Analysis of La4Ni3O10±δ-BaCe0.9Y0.1O3-δ Composite Cathodes for Proton Ceramic Fuel Cells

Abstract

Layered Ruddlesden-Popper (RP) lanthanide nickelates, Lnn+1NinO3n+1 (Ln = La, Pr, and Nd; n = 1, 2, and 3) have generated great interest as potential cathodes for proton conducting fuel cells (PCFCs). The high-order phase (n = 3) is especially intriguing, as it possesses the property of a high and metallic-type electronic conductivity that persists to low temperatures. To provide the additional requirement of high ionic conductivity, a composite electrode is here suggested, formed by a combination of La4Ni3O10±δ with the proton conducting phase BaCe0.9Y0.1O3-δ (40 vol%). Electrochemical impedance spectroscopy (EIS) is used to analyse this composite electrode in both wet (pH2O ~ 10−2 atm) and low humidity (pH2O ~ 10−5 atm) conditions in an O2 atmosphere (400–550 °C). An extended analysis that first tests the stability of the impedance data through Kramers-Kronig and Bayesian Hilbert transform relations is outlined, that is subsequently complemented with the distribution function of relaxation times (DFRTs) methodology. In a final step, correction of the impedance data against the short-circuiting contribution from the electrolyte substrate is also performed. This work offers a detailed assessment of the La4Ni3O10±δ-BaCe0.9Y0.1O3-δ composite cathode, while providing a robust analysis methodology for other researchers working on the development of electrodes for PCFCs.

A new layered barium cobaltite electrode for protonic ceramic cells

“…6a, the electrode contribution occurs at very low frequencies, in a region typical of the following electrode processes: adsorption, dissociation, or the surface diffusion of intermediate oxygen species. 52 Moreover, in contrast to what has been previously observed in the SOC literature, where one or more processes at high frequencies are typically attributed to interfacial charge-transfer phenomena, 50–53 such processes are not observed in our current study. This behaviour is likely a consequence of the fast transfer of protons at the electrode/electrolyte interface and electrons at the current collector/electrode interface.…”

Boosted electrochemical performance of ca‐cobaltite‐based composite electrodes for reversible solid oxide cells

“…22 In contrast, the electrochemical measurements were performed in our work in an oxygen atmosphere, where this effect is shown to be less significant. 23,24 Hence, any electronic short circuiting from the electrolyte substrate 25,26 is not expected in this case.…”

Bioimpedance Measurement under Feature Combination of Time-Frequency Domain and Application for E. coli Detection

“…The DRT method has made progress in the study of the working mechanism of solid fuel cells and lithium batteries. [27][28][29][30] By identifying the number of polarization processes to construct a more reasonable equivalent circuit model, DRT method helps to reveal the conduction process of electrons in electrodes or electrolytes at different frequencies and understand complex impedance systems. Although DRT has been successfully applied to detect biological cells in suspension, 31,32 there is still bottleneck in how to study the dynamic processes of bioimpedance systems through peak inversion identification.…”