Reducing losses in energy conversion is one of the most challenging tasks of the society, as to this day, most fuels are burned in combustion engines with low efficiency. Increasing energy conversion efficiency has direct positive impact on lowering environmental pollution and contributing to sustainable use of natural resources – both immensely important problems in modern day society. Resource efficiency and reduced burden on environment have also been identified as critical components of future EU economy (e.g. The European Green Deal).
Fuel cells hold great promise for the long waited revolution in efficient energy conversion. Although efficient solid oxide fuel cells (SOFCs) are available, their widespread dissemination into portable devices is severely hindered by lack of durability, slow start up times and high cost. To overcome these problems, tubular instead of planar systems are proposed. The disadvantage of macroscale tubular configurations is their low power output per volume. However, tubular geometries are principally easier to miniaturize and provide use convenience not available on planar fuel cell systems.
This project aims to demonstrate SOFC based on smallest microtubes made of metal oxide materials (yttria stabilized zirconia – YSZ). Material precursors developed by researchers at the Institute of Physics, University of Tartu are optimized for making uniform metal oxide microtubes with approximately 100 micron diameter and 10 micron wall thickness. These optical quality microtubes are characterized to reveal their mechanical and electrochemical properties. Covered with suitable electrode materials, fuel cell element based on single microtube and multiple microtubes (a fuel cell stack) are constructed and tested to validate in the laboratory the technology that would allow to build the world’s smallest solid oxide fuel cell.
