| 1. |
- Fan, Liangdong, et al.
(författare)
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Electrochemical study of lithiated transition metal oxide composite as symmetrical electrode for low temperature ceramic fuel cells
- 2013
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 38:26, s. 11398-11405
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Tidskriftsartikel (refereegranskat)abstract
- In this work, Lithiated NiCuZnOx (LNCZO) composite is synthesized and evaluated as a potential symmetrical electrode for ceria-carbonate composite electrolyte based low temperature ceramic fuel cells. Its crystal structures, the hydrogen oxidation/oxygen reduction electrochemical activities and fuel cell performances are systematically examined on the symmetrical cell configuration. Nano crystallite particles in the form of composite are observed for these oxides. The LNCZO shows relatively high catalytic activities for hydrogen oxidation and oxygen reduction reaction according to the electrochemical impedance spectroscopy measurements. A remarkable low oxygen reduction activation energy of 42 kJ mol(-1) is obtained on the LNCZO/ceria-carbonate composite, demonstrating excellent electro-catalytic activity. Especially, the catalytic activity can be further improved in the presence of water in the cathode chamber. The results show that the lithiated transition metal oxide composite is a promising symmetrical electrode for ceria-carbonate electrolyte and composite approach might a probable solution to develop super-performance electrodes for reduced temperature ceramic fuel cells.
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| 2. |
- Fan, Liangdong, et al.
(författare)
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Mixed ion and electron conductive composites for single component fuel cells : I. Effects of composition and pellet thickness
- 2012
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 217, s. 164-169
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical performances of single component fuel cells (SCFCs) based on mixed ion and electron conductors have been studied as a function of composition and pellet thickness by polarization curves and electrochemical impedance spectroscopy. The electronic conductor of LNCZO shows conductivities of 21.7 and 5.3 S cm(-1) in H-2 and in air, respectively. SCFC using 40 wt. % of LNCZO and 60 wt. % of ion conductive SDC-Na2CO3 with a thickness of 1.10 mm shows the highest power density of 0.35 W cm(-2) at 550 degrees C. The performance is correlated to the mixed conduction properties (ionic and electronic, p and n-type) and the microstructure of the functional SCFC layer.
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| 3. |
- Fan, Liangdong, et al.
(författare)
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Understanding the electrochemical mechanism of the core-shell ceria-LiZnO nanocomposite in a low temperature solid oxide fuel cell
- 2014
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 2:15, s. 5399-5407
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Tidskriftsartikel (refereegranskat)abstract
- Ceria based solid solutions have been considered some of the best candidates to develop intermediate/low temperature solid oxide fuel cells (IT/LT-SOFCs, 600-800 degrees C). However, the barrier to commercialization has not been overcome even after numerous research activities due to its inherent electronic conduction in a reducing atmosphere and inadequate ionic conductivity at low temperatures. The present work reports a new type of all-oxide nanocomposite electrolyte material based on a semiconductor, Li-doped ZnO (LixZnO), and an ionic conductor, samarium doped ceria (SDC). This electrolyte exhibits superionic conductivity (>0.1 S cm(-1) over 300 degrees C), net-electron free and excellent electrolytic performances (400-630 mW cm(-2)) between 480 and 550 degrees C. Particularly, defects related to interfacial conduction and the intrinsic and extrinsic properties of ions are analysed. An internal or interfacial redox process on two-phase particles is suggested as a powerful methodology to overcome the internal short-circuit problem of ceria-based single phase materials and to develop new advanced materials for energy related applications. The combination of the above promising features makes the SDC-LiZnO nanocomposite a promising electrolyte for LTSOFCs.
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| 4. |
- He, Yunjuan, et al.
(författare)
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Cobalt oxides coated commercial Ba0.5Sr0.5Co0.8Fe0.2O3-delta as high performance cathode for low-temperature SOFCs
- 2016
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Ingår i: Electrochimica Acta. - : Elsevier. - 0013-4686 .- 1873-3859. ; 191, s. 223-229
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Tidskriftsartikel (refereegranskat)abstract
- In order to improve the catalytic activity of commercial Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) for low-temperature solid oxide fuel cells (LTSOFC) (300-600 degrees C), CoOx has been used to modify the commercial BSCF through a solution coating approach. Phase and morphology of samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive spectrometry (EDS), respectively. BSCF with 10 wt% CoOx exhibited an improved conductivity of 44 S/cm, and achieved a peak power density of 463 mW/cm(2) at 550 degrees C for LTSOFC, which is a 100% enhancement than that with the BSCF cathode. The cathode oxygen reduction reaction (ORR) promoted by CoOx and enhanced device performance mechanism have been proposed. This work provides a new way for the exploitation of high effective cathode materials for LTSOFCs.
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| 5. |
- Hu, Enyi, et al.
(författare)
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Junction and energy band on novel semiconductor-based fuel cells
- 2021
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 24:3
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Forskningsöversikt (refereegranskat)abstract
- Fuel cells are highly efficient and green power sources. The typical membrane electrode assembly is necessary for common electrochemical devices. Recent research and development in solid oxide fuel cells have opened up many new opportunities based on the semiconductor or its heterostructure materials. Semiconductor-based fuel cells (SBFCs) realize the fuel cell functionality in a much more straightforward way. This work aims to discuss new strategies and scientific principles of SBFCs by reviewing various novel junction types/interfaces, i.e., bulk and planar p-n junction, Schottky junction, and n-i type interface contact. New designing methodologies of SBFCs from energy band/alignment and built-in electric field (BIEF), which block the internal electronic transport while assisting interfacial superionic transport and subsequently enhance device performance, are comprehensively reviewed. This work highlights the recent advances of SBFCs and provides new methodology and understanding with significant importance for both fundamental and applied R&D on new-generation fuel cell materials and technologies.
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| 6. |
- Li, Yihang, et al.
(författare)
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Efficient reversible CO/CO2 conversion in solid oxide cells with a phase-transformed fuel electrode
- 2021
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Ingår i: SCIENCE CHINA Materials. - : Springer Science and Business Media LLC. - 2095-8226 .- 2199-4501. ; 64:5, s. 1114-1126
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Tidskriftsartikel (refereegranskat)abstract
- The reversible solid oxide cell (RSOC) is an attractive technology to mutually convert power and chemicals at elevated temperatures. However, its development has been hindered mainly due to the absence of a highly active and durable fuel electrode. Here, we report a phase-transformed CoFe-Sr3Fe1.25Mo0.75O7−δ (CoFe-SFM) fuel electrode consisting of CoFe nanoparticles and Ruddlesden-Popper-layered Sr3Fe1.25Mo0.75O7−δ (SFM) from a Sr2Fe7/6Mo0.5Co1/3O6−δ (SFMCo) perovskite oxide after annealing in hydrogen and apply it to reversible CO/CO2 conversion in RSOC. The CoFe-SFM fuel electrode shows improved catalytic activity by accelerating oxygen diffusion and surface kinetics towards the CO/CO2 conversion as demonstrated by the distribution of relaxation time (DRT) study and equivalent circuit model fitting analysis. Furthermore, an electrolyte-supported single cell is evaluated in the 2:1 CO-CO2 atmosphere at 800°C, which shows a peak power density of 259 mW cm−2 for CO oxidation and a current density of −0.453 A cm−2 at 1.3 V for CO2 reduction, which correspond to 3.079 and 3.155 mL min−1 cm−2 for the CO and CO2 conversion rates, respectively. More importantly, the reversible conversion is successfully demonstrated over 20 cyclic electrolysis and fuel cell switching test modes at 1.3 and 0.6 V. This work provides a useful guideline for designing a fuel electrode through a surface/interface exsolution process for RSOC towards efficient CO-CO2 reversible conversion.
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| 7. |
- Zhu, Bin, et al.
(författare)
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A new energy conversion technology based on nano-redox and nano-device processes
- 2013
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855. ; 2:6, s. 1179-1185
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Tidskriftsartikel (refereegranskat)abstract
- Electrolyte-separator-free fuel cell (EFFC) is a new emerging energy conversion technology. The EFFC consists of a single-component of nanocomposite material which works as a one-layer fuel cell device contrary to the traditional three-layer anode-electrolyte-cathode structure, in which an electrolyte layer plays a critical role. The nanocomposite of a single homogenous layer consists of a mixture of semiconducting and ionic materials that provides the necessary electrochemical reaction sites and charge transport paths for a fuel cell. These can be accomplished through tailoring ionic and electronic (n, p) conductivities and catalyst activities, which enable redox reactions to occur on nano-particles and finally accomplish a fuel cell function.
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| 8. |
- Zhu, Bin, 1956-, et al.
(författare)
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A new energy conversion technology joining electrochemical and physical principles
- 2012
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Ingår i: RSC Advances. - 2046-2069. ; 2:12, s. 5066-5070
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Tidskriftsartikel (refereegranskat)abstract
- We report a new energy conversion technology joining electrochemical and physical principles. This technology can realize the fuel cell function but built on a different scientific principle. The device consists of a single component which is a homogenous mixture of ceria composite with semiconducting materials, e.g. LiNiCuZn-based oxides. The test devices with hydrogen and air operation delivered a power density of 760mWcm(-2) at 550 degrees C. The device has demonstrated a multi-fuel flexibility and direct alcohol and biogas operations have delivered 300-500 mW cm(-2) at the same temperature. Device physics reveal a key principle similar to solar cells realizing the function based on an effective separation of electronic and ionic conductions and phases within the single-component. The component material multi-functionalities: ion and semi-conductions and bi-catalysis to H-2 or alcohol (methanol and ethanol) and air (O-2) enable this device realized as a fuel cell.
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