Steady-State and Dynamic Modeling of Intermediate-Temperature Protonic Ceramic Fuel Cells

Abstract

Protonic ceramic fuel cells (PCFC) have emerged as a promising candidate for distributed power generation. The reduced temperature cells (∼500°C) have the potential to enable faster start-up times, longer life, and lower cost materials compared to oxygen-ion conducting fuel cells. However, the modeling of PCFCs is confounded by several challenges, including estimating open circuit conditions for mixed charged conductors. Here we present the development of a PCFC computational framework for a predictive celllevel, interface charge transfer model capturing mixed conduction, as well as transients. Our approach employs a 1-D heterogeneous channel-level modeling strategy that resolves fuel depletion and flow configuration effects along the length of the channel and is coupled to a semi-empirical electrochemical model. The model is formulated in such a way that allows for easy integration of modeling parameters extracted from button cell experiments and performance scale-up to cell-level predictions. Humidified methane-fueled simulations display power densities above 0.125 W-cm −2 at 500°C, 0.15 A cm −2 , and 80% fuel utilization cell conditions. Dynamic simulations indicate that the lower power density PCFCs (relative to solid oxide fuel cells) result in relatively slow thermal transients that could potentially dampen harmful effects of current-based fuel control during load-following operation.

Bilayer Cell Model and System Design of Highly Efficient Protonic Ceramic Fuel Cells

“…The values of 𝑖 and 𝑉 are fixed based on the optimization results for the bilayer cells in the previous section. The fuel utilization, 𝑈 , is defined as a ratio between the hydrogen consumption and the hydrogen obtained from the complete reforming of methane (12),…”

H/D isotopic exchange and electrochemical kinetics of hydrogen oxidation on Ni-cermets with oxygen-ionic and protonic electrolytes

“…Grow energy demands in the last decades have necessitated the search for alternative sources of energy. Solid oxide fuel cells (SOFC) have been one of the most promising concepts of such sources [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These devices transform chemical energy of the redox reaction between oxygen and a fuel (e.g., hydrogen) to electrical power.…”

“…In order to solve this problem, a new kind of SOFC has recently been proposed. This type of SOFC was named protonic ceramic fuel cells (PCFC) [13][14][15][16][17][18][19][20]. In contrast to conventional SOFC, PCFC are composed of proton-conducting oxides and are applicable at lower temperatures (<700 ᵒC) [13][14][15][16][17][18][19][20].…”

“…This type of SOFC was named protonic ceramic fuel cells (PCFC) [13][14][15][16][17][18][19][20]. In contrast to conventional SOFC, PCFC are composed of proton-conducting oxides and are applicable at lower temperatures (<700 ᵒC) [13][14][15][16][17][18][19][20]. The main advantage of proton-conducting materials is their ability to incorporate a hydrogen from the gas phase into an oxide structure .…”

A Direct Methane Fuel Cell with Double-Layered Electrolyte Using Proton Conducting Oxide

“…This enables the generation of electrical energy from hydrogen, ammonia, and hydrocarbons as the fuels. An advantage of the PCFCs is their lower operating temperature, which reduces the cost (7) and system start-up time. Moreover, the power generation efficiency is higher than the solid oxide fuel cell (SOFC) using yttria stabilized zirconia due to high fuel utilization rate (8).…”