High entropy oxide coated BaTiO3 enabling high ionic transport

Abstract

High entropy oxides (HEOs) have gained significant attention for their diverse applications in various fields, including energy-related research. However, their potential in solid oxide fuel cells (SOFCs) remains unexplored. This research presents a practical approach to creating a local gradient field by coating BaTiO3 (BTO) with HEO, enabling efficient and stable ionic transport for fuel cell applications. The coating of 10% HEO on BTO resulted in the HEO@BTO powders demonstrating a maximum power density of 640 mWcm−2 and suitable open circuit voltage (OCV) of 1.085 V at 520 °C. We propose that the local entropy gradient created by the HEO coating on the BTO surface establishes a core-shell structure and facilitates high ion transport through the induced built-in electric field. This work sheds light on the mechanisms underlying the enhanced performance of HEO-coated BTO and offers insights into the design of advanced materials for efficient ionic transport in fuel cell technologies.