Japanese scientists have successfully developed a small solid-oxide fuel cell (SOFC) bundle the size of a sugar cube which can operate at far lower temperatures.
The cube was a joint development between the National Institute of Advanced Industrial Science and Technology (AIST), the Fine Ceramics Research Association (FCRA) and NGK Spark Plug.
The applications of SOFCs have previously been limited by their high operating temperatures, typically 800–1000°C. Toho Gas confirmed that the SOFC bundle can produce a high power density per volume of more than two watts per cubic centimeter, even at operating temperatures of below 600°C.
This achievement should open the way to marketing practical micro SOFC systems for auxiliary power supplies for vehicles, small cogeneration systems, and portable power units.
Because typical SOFCs are operated at higher temperatures than other fuel cells, it can use heat exhausts for fuel reformation and hot-water storage to improve overall efficiency. At the same time, SOFCs are durable because they can be made entirely of ceramics.
To date, because SOFCs have to be operated at high temperatures they have only been applied in power-generation infrastructure operations with a low thermal cycle and few load changes. The new type of SOFC could be used in distributed household power systems to power mobile electronic devices, or as an auxiliary power source for vehicles. These applications would require rapid operation and the ability to be operated at below 650°C.