钡钴氧正极的高温结构和电学性质

High-Temperature Structural and Electrical Properties of BaCoO Positrodes.

作者信息

Szpunar Iga, Strandbakke Ragnar, Sørby Magnus Helgerud, Wachowski Sebastian Lech, Balaguer Maria, Tarach Mateusz, Serra José M, Witkowska Agnieszka, Dzik Ewa, Norby Truls, Gazda Maria, Mielewczyk-Gryń Aleksandra

机构信息

Nanotechnology Centre A, Faculty of Applied Physics and Mathematics and Advanced Materials Centre, Gdańsk University of Technology, ul. Narutowicza 11/12, 80-233 Gdańsk, Poland.

Department of Chemistry, Centre for Materials Science and Nanotechnology, University of Oslo, FERMiO, Gaustadalléen 21, NO-0349 Oslo, Norway.

出版信息

Materials (Basel). 2020 Sep 11;13(18):4044. doi: 10.3390/ma13184044.

DOI:10.3390/ma13184044

PMID:32933063

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7558619/

Abstract

The application of double perovskite cobaltites BaCoO ( = lanthanide element) in electrochemical devices for energy conversion requires control of their properties at operating conditions. This work presents a study of a series of BaCoO ( = La, Pr, Nd) with a focus on the evolution of structural and electrical properties with temperature. Symmetry, oxygen non-stoichiometry, and cobalt valence state have been examined by means of Synchrotron Radiation Powder X-ray Diffraction (SR-PXD), thermogravimetry (TG), and X-ray Absorption Spectroscopy (XAS). The results indicate that all three compositions maintain mainly orthorhombic structure from RT to 1000 °C. Chemical expansion from Co reduction and formation of oxygen vacancies is observed and characterized above 350 °C. Following XAS experiments, the high spin of Co was ascertained in the whole range of temperatures for BLC, BPC, and BNC.

摘要

双钙钛矿钴酸盐BaCoO（ =镧系元素）在用于能量转换的电化学装置中的应用需要在操作条件下控制其性能。这项工作对一系列BaCoO（ = La、Pr、Nd）进行了研究，重点关注结构和电学性能随温度的演变。通过同步辐射粉末X射线衍射（SR-PXD）、热重分析（TG）和X射线吸收光谱（XAS）研究了对称性、氧非化学计量比和钴价态。结果表明，所有三种成分在室温至1000°C范围内主要保持正交结构。在350°C以上观察到并表征了由于Co还原和氧空位形成导致的化学膨胀。通过XAS实验，确定了BLC、BPC和BNC在整个温度范围内Co的高自旋态。