LIB). However, FIB using the metal/metal fluoride conversion reaction, which has a high potential for energy density, has not been fabricated with good reversibility as the current LIB. On the other hand, the FIB using a crystal capable of intercalation (insertion-extraction) reaction of fluoride ions as the active material has been developed [1]. Recently, an all-solid-state fluoride ion battery using an oxyfluorosulfide (Sr2F2Fe2OS2; SFFOS) as the intercalation-type positive active material has been reported, and the battery has operated with high capacity and good reversibility at 413 K [2]. In this study, SFFOS was evaluated as an active material for liquid-based FIB. In particular, the thermal effect on the intercalation reaction of SFFOS in ionic liquid-based electrolyte solution was measured. The SFFOS was synthesized from four kinds of powder, SrF2, SrO, Fe and S, with molar ratio of 1:1:2:2 referring to the previous papers [2, 3]. These powders were mechanically ground under argon and pressed at 6 MPa to form a pellet. The resulting pellet was vacuum sealed in ...