Low Area Specific Resistance La-Doped Bi<sub>2</sub>O<sub>3</sub> Nanocomposite Thin Film Cathodes for Solid Oxide Fuel Cell Applications.

Lovett, Adam J; Wells, Matthew P; Zhang, Yizhi; Song, Jiawei; Miller, Thomas S; Wang, Haiyan; MacManus-Driscoll, Judith L · Nano Lett · 2024

basic_science · Level V

Where this comes from

Abstract

In the context of solid oxide fuel cells (SOFCs), vertically aligned nanocomposite (VAN) thin films have emerged as a leading material type to overcome performance limitations in cathodes. Such VAN films combine conventional cathodes like La<sub><i>x</i></sub>Sr<sub>1-<i>x</i></sub>Co<sub><i>y</i></sub>Fe<sub>1-<i>y</i></sub>O<sub>3</sub> (LSCF) and La<sub>1-x</sub>Sr<sub><i>x</i></sub>MnO<sub>3</sub> (LSM) together with highly O<sup>2-</sup> ionic conducting materials including yttria-stabilized zirconia (YSZ) or doped CeO<sub>2</sub>. Next-generation SOFCs will benefit from the exceptionally high ionic conductivity (1 S cm<sup>-1</sup> at 730 °C) of Bi<sub>2</sub>O<sub>3</sub>-based materials. Therefore, an opportunity exists to develop Bi<sub>2</sub>O<sub>3</sub>-based VAN cathodes. Herein, we present the first growth and characterization of a Bi<sub>2</sub>O<sub>3</sub>-based VAN cathode, containing epitaxial La-doped Bi<sub>2</sub>O<sub>3</sub> (LDBO) columns embedded in a LSM matrix. Our novel VANs exhibit low area specific resistance (ASR) (8.3 Ω cm<sup>2</sup> at 625 °C), representing ∼3 orders of magnitude reduction compared to planar LSM. Therefore, by demonstrating a high-performance Bi<sub>2</sub>O<sub>3</sub>-based cathode, this work provides an important foundation for future Bi<sub>2</sub>O<sub>3</sub>-based VAN SOFCs.