气候变化领域集成服务门户(CCPortal): The application of hierarchical structures in energy devices: New insights into the design of solid oxide fuel cells with enhanced mass transport

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DOI	10.1039/c8ee01064a
	The application of hierarchical structures in energy devices: New insights into the design of solid oxide fuel cells with enhanced mass transport
	Lu X.; Li T.; Bertei A.; Cho J.I.S.; Heenan T.M.M.; Rabuni M.F.; Li K.; Brett D.J.L.; Shearing P.R.
发表日期	2018
ISSN	17545692
起始页码	2390
结束页码	2403
卷号	11 期号:9
英文摘要	Mass transport can significantly limit the rate of reaction and lead to concentration polarisation in electrochemical devices, especially under the conditions of high operating current density. In this study we investigate hierarchically structured micro-tubular solid oxide fuel cells (MT-SOFC) fabricated by a phase inversion technique and quantitatively assess the mass transport and electrochemical performance improvement compared to a conventional tubular SOFC. We present pioneering work to characterise the effective mass transport parameters for the hierarchically porous microstructures by an integrated computed fluid dynamics simulation, assisted by multi-length scale 3D X-ray tomography. This has been historically challenging because either imaging resolution or field of view has to be sacrificed to compensate for the wide pore size distribution, which supports different transport mechanisms, especially Knudsen flow. Results show that the incorporation of radially-grown micro-channels helps to decrease the tortuosity factor by approximately 50% compared to the conventional design consisting of a sponge-like structure, and the permeability is also improved by two orders of magnitude. When accounting for the influence of Knudsen diffusion, the molecule/wall collisions yield an increase of the tortuosity factor from 11.5 (continuum flow) to 23.4 (Knudsen flow), but the addition of micro-channels helps to reduce it down to 5.3. Electrochemical performance simulations using the measured microstructural and mass transport parameters show good agreement with the experimental results at elevated temperatures. The MT-SOFC anode displays 70% lower concentration overpotential, 60% higher power density (0.98 vs. 0.61 W cm-2) and wider current density window for maximum power density than the conventional design. © 2018 The Royal Society of Chemistry.
英文关键词	Pore size; Transport properties; Concentration overpotential; Concentration polarisation; Electrochemical devices; Electrochemical performance; Fluid dynamics simulations; Micro-tubular solid oxide fuel cells; Operating current densities; Phase inversion techniques; Solid oxide fuel cells (SOFC); concentration (composition); design method; electrochemical method; fuel cell; hierarchical system; instrumentation; mass transport; oxide; performance assessment
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190138
作者单位	Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, United Kingdom; Barrer Center, Department of Chemical Engineering, Imperial College London, London, SW7 2AZ, United Kingdom; Department of Earth Science and Engineering, Imperial College London, London, SW7 2AZ, United Kingdom; Department of Civil and Industrial Engineering, University of Pisa, Pisa, 56122, Italy
推荐引用方式 GB/T 7714	Lu X.,Li T.,Bertei A.,et al. The application of hierarchical structures in energy devices: New insights into the design of solid oxide fuel cells with enhanced mass transport[J],2018,11(9).
APA	Lu X..,Li T..,Bertei A..,Cho J.I.S..,Heenan T.M.M..,...&Shearing P.R..(2018).The application of hierarchical structures in energy devices: New insights into the design of solid oxide fuel cells with enhanced mass transport.Energy & Environmental Science,11(9).
MLA	Lu X.,et al."The application of hierarchical structures in energy devices: New insights into the design of solid oxide fuel cells with enhanced mass transport".Energy & Environmental Science 11.9(2018).