Recently, Dr. Zhang Yuan and Dr. Chen Bin and Prof. Xie Heping of the Institute of Deep Earth Science and Green Energy in the college of civil and transportation engineering, Shenzhen university published a research paper entitled "Thermal-expansion offset for high-performance fuel cell cathodes" in the official issue of Nature(Nature, 2021, 591, 246–251), as the first and second authors,
In their work, the concept of "negative thermal expansion offset" is put forward for the first time and the mechanical equilibrium effect model of mechanical anchoring at the interface between negative expansive material and perovskite is established. The strengthening mechanism of anchoring effect at the interface between negative expansion material and perovskite material is also analyzed. At the same time, the negative expansion material and perovskite material are compounded effectively, the thermal expansion coefficient of composite electrode is reduced successfully, and the interface between electrode and electrolyte material is optimized. This study successfully solved the problem of mismatch of thermal expansion coefficient at the electrode-electrolyte interface of solid oxide fuel cell. It is found that the excellent electrochemical performance of the composite electrode is promoted by the decrease of the coefficient of thermal expansion, the optimization of perovskite phase structure and the improvement of thermomechanical stability. This result provides a solid technical support and guarantee for the development of a new high-performance electrode material of "Zero carbon Emission Direct Coal solid oxide fuel Cell" that the team is working on.
This work is conducted in cooperation between Institute of Deep earth Science and Green Energy of Shenzhen University, the group of Professor Zongping Shao and Professor Wei Zhou of Nanjing University of Technology and the group of Professor Ni Meng of Hong Kong Polytechnic University.