Researchers from The University of Tokyo have made a significant breakthrough in understanding the inner workings of Solid Oxide Fuel Cell, SOFC. For the first time, they have directly observed the space charge layers inside the solid electrolyte of a fuel cell.
Potential of SOFC
SOFCs are a promising source of clean energy due to their low carbon dioxide emissions and high-power generation efficiency. These fuel cells use yttria-stabilized cubic zirconia (YSZ) and other oxygen ion conductors as solid electrolytes. However, there is a big problem with how ions move at the edges of tiny crystals in the material. These tiny crystals are known as crystal grains. We refer to the edges between these grains as grain boundaries. At these boundaries, the mobility of ions significantly decreases. We refer to this decrease in movement as a drop in ionic conductivity. This issue has been a difficult challenge for a long time.
Meet the Team that Made this Possible
The research team, led by Assistant Professor Satoko Toyama, Lecturer Takehito Seki, Project Associate Professor Bin Feng, Specially Appointed Research Professor Yuichi Ikuhara, and Director and Professor Naoya Shibata. They are from the Institute of Engineering Innovation, Graduate School of Engineering, The University of Tokyo. The team has now succeeded in directly demonstrating the existence of space charge layers at the grain boundaries of YSZ.
Space Charge Layers in SOFC
The researchers used advanced electron microscopy to observe local electric fields. They observed a close relationship between the orientation of the crystal and the space charge layers. These layers also relate to the atomic structure at the grain boundaries. Grain boundaries are the edges where different crystals in a material meet each other.
The researchers also found something important. They can remove the space charge layer by adjusting the structure of these grain boundaries. This removal helps to lower the resistance to ion conduction. Resistance to ion conduction means how difficult it is for ions to move through a material. Ions are charged particles. This describes how hard it is for these particles to travel through a substance.
Improved Performance of Battery Materials
This research represents a major step forward in understanding the cause of ion conduction resistance at grain boundaries in battery materials. It promises to lead to the establishment of new guidelines for improving the performance of battery materials in the future.
About the Project
The study was supported by the Japan Science and Technology Agency (JST) under the Strategic Basic Research Program ERATO. This project aims to develop a new measurement technique called ultra-atomic resolution electron microscopy, which can simultaneously observe atomic-scale structures and electromagnetic field distributions.
By shedding light on the fundamental mechanisms behind ion conduction in solid electrolytes, this research represents a significant step forward in the development of more efficient and reliable energy storage and conversion technologies.
To stay updated with the latest developments in STEM research, visit ENTECH Online. This is our digital magazine for science, technology, engineering, and mathematics.
At ENTECH Online, you’ll find a wealth of information. We offer insights and resources to fuel your curiosity. Our goal is to inspire your passion for new scientific discoveries.
Everything a teen wants to know for career planning.
