Characterization of Spatial Distribution of Electrolyte in Molten Carbonate Fuel Cell Cathodes

Abstract

High-resolution computed X-ray tomography (XCT) is applied in this study to characterize the microstructure of Molten Carbonate Fuel Cell (MCFC) cathodes after operation, where a "virgin cathode" formed by porous nickel has been in situ oxidized and infiltrated by liquid electrolyte. This technique extends state-of-the art methodology to characterize pores such as porosity analysis using Mercury porosimetry. XCT enables 3D imaging of the internal structure of the electrodes including all components present at the cathode side, particularly NiO, pores, and electrolyte. The quantitative 3D microstructure analysis based on high-resolution XCT provides topological information for each component and their mutual spatial distribution, which is significant for the enhancement of the MCFC performance. In particular, volume fraction, specific surface area, continuity of each phase, as well as the Triple Phase Boundary (TPB) density are calculated from the experimental data. The results indicate that superior properties of the multi-modal pore sized cathode, used in this study, can be attributed to the formation of three selfinterpenetrating networks of pathways for the transport of gasses, electrons, as well as ions throughout pores, NiO, and electrolyte, respectively.

Fabrication and Characterization of a Composite Ni-SDC Fuel Cell Cathode Reinforced by Ni Foam

“…Secondly, the solvent (distilled water), additional plasticizer (glycerin), defoamer (AGITAN 282), and dispersant (METOLAT 388) were added and homogenized at 600 rpm for 10 min under vacuum conditions (40 kPa). Thirdly, to obtain a complex porous structure that was previously optimized [ 20 ], two porogens (starch and polyvinyl butyral; Mowital B 60 H, Kuraray) were added and mixed at 800 rpm for 10 min under vacuum conditions (0.6 kPa). Finally, the nickel and SDC powders were added as different volume ratios of SDC (20%, 40%, 50%, and 60%).…”

“…The reaction rate on the cathode side is the limiting factor for SOFC and MCFC performance [ 15 ]. This rate depends on chemical composition [ 16 , 17 , 18 ] and microstructure [ 19 , 20 ]. In traditional SOFC technology, the main problems are the high working temperatures, which creates a complicated and expensive manufacturing process for the solid ceramic electrolyte [ 21 ].…”

Investigation of Molten Metal Infiltration into Micropore Carbon Refractory Materials Using X-ray Computed Tomography

“…This can be achieved by using nondestructive investigation methods, among which X-ray computed tomography (XCT) is a promising candidate. XCT can be used to investigate the microstructure of multiphase materials [18][19][20] and pore structure [21,22]. Based on the XCT measurements, methods for determining parameters describing pore structure-tortuosity [23] and constrictivity [24]-were developed.…”