7 documents found, page 1 of 1
Antimony-lead melts for high temperature electrochemical applications
Mikhalev, S. M.; Julião, Paulo S.B.; Loureiro, F. J.A.; Shaula, A. L.; Fagg, D. P.The electrochemical behaviour of antimony-lead melt on saturation with oxygen was studied to assess further prospects of such melts as anode materials for high-temperature fuel cells. A perovskite ceramic was used as a robust current collector material. The related mechanisms of alloying and phase segregation were revealed at different melt oxidation levels using combined impedance spectroscopy and thermodynami...
Antimony-lead melts for high temperature electrochemical applications
Mikhalev, S. M.; Julião, Paulo S.B.; Loureiro, F. J.A.; Shaula, A. L.; Fagg, D. P.The electrochemical behaviour of antimony-lead melt on saturation with oxygen was studied to assess further prospects of such melts as anode materials for high-temperature fuel cells. A perovskite ceramic was used as a robust current collector material. The related mechanisms of alloying and phase segregation were revealed at different melt oxidation levels using combined impedance spectroscopy and thermodynami...
Designing strontium titanate-based thermoelectrics: insight into defect chemist...
Kovalevsky, A. V.; Aguirre, M. H.; Populoh, S.; Patrício, S. G.; Ferreira, N. F.; Mikhalev, S. M.; Fagg, D. P.; Weidenkaff, A.; Frade, J.Driven by a need to develop low-cost and thermally stable materials for thermoelectric applications, donor-substituted strontium titanate is considered as a promising alternative to traditional thermoelectrics. The complex defect chemistry of SrTiO3-based materials imposes various limitations on identifying the relevant effects exerted on the electronic band structure and heat transfer, being a subject of debat...
Guidelines to design multicomponent ferrospinels for high-temperature applications
Ferreira, N. M.; Ferro, M. C.; Mikhalev, S. M.; Costa, F. M.; Frade, J. R.; Kovalevsky, A. V.This work explores the possibilities to design magnetite-based spinels through multiple simultaneous co-substitutions with transition metal cations, with emphasis on redox behavior and electronic transport. For the first time this approach was assessed for high-temperature applications, which is of particular interest for the development of consumable anodes for pyroelectrolysis, an alternative carbon-lean stee...
Prospects and challenges of iron pyroelectrolysis in magnesium aluminosilicate ...
Ferreira, N. M.; Kovalevsky, A. V.; Mikhalev, S. M.; Costa, F. M.; Frade, J. R.Although steel production by molten oxide electrolysis offers potential economic and environmental advantages over classic extractive metallurgy, its feasibility is far from being convincingly demonstrated, mainly due to inherent experimental difficulties exerted by harsh conditions and lack of knowledge regarding relevant mechanisms and physico-chemical processes in the melts. The present work was intended to ...
Thermochemical expansion of mixed-conducting (Ba,Sr)Co0.8Fe0.2O3-delta ceramics
Yaremchenko, A. A.; Mikhalev, S. M.; Kravchenko, E. S.; Frade, J. R.The thermal and chemical expansion of Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) and SrCo0.8Fe0.2O3-delta (SCF) mixed ionic-electronic conductors were studied in combination with oxygen nonstoichiometry (delta) at 298-1223 K and p(O-2) = 10(-4) to 1.00 atm. In order to minimize the effects of phase separation or oxygen-vacancy ordering processes, the data were collected in dynamic cooling mode using dense ceramic samp...
Redox stability and high-temperature electrical conductivity of magnesium-and a...
Kovalevsky, A. V.; Yaremchenko, A. A.; Naumovich, E. N.; Ferreira, N. M.; Mikhalev, S. M.; Costa, F. M.; Frade, J. R.Spinel-type magnetite-based oxides, possessing relatively high electrical conductivity, are considered as promising consumable anode materials for high temperature pyroelectrolysis, a breakthrough low-CO2 steel technology to overcome the environmental impact of classical extractive metallurgy. The present work was focused on the analysis of phase stability, thermal expansion and high-temperature electrical cond...