High-Entropy Perovskite Oxide: A New Opportunity for Developing Highly Active and Durable Air Electrode for Reversible Protonic Ceramic Electrochemical Cells

Zuoqing Liu; Zhengjie Tang; Yufei Song; Guangming Yang; Wanru Qian; Meiting Yang; Yinlong Zhu; Ran Ran; Wei Wang; Wei Zhou; Zongping Shao

doi:10.1007/s40820-022-00967-6

High-Entropy Perovskite Oxide: A New Opportunity for Developing Highly Active and Durable Air Electrode for Reversible Protonic Ceramic Electrochemical Cells

Nanomicro Lett. 2022 Nov 9;14(1):217. doi: 10.1007/s40820-022-00967-6.

Authors

Zuoqing Liu¹, Zhengjie Tang¹, Yufei Song², Guangming Yang³, Wanru Qian¹, Meiting Yang¹, Yinlong Zhu⁴, Ran Ran¹, Wei Wang¹, Wei Zhou¹, Zongping Shao^{5

6}

Affiliations

¹ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China.
² Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, People's Republic of China.
³ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China. ygm89525@njtech.edu.cn.
⁴ Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, People's Republic of China. zhuyl1989@nuaa.edu.cn.
⁵ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China. shaozp@njtech.edu.cn.
⁶ WA School of Mines: Minerals, Energy and Chemical Engineering (WASM-MECE), Curtin University, Perth, WA, 6845, Australia. shaozp@njtech.edu.cn.

Abstract

Reversible proton ceramic electrochemical cell (R-PCEC) is regarded as the most promising energy conversion device, which can realize efficient mutual conversion of electrical and chemical energy and to solve the problem of large-scale energy storage. However, the development of robust electrodes with high catalytic activity is the main bottleneck for the commercialization of R-PCECs. Here, a novel type of high-entropy perovskite oxide consisting of six equimolar metals in the A-site, Pr_1/6La_1/6Nd_1/6Ba_1/6Sr_1/6Ca_1/6CoO_3-δ (PLNBSCC), is reported as a high-performance bifunctional air electrode for R-PCEC. By harnessing the unique functionalities of multiple elements, high-entropy perovskite oxide can be anticipated to accelerate reaction rates in both fuel cell and electrolysis modes. Especially, an R-PCEC utilizing the PLNBSCC air electrode achieves exceptional electrochemical performances, demonstrating a peak power density of 1.21 W cm^-2 for the fuel cell, while simultaneously obtaining an astonishing current density of - 1.95 A cm^-2 at an electrolysis voltage of 1.3 V and a temperature of 600 °C. The significantly enhanced electrochemical performance and durability of the PLNBSCC air electrode is attributed mainly to the high electrons/ions conductivity, fast hydration reactivity and high configurational entropy. This research explores to a new avenue to develop optimally active and stable air electrodes for R-PCECs.

Keywords: Air electrode; High-entropy oxide; Oxygen evolution reaction; Oxygen reduction reaction; Reversible proton ceramic electrochemical cells.