【Frontiers in HaiChuan Chemical Technology】Nanjing Tech University overcomes key bottlenecks in hydrogen production materials

Thread Content

The development of solid oxide electrolysis cell hydrogen production technology (SOEC) has attracted much attention, yet its industrialization is hindered by issues such as the degradation of oxygen electrode performance and structural cracking under high temperature and humidity conditions. A research team from Nanjing Tech University, in collaboration with the ** Laboratory in Suzhou, has made breakthrough advances in the field of key materials for solid oxide electrolysis water splitting. By adopting a new approach focused on regulating the \"distribution quality\" of oxygen ion transport channels, they have successfully developed new types of oxygen electrode materials that feature high efficiency and long durability. Recently, these research findings were published online in the international journal Nature Communications. 　　“Traditional approaches to improving the performance of electrolytes focus mainly on increasing the ‘number’ of oxygen ion transport channels or widening their ‘width’. Based on years of research, we have for the first time shifted our focus to the ‘quality of distribution’ of these channels. ”Professor Zhou Wei from Nanjing Tech University used an analogy: “You can think of the movement of oxygen ions within a material as people walking inside a building.” The traditional approach was to build more rooms and make the doors larger to facilitate easy movement. But if the rooms are arranged in a chaotic manner, with some areas crowded and others filled with walls, people still can’t move through easily and have to take longer routes, resulting in a lower overall speed. ” 　　To this end, the team innovatively adopted a \"local high-entropy\" strategy, incorporating six trace metal elements including zirconium, titanium, and zinc into the barium-cobalt-based perovskite material, thereby creating a complex \"composite oxide formula\". “This not only increases the number of active sites available for oxygen ion transport, but also ensures a highly uniform and dispersed distribution of these sites throughout the material, thereby creating an efficient and smooth ion transport network. ”Wang Xiaoyu, a doctoral student at Nanjing Tech University, explained. 　　Experiments have shown that this new type of oxygen electrode material not only significantly reduces the resistance to oxygen ion diffusion, but also greatly enhances the material’s thermomechanical stability and its ability to absorb protons. The electrolytic cell assembled using this material exhibits excellent performance at an operating temperature of 600°C: the electrolytic current density reaches as high as 2.0 A/cm2, which is far higher than that of conventional materials. During nearly 800 hours of long-term stability testing and 40 severe \"thermal shock\" cycle tests, the rate of performance degradation was extremely low. 　　Currently, the industrial-scale development of this technology is being accelerated at the **lab in Suzhou. The team has successfully established China’s first megawatt-class pilot production line. The hydrogen production system developed achieves international advanced levels in key metrics such as energy efficiency, and it is expected to provide critical technical support for the green transformation of energy-intensive industries such as chemicals and steel manufacturing.