High-Temperature Behavior, Oxygen Transport Properties, and Electrochemical Performance of Cu-Substituted Nd<sub>1.6</sub>Ca<sub>0.4</sub>NiO<sub>4+</sub><sub>δ</sub> Electrode Materials

oleh: Tatiana Maksimchuk, Elena Filonova, Denis Mishchenko, Nikita Eremeev, Ekaterina Sadovskaya, Ivan Bobrikov, Andrey Fetisov, Nadezhda Pikalova, Alexander Kolchugin, Alexander Shmakov, Vladislav Sadykov, Elena Pikalova

Format: Article
Diterbitkan: MDPI AG 2022-04-01

Deskripsi

In this study, Nd<sub>1.6</sub>Ca<sub>0.4</sub>Ni<sub>1−y</sub>Cu<sub>y</sub>O<sub>4+δ</sub>-based electrode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) are investigated. Materials of the series (y = 0–0.4) are obtained by pyrolysis of glycerol-nitrate compositions. The study of crystal structure and high-temperature stability in air and under low oxygen partial pressure atmospheres are performed using high-resolution neutron and in situ X-ray powder diffraction. All the samples under the study assume a structure with <i>Bmab</i> sp.gr. below 350 °C and with <i>I4/mmm</i> sp.gr. above 500 °C. A transition in the volume thermal expansion coefficient values from 7.8–9.3 to 9.1–12.0 × 10<sup>−6</sup>, K<sup>−1</sup> is observed at approximately 400 °C in air and 500 °C in helium.The oxygen self-diffusion coefficient values, obtained using isotope exchange, monotonically decrease with the Cu content increasing, while concentration dependence of the charge carriers goes through the maximum at x = 0.2. The Nd<sub>1.6</sub>Ca<sub>0.4</sub>Ni<sub>0.8</sub>Cu<sub>0.2</sub>O<sub>4+δ</sub> electrode materialdemonstrates chemical compatibility and superior electrochemical performance in the symmetrical cells with Ce<sub>0.8</sub>Sm<sub>0.</sub><sub>2</sub>O<sub>1.9</sub>, BaCe<sub>0.8</sub>Sm<sub>0.2</sub>O<sub>3−δ</sub>, BaCe<sub>0.8</sub>Gd<sub>0.19</sub>Cu<sub>0.1</sub>O<sub>3−δ</sub> and BaCe<sub>0.5</sub>Zr<sub>0.3</sub>Y<sub>0.1</sub>Yb<sub>0.1</sub>O<sub>3−δ</sub> solid electrolytes, potentially for application in IT-SOFCs.