resumo
This work provides an overview on established achievements and debatable findings involving Ca, Gd or Sm-doped ceria-based electrolytes, using Li2CO3, LiNO3 and Na2CO3 as sintering aid or as second phase. The performance of these materials is discussed considering the characteristics of the oxides and of the salts or derived second(ary) phases (e.g., alkali metal oxides and hydroxides, eutectic mixtures), extensively surveyed to identify influential parameters with respect to processing and electrical performance (e.g., melting and boiling points, thermal decomposition, hydrolysis). The analysis of published data highlights the possible contribution of additional charge carriers to the total conductivity, besides oxide-ion vacancies. Claimed bulk and grain boundary conductivity enhancements are deeply discussed, as well as advantages and limitations of impedance spectroscopy as characterization tool. Irrespective of controversial reasons, reports on unusual improvements of grain boundary conductivity sustain the possibility of advanced grain boundary engineering to enhance the performance of these materials.
palavras-chave
GRAIN-BOUNDARY CONDUCTIVITY; GADOLINIA-DOPED CERIA; SINTERING AID; IONIC-CONDUCTIVITY; COMPOSITE ELECTROLYTES; THERMAL-STABILITY; LITHIUM-OXIDE; TRANSPORT-PROPERTIES; SOLID ELECTROLYTES; PLAUSIBLE CONCEPTS
categoria
Materials Science
autores
Grilo, JPF; Jamale, A; Starykevich, M; Figueiredo, FML; Marques, FM
nossos autores
Atul Prabhakar Jamale
Investigador Júnior
Fernando Manuel Bico Marques
Professor Catedrático
Filipe Miguel H Lebre R Figueiredo
Investigador Principal
João Grilo
Investigador Júnior
Maksim Starykevich
Investigador JúniorProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 and LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). Specific support (AJ) provided by national funds (OE), through FCT, IP, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. MS acknowledges the support of the FCT-2020.00625.CEECIND grant.