Study of the transient behavior and microstructure degradation of a SOFC cathode using an oxygen reduction model based on steepest-entropy-ascent quantum thermodynamics

Li, G. and von Spakovsky, M. R. (2016) Study of the transient behavior and microstructure degradation of a SOFC cathode using an oxygen reduction model based on steepest-entropy-ascent quantum thermodynamics. In: ASME 2015 International Mechanical Engineering Congress and Exposition: Volume 6B: Energy, Houston, Texas, USA, November 13–19 2015, IMECE2015-53726. ISBN 9780791857441 (doi: 10.1115/IMECE2015-53726)

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Abstract

Oxygen reduction in a solid oxide fuel cell (SOFC) cathode involves a non-equilibrium process of coupled mass and heat diffusion and electrochemical and chemical reactions. These phenomena occur at multiple temporal and spatial scales, from the mesoscopic to the atomistic level, making the modeling, especially in the transient regime, very difficult. Nonetheless, multi-scale models are needed to improve an understanding of oxygen reduction and guide fuel cell cathode design. Existing methods are typically phenomenological or empirical in nature so their application is limited to the continuum realm and quantum effects are not captured. Steepest-entropy-ascent quantum thermodynamics (SEAQT) can be used to model non-equilibrium processes (even those far-from equilibrium) from the atomistic to the macroscopic level. The non-equilibrium relaxation is characterized by the entropy generation, and the study of coupled heat and mass diffusion as well as electrochemical and chemical activity are unified into a single framework. This framework is used here to study the transient and steady state behavior of oxygen reduction in an SOFC cathode system. The result reveals the effects on performance of the different timescales of the varied phenomena involved and their coupling. In addition, the influence of cathode microstructure changes on performance is captured.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Li, Dr Guanchen
Authors: Li, G., and von Spakovsky, M. R.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
ISBN:9780791857441
Published Online:07 March 2016
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