SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Wang Baoyuan) "

Sökning: WFRF:(Wang Baoyuan)

  • Resultat 1-33 av 33
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Kristanl, Matej, et al. (författare)
  • The Seventh Visual Object Tracking VOT2019 Challenge Results
  • 2019
  • Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
  • Konferensbidrag (refereegranskat)abstract
    • The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
  •  
2.
  • Liu, Xueqi, et al. (författare)
  • Study on charge transportation in the layer-structured oxide composite of SOFCs
  • 2018
  • Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 43:28, s. 12773-12781
  • Tidskriftsartikel (refereegranskat)abstract
    • In the past few years, triple (H+/O2-/e(-)) conducting materials have been regarded as one of the most promising electrode categories for solid oxide fuel cells (SOFCs). In this work, a layer-structured LiNi0.8Co0.15Al0.05O2-delta (LNCA) with triple conduction has been studied. The semiconductor-ionic conductor (SIC) LNCA-SDC composite has been fabricated by compositing the LNCA material with ionic conductor, i.e., samarium doped ceria (SDC). The electrochemical performance of the LNCA-SDC composite was studied by electrochemical impedance spectroscopy, while its electronic conductivity was confirmed by d.c. polarization method. It is found that the ionic conductivity of the composite is higher than the electronic conductivity by several orders of magnitude. The charge carriers and transportation properties of LNCA-SDC were studied using H+ and O2- blocking layer cells respectively. Results prove that the LNCA-SDC composite is a hybrid oxygen ion-proton conducting material. The oxygen ion conduction is dominated at low temperature (425 -500 degrees C), however, it is comparable with H+ conduction at high temperature (550 degrees C). Additionally, the formation of Li2CO3 under fuel cell operation environment was observed and the mechanism of the hybrid conductivity of LNCA-SDC was studied.
  •  
3.
  • Wang, Baoyuan, et al. (författare)
  • Fast ionic conduction in semiconductor CeO2-delta electrolyte fuel cells
  • 2019
  • Ingår i: NPG ASIA MATERIALS. - : Nature Publishing Group. - 1884-4049 .- 1884-4057. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Producing electrolytes with high ionic conductivity has been a critical challenge in the progressive development of solid oxide fuel cells (SOFCs) for practical applications. The conventional methodology uses the ion doping method to develop electrolyte materials, e.g., samarium-doped ceria (SDC) and yttrium-stabilized zirconia (YSZ), but challenges remain. In the present work, we introduce a logical design of non-stoichiometric CeO2-delta based on non-doped ceria with a focus on the surface properties of the particles. The CeO2-delta reached an ionic conductivity of 0.1 S/cm and was used as the electrolyte in a fuel cell, resulting in a remarkable power output of 660 mW/cm(2) at 550 degrees C. Scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) clearly clarified that a surface buried layer on the order of a few nanometers was composed of Ce3+ on ceria particles to form a CeO2-delta@CeO2 core-shell heterostructure. The oxygen deficient layer on the surface provided ionic transport pathways. Simultaneously, band energy alignment is proposed to address the short circuiting issue. This work provides a simple and feasible methodology beyond common structural (bulk) doping to produce sufficient ionic conductivity. This work also demonstrates a new approach to progress from material fundamentals to an advanced low-temperature SOFC technology.
  •  
4.
  • Wang, Baoyuan, et al. (författare)
  • Preparation and characterization of Sm and Ca co-doped ceria-La0.6Sr0.4Co0.2Fe0.8O3-delta semiconductor-ionic composites for electrolyte-layer-free fuel cells
  • 2016
  • Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 4:40, s. 15426-15436
  • Tidskriftsartikel (refereegranskat)abstract
    • A series of Sm and Ca co-doped ceria, i.e. Ca0.04Ce0.96-xSmxO2-delta (x = 0, 0.09, 0.16, and 0.24) (SCDC), were synthesized by a co-precipitation method. Detailed morphology, composition, crystal structure and electrochemical properties of the prepared materials were characterized. The results revealed that Sm and Ca co-doping could enhance the ionic conductivity in comparison with that of single Ca-doped samples. The composition as Ca0.04Ce0.80Sm0.16O2-delta exhibited a highest ionic conductivity of 0.039 S cm(-1) at 600 degrees C in comparison with the rest of the series, and the optimal ionic conductivity can be interpreted by the coupling effect of oxygen vacancies and mismatch between the dopant ionic radius and critical radius. Composite formation between the semiconductor La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and the as-prepared SCDC contributed to a remarkable improvement in the ionic conductivity, an unexpectedly high ionic conductivity of 0.188 S cm(-1) was obtained for LSCF-SCDC composites at 600 degrees C, which was four times higher than that of pure SCDC. Using transmission electron microscopy and spectroscopy approaches, we detected an enrichment of oxygen in the LSCF-SCDC interface region and a depletion of oxygen vacancies in LSCF-SCDC and LSCF-LSCF grain boundaries was significantly mitigated, which resulted in the enhancement of ionic conductivity of semiconductor-ionic LSCF-SCDC composites. The electrolyte-layer-free fuel cell (EFFC) fabricated from the LSCF-SCDC semiconductor-ionic membrane demonstrated excellent performances, e.g. 814 mW cm(-2) at 550 degrees C for using the LSCF-Ca0.04Ce0.80Sm0.16O2-delta (SCDC2).
  •  
5.
  • Wang, Xunying, et al. (författare)
  • La0.1SrxCa0.9-xMnO3-δ -Sm0.2Ce0.8O1.9 composite material for novel low temperature solid oxide fuel cells
  • 2017
  • Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 42:27, s. 17552-17558
  • Tidskriftsartikel (refereegranskat)abstract
    • 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 semiconductorNi0.8Co0.15Al0.05LiO2- 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.
  •  
6.
  • Cai, Yixiao, et al. (författare)
  • Bioderived Calcite as Electrolyte for Solid Oxide Fuel Cells : A Strategy toward Utilization of Waste Shells
  • 2017
  • Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 5:11, s. 10387-10395
  • Tidskriftsartikel (refereegranskat)abstract
    • The excessive consumption of synthesized materials and enhanced environmental protection protocols necessitate the exploitation of desirable functionalities to handle our solid waste. Through a simple calcination and composite strategy, this work envisages the first application of biocalcite derived from the waste of crayfish shells as an electrolyte for solid oxide fuel cells (SOFCs), which demonstrates encouraging performances within a low temperature range of 450-550 degrees C. The single cell device, assembled from calcined waste shells at 600 degrees C (CWS600), enables a peak power density of 166 mW cm(-2) at 550 degrees C, and further renders 330 and 256 mW cm(-2) after compositing with perovskite La0.6Sr0.4Co0.8Fe0.2O3-delta (LSCF) and layer-structured LiNi0.8Co0.15Al0.05O2 (LNCA), respectively. Notably, an oxygen-ion blocking fuel cell is used to confirm the proton-conducting property of CWS600 associated electrolytes. The practical potential of the prepared fuel cells is also validated when the cell voltage of the cell is kept constant value over 10 h during a galvanostatic operation using a CWS600-LSCF electrolyte. These interesting findings may increase the likelihood of transforming our solid municipal waste into electrochemical energy devices, and also importantly, provide an underlying approach for discovering novel electrolytes for low-temperature SOFCs.
  •  
7.
  • Deng, Hui, et al. (författare)
  • The electrolyte-layer free fuel cell using a semiconductor-ionic Sr2Fe1.5Mo0.5O6-delta - Ce0.8Sm0.2O2-delta composite functional membrane
  • 2017
  • Ingår i: International journal of hydrogen energy. - : Pergamon Press. - 0360-3199 .- 1879-3487. ; 42:39, s. 25001-25007
  • Tidskriftsartikel (refereegranskat)abstract
    • Commercial double Perovskite Sr2Fe1.5Mo0.5O6-delta (SFM), a high performance and redox stable electrode material for solid oxide fuel cell (SOFC), has been used for the electrolyte (layer)-free fuel cell (EFFC) and also as the cathode for the electrolyte based SOFC in a comprehensive study. The EFFC with a homogeneous mixture of Ce0.8Sm0.2O2-delta (SDC) and SFM achieved a higher power density (841 mW cm(-2)) at 550 degrees C, while the SDC electrolyte based SOFC, using the SDC-SFM composite as cathode, just reached 326 mW cm(-2) at the same temperature. The crystal structure and the morphology of the SFM-SDC composite were characterized by X-ray diffraction analysis (XRD), and scanning electron microscope (SEM), respectively. The electrochemical impedance spectroscopy (EIS) results showed that the charge transfer resistance of EFFCs were much lower than that of the electrolyte-based SOFC. To illustrate the operating principle of EFFC, we also conducted the rectification characteristics test, which confirms the existence of a Schottky junction structure to avoid the internal electron short circuiting. This work demonstrated advantages of the semiconductor-ionic SDC-SFM material for advanced EFFCs.
  •  
8.
  • Feng, Chu, et al. (författare)
  • Thin-Film Fuel Cells using a Sodium Silicate Binder with La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and LaCePr Oxides (LCP) Membranes
  • 2018
  • Ingår i: Energy Technology. - : Wiley-VCH Verlagsgesellschaft. - 2194-4288. ; 6:2, s. 312-317
  • Tidskriftsartikel (refereegranskat)abstract
    • Sodium silicate was used as a binder to prepare LaCePr oxides (LCP) and La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) thin films on a Ni0.8Co0.15Al0.05Li oxide ceramic substrate for the first time. The microstructure, morphology, and electrical properties of the LSCF-LCP thin films were characterized and investigated by using XRD, SEM, energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. The film sintered at 600 degrees C presents promising density and has been successfully applied as the electrolyte membrane for solid-oxide fuel cells (SOFCs). Such a device achieved a respectable electrochemical performance with an open-circuit voltage of 1.04V and a maximum power output of 545mWcm(-2) at 575 degrees C. These findings suggest that sodium silicate is a suitable binder for the preparation of dense thin-film membranes for SOFCs. Moreover, the preparation technology based on sodium silicate eliminated degumming and high-temperature sintering, which resulted in greatly simplifying the preparation process of the thin-film fuel cell towards potential fuel cell commercialization.
  •  
9.
  • Jiang, Cong, et al. (författare)
  • F-doped LiNi0.8Co0.15Al0.05O2-? : cathodes with enhanced ORR catalytic activity for LT-SOFCs
  • 2023
  • Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 940
  • Tidskriftsartikel (refereegranskat)abstract
    • Developing highly effective catalysts for oxygen reduction reaction (ORR) is crucial to enable the low-temperature operation of solid oxide fuel cells (SOFCs). Recent studies have proposed a promising O2-/H+/e- conducting oxide, LiNi0.8Co0.15Al0.05O2-delta (LNCA) with good ORR catalytic activity for SOFC cathode uses. Herein, to further optimize the cathode functionality of LNCA, a fluorine anion (F-) doping strategy is ap-plied to develop highly active LNCAF0.1 and LNCAF0.2 cathodes for Sm-doped ceria (SDC) electrolyte-based SOFCs. It is found the successful doping of F- in the oxygen site of LNCA leads to improved oxygen ionic conductivity and facilitated surface exchange and bulk diffusion of oxygen in LNCAF0.1 and LNCAF0.2, which thus gain distinctly promoted ORR catalytic activity at 450-550 degrees C, as confirmed by the decreased area specific resistances (ASR) and activation energy on symmetrical cells. The as-fabricated two SDC-based SOFCs with LNCAF0.1 and LNCAF0.2 cathodes exhibit peak power densities of 497 and 591 mW cm-2 at 550 degrees C, respectively, which are higher than that of the cell with LNCA cathode. Furthermore, the single cell with the best-performing LNCAF0.2 cathode demonstrates a good stability for 110 h at 550 degrees C. The present study thus provides a feasible strategy of F anion doping to promote the ORR catalytic activity of LNCA cathode for developing low-temperature SOFCs.
  •  
10.
  • Lu, Yuzheng, et al. (författare)
  • Nanotechnology Based Green Energy Conversion Devices with Multifunctional Materials at Low Temperatures
  • 2017
  • Ingår i: RECENT PATENTS ON NANOTECHNOLOGY. - : BENTHAM SCIENCE PUBL LTD. - 1872-2105. ; 11:2, s. 85-92
  • Forskningsöversikt (refereegranskat)abstract
    • 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.
  •  
11.
  • Lu, Yuzheng, et al. (författare)
  • Progress in Electrolyte-Free Fuel Cells
  • 2016
  • Ingår i: FRONTIERS IN ENERGY RESEARCH. - : FRONTIERS MEDIA SA. - 2296-598X. ; 4
  • Forskningsöversikt (refereegranskat)abstract
    • Solid oxide fuel cell (SOFC) represents a clean electrochemical energy conversion technology with characteristics of high conversion efficiency and low emissions. It is one of the most important new energy technologies in the future. However, the manufacture of SOFCs based on the structure of anode/electrolyte/cathode is complicated and time-consuming. Thus, the cost for the entire fabrication and technology is too high to be affordable, and challenges still hinder commercialization. Recently, a novel type of electrolyte-free fuel cell (EFFC) with single component was invented, which could be the potential candidate for the next generation of advanced fuel cells. This paper briefly introduces the EFFC, working principle, performance, and advantages with updated research progress. A number of key R&D issues about EFFCs have been addressed, and future opportunities and challenges are discussed.
  •  
12.
  • Meng, Yuanjing, et al. (författare)
  • High-performance SOFC based on a novel semiconductor-ionic SrFeO3-delta-Ce0.8Sm0.2O2-delta membrane
  • 2018
  • Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 43:28, s. 12697-12704
  • Tidskriftsartikel (refereegranskat)abstract
    • The semiconductor-ionic composite membrane has been recently developed for a novel solid oxide fuel cell (SOFC), i.e., the semiconductor-ion membrane fuel cell (SIMFC). In this work, the perovskite-type SrFeO3-delta (SFO) as semiconductor material was composited with ionic conductor Ce0.8Sm0.2O2-delta (SDC) to form the SFO-SDC composite membrane for SIMFCs. The SFO-SDC SIMFCs using the optimized weight ratio of 3:7 SFO-SDC membrane obtained the best performances, 780 mW cm(-2) at 550 degrees C, compared to 348 mW cm(-2) obtained from the pure SDC electrolyte fuel cell. Introduction of SFO into SDC can extend the triple phase boundary and provide more active sites for accelerating the fuel cell reactions, thus significantly enhanced the cell power output. Moreover, SFO was employed as the cathode, and a higher power output, 907 mW cm(-2) was achieved, suggesting that SFO cathode is more compatible for the SFO-SDC system in SIMFCs. This work provides an attractive strategy for the development of low temperature SOFCs.
  •  
13.
  • Wang, Baoyuan, et al. (författare)
  • CoFeZrAl-oxide based composite for advanced solid oxide fuel cells
  • 2016
  • Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 73, s. 15-19
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel CoFeZrAl-oxide (CFZA) consisted of FeAl2O4, Co3O4 and ZrO2 was prepared by an auto ignition process, displaying a typical morphology of nanorods. The corresponding fuel cell was constructed by using CFZA as the ion-conducting membrane, incorporated between two layers of Ni0.8Co0.15Al0.05Li-oxide pasted on nickel foam (Ni-NCAL), which was used as both electrodes and current collectors. The fuel cell presented an open circuit voltage of 1.07 V and maximum power density of 631 mW/cm(2) at 600 degrees C. The reduction of FeAl2O4 to oxygen-deficient FeAl2O4 (delta) under H-2 condition contributed to the ionic conduction, then the ionic conductor FeAl2O4 (-) (delta) composited with insulator ZrO2 to further enhance the ionic conductivity due to composite effect.
  •  
14.
  • Wang, Baoyuan, et al. (författare)
  • Photovoltaic properties of LixCo3-xO4/TiO2 heterojunction solar cells with high open-circuit voltage
  • 2016
  • Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 157, s. 126-133
  • Tidskriftsartikel (refereegranskat)abstract
    • All-oxide solar cells are presently attracting extensive research interest due to their excellent stability, low-cost and non-toxicity. However, the band gap of metal oxides is lack of effective optimization and results in poor photovoltaic performance, thus hindering their practical applications. In this work, Co3O4 was investigated for application as a photo-absorber in all-oxide solar cells, and its band gap was optimized by introducing Li dopant into the spinel structure. LixCo3-xO4 nanoparticles, prepared via the hydrothermal method, were homogenously coated onto TiO2 mesoporous films, which were then used to fabricate planar heterojunction TiO2/LixCo3-xO4 solar cells (SCs). The effects of Li-doping on the heterojunction solar cell performance were further investigated. The findings revealed that the incorporation of Li ions into Co3O4 led to a significant enhancement in short-circuit current density (J(sc)). Remarkably, a high open-circuit voltage (V-oc) of 0.70 V was also achieved. Besides, reasons for the enhanced cell performance are the narrower band gap, reduced photogenerated carrier recombination and the more favorable energy band structure as compared with SCs assembled from pure Co3O4.
  •  
15.
  • Wang, Baoyuan, et al. (författare)
  • Semiconductor-ionic Membrane of LaSrCoFe-oxide-doped Ceria Solid Oxide Fuel Cells
  • 2017
  • Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 248, s. 496-504
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
  •  
16.
  • Zhu, Bin, et al. (författare)
  • Charge separation and transport in La0.6Sr0.4Co0.2Fe0.8O3-delta and ion-doping ceria heterostructure material for new generation fuel cell
  • 2017
  • Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 37, s. 195-202
  • Tidskriftsartikel (refereegranskat)abstract
    • Functionalities in heterostructure oxide material interfaces are an emerging subject resulting in extraordinary material properties such as great enhancement in the ionic conductivity in a heterostructure between a semiconductor SrTiO3 and an ionic conductor YSZ (yttrium stabilized zirconia), which can be expected to have a profound effect in oxygen ion conductors and solid oxide fuel cells [1-4]. Hereby we report a semiconductorionic heterostructure La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and Sm-Ca co-doped ceria (SCDC) material possessing unique properties for new generation fuel cells using semiconductor-ionic heterostructure composite materials. The LSCF-SCDC system contains both ionic and electronic conductivities, above 0.1 S/cm, but used as the electrolyte for the fuel cell it has displayed promising performance in terms of OCV (above 1.0 V) and enhanced power density (ca. 1000 mW/cm(2) at 550 degrees C). Such high electronic conduction in the electrolyte membrane does not cause any short-circuiting problem in the device, instead delivering enhanced power output. Thus, the study of the charge separation/transport and electron blocking mechanism is crucial and can play a vital role in understanding the resulting physical properties and physics of the materials and device. With atomic level resolution ARM 200CF microscope equipped with the electron energy-loss spectroscopy (EELS) analysis, we can characterize more accurately the buried interface between the LSCF and SCDC further reveal the properties and distribution of charge carriers in the heterostructures. This phenomenon constrains the carrier mobility and determines the charge separation and devices' fundamental working mechanism; continued exploration of this frontier can fulfill a next generation fuel cell based on the new concept of semiconductor-ionic fuel cells (SIFCs).
  •  
17.
  • Zhu, Bin, et al. (författare)
  • Novel fuel cell with nanocomposite functional layer designed by perovskite solar cell principle
  • 2016
  • Ingår i: Nano Energy. - : Elsevier. - 2211-2855. ; 19, s. 156-164
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel fuel-to-electricity conversion technology resembling a fuel cell has been developed based on the perovskite solar cell principle using a perovskite, e.g. La0.6Sr0.4Co0.2Fe0.8O3-δ and an ionic nanocomposite material as a core functional layer, sandwiched between n- and p-conducting layers. The conversion process makes use of semiconductor energy bands and junctions properties. The physical properties of the junction and alignment of the semiconductor energy band allow for direct ion transport and prevent internal electronic short-circuiting, while at the same time avoiding losses at distinct electrolyte/electrode interfaces typical to conventional fuel cells. The new device achieved a stable power output of 1080mWcm-2 at 550°C in converting hydrogen fuel into electricity.
  •  
18.
  • Afzal, Muhammad, et al. (författare)
  • Fabrication of novel electrolyte-layer free fuel cell with semi-ionic conductor (Ba0.5Sr0.5Co0.8Fe0.2O3-delta- Sm0.2Ce0.8O1.9) and Schottky barrier
  • 2016
  • Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 328, s. 136-142
  • Tidskriftsartikel (refereegranskat)abstract
    • Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) is synthesized via a chemical co-precipitation technique for a low temperature solid oxide fuel cell (LTSOFC) (300-600 degrees C) and electrolyte-layer free fuel cell (EFFC) in a comprehensive study. The EFFC with a homogeneous mixture of samarium doped ceria (SDC): BSCF (60%:40% by weight) which is rather similar to the cathode (SDC: BSCF in 50%:50% by weight) used for a three layer SOFC demonstrates peak power densities up to 655 mW/cm(2), while a three layer (anode/ electrolyte/cathode) SOFC has reached only 425 mW/cm(2) at 550 degrees C. Chemical phase, crystal structure and morphology of the as-prepared sample are characterized by X-ray diffraction and field emission scanning electron microscopy coupled with energy dispersive spectroscopy. The electrochemical performances of 3-layer SOFC and EFFC are studied by electrochemical impedance spectroscopy (EIS). As-prepared BSCF has exhibited a maximum conductivity above 300 S/cm at 550 degrees C. High performance of the EFFC device corresponds to a balanced combination between ionic and electronic (holes) conduction characteristic. The Schottky barrier prevents the EFFC from the electronic short circuiting problem which also enhances power output. The results provide a new way to produce highly effective cathode materials for LTSOFC and semiconductor designs for EFFC functions using a semiconducting-ionic material.
  •  
19.
  • Dong, Wenjing, et al. (författare)
  • Charge transport study of perovskite solar cells through constructing electron transport channels
  • 2017
  • Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley-VCH Verlagsgesellschaft. - 1862-6300 .- 1862-6319. ; 214:10
  • Tidskriftsartikel (refereegranskat)abstract
    • Perovskite solar cells (PSC) have attracted much attention in the recent years. It is important to understand their working principle in order to uncover the reasons behind their high efficiency. In this study, the carrier transport mechanism of PSC by controlling the structure of a scaffold is investigated. CeO2 is used as an electron blocking material in PSCs to study the electron transport behavior for the first time. The influence of light absorption can be excluded because CeO2 has a similar bandgap to TiO2. A variety of scaffolds are constructed using nano-TiO2 and CeO2. The results show that electrons can transport from light absober (perovskite) to FTO electrode (external circuit) through two kinds of channels. The energy band level, as well as the electronic conductivity of the scaffolds, is are key issues that affect electron transport. Although perovskites are able to transport both electrons and holes, it is still necessary to have effective electron transport channels (ETCs) between perovskite and external circuit for the sake of high efficiency. Electrochemical impedance spectroscopy analysis suggests that the lack of such channels will result in high recombination. The number of ETCs and effecient electron-hole separation are also proven to be important for cell performance.
  •  
20.
  • Liu, Yanyan, et al. (författare)
  • Industrial grade rare-earth triple-doped ceria applied for advanced low-temperature electrolyte layer-free fuel cells
  • 2017
  • Ingår i: International journal of hydrogen energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-3199 .- 1879-3487. ; 42:34, s. 22273-22279
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
  •  
21.
  • Liu, Yanyan, et al. (författare)
  • Natural CuFe2O4 mineral for solid oxide fuel cells
  • 2017
  • Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 42:27, s. 17514-17521
  • Tidskriftsartikel (refereegranskat)abstract
    • Natural mineral, cuprospinel (CuFe2O4) originated from natural chalcopyrite ore (CuFeS2), has been used for the first time in low temperature solid oxide fuel cells. Three different types of devices are fabricated to explore the optimum application of CuFe2O4 in fuel cells. Device with CuFe2O4 as a cathode catalyst exhibits a maximum power density of 180 mW/cm(2) with an open circuit voltage 1.07 V at 550 degrees C. And a power output of 587 mW/cm(2) is achieved from the device using a homogeneous mixture membrane of CuFe2O4, Li2O-ZnO-Sm0.2Ce0.8O2 and LiNi0.8Co0.15Al0.05O2. Electrochemical impedance spectrum analysis reveals different mechanisms for the devices. The results demonstrate that natural mineral, chalcopyrite, can provide a new implementation to utilize the natural resources for next generation fuel cells being cost-effective and make great contributions to the environmentally friendly sustainable energy.
  •  
22.
  • Liu, Yanyan, et al. (författare)
  • Superionic Conductivity of Sm3+, Pr3+, and Nd3+ Triple-Doped Ceria through Bulk and Surface Two-Step Doping Approach
  • 2017
  • Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:28, s. 23614-23623
  • Tidskriftsartikel (refereegranskat)abstract
    • Sufficiently high oxygen ion conductivity of electrolyte is critical for good performance of low-temperature solid oxide fuel cells (LT-SOFCs). Notably, material conductivity, reliability, and manufacturing cost are the major barriers hindering LT-SOFC commercialization. Generally, surface properties control the physical and chemical functionalities of materials. Hereby, we report a Sm3+, Pr3+, and Nd3+ triple-doped ceria, exhibiting the highest ionic conductivity among reported doped-ceria oxides, 0.125 S cm(-1) at 600 degrees C. It was designed using a two-step wet-chemical coprecipitation method to realize a desired doping for Sm3+ at the bulk and Pr3+/Nd3+ at surface domains (abbreviated as PNSDC). The redox couple Pr3+ Pr4+ contributes to the extraordinary ionic conductivity. Moreover, the mechanism for ionic conductivity enhancement is demonstrated. The above findings reveal that a joint bulk and surface doping methodology for ceria is a feasible approach to develop new oxide-ion conductors with high impacts on advanced LT-SOFCs.
  •  
23.
  • Mushtaq, Naveed, et al. (författare)
  • Tuning the Energy Band Structure at Interfaces of the SrFe0.75Ti0.25O3-delta-Sm0.25Ce0.75O2-delta Heterostructure for Fast Ionic Transport
  • 2019
  • Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:42, s. 38737-38745
  • Tidskriftsartikel (refereegranskat)abstract
    • Interface engineering holds huge potential for enabling exceptional physical properties in heterostructure materials via tuning properties at the atomic level. In this study, a heterostructure built by a new redox stable semiconductor SrFe0.75Ti0.25O3-delta (SFT) and an ionic conductor Sm0.25Ce0.75O2 (SDC) is reported. The SFT-SDC heterostructure exhibits a high ionic conductivity >0.1 S/cm at 520 degrees C, which is 1 order of magnitude higher than that of bulk SDC. When it was applied into the fuel cell, the SFT-SDC can realize favorable electrolyte functionality and result in an excellent power density of 920 mW cm(-2) at 520 degrees C. The prepared SFT-SDC heterostructure materials possess both electronic and ionic conduction, where electron states modulate local electrical field to facilitate ion transport. Further investigations to calculate the structure and electronic structure/state of SFT and SDC are done using density functional theory (DFT). It is found that the reconstruction of the energy band at interfaces is responsible for such enhanced ionic conductivity and cell power output. The current study about the perovskite-based heterostructure presents a novel strategy for developing advanced ceramic fuel cells.
  •  
24.
  • Xia, Chen, et al. (författare)
  • Electrochemical properties of LaCePr-oxide/K2WO4 composite electrolyte for low-temperature SOFCs
  • 2017
  • Ingår i: Electrochemistry communications. - : ELSEVIER SCIENCE INC. - 1388-2481 .- 1873-1902. ; 77, s. 44-48
  • Tidskriftsartikel (refereegranskat)abstract
    • In this study, we introduced tungstate into solid oxide fuel cells (SOFCs) for the first time by using a La/Pr-doped CeO2 (LCP)/K2WO4 composite as the electrolyte, which exhibited remarkably enhanced grain boundary conduction compared to that of single-phase LCP. The composition dependence of the electrical conductivity was investigated. As a result, the composite with 10 wt% K2WO4 was proven to be the optimum ratio, revealing a significantly higher ionic conductivity than LCP, along with a negligible electronic conductivity. The fuel cell using the LCP/K2WO4 electrolyte displayed an encouraging performance of 500 mW cm(-2) at 550 degrees C. These findings indicate that the LCP/K2WO4 composite is a promising electrolyte for low-temperature SOFCs.
  •  
25.
  • Xia, Chen, et al. (författare)
  • Industrial-grade rare-earth and perovskite oxide for high-performance electrolyte layer-free fuel cell
  • 2016
  • Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 307, s. 270-279
  • Tidskriftsartikel (refereegranskat)abstract
    • In the present work, we report a composite of industrial-grade material LaCePr-oxide (LCP) and perovskite La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) for advanced electrolyte layer-free fuel cells (EFFCs). The microstructure, morphology, and electrical properties of the LCP, LSCF, and LCP-LSCF composite were investigated and characterized by XRD, SEM, EDS, TEM, and EIS. Various ratios of LCP to LSCF in the composite were modulated to achieve balanced ionic and electronic conductivities. Fuel cell with an optimum ratio of 60 wt% LCP to 40 wt% LSCF reached the highest open circuit voltage (OCV) at 1.01 V and a maximum power density of 745 mW cm-2 at 575°C, also displaying a good performance stability. The high performance is attributed to the interfacial mechanisms and electrode catalytic effects. The findings from the present study promote industrial-grade rare-earth oxide as a promising new material for innovative low temperature solid oxide fuel cell (LTSOFC) technology.
  •  
26.
  • Xia, Chen, et al. (författare)
  • Natural Mineral-Based Solid Oxide Fuel Cell with Heterogeneous Nanocomposite Derived from Hematite and Rare-Earth Minerals
  • 2016
  • Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:32, s. 20748-20755
  • Tidskriftsartikel (refereegranskat)abstract
    • Solid oxide fuel cells (SOFCs) have attracted much attention worldwide because of their potential for providing clean and reliable electric power. However, their commercialization is subject to the high operating temperatures and costs. To make SOFCs more competitive, here we report a novel and attractive nanocomposite hematite LaCePrOx (hematite LCP) synthesized from low-cost natural hematite and LaCePr-carbonate mineral as an electrolyte candidate. This heterogeneous composite exhibits a conductivity as high as 0.116 S cm(-1) at 600 degrees C with an activation energy of 0.50 eV at 400-600 degrees C. For the first time, a fuel cell using such a natural mineral-based composite demonstrates a maximum power density of 625 mW cm(-2) at 600 degrees C and notable power output of 386 mW cm(-2) at 450 degrees C. The extraordinary ionic conductivity and device performances are primarily attributed to the heterophasic interfacial conduction effect of the hematite-LCP composite. These superior properties, along with the merits of ultralow cost, abundant storage, and eco-friendliness, make the new composite a highly promising material for commercial SOFCs.
  •  
27.
  • Xia, Chen, et al. (författare)
  • Shaping triple-conducting semiconductor BaCo0.4Fe0.4Zr0.1Y0.1O3-delta into an electrolyte for low-temperature solid oxide fuel cells
  • 2019
  • Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • Interest in low-temperature operation of solid oxide fuel cells is growing. Recent advances in perovskite phases have resulted in an efficient H+/O2-/e(-) triple-conducting electrode BaCo0.4Fe0.4Zr0.1Y0.1O3-delta for low-temperature fuel cells. Here, we further develop BaCo0.4Fe0.4Zr0.1Y0.1O3-delta for electrolyte applications by taking advantage of its high ionic conduction while suppressing its electronic conduction through constructing a BaCo0.4Fe0.4Zr0.1Y0.1O3-delta-ZnO p-n heterostructure. With this approach, it has been demonstrated that BaCo0.4Fe0.4Zr0.1Y0.1O3-delta can be applied in a fuel cell with good electrolyte functionality, achieving attractive ionic conductivity and cell performance. Further investigation confirms the hybrid H+/O2- conducting capability of BaCo0.4Fe0.4Zr0.1Y0.1O3-delta-ZnO. An energy band alignment mechanism based on a p-n heterojunction is proposed to explain the suppression of electronic conductivity and promotion of ionic conductivity in the heterostructure. Our findings demonstrate that BaCo0.4Fe0.4Zr0.1Y0.1O3-delta is not only a good electrode but also a highly promising electrolyte. The approach reveals insight for developing advanced low-temperature solid oxide fuel cell electrolytes.
  •  
28.
  • Xia, Chen, et al. (författare)
  • Strategy towards cost-effective low-temperature solid oxide fuel cells : A mixed-conductive membrane comprised of natural minerals and perovskite oxide
  • 2017
  • Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 342, s. 779-786
  • Tidskriftsartikel (refereegranskat)abstract
    • Our previous work has revealed the feasibility of natural hematite as an electrolyte material for solid oxide fuel cells (SOFCs), tailoring SOFCs to be a more economically competitive energy conversion technology. In the present work, with the aim of exploring more practical uses of natural minerals, a novel composite hematite/LaCePrOx-La0.6Sr0.4Co0.2Fe0.8O3-δ (hematite/LCP-LSCF) has been developed from natural hematite ore, rare-earth mineral LaCePr-carbonate, and perovskite oxide LSCF as a functional membrane in SOFCs. The heterogeneity, nanostructure and mixed-conductive property of the composite were investigated. The results showed that the hematite/LCP-30 wt% LSCF composite possessed balanced ionic and electronic conductivities, with an ionic conductivity as high as 0.153 S cm−1 at 600 °C. The as-designed fuel cell using the hematite/LCP-LSCF membrane exhibited encouraging power outputs of 303 – 662 mW cm−2 at 500 – 600 °C. These findings show that the hematite/LCP-LSCF based fuel cell is a viable strategy for developing cost-effective and practical low-temperature SOFCs (LTSOFCs).
  •  
29.
  • Yousaf, Muhammad, et al. (författare)
  • Electrochemical properties of Ni0.4Zn0.6 Fe2O4 and the heterostructure composites (Ni-Zn ferrite-SDC) for low temperature solid oxide fuel cell (LT-SOFC)
  • 2020
  • Ingår i: Electrochimica Acta. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0013-4686 .- 1873-3859. ; 331
  • Tidskriftsartikel (refereegranskat)abstract
    • In solid oxide fuel cell, the redox reactions (HOR and ORR) demand good catalyst functions at the anode and cathode. Triple phase boundary (TPB) is an important mechanism to determine HOR and ORR as key factors to improve the reaction rate, charge transfer and ion diffusion processes. In the present work, Ni0.4Zn0.6Fe2O4 (Ni-Zn ferrite) and its heterostructures with Sm0.2Ce0.8O2 (SDC) are prepared and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze the phase structure and morphology of the material. X-ray photoelectron spectroscopy (XPS) confirms the phase of Ni-Zn ferrite nanoparticles (NPs) and chemical states on the heterostructure surface. The electrical and conductive behaviors of synthesized samples are investigated through electrochemical impedance spectroscopy (EIS) and fuel cell measurements. Unlike to conventional way, the as-prepared samples promote redox reactions from two aspects: a) as an electrolyte for ion transport; b) as a mixed conductor to extend the ionic transport on TPB region. The ionic transfer mechanism of Ni-Zn ferrite/SDC composite leads the improved fuel cell performance up to 760 mW/cm(2) at 550 degrees C. Further investigations verify the appreciable proton conduction in the prepared devices in a range of 0.012-0.048 Scm(-1).
  •  
30.
  • Zhang, Wei, et al. (författare)
  • Mixed ionic-electronic conductor membrane based fuel cells by incorporating semiconductor Ni0.8Co0.15Al0.05LiO2-delta into the Ce0.8Sm0.2O2-delta-Na2CO3 electrolyte
  • 2016
  • Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 41:34, s. 15346-15353
  • Tidskriftsartikel (refereegranskat)abstract
    • In the present study, a novel composite was fabricated by incorporating the semiconductor Ni0.8Co0.15Al0.05LiO2-delta (NCAL) into the ionic electrolyte Ce0.8Sm0.2O2-delta-Na2CO3 (NSDC), and further developed as a mixed-conducting membrane for single layer fuel cell (SLFC) applications. Experimentally, the crystal structure, morphology, chemical composition and thermo-stability of the composite were characterized by XRD, SEM and TGA. The best cell performance was investigated when the NSDC-NCAL membrane was optimized at a weight ratio of 6:4. On this basis, a number of interesting findings were obtained: i) the mixed conducting membrane did not cause any short circuit; on the contrary, the cell reached a decent open circuit voltage (OCV) of similar to 1.0 V. a high power density of 1072 mW cm(-2) was achieved at 550 degrees C for the NSDC-NCAL membrane based cell, which was much better than that using a pure NSDC electrolyte membrane. Electrochemical impedance spectroscopy (EIS) showed that the NSDC-NCAL composite exhibited significantly improved grain boundary conduction and reduced electrode polarizations, contributing to the resultant performance. To consolidate the usefulness of the device, we also conducted the durability test. The above findings indicate the strategy of introducing mixed NSDC-NCAL membrane is feasible for high-performance SLFCs operating at low temperatures.
  •  
31.
  • Zhang, Wei, et al. (författare)
  • The fuel cells studies from ionic electrolyte Ce0.8Sm0.05Ca0.15O2-delta to the mixture layers with semiconductor Ni0.8Co0.15Al0.05LiO2-delta
  • 2016
  • Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 41:41, s. 18761-18768
  • Tidskriftsartikel (refereegranskat)abstract
    • The mixture of ionic electrolyte Ce0.8Sm0.05Ca0.15O2-delta (SCDC) and semiconductor Ni0.8Co0.15Al0.05LiO2-delta (NCAL) layers was used for low temperature solid oxide fuel cell (LT-SOFC) applications. Using the as-prepared SCDC-NCAL semiconductor-ionic layer to replace the ionic SCDC electrolyte, following results have been obtained: the SCDC electrolyte fuel cell reached a lower voltage, 1.05 V, and lower power output, 415 mW cm(-2), compared to that using the semiconductor-ionic layer, 1.06 V and 617 mW cm(-2) at 550 degrees C. The electrochemical impedance spectroscopy (EIS) was applied to investigate the electrochemical processes of the device; X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) for the microstructure and morphology of the as-prepared materials. The results have illuminated that the introduction of semiconductor into ionic electrolyte could make extended triple phase boundary (TPB) area, which can provide more active sites to accelerate the fuel cell reactions and enhance the cell performance. Furthermore, we also discovered that the ionic SCDC and electronic NCAL should be in an appropriate composition to achieve a balanced ionic and electronic conductivity, which is the key issue for high performance semiconductor-ionic fuel cells.
  •  
32.
  •  
33.
  • Zhao, Yuli, et al. (författare)
  • Relationships between individual small tree canopy structure and rainfall interception
  • 2014
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Among the layers of a plant community, the canopy has the most important hydrological function in water circulation. Understanding the canopy’s inner structure and its relationship to water transport is fundamental for the functional mechanisms of the vegetation canopy. Using an artificial rainfall simulator to supply three levels of rainfall intensity, the interception of rainfall by the canopy was measured to study the characteristics of individual trees using different rainfall conditions and structural parameters. The study was done for four small native tree species: Platycladus orientalis, Pinus tabulaeformis, Quercus variabilis and Acer elegantulum. The resulting variations in the process of canopy interception could be divided into periods of increasing, slightly decreasing in some species, and stable levels of interception. In addition, duration of the initial period of increasing interception shortened as rainfall intensity increased. When rainfall was less intense, the percentage of gross rainfall intercepted by P. orientalis, P. tabulaeformis and A. elegantulum canopy layers was in the order mid > upper > lower canopy, while for Q. variabilis the sequence was upper > mid > lower canopy. These sequences indicate that canopy superstructure was more important than canopy substructure regarding the ability of the canopy to intercept precipitation and thus prevent soil erosion. Furthermore, it was found that exponential and logarithmic functions could be used to describe the relationship between interception of coniferous and deciduous species, respectively, and their own canopy body types. This study provided preliminary criteria for determining the optimal crown type for rainfall interception.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-33 av 33

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy