Materials for Proton Conducting Solid Oxide Fuel Cells (H-SOFCs)

Abstract

In this paper, we report our steps forward in the search of proton conducting metal oxides possessing disordered perovskite-type and B-site ordered double perovskites for application in solid oxide fuel cells (SOFCs) and mixed proton-electron conductors as anodes for SOFCs. Role of A- and B- site cations in the perovskite structures on electrical properties and their corresponding chemical stability in CO2, H2S and H2O have been studied. Partial substitution of the parent phase is one of the most effective and popular approaches in which certain ions in the lattice are replaced by foreign species. However, "the right recipes" are not usually obvious; optimization on the functional physical and chemical properties is often based upon "the trial and error" strategy. Here, we review our progress since 2005 in the development of the proton conducting solid oxide fuel cells (H-SOFCs).

Studies on Polymorphic Sequence during the Formation of the 1:1 Ordered Perovskite-Type BaCa0.335M0.165Nb0.5O3-δ (M = Mn, Fe, Co) Using in Situ and ex Situ Powder X-ray Diffraction

“…However, the B-site disordered primitive perovskite structure was not reported for any member with a general formula of Ba 3 Ca 1+ x Nb 2– x O 9−δ ( x = 0–1). Similarly, many B-site-doped Ba 3 Ca 1+ x – y Nb 2– x – z M y + z O 9‑δ (M = Ti, Mn, Fe, Co, Zn, Ta, Ce) samples were revealed to have the B-site 1:1 ordered perovskite-type structure. − , The above samples were all sintered at an elevated temperature range of 1300–1500 °C in air.…”

“…Similarly, many Bsite-doped Ba 3 Ca 1+x−y Nb 2−x−z M y+z O 9-δ (M = Ti, Mn, Fe, Co, Zn, Ta, Ce) samples were revealed to have the B-site 1:1 ordered perovskite-type structure. [19][20][21][22][23][24]31 The above samples were all sintered at an elevated temperature range of 1300− 1500 °C in air.…”

Effect of substitution of B-sites by Mn, Fe and Co in double perovskite-type Ba3CaNb2O9 on structure and electrical properties

“…The presence of the low-frequency intercepts on Z 0 suggests the non-blocking at the electrode and material interface. 26,27,[35][36][37] The Arrhenius plots for the total conductivities of Ba 2 Ca (1ÀxÀy) M (x+z) Nb (1Àz+y) O 6Àd in air, H 2 , 3% H 2 O in air and 3% H 2 O in H 2 are shown in Fig. 6.…”