A reduced temperature solid oxide fuel cell with nanostructured anodes

Zhan, Zhongliang; Bierschenk, David M.; Cronin, J. Scott; Barnett, Scott A.

doi:10.1039/c1ee01982a

Cited by 133 publications

(86 citation statements)

References 27 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the definition of infiltration loading in the present study, a threshold loading of 6 vol.% of entire volume corresponds to 10.7 vol.% of solid volume, which is still much lower than the normal threshold (for percolation purpose) loading of 30 vol.% for the conventional composite electrodes, in consistent with the experimental observations. 22,26 In other words, a remarkable conductivity of infiltration phase can be obtained at relative low infiltration loadings. Since the conventional infiltration inks usually produces a limited amount of infiltration phase (i.e.…”

Section: Resultsmentioning

confidence: 99%

“…2. Thus the probability of coating on the nanoparticles surface is, 21 2011 The Royal Society of Chemistry for, 22 and 2011 Elsevier for. 23 ).…”

Section: Numerical Infiltration Methodologymentioning

confidence: 99%

“…1 shows some typical infiltrated electrode microstructures, including LSM infiltrated YSZ electrode 21 ( Fig. 1a), Ni infiltrated magnesium -doped lanthanum gallate (LSGM) electrode 22 ( Fig. 1b), and Pd infiltrated YSZ electrode 23 ( Fig.…”

Section: Numerical Infiltration Methodologymentioning

confidence: 99%

See 2 more Smart Citations

Geometric Properties of Nanostructured Solid Oxide Fuel Cell Electrodes

Zhang

Sun

Xia

et al. 2013

J. Electrochem. Soc.

View full text Add to dashboard Cite

3D microstructures for nanostructured solid oxide fuel cell (SOFC) electrodes fabricated by infiltration/impregnation method are constructed numerically, by using a phenomenological procedure. Key geometric properties of the constructed electrodes are calculated at various infiltration loadings, including the percolation probabilities of pores and infiltrated nanoparticles, the total and active three-phase boundary (TPB) length, backbone and nanoparticles surface areas, and backbone-nanoparticles boundary area. The effects of backbone particle size, backbone porosity, nanoparticle size, and its aggregation risk are studied systematically. Analytical models are developed to predict these geometric properties, and agree well with the numerical infiltration results, as well as the literature data. It is found that the peak TPB length can be achieved at 63% coverage of the backbone surface by infiltrated nanoparticles. More interestingly, the backbone structure has little effect on nanoparticles surface area, but significantly affects TPB length, suggesting an strategy to identify electrode reaction mechanisms. Decreasing infiltrated particle size increases its surface area, enhances the peak TPB length, and decreases the optimal infiltration loading, indicating small infiltrated particles essentially benefits electrode performance. The results provide valuable information for understanding the geometric properties of the infiltrated SOFC electrodes and contribute to the design of high performance SOFC electrodes.

show abstract

Section: Resultsmentioning

confidence: 99%

“…2. Thus the probability of coating on the nanoparticles surface is, 21 2011 The Royal Society of Chemistry for, 22 and 2011 Elsevier for. 23 ).…”

Section: Numerical Infiltration Methodologymentioning

confidence: 99%

See 1 more Smart Citation

Geometric Properties of Nanostructured Solid Oxide Fuel Cell Electrodes

Zhang

Sun

Xia

et al. 2013

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…8 In the work by Zhan et al, Ni-infiltrated LSGM anodes were studied. The porosity of the LSGM scaffolding prior to infiltration of the Ni phase was 30%, the average feature size of the LSGM phase was 1.5 μm, and the Ni infiltrate loading was 2.5 vol%.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6] Second, a higher three-phase boundary (TPB) density can be achieved, which is attributed to the smaller particle sizes. 2,3,[7][8][9] These two advantages result from a lower processing temperature of the infiltrated phase compared to conventional sintering temperatures required of co-sintered electrodes.…”

mentioning

confidence: 99%

Insights into the Design of SOFC Infiltrated Electrodes with Optimized Active TPB Density via Mechanistic Modeling

Reszka

Snyder

Gross

2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

A mechanistic model for the prediction of total and active three phase boundary density (TPB), in combination with effective conductivity, of infiltrated solid oxide fuel cell (SOFC) electrodes is presented. Varied porosities, scaffold:infiltrate size ratios, and pore:infiltrate size ratios were considered, each as a function of infiltrate loading. The results are presented in dimensionless form to allow for the calculation of any infiltrate particle size. The model output compares favorably to the available experimental result. The results show that the scaffold:infiltrate size ratio has the greatest impact on the TPB density, followed by the porosity and then the pore:infiltrate size ratio. The TPB density is shown to monotonically decrease with increasing scaffold:infiltrate and pore:infiltrate size ratios; however, it shows a maximum with respect to porosity. Each of these results are explained by examining the interfacial areas of each of the three phases as a function of the infiltrate loading. The model provides insight toward the rational design of infiltrated electrodes. Infiltrated solid oxide fuel cell (SOFC) electrodes offer numerous advantages over conventional co-sintered electrodes. First, a broader choice of electrode materials is possible because materials that melt or chemically react with the electrolyte at conventional sintering temperatures can be considered.1-6 Second, a higher three-phase boundary (TPB) density can be achieved, which is attributed to the smaller particle sizes.2,3,7-9 These two advantages result from a lower processing temperature of the infiltrated phase compared to conventional sintering temperatures required of co-sintered electrodes.Three additional advantages of infiltrated electrodes are associated with the unique morphology created by coating the surface of a presintered porous scaffolding with an infiltrated phase. The first morphological advantage is a mitigation of the coefficient of thermal expansion (CTE) mismatch between the electrolyte and the electrode. 10,11The second advantage is a stabilization of the electrode mechanical properties during redox cycling, 5,12 Finally, less material is needed to form an interconnected network of the infiltrated phase throughout the electrode. 6,10,[12][13][14][15] Although the benefits of infiltrated electrodes have been clearly demonstrated experimentally, researchers suggest that the electrode designs are not optimized. 3,5,6,14,16 This is understandable because it is laborious to consider all of the combinations and permutations of the sizes and shapes of infiltrate particles, scaffold particles, and pores as well as the wide range of possible porosities. In order to more effectively and efficiently design electrodes, several computational models have been recently reported. Zhang et al. utilized a particle-layer model to estimate the TPB density, effective thickness of the electrochemically active region, and polarization resistance of cathodes.9 A more recent report by Zhang et al. utilized a numerically generated thr...

show abstract