| 1. |
- 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.
|
|
| 2. |
- 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.
|
|
| 3. |
- 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.
|
|
| 4. |
- 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.
|
|
| 5. |
- 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.
|
|
| 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. |
- 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.
|
|
| 9. |
- 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.
|
|
| 10. |
- 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.
|
|
