A distributed real-time model of degradation in a solid oxide fuel cell, part I: Model characterization

Abstract

Despite the high efficiency and flexibility of fuel cells, which make them an attractive technology for the future energy generation, their economic competitiveness is still penalized by their short lifetime, due to multiple degradation phenomena. As a matter of fact, electrochemical performance of solid oxide fuel cells (SOFCs) is reduced because of different degradation mechanisms, which depend on operating conditions, fuel and air contaminants, impurities in materials, and others. In this work, a real-time, one dimensional (1D) model of a SOFC is used to simulate the effects of voltage degradation in the cell. Different mechanisms are summarized in a simple empirical expression that relates degradation rate to cell operating parameters (current density, fuel utilization and temperature), on a localized basis. Profile distributions of different variables during cell degradation are analyzed. In particular, the effect of degradation on current density, temperature, and total resistance of the cell are investigated. An analysis of localized degradation effects shows how different parts of the cell degrade at a different time rate, and how the various profiles are redistributed along the cell as consequence of different degradation rates.

A distributed real-time model of degradation in a solid oxide fuel cell, part II: Analysis of fuel cell performance and potential failures

“…An analysis of key operating parameters behavior during cell degradation was the object of Part I of this paper [19] and is summarized here. With the chosen syngas composition, at the beginning of the cell life, current density is higher at the cell inlet, following the hydrogen concentration.…”

“…In Part I of this paper the real-time, one dimensional model of a SOFC with localized degradation was described and the behavior of the main parameters during degradation was shown [19]. All the details about the model and the employed empirical expression of the degradation rate were presented in Part I.…”

“…The 1D, real-time model of a co-flow, planar SOFC used in this work is described in detailed in the Part I of this paper [19]. A coupled approach of finite difference and finite volume is employed to solve respectively thermal and electrochemical equations [20].…”

Multi-physics modeling assisted design of non-coking anode for planar solid oxide fuel cell fueled by low steam methane

“…To realize the use of low steam methane fuel, materials to avoid anode coking are critically important and are actively pursued [3][4][5][6][7][8][9][10][11][12][13][14]. A common approach to avoid anode carbon deposition is to eliminate the use of Ni in the anode [5][6][7][8][9][10].…”

“…A common approach to avoid anode carbon deposition is to eliminate the use of Ni in the anode [5][6][7][8][9][10]. Alternatively, methods of modifying the Ni containing anode with coking resistant material are developed [4,[11][12][13][14][15]. Unfortunately, there are serious drawbacks associated with all the known material designs of coking resistant anode, e.g., low electronic conductivity, poor chemical compatibility with other cell components and high material cost [4,15].…”