Kim Chan Gyu, Woo Sung Hun, Song Kyeong Eun, Baek Seung-Wook, Kang Hyunil, Choi Won Seok, Kim Jung Hyun
Department of Advanced Materials Science and Engineering, Hanbat National University, Daejeon, South Korea.
Interdisciplinary Materials Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea.
Front Chem. 2021 Apr 21;9:633868. doi: 10.3389/fchem.2021.633868. eCollection 2021.
In this study, electrochemical properties of layered perovskites having non-stoichiometric compositions (SmBaCoO, = 0, 0. 01, 0.02, 0.03, 0.04, 0.05, 0.10, and 0.15) were analyzed for the direct application of cathode materials for Intermediate Temperature-operating Solid Oxide Fuel Cells (IT-SOFC). From the SmBaCoO oxide systems calcined at 1,100°C for 8 h, single phase (SmBaCoO, SBCO_1) was maintained only in the case of the = 0 composition. In the compositions of = 0.05-0.10, BaCoO was mixed with the pattern of SBCO. In addition, in the composition of = 0.15, it was confirmed that BaCoO and CoO phases coexisted with SBCO. In the compositions of SmBaCoO, the overall Area Specific Resistance (ASR) values decreased as the removal amount of Sm increased from = 0-0.10; then, the values increased for compositions from = 0.15. For example, the ASRs of SBCO_1, SmBaCoO (SBCO_0.95), SmBaCoO (SBCO_0.90), and SmBaCoO (SBCO_0.85) measured at 600°C were 0.301, 0.147, 0.119, and 0.179 Ω cm, respectively. In particular, SBCO_0.90 was found to have an excellent ASR property of about 0.035 Ω cm at 700°C. Typical properties of the metal-insulator transition (MIT) electrical conductivity were shown in all measured compositions. The temperature at which MIT occurred increased as the non-stoichiometric composition increased.
在本研究中，对具有非化学计量组成（SmBaCoO，x = 0、0.01、0.02、0.03、0.04、0.05、0.10和0.15）的层状钙钛矿的电化学性质进行了分析，以直接应用于中温固体氧化物燃料电池（IT - SOFC）的阴极材料。在1100°C下煅烧8小时的SmBaCoO氧化物体系中，仅在x = 0的组成情况下保持单相（SmBaCoO，SBCO_1）。在x = 0.05 - 0.10的组成中，BaCoO与SBCO的模式混合。此外，在x = 0.15的组成中，证实BaCoO相和CoO相与SBCO共存。在SmBaCoO的组成中，随着Sm的去除量从x = 0增加到0.10，总体面积比电阻（ASR）值降低；然后，对于x = 0.15的组成，该值增加。例如，在600°C下测量的SBCO_1、SmBaCoO（SBCO_0.95）、SmBaCoO（SBCO_0.90）和SmBaCoO（SBCO_0.85）的ASR分别为0.301、0.147、0.119和0.179Ω·cm。特别是，发现SBCO_0.90在700°C时具有约0.035Ω·cm的优异ASR性能。在所有测量的组成中都显示出金属 - 绝缘体转变（MIT）电导率的典型特性。发生MIT的温度随着非化学计量组成的增加而升高。
