The microtube SOFC
The microtube SOFC
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The Advanced Manufacturing Research Institute (AMRI) of Japan's National Institute of Advanced Industrial Science and Technology (AIST) developed a portable fuel cell system.

AMRI manufactured tubes with fuel electrode materials and used a microtube-type solid-oxide fuel cell (SOFC) made by forming electrolyte and air electrodes on the surface of the tubes.

By controlling the electrode structure in increments of nanometers, it became possible to directly use general-purpose fuels that can be easily transported such as liquefied petroleum gas (LPG). Because the fuel cell system is portable and can be quickly started up, AMRI expects that it will be used as an outdoor power source.

To use LPG, AMRI applied nanoparticulated cerium (nanoceria), which has a property modification function, to the entire base material for the fuel (negative) electrode. With this method, it developed an electrode that has a higher durability.

When butane, which is one of the main components of LPG, is directly supplied to a fuel cell, it rapidly deteriorates fuel electrodes. Therefore, to use butane for an SOFC, it is necessary to modify butane in advance with an external reformer using a precious metal catalyst. On the other hand, the newly-developed fuel electrode has the property modification function, making it possible to directly supply butane.

Furthermore, with the improved durability, it became possible to quickly start up the fuel cell by using an LPG burner. The temperature of the fuel cell reaches to 400°C in two minutes, which is half the time it takes for other microtube SOFCs to reach that temperature.