11 documents found, page 1 of 2
Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic F...
Constantinescu, Gabriel; Mikhalev, Sergey M.; Lisenkov, Aleksey D.; Lopes, Daniela V.; Sarabando, Artur R.; Ferro, Marta C.; Silva, Tiago F. daThis work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar...
Exploring the high-temperature thermoelectric performance of Al-doped ZnO ceram...
Constantinescu, Gabriel; Mikhalev, Sergey M.; Zakharchuk, Kiryl V.; Kovalevsky, Andrei V.Zinc oxide (ZnO) is a highly versatile and well-known material, widely used for its useful optoelectronic, catalytic, and photochemical properties [1]. In the search for alternative energy sources, ZnO-based ceramics emerge as promising materials for high-temperature thermoelectric (TE) applications [2], capable of direct conversion of (waste) heat to electricity, thanks to the Seebeck effect. Owing to the spec...
Specific microstructural effects on the performance of thermoelectric oxides
Kovalevsky, Andrei V.; Arias-Serrano, Blanca I.; Mikhalev, Sergey M.; Constantinescu, Gabriel; Zakharchuk, Kiryl V.; Sergiienko, Sergii A.Oxide materials possess notable high-temperature and chemical stability, thus representing certain advantages over traditional thermoelectrics. The thermoelectric performance of oxides is strongly affected by the microstructure, often even dominating over the chemical composition effects. Thus, engineering the microstructure in these materials represents a powerful tool towards improving their thermoelectric pe...
On the high-temperature degradation mechanism of ZnO-based thermoelectrics
Arias-Serrano, Blanca I.; Mikhalev, Sergey M.; Ferro, Marta C.; Tobaldi, David M.; Frade, Jorge R.; Kovalevsky, Andrei V.The stability and reproducibility of the electric properties in n-type doped ZnO represent known bottlenecks towards potential thermoelectric applications. The degradation is promoted by the vanishing of the electronic defects on oxidation and irreversible exsolution of the phase impurities. This work proposes a microstructural mechanism showing that these processes take place mainly in the pores and highlighti...
Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic F...
Constantinescu, Gabriel; Mikhalev, Sergey M.; Lisenkov, Aleksey D.; Lopes, Daniela V.; Sarabando, Artur R.; Ferro, Marta C.; Silva, Tiago F. daThis work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar...
Electrochemical behaviour of magnesium hydride-added titania anode for Li-ion b...
Loureiro, Francisco J.A.; PukazhSelvan, D.; Bdikin, Igor; Shaula, Aliaksandr L.; Mikhalev, Sergey M.; Fagg, Duncan P.This work explores the electrochemical performance of a 10 wt.% MgH2 added titania anode for Li-ion half-cell batteries. We used a distribution function of relaxation times (DFRT) analysis to quantify the sources of polarisation losses from the impedance data. We observed a notable increase in both ohmic and polarisation resistance terms for the TiO2+10 wt.% MgH2 compared to the standard titania anode. Nonethel...
Redox engineering of strontium titanate-based thermoelectrics
Kovalevsky, Andrei V.; Zakharchuk, Kiryl V.; Aguirre, Myriam H.; Xie, Wenjie; Patrício, Sonia G.; Ferreira, Nuno M.; Lopes, Diogo; Sergiienko, Sergii A.The development of thermoelectrics for high-temperature applications imposes several essential requirements on the material properties. In some energy-conversion scenarios, the cost and thermal stability requirements may dominate over efficiency issues, making abundant, high-temperature-stable and low-toxic oxides attractive alternative thermoelectric materials. As compared to “traditional” thermoelectrics, oxi...
Strontium titanate and zinc-oxide-based materials for high-temperature thermoel...
Kovalevsky, Andrei V.; Zakharchuk, Kiryl V.; Ferreira, Nuno M.; Xie, Wenjie; Patrício, Sonia G.; Arias-Serrano, Blanca I.; Mikhalev, Sergey M.Broad societal needs have focused increased attention to providing a sustainable energy supply to the population, based on technologies with minimal environmental impact and reduced fossil fuels usage. One solution is to improve energy conversion efficiency in key consuming sectors. Since most of the energy (60-70%) used worldwide is discharged as waste heat, ”green” thermoelectric (TE) conversion has received ...
Synergistic effects of zirconium- and aluminum co-doping on the thermoelectric ...
Zakharchuk, Kiryl V.; Tobaldi, David M.; Xiao, Xingxing; Xie, Wenjie; Mikhalev, Sergey M.; Martins, João F.; Frade, Jorge R.; Weidenkaff, AnkeThis work aims to explore zirconium as a possible dopant to promote thermoelectric performance in bulk ZnO-based materials, both within the single-doping concept and on simultaneous co-doping with aluminum. At 1100–1223 K mixed-doped samples demonstrated around ∼2.3 times increase in ZT as compared to single-doped materials, reaching ∼0.12. The simultaneous presence of aluminum and zirconium imposes a synergist...
Porous carrageenan-derived carbons for efficient ciprofloxacin removal from water
Nogueira, João; António, Maria; Mikhalev, Sergey M.; Fateixa, Sara; Trindade, Tito; Daniel-da-Silva, Ana L.Porous carbon materials derived from biopolymers are attractive sorbents for the removal of emerging pollutants from water, due to their high specific surface area, high porosity, tunable surface chemistry, and reasonable cost. However, carrageenan biopolymers were scarcely investigated as a carbon source to prepare porous carbon materials. Herein, hydrochars (HCs) and porous activated carbons (ACs) derived fro...