Premium
Electrochemical Behavior of Gel‐Derived Lanthanum Calcium Cobalt Ferrite Cathode in Contact with LAMOX Electrolyte
Author(s) -
Jin TsuYung,
Tsai DahShyang,
Chung WenHung,
Liu FengJiin
Publication year - 2008
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2008.02446.x
Subject(s) - electrolyte , capacitance , cathode , electrochemistry , lanthanum , analytical chemistry (journal) , chemistry , cobalt , materials science , inorganic chemistry , electrode , chromatography
The electrochemical performance and structural features of (La 1− y Ca y )(Co x Fe 1− x )O 3 cathode prepared via a citrate acid gel route are studied when it is interfaced with the (La 1.8 Dy 0.2 )(Mo 2− z W z )O 9 electrolyte. The resistance and chemical capacitance of a low‐frequency arc are extracted from the impedance results to evaluate its catalytic activity in oxygen reduction reaction (ORR). (La 0.75 Ca 0.25 )(Co 0.8 Fe 0.2 )O 3 cathode exhibits the minimum area‐specific resistance of 0.9 Ω cm 2 and maximum capacitance of 5.7 mF/cm 2 at 800°C among the compositions of x =0.1–0.9 and y =0.25. As the Co content increases, the decrease in resistance outweighs the increase in capacitance so that the product of resistance and capacitance ( RC time constant) decreases. In contrast, when varying the Ca content of the A‐site, the changes in resistance and the capacitance compensate each other; hence the RC time constant is virtually unchanged with respect to the calcium content. Thus, Co is a more influential element than Ca on the ORR catalytic activity. The pore structure study reveals a small amount of Mo diffuses from the electrolyte into the cathode, and its quantity is reduced when interfaced to an electrolyte of high W content.