Tuning Electrochemical Performance by Microstructural Optimization of the Nanocrystalline Functional Oxygen Electrode Layer for Solid Oxide Cells
Abstract
Further development of solid oxide fuel cell (SOFC) oxygen electrodes can be achieved through improvements in oxygen electrode design by microstructure miniaturisation alongside nanomaterials implementation. In this work, improved electrochemical performance of an La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) cathode was achieved by the controlled modification of the La0.6Sr0.4CoO3-d (LSC) nanocrystalline interlayer introduced between a porous oxygen electrode and dense electrolyte. The evaluation was carried out for various LSC layer thicknesses, annealing temperatures, oxygen partial pressures, and temperatures, as well as subjected to long-term stability tests and evaluated in typical operating conditions in an intermediate temperature SOFC. Electrochemical impedance spectroscopy (EIS) and a distribution of relaxation times analysis (DRT) were performed to reveal the rate-limiting electrochemical processes that limit the overall electrode performance. The main processes with an impact on the electrode performance were the adsorption of gaseous oxygen O2, dissociation of O2, and charge transfer-diffusion (O2-). The introduction of a nanoporous and nanocrystalline interlayer with extended electrochemically active surface area accelerates the oxygen surface exchange kinetics and oxygen ion diffusions, reducing polarisation resistances. The polarisation resistance of the reference LSCF was lowered by one order of magnitude from 0.77Ω∙cm2 to 0.076 Ω∙cm2 at 600°C by the deposition of a 400 nm LSC interlayer at the interface. The developed electrode tested in the anode-supported fuel cell configuration showed a higher cell performance by 20% compared to the cell with the reference electrode. The maximum power density at 700°C reaches 675 and 820 mW∙cm-2 for the reference cell and the cell with the LSC interlayer, respectively. Ageing tests at 700°C under a high load of 1 A∙cm2 were performed.
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- Accepted or Published Version
- DOI:
- Digital Object Identifier (open in new tab) 10.1021/acsami.2c18951
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- Copyright (2022 American Chemical Society)
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- Category:
- Articles
- Type:
- artykuły w czasopismach
- Published in:
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ACS Applied Materials & Interfaces
no. 14,
pages 57449 - 57459,
ISSN: 1944-8244 - Language:
- English
- Publication year:
- 2022
- Bibliographic description:
- Kamecki B., Cempura G., Jasiński P., Wang S., Molin S.: Tuning Electrochemical Performance by Microstructural Optimization of the Nanocrystalline Functional Oxygen Electrode Layer for Solid Oxide Cells// ACS Applied Materials & Interfaces -Vol. 14,iss. 51 (2022), s.57449-57459
- DOI:
- Digital Object Identifier (open in new tab) 10.1021/acsami.2c18951
- Sources of funding:
- Verified by:
- Gdańsk University of Technology
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