Synthesis and anode properties of corundum-type structured (Fe^sub 2^O^sub 3^)^sub 1-x^(Al^sub 2^O^sub 3^)^sub x^ solid solutions in the whole compositional range

• Published in: Solid state ionics 2017-12, Vol.313, p.1
• Main Authors: Takai, Shigeomi, Sawada, Eisuke, Harada, Junpei, Park, Seungwon, Oda, Masaya, Esaki, Shogo, Nishijima, Motoaki, Yoshie, Tomohisa, Yabutsuka, Takeshi, Yao, Takeshi
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Chemical synthesis; Corundum; Electrostatic discharges; Hematite; Iron; Iron oxides; Lattice parameters; Mathematical analysis; Solid solutions; Solid state physics; Studies
• ISSN: 0167-2738; 1872-7689

We have successfully synthesized corundum-type structured solid solutions of (Fe2O3)1-x(Al2O3)x/ in the whole compositional range (0 ≤ ≤ = 1) by means of mechanochemical synthesis route starting from y-Fe2O3 and y-Al2O3 mixture. The lattice parameters of the obtained solid solution coincide with the calculated values assuming Vegard's rule based on the JCPDS card data of α-Fe2O3 (33-664) and α-Al2O3 (46-1212), indicating that the composition of the obtained solid solution is essentially equivalent to the initial Fe2O3/Al2O3 ratio in the starting materials. The test cells using the obtained solid solution as the active material exhibited good cycle performances. Especially in the compositional range in 0.33 ≤ x ≤ 0.45, after a gradual decrease in charge-discharge capacity down to ~ 300 mAhg- 1 for around 100 cycles, the capacity recovers again. Even for x = 0.95, the capacity retains at least 100 mAhg- 1 after 260th cycles, which is larger than the estimated from the Fe2O3 amount.