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Afzal, M. (2019). Semiconductor-ionic Materials for Low Temperature Solid Oxide Fuel Cells. (Doctoral dissertation). Stockholm, Sweden: KTH Royal Institute of Technology
Open this publication in new window or tab >>Semiconductor-ionic Materials for Low Temperature Solid Oxide Fuel Cells
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Solid oxide fuel cell (SOFC) is considered as an attractive candidate for energy conversion within the fuel cell (FC) family due to several advantages including environment friendly, use of non-noble materials and fuel flexibility. However, due to high working temperatures, conventional SOFC faces many challenges relating to high operational and capital costs besides the limited selection of the FC materials and their compatibility issues. Recent SOFC research is focused on how to reduce its operational temperature to 700 ºC or lower. Investigation of new electrolytes and electrode materials, which can perform well at low temperatures, is a comprehensive route to lowering the working temperature of SOFC. Meanwhile, semiconductor-ionic materials based on semiconductors (perovskite/composite) and ionic materials (e.g. ceria based ion conductors) have been identified as potential candidates to operate in low temperature range with adequate SOFC power outputs.

This investigation focuses on the development of semiconductor-ionic materials for low temperature solid oxide fuel cell (SOFC) and electrolyte-layer free fuel cell (EFFC). The content of this work is divided into four parts:

First part of the thesis consists of the work on conventional SOFC to build knowledge and bridge from conventional SOFC to the new EFFC. Novel composite electrode (semiconductor) materials are synthesized and studied using established electrochemical and analytical methods such as x-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The phase structure, morphology and microstructure of the composite electrodes are studied using XRD and SEM, and the weight loss is determined using TGA. An electrical conductivity of up to 143 S/cm of as-prepared material is measured using DC 4 probe method at 550 ºC. An electrolyte, samarium doped ceria (SDC) is synthesized to fabricate a conventional three component SOFC device. The maximum power density of 325 mW/cm2 achieved from the conventional device at 550 ºC.

In the second part of the thesis, semiconductor-ionic materials based on perovskite and composite materials are prepared for low temperature SOFC and EFFC devices. Semiconductor-ionic materials are prepared via nanocomposite approach based on two-phase semiconductor electrode and ionic electrolyte. This semiconductor-ionic functional component was shown to integrate all fuel cell components anode, electrolyte and cathode functions into a single component, i.e. “three in one”, resulting in enhanced catalytic activity and improved SOFC performance.

The third part of the thesis addresses the development and optimization of the EFFC technologies by studying the Schottky junction mechanism in such semiconductor-ionic type devices. Perovskite and functional nanocomposites (semiconductor-ionic materials) are developed for EFFC devices. Materials characterizations are performed using a number of standard experimental and analytical techniques. Maximum power densities from 600 mW/cm2 up to 800 mW/cm2 have been achieved at 600 ºC.

Fourth part of the thesis describes the theoretical simulation of EFFCs. In this work, an updated numerical model is applied in order to study the EFFC device, which introduces some modifications to the existing relations for traditional fuel cell models. The simulated V-I and P-I curves have been compared with experimental curves, and both types of curves show a good consistency.

Abstract [sv]

Bränsleceller av typen fastoxid (SOFC) anses vara en attraktiv kandidat för energiomvandling bland bränsleceller (FC) beroende på flera fördelar som bl.a. miljövänlighet, användning av icke-ädla material och deras bränsleflexibilitet. På grund av hög driftstemperatur står dock konventionella SOFC inför många utmaningar. Bland dessa finns höga drifts- och kapitalkostnader samt det begränsade urvalet av FC-material och relaterade kompatibilitetsproblem. En trend inom SOFC-forskning är inriktning på hur man sänker driftstemperaturen åtminstone till 700 ºC eller lägre. Undersökning av nya elektrolyt- och elektrodmaterial som kan fungera bra vid låga temperaturer är en mödosam väg för att sänka SOFCs arbetstemperatur. Som alternativ finns halvledande-jonledande material som är baserade på perovskit/komposit- och jonledande material. Dessa är potentiella kandidater att arbeta i ett lågt temperaturområde med tillräckliga SOFC-prestanda.

Denna forskning fokuserar på utveckling av halvledar-joniska material för lågtemperatur-solid oxid bränsleceller och elektrolytskikt-fria bränsleceller (EFFC). Detta arbete är indelat i fyra delar:

Den första delen av avhandlingen handlar om arbetet med konventionell SOFC för att bygga kunskap och att överbrygga från konventionell SOFC till det nya EFFC. Nya halvledande kompositelektrodmaterial syntetiseras och studeras med hjälp av etablerade elektrokemiska och analytiska metoder, såsom röntgendiffraktion (XRD), scanning-elektronmikroskopi (SEM) och termogravimetrisk analys (TGA). Fasstrukturen, morfologin och mikrostrukturen hos kompositelektroderna studeras med användning av XRD och SEM, och viktminskningen bestäms med användning av TGA. En elektrisk ledningsförmåga på 143 S/cm av sådant framställt material har uppmätts med användning av DC 4-sond-metoden vid 550 ºC. En elektrolyt, Samarium-dopad Ceriumoxid (SDC) syntetiseras för att tillverka en konventionell SOFC-enhet baserad på tre komponenter. En maximal effekttäthet på 325 mW/cm2 har uppnåtts från den konventionella enheten vid 550 ºC.

I andra delen av avhandlingen är halvledarjoniska material baserade på perovskit och kompositmaterial förberedda för SOFC- och EFFC-enheter med låg temperatur. Halvledar-joniska material har konstruerats genom att skapa en komposit av nano-partiklar (nanokomposit) baserat på halvledarelektrod och elektrolyt i olika kristallina faser som kombineras i en tvåfas-struktur. Denna halvledar-joniska funktionella komponent har visats integrera alla anod-, elektrolyt- och katodfunktioner i bränslecellkomponenterna i en enda komponent, dvs "tre i en", vilket resulterade i förbättrad katalytisk aktivitet och förbättrad SOFC-prestanda.

Tredje delen av avhandlingen tar upp utvecklingen och optimeringen av EFFC-tekniken genom att studera Schottky-kopplingsmekanismen i sådana anordningar av halvledar-jonisk typ. Perovskit och funktionella nanokompositer (halvledar-joniska material) har utvecklats för EFFC-enheter. Materialkarakteriseringar utförs med användning av ett antal standardiserade experimentella och analytiska metoder. En maximal effekttäthet från 600 mW/cm2 upp till och 800 mW/cm2 har uppnåtts vid 600 ºC.

Den fjärde delen av avhandlingen beskriver den teoretiska simuleringen av EFFCs. I detta arbete tillämpas en uppdaterad numerisk modell för att studera EFFC-enheten som introducerar vissa modifieringar av de rådande sambanden i traditionella bränslecellsmodeller. De simulerade V-I- och P-I-kurvorna har jämförts med experimentella kurvor, och båda typerna av kurvor visar god samstämmighet.

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2019. p. 92
Series
TRITA-ITM-AVL ; 2019:7
Keywords
Semiconductor-ionic materials; electrolyte-layer free fuel cell; low temperature solid oxide fuel cell; fuel to electricity conversion; Schottky junction; theoretical and experimental curves, Halvledar-joniska material; elektrolytskikt-fri bränslecell; lågtemperatur fastoxidbränslecell; bränsle till elomvandling; Schottky junction; teoretiska och experimentella kurvor
National Category
Engineering and Technology
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-245185 (URN)978-91-7873-132-9 (ISBN)
Public defence
2019-03-29, Kollegiesalen, Brinellvägen 8, Stockholm, 10:00 (English)
Opponent
Supervisors
Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-03-06Bibliographically approved
Qiao, Z., Xia, C., Cai, Y., Afzal, M., Wang, H., Qiao, J. & Zhu, B. (2018). Electrochemical and electrical properties of doped CeO2-ZnO composite for low-temperature solid oxide fuel cell applications. Journal of Power Sources, 392, 33-40
Open this publication in new window or tab >>Electrochemical and electrical properties of doped CeO2-ZnO composite for low-temperature solid oxide fuel cell applications
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2018 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 392, p. 33-40Article in journal (Refereed) Published
Abstract [en]

Zinc oxide (ZnO) as a multi-function semiconductor is widely known for photocatalysis and electronic applications but exceptionally new in Solid State Ionics. In this study, a new semiconducting-ionic conductor is reported for solid oxide fuel cells (SOFCs) applications by composing ZnO with an ionic conductor La/Pr co-doped CeO2 (LCP) in various mass ratios. The prepared composites acting as membranes are sandwiched between two Ni0.8Co0.15Al0.05LiO2-δ (NCAL) electrodes to construct fuel cells. A remarkable maximum power output of 1055 mW cm−2 is attained along with a high open circuit voltage (OCV) of 1.04 V at 550 °C by the fuel cell using an optimal composition of 7LCP-3ZnO. The electrical properties of the composites as a function of LCP/ZnO ratio are studied through EIS measurements and polarization curves. It has been found that the composite of 7LCP-3ZnO exhibits a higher ionic conductivity than other composite samples at 475–550 °C, while possessing both high electronic and ionic conduction. Our further investigation also verifies the appreciable protonic conduction in LCP-ZnO, suggesting that the developed composite is a triple O2-/H+/e− conducting material. Additionally, rectification characteristic of the best-performance cell is also measured to interpret the high OCVs and power outputs of LCP-ZnO fuel cells.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
High ionic conductivity, Rectification characteristic, Semiconducting-ionic conductor, Solid oxide fuel cells, Triple O2-/H+/e− conduction, Zinc oxide
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-228718 (URN)10.1016/j.jpowsour.2018.04.096 (DOI)000435055500005 ()2-s2.0-85046400190 (Scopus ID)
Funder
Swedish Research Council, 621-2011-4983
Note

QC 20180530

Available from: 2018-05-30 Created: 2018-05-30 Last updated: 2018-07-17Bibliographically approved
Ali, A., Shehzad Bashir, F., Raza, R., Rafique, A., Kaleem Ullah, M., Alvi, F., . . . Belova, L. (2018). Electrochemical study of composite materials for coal-based direct carbon fuel cell. International journal of hydrogen energy, 43(28), 12900-12908
Open this publication in new window or tab >>Electrochemical study of composite materials for coal-based direct carbon fuel cell
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2018 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 28, p. 12900-12908Article in journal (Refereed) Published
Abstract [en]

The efficient conversion of solid carbon fuels into energy by reducing the emission of harmful gases is important for clean environment. In this regards, direct carbon fuel cell (DCFC) is a system that converts solid carbon directly into electrical energy with high thermodynamic efficiency (100%), system efficiency of 80% and half emission of gases compared to conventional coal power plants. This can generate electricity from any carbonaceous fuel such as charcoal, carbon black, carbon fiber, graphite, lignite, bituminous coal and waste materials. In this paper, ternary carbonate-samarium doped ceria (LNK-SDC) electrolyte has been synthesized via co-precipitation technique, while LiNiCuZnFeO (LNCZFO) electrode has been prepared using solid state reaction method. Due to significant ionic conductivity of electrolyte LNK-SDC, it is used in DCFC. Three types of solid carbon (lignite, bituminous, sub-bituminous) are used as fuel to generate power. The X-ray diffraction confirmed the cubic crystalline structure of samarium doped ceria, whereas XRD pattern of LNCZFO showed its composite structure. The proximate and ultimate coal analysis showed that fuel (carbon) with higher carbon content and lower ash content was promising fuel for DCFC. The measured ionic conductivity of LNK-SDC is 0.0998 Scm−1 and electronic conductivity of LNCZFO is 10.1 Scm−1 at 700 °C, respectively. A maximum power density of 58 mWcm−2 is obtained using sub-bituminous fuel.

Place, publisher, year, edition, pages
Elsevier Ltd, 2018
Keywords
Bituminous, Lignite, LNK-SDC, Proximate and ultimate analysis, Sub-bituminous, Bituminous coal, Carbon black, Carbon fibers, Cerium oxide, Charcoal, Copper compounds, Electrolytes, Energy efficiency, Fuel cell power plants, Ionic conductivity, Iron compounds, Lithium compounds, Nickel compounds, Samarium, Solid state reactions, Zinc compounds, Electrochemical studies, Electronic conductivity, Solid state reaction method, Thermodynamic efficiency, Ultimate analysis, Direct carbon fuel cells (DCFC)
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-238082 (URN)10.1016/j.ijhydene.2018.05.104 (DOI)000439678700036 ()2-s2.0-85048539184 (Scopus ID)
Note

Export Date: 30 October 2018; Article; CODEN: IJHED; Correspondence Address: Raza, R.; Clean Energy Research Lab (CERL), Department of Physics, COMSATS University Islamabad, Lahore CampusPakistan; email: razahussaini786@gmail.com

QC 20190111

Available from: 2019-01-11 Created: 2019-01-11 Last updated: 2019-01-11Bibliographically approved
Mi, Y., Xia, C., Zhu, B., Raza, R., Afzal, M. & Riess, I. (2018). Experimental and physical approaches on a novel semiconducting-ionic membrane fuel cell. Paper presented at Forum of Hydrogen and Fuel Cells, DEC 11-13, 2017, Hubei Univ, Wuhan, China. International journal of hydrogen energy, 43(28), 12756-12764
Open this publication in new window or tab >>Experimental and physical approaches on a novel semiconducting-ionic membrane fuel cell
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2018 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 28, p. 12756-12764Article in journal (Refereed) Published
Abstract [en]

Semiconducting-ionic membranes (SIMs) have exhibited significant superiority to replace the conventional ionic electrolytes in solid oxide fuel cells (SOFCs). One interesting phenomenon is that the SIMs can successfully avoid the underlying short-circuiting issue and power losses while bringing significantly enhanced power output. It is crucial to understand the physics in such devices as they show distinct electrochemical processes with conventional fuel cells. We first presented experimental studies of a SIM fuel cell based on a composite of semiconductor LiCo0.8Fe0.2O2 (LCF) and ionic conductor Sm-doped CeO2 (SDC), which achieved a remarkable power density of 1150 mW cm(-2) at 550 degrees C along with a high open circuit voltage (OCV) of 1.04 V. Then, for the first time we used a physical model via combining a semiconductor-ionic contact junction with a rectifying layer which blocks the electron leakage to describe such unique SIM device and excellent performance. Current and power are the most important characteristics for the device, by introducing the rectifying layer we described the SIM physical nature and new device process. This work presented a new view on advanced SIM SOFC science and technology from physics.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Semiconducting-ionic membrane, LCF-SDC composite, Solid oxide fuel cell, Rectifying layer, Physics model
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-240212 (URN)10.1016/j.ijhydene.2018.03.204 (DOI)000439678700021 ()2-s2.0-85046152995 (Scopus ID)
Conference
Forum of Hydrogen and Fuel Cells, DEC 11-13, 2017, Hubei Univ, Wuhan, China
Note

QC 20181217

Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2018-12-17Bibliographically approved
Liu, Y., Meng, Y., Zhang, W., Wang, B., Afzal, M., Xia, C. & Zhu, B. (2017). Industrial grade rare-earth triple-doped ceria applied for advanced low-temperature electrolyte layer-free fuel cells. Paper presented at 5th Global Conference on Materials Science and Engineering (CMSE), NOV 08-11, 2016, Tunghai Univ, Taichung, TAIWAN. International journal of hydrogen energy, 42(34), 22273-22279
Open this publication in new window or tab >>Industrial grade rare-earth triple-doped ceria applied for advanced low-temperature electrolyte layer-free fuel cells
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2017 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 34, p. 22273-22279Article in journal (Refereed) Published
Abstract [en]

In this study, the mixed electron-ion conductive nanocomposite of the industrial-grade rare-earth material (Le(3+), Pr3+ and Nd3+ triple-doped ceria oxide, noted as LCPN) and commercial p-type semiconductor Ni0.8Co0.15Al0.05Li-oxide (hereafter referred to as NCAL) were studied and evaluated as a functional semiconductor-ionic conductor layer for the advanced low temperature solid oxide fuel cells (LT-SOFCs) in an electrolyte layer-free fuel cells (EFFCs) configuration. The enhanced electrochemical performance of the EFFCs were analyzed based on the different semiconductor-ionic compositions with various weight ratios of LCPN and NCAL. The morphology and microstructure of the raw material, as prepared LCPN as well the commercial NCAL were investigated and characterized by Xray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectrometer (EDS), respectively. The EFFC performances and electrochemical properties using the LCPN-NCAL layer with different weight ratios were systematically investigated. The optimal composition for the EFFC performance with 70 wt% LCPN and 30 wt% NCAL displayed a maximum power density of 1187 mW cm(-2) at 550 degrees C with an open circuit voltage (OCV) of 1.07 V. It has been found that the well-balanced electron and ion conductive phases contributed to the good fuel cell performances. This work further promotes the development of the industrial-grade rare-earth materials applying for the LTSOFC technology. It also provides an approach to utilize the natural source into the energy field.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2017
Keywords
Industrial-grade rare-earth doped, ceria, Electrolyte layer-free fuel cells, Ionic conductor, Electronic conductor, Electrochemical performance
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-215836 (URN)10.1016/j.ijhydene.2017.04.075 (DOI)000411545300073 ()2-s2.0-85020065957 (Scopus ID)
Conference
5th Global Conference on Materials Science and Engineering (CMSE), NOV 08-11, 2016, Tunghai Univ, Taichung, TAIWAN
Note

QC 20171017

Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2017-10-17Bibliographically approved
Wang, X., Afzal, M., Deng, H., Dong, W., Wang, B., Mi, Y., . . . Zhu, B. (2017). La0.1SrxCa0.9-xMnO3-δ -Sm0.2Ce0.8O1.9 composite material for novel low temperature solid oxide fuel cells. International journal of hydrogen energy, 42(27), 17552-17558
Open this publication in new window or tab >>La0.1SrxCa0.9-xMnO3-δ -Sm0.2Ce0.8O1.9 composite material for novel low temperature solid oxide fuel cells
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2017 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 27, p. 17552-17558Article in journal (Refereed) Published
Abstract [en]

Lowering the operating temperature of the solid oxide fuel cells (SOFCs) is one of the world R&D tendencies. Exploring novel electrolytes possessing high ionic conductivity at low temperature becomes extremely important with the increasing demands of the energy conversion technologies. In this work, perovskite La0.1SrxCa0.9-xMnO3-δ (LSCM) materials were synthesized and composited with the ionic conductor Sm0.2Ce0.8O1.9 (SDC). The LSCM-SDC composite was sandwiched between two nickel foams coated with semiconductor

Ni0.8Co0.15Al0.05LiO2- δ (NCAL) to form the fuel cell device. The strontium content in theLSCM and the ratios of LSCM to SDC in the LSCM-SDC composite have significant effects on the electrical properties and fuel cell performances. The best performance has been achieved from LSCM-SDC composite with a weight ratio of 2:3. The fuel cells showed OCV over 1.0 V and excellent maximum output power density of 800 mW/cm2 at 550 ºC. Device processes and ionic transport processes were also discussed.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Perovskite ionic-conductor; composite material; Electrolyte; Low temperature SOFCs
National Category
Ceramics
Research subject
Energy Technology; Materials Science and Engineering
Identifiers
urn:nbn:se:kth:diva-245070 (URN)10.1016/j.ijhydene.2017.05.158 (DOI)000406725500064 ()2-s2.0-85020691094 (Scopus ID)
Funder
Swedish Research Council, 621-2011-4983EU, FP7, Seventh Framework Programme, 303454
Note

QC 20190306

Available from: 2019-03-05 Created: 2019-03-05 Last updated: 2019-03-06Bibliographically approved
Raza, R., Ullah, M. K., Afzal, M., Rafique, A., Ali, A., Arshad, S. & Zhu, B. (2017). Low-temperature solid oxide fuel cells with bioalcohol fuels. In: Bioenergy Systems for the Future: Prospects for Biofuels and Biohydrogen (pp. 521-539). Elsevier
Open this publication in new window or tab >>Low-temperature solid oxide fuel cells with bioalcohol fuels
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2017 (English)In: Bioenergy Systems for the Future: Prospects for Biofuels and Biohydrogen, Elsevier, 2017, p. 521-539Chapter in book (Refereed)
Abstract [en]

Energy and environmental issues become key factors for sustainable development of society and national economy. Sustainable energy targeting opportunities for economic friendly growth of a country are commonly recognized. The growing interest is focused on the renewable energy resources because of the global energy demands increasing day by day. To meet the demands, an extensive research is aimed to develop sustainable energy devices such as solar cells, rechargeable batteries, and fuel cells. In recent years, solid oxide fuel cell (SOFC) among fuel-cell types has got more attention especially due to its fuel flexibility (e.g., different hydrocarbons, alcohols, and gasoline/diesel), high efficiency, and low emission. Thus, LTSOFC fed by direct bioethanol is receiving considerable attention as a clean, highly efficient for the production of both electricity and high-grade waste heat. These multifuel advantages provide the opportunities to develop an advanced SOFC system especially bioalcohol SOFC systems. This is a very dynamic area for SOFC applications with a promising future. It may create great energy savings and pollution reductions, if the bioalcohol fuel-based-technologies in these applications come into practical use.This chapter is focused on the development of LTSOFC operated by direct bioalcohol (bioethanol and biomethanol) for sustainable development. The content of this chapter is divided into three parts: (i) development of materials, (ii) characterization and analysis, (iii) demonstration of the nanocomposite materials in a bioalcohol FC, and (iv) case studies. Such bioalcohol FC research and development can enhance the use of sustainable/renewable energy for the society, and results achieved for applications have great potential to revolutionize the energy technology in an environmentally friendly and sustainable way.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Bioethanol and biomethanol, Bioethanol fuel-cell car, Hydrocarbon fuel, LTSOFC, Nanocomposite
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-218480 (URN)10.1016/B978-0-08-101031-0.00015-6 (DOI)2-s2.0-85032163701 (Scopus ID)9780081010266 (ISBN)9780081010310 (ISBN)
Note

QC 20171129

Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2017-11-29Bibliographically approved
Fan, L., Afzal, M., He, C. & Zhu, B. (2017). Nanocomposites for "nano green energy" applications. In: Bioenergy Systems for the Future: Prospects for Biofuels and Biohydrogen (pp. 421-449). Elsevier
Open this publication in new window or tab >>Nanocomposites for "nano green energy" applications
2017 (English)In: Bioenergy Systems for the Future: Prospects for Biofuels and Biohydrogen, Elsevier, 2017, p. 421-449Chapter in book (Refereed)
Abstract [en]

The efficient conversion of fuel's chemical energy into electricity in solid oxide fuel cell (SOFC), one of the promising candidates to replace the current combustion process, requires highly active cell components for quick charge transfer and reaction kinetics in the current low-temperature range. Operation at low temperatures enables the deployment of nanostructured materials, while the nanostructured cell components with improved electric properties further assist the reduction of the temperature for given power output. One of the major issues of the single-phase nanoparticle is its aggregation properties under harsh fuel-cell condition, which could be overcome or alleviated by the advanced approaches. Nanocomposite approach not only addresses the instability and some intrinsic issues with the single-phase materials but also brings the interesting synergetic electric properties with multifunctionality. We summarize the research activities in a range of nanocomposite materials in SOFCs in finding the positive roles to improve the cell components (anode, electrolyte, and cathode) electrochemical performances and cell efficiency for green energy applications.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Green energy, Heterostructure, Impregnation, Nanocomposite, Solid oxide fuel cell
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-218478 (URN)10.1016/B978-0-08-101031-0.00012-0 (DOI)2-s2.0-85032150394 (Scopus ID)9780081010266 (ISBN)9780081010310 (ISBN)
Note

QC 20171129

Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2017-11-29Bibliographically approved
Lu, Y., Afzal, M., Zhu, B., Wang, B., Wang, J. & Xia, C. (2017). Nanotechnology Based Green Energy Conversion Devices with Multifunctional Materials at Low Temperatures. RECENT PATENTS ON NANOTECHNOLOGY, 11(2), 85-92
Open this publication in new window or tab >>Nanotechnology Based Green Energy Conversion Devices with Multifunctional Materials at Low Temperatures
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2017 (English)In: RECENT PATENTS ON NANOTECHNOLOGY, ISSN 1872-2105, Vol. 11, no 2, p. 85-92Article, review/survey (Refereed) Published
Abstract [en]

Background: Nanocomposites (integrating the nano and composite technologies) for advanced fuel cells (NANOCOFC) demonstrate the great potential to reduce the operational temperature of solid oxide fuel cell (SOFC) significantly in the low temperature (LT) range 300-600 degrees C. NANOCOFC has offered the development of multi-functional materials composed of semiconductor and ionic materials to meet the requirements of low temperature solid oxide fuel cell (LTSOFC) and green energy conversion devices with their unique mechanisms. Description: This work reviews the recent developments relevant to the devices and the patents in LTSOFCs from nanotechnology perspectives that reports advances including fabrication methods, material compositions, characterization techniques and cell performances. Conclusion: Finally, the future scope of LTSOFC with nanotechnology and the practical applications are also discussed.

Place, publisher, year, edition, pages
BENTHAM SCIENCE PUBL LTD, 2017
Keywords
Green energy, ionic materials, LTSOFC, multi-functional nanocomposites, NANOCOFC, nanotechnology, semiconductor-ionic material
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-211627 (URN)10.2174/1872210510666161107085439 (DOI)000405614300002 ()2-s2.0-85027279316 (Scopus ID)
Funder
Swedish Research Council, 621-2011-4983EU, FP7, Seventh Framework Programme, 303454VINNOVA
Note

QC 20170810

Available from: 2017-08-10 Created: 2017-08-10 Last updated: 2019-03-06Bibliographically approved
Wang, B., Cai, Y., Xia, C., Kim, J.-S., Liu, Y., Dong, W., . . . Zhu, B. (2017). Semiconductor-ionic Membrane of LaSrCoFe-oxide-doped Ceria Solid Oxide Fuel Cells. Electrochimica Acta, 248, 496-504
Open this publication in new window or tab >>Semiconductor-ionic Membrane of LaSrCoFe-oxide-doped Ceria Solid Oxide Fuel Cells
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2017 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 248, p. 496-504Article in journal (Refereed) Published
Abstract [en]

A novel semiconductor-ionic La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF)-Sm/Ca co-doped CeO2 (SCDC) nanocomposite has been developed as a membrane, which is sandwiched between two layers of Ni0.8Co0.15Al0.05Li-oxide (NCAL) to construct semiconductor-ion membrane fuel cell (SIMFC). Such a device presented an open circuit voltage (OCV) above 1.0 V and maximum power density of 814 mW cm(-2) at 550 degrees C, which is much higher than 0.84 V and 300 mW cm(-2) for the fuel cell using the SCDC membrane. Moreover, the SIMFC has a relatively promising long-term stability, the voltage can maintain at 0.966 V for 60 hours without degradation during the fuel cells operation and the open-circuit voltage (OCV) can return to 1.06 V after long-term fuel cell operation. The introduction of LSCF electronic conductor into the membrane did not cause any short circuit but brought significant enhancement of fuel cell performances. The Schottky junction is proposed to prevent the internal electrons passing thus avoiding the device short circuiting problem.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2017
Keywords
semiconductor-ionic membrane, solid oxide fuel cells, co-doped ceria, Schottky junction, short circuit
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-214874 (URN)10.1016/j.electacta.2017.07.128 (DOI)000409525300055 ()2-s2.0-85026786096 (Scopus ID)
Note

QC 20171024

Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2019-03-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8244-6572

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