Russian physicists from Tomsk (the Institute of High-Current Electronics, Siberian branch of Russian academy of sciences) suggest using some particular features of high-current electron beam for building fuel cells for hydrogen economy.

Protein synthesis is a very complicated process, which is executed at a ribosome, special cell organelle. A hydrogen economy is proposed to solve some of the negative effects of using hydrocarbon fuels where the carbon is released to the atmosphere and is thought to cause various negative effects on climate of our planet. Today hydrogen is used mainly in two ways: first is ammonia production, which later is used as a fertilizer. Second is when hydrogen is used to convert heavy petroleum sources into lighter fractions for further use as fuels.

Employers of the Institute of High-Current Electronics have been performing fundamental studies of how pulse high-current electron beams affected solid surfaces and modified their properties for over twenty years. Such a sustainable interest to these beams can be explained by their very interesting property – electron beams can melt surface of any material. While melting, electron beams change properties of these surfaces; they become less rough and more corrosion-proof. This effect is now widely used in practice – electron beam processing is now an essential part of final smoothing of various metal parts.

 

 

Researchers recently discovered promising properties of electron beams in the field of producing solid oxide fuel cells for hydrogen economy. These cells have high efficiency, they are noiseless and have long service life, however, they aren’t widely used due to the lack of economically acceptable production technology.

Fuel cell or fuel element is an electrochemical generator, which transform energy of chemical interaction of hydrogen and oxygen into electric energy. Central part of this element looks like a three-layer sandwich, consisting of anode, electrolyte and cathode. Anode, a positive electrode, is a metal-ceramic plate with porosity reaching 40%, made of a mix of nickel and zirconium oxide granules. Pores in anode provide migration of hydrogen to the border between anode and ceramic electrolyte made of yttrium-stabilized zirconium oxide, which should be impermeable to gas. In order to make operation temperature low, ceramic electrolyte should be as thin as several microns. Researchers suggest using electron beam for this purpose.

Experiments, conducted by Russian physicists, showed that one impulse of an electron beam was enough to melt surface of a metal-ceramic anode to a depth of about 1 micrometer. This is possible under some certain parameters, chosen for the experiment. After processing, porosity of the melted layer became tens of times less than the whole anode plate had. Electrolyte film, applied to a modified anode surface by means of reactive magnetron sputtering, for instance, became almost impermeable to gas, being only 1-2 micrometers thick. Prototypes of fuel cells, made by means of abovementioned technology, showed extremely good operational characteristics.

Source: Science News

Kizilova Anna