In the time, actually, it is a fact that the fuel cell industry is already formed offering to customers electric power generators performing from microwatts to hundreds of watts and more sophisticated combined heat and power (CHP) devices performing up to megawatts. The leading countries of the world, foremost the USA, orient the economy on the application of fuel cell technologies to secure electric power production reliability and diminish a negative impact on the ecology. Thousands of industrial companies and research centres were already joined in development and introduction of fuel cells. The leader in this field is Fuelcell Energy, Danbury, USA, which occupies the most segment of world market.
One of the primary requirements to fuel cells, aside from the decrease of equipment cost (the USA government decree is about 400 US dollars per kW) and increase of the durability (40 thousand hours and more), is a decrease of working temperature to ~600 °C and decrease the term of run up to the operating condition of fuel cell system to a several tens of minutes.
The listed parameters are recondite inside in the structure of fuel cell, which should be considered as macro multi-layered composite. Engineering of its structure is able to provide comparatively low working temperature at the high enough power output and large uninterrupted term of their work. Also designing of fuel cell together with the proper heaters is able to provide a fast run up to working state of fuel cell system. Resistance to both repeated and rapid thermal cycling could be provided for the selection of fuel cell materials component with the proper coefficient of thermal expansion and their structure from the point of their compatibility. The low working temperature allows the use of metallic construction materials on the basis of iron as a support of a whole fuel cell and interconnectors.
This project is aimed to development of low cost middle temperature fuel cells resistant to thermal cycling and fast run up to the operating condition.
In the framework of this project a problem of novel materials obtaining with aim to develop highly efficient solid oxide fuel cells (SOFC) is observed. Comparative analysis of mechanical and electrical properties of ceramics made of 10Sс1CeSZ powders from three different manufacturers - Praxair (USA), DKKK (Japan) and own development was carried out. It was shown that 10Sс1CeSZ powders developed in IPMS NASU appeared to be the most suitable for SOFC manufacturing. Electrolyte ceramics made of IPMS NASU powder exhibit high ionic conductivity and mechanical behavior, and demonstrate a low tendency toward recristalization resulting in deterioration of properties. A proper techniques for synthesis of cathode materials based on lanthanum cobaltates with perovskite-like structure was elaborated. Cathode powders with uniform morphology of particle and narrow size distribution were obtained. A five fuel cell stack was fabricated and tested at 600 °С with feed of natural gas.
Keywords: fuel cells, zirconium oxide, powder, ceramics, electrolyte, cathode, fuel cell stack