Perovskite oxide-based electrodes with asymmetric structures have faced challenges due to limited proton mobility within the lattice, resulting in low catalytic activity and reduced fuel cell performance. To address this issue, a research team led by Professors Kang Taek Lee and Woochul Jung at KAIST, Dr. Chan-Woo Lee at KIER, and Professor Sun-Ju Song at Chonnam National University selected and doped candidate bi-metal elements, successfully transforming the asymmetric structure, difficult to move, into a symmetric structure and thereby maximizing the proton transport properties (Figure 1). This breakthrough paves the way for the design of high-performance electrodes. Additionally, the team utilized computational chemistry to model and to predict the structure and reactivity of chemical systems theoretically, elucidating the correlation between the crystal structure of the electrode and the proton transport properties.

The electrode material developed by the research team has been applied to protonic ceramic electrochemical cells, demonstrating the highest power conversion performance reported to date (3.15 W/cm² at 650°C). Additionally, the material exhibited high production efficiency for green hydrogen, with no carbon dioxide emissions during the production process (approximately 770 ml/cm² per hour at 650°C). After 500 hours of continuous operation, the electrode showed stable performance even during reversible operation (alternating between power and green hydrogen production), proving the effectiveness of the proposed electrode design method (Figure 2).