[14p-D215-1~7] 【CS.5】 Code-sharing Session of 7.4 & 9.5

[14p-D215-7] A ternary fluoride: synthesis, magnetic properties, and cathode performance in F-ion batteries

〇Tsuyoshi Takami¹, Katsumi Kawahara¹, Takashi Saito², Takashi Kamiyama², Toshiharu Fukunaga¹, Takeshi Abe¹ (1.Kyoto Univ., 2.KEK)

Keywords:new material, fluoride, antiferromagnetic

We synthesized a BiFe_0.5F_y (BFF) phase via a non-topochemical reaction with a fluorination agent. Its crystal structure was the R3c space group, along with the defect structure. The linear relationship between magnetization and magnetic field, and the sudden decrease in magnetic susceptibility below 250 K indicate that BFF is an antiferromagnetic material. When we applied BFF as a cathode in F-ion batteries, a reversible capacity of 200 mAh/g was achieved at 140 °C. Magnetization and XRD measurements confirmed that the F ions were transferred from the cathode to the counter electrode in the discharging process and vice versa in the charging process.