| 1. |
- Hu, Huiqing, et al.
(författare)
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Effects of composition on the electrochemical property and cell performance of single layer fuel cell
- 2015
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 275, s. 476-482
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the enhanced electrochemical performance of single layer fuel cells (SLFCs) based upon mixed ion and electron conductors is analyzed as a function of composition. We synthesize a series of Ce0.8Sm0.2O2-delta-Li0.3Ni0.6Cu0.07Sr0.03O2-delta (SDC-LNCS) with different weight ratios. The microstructure and morphology of the composite materials are characterized through X-ray diffraction (XRD), transmission electron microscope (TEM), and energy-dispersive X-ray spectrometer (EDS). Stability of the synthesized samples is evaluated by thermal gravity analysis (TGA). The SLFC with 6SDC-4LNCS exhibits a uniform distribution of the two compositions as well as demonstrates the highest power density of 312 mW cm-2 at 550 mu C. The performance is correlated to the balance of the conduction properties (ionic and electronic) of the functional SLFC layer. The results are a critical contribution to further development of this new energy transfer device.
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| 2. |
- Hu, Huiqing, et al.
(författare)
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Fabrication of electrolyte-free fuel cell with Mg0.4Zn0.6O/Ce0.8Sm0.2O2-delta-Li0.3Ni0.6Cu0.07Sr0.03O2-delta layer
- 2014
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 248, s. 577-581
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Tidskriftsartikel (refereegranskat)abstract
- Electrolyte-free fuel cell (EFFC) which holds the similar function with the traditional solid oxide fuel cell (SOFC) but possesses a completely different structure, has draw much attention during these years. Herein, we report a complex of MZSDC LNCS (Mg0.4Zn0.6O/Ce0.8Sm0.2O2-delta-Li0.3Ni0.6Cu0.07Sr0.03O2-delta) for EFFC that demonstrates a high electrochemical power output of about 600 mW cm(-2) at 630 degrees C. The co-doped MZSDC is synthesized by a co-precipitation method. Semiconductor material of LNCS is synthesized by direct solid state reaction. The microstructure and morphology of the composite materials are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive Xray spectrometer (EDS). The performance of the cell with a large size (6 x 6 cm(2)) is comparable or even better than that of the conventional solid oxide fuel cells with large sizes. The maximum power output of 9.28 W is obtained from the large-size cell at 600 degrees C. This paper develops a new functional nanocomposite for EFFC which is conducive to its commercial use.
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| 3. |
- Hu, Huiging, et al.
(författare)
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Time-dependent performance change of single layer fuel cell with Li0.4Mg0.3Zn0.3O/Ce0.8Sm0.2O2-delta composite
- 2014
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 39:20, s. 10718-10723
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Tidskriftsartikel (refereegranskat)abstract
- A Large-size engineering single layer fuel cell (SLFC) consisting of a nano-structured Li0.4Mg0.3Zn0.3O2-delta/Ce0.8Sm0.2O2-delta (LMZSDC) composite with an active area of 25 cm(2) (6 cm x 6 cm x 0.1 cm) is successfully fabricated. The SLFC is evaluated by testing the cell durability with a time-dependent degradation using an H-2 fuel and an air oxidant at 600 degrees C for over 120 h. A maximum power of 12.8 W (512 mW cm(-2)) is achieved at 600 degrees C. In the initial operation stage around 50 h, the cell's performance decreases from 12.8 to 11.2 W; however, after this point, the performance was consistently stable, and no significant degradation is observed in the current density or the cell performance. The device performed excellently at low temperatures with a delivered power output of more than 250 mW cm(-2) at a temperature as low as 400 degrees C. By curve fitting the X-ray photoelectron spectroscopy (XPS) results, the ratio of Ce3+/(Ce3++Ce4+) before and after the long-time operation is analyzed. The ratio increased from 28.2% to 31.4% in the electrolyte which indicates a reduction occurs in the beginning operation that causes an initial performance loss for the device power output and OCV. Electrochemical impedance analyses indicate that the LMZSDC had a high ionic transport, and the device had quick dynamic processes and, thus, a high fuel cell performance. The LMZSDC is a new type of ionic material that has been successfully applied to SLFCs.
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| 4. |
- 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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| 5. |
- Hu, Zimeng, et al.
(författare)
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Deciphering the peculiar hysteresis loops of 0.05Pb(Mn1/3Sb2/3)O3–0.95Pb(Zr0.52Ti0.48)O3 piezoelectric ceramics
- 2023
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 244
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Tidskriftsartikel (refereegranskat)abstract
- The majority of piezoelectric ceramics based on Pb(Zr, Ti)O3 (PZT) exhibit hysteretic behavior, which varies depending on various factors, including composition, microstructure and processing conditions. The ternary system 0.05Pb(Mn1/3Sb2/3)O3–0.95Pb(Zr0.52Ti0.48)O3 (5PMS-PZT) has shown attractive piezoelectric properties with superior thermal stability compared to pure Pb(Zr0.52Ti0.48)O3, but the underlying mechanisms of its complex hysteretic behavior have not been fully clarified yet. This work further delves into the hysteretic aspects of 5PMS-PZT ceramics and describes hysteresis features that have not been yet reported for any known piezoelectric system. Four current peaks in I-E loops and S-E loops with unconventional shapes, which have a significant dependence on applied field amplitude, frequency and electrical history have been observed here. This peculiar hysteretic behavior is influenced by convoluted effects of domain switching, electric field-induced structural transitions, point defects and aging/de-aging processes, whose combinations lead to unique hysteresis features.
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| 6. |
- Li, Shaowen, et al.
(författare)
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A Multiscale, Dynamic Elucidation of Li Solubility in the Alloy and Metallic Plating Process
- 2023
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Ingår i: Advanced Materials. - : Wiley-VCH Verlagsgesellschaft. - 0935-9648 .- 1521-4095. ; 35:47
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Tidskriftsartikel (refereegranskat)abstract
- Li-containing alloys and metallic deposits offer substantial Li+ storage capacities as alternative anodes to commercial graphite. However, the thermodynamically in sequence, yet kinetically competitive mechanism between Li solubility in the solid solution and intermediate alloy-induced Li deposition remains debated, particularly across the multiple scales. The elucidation of the mechanism is rather challenging due to the dynamic alloy evolution upon the non-equilibrium, transient lithiation processes under coupled physical fields. Here, influential factors governing Li solubility in the Li-Zn alloy are comprehensively investigated as a demonstrative model, spanning from the bulk electrolyte solution to the ion diffusion within the electrode. Through real-time phase tracking and spatial distribution analysis of intermediate alloy/Li metallic species at varied temperatures, current densities and particle sizes, the driving force of Li solubility and metallic plating along the Li migration pathway are probed in-depth. This study investigates the correlation between kinetics (pronounced concentration polarization, miscibility gap in lattice grains) and rate-limiting interfacial charge transfer thermodynamics in dedicating the Li diffusion into the solid solution. Additionally, the lithiophilic alloy sites with the balanced diffusion barrier and Li adsorption energy are explored to favor the homogeneous metal plating, which provides new insights for the rational innovation of high-capacity alloy/metallic anodes.
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| 7. |
- Yang, Chaoran, et al.
(författare)
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Alternate-stacked Li4Ti5O12 nanosheets/d-Ti3C2 flexible film as a current collector-free, high-capacity and robust cathode for rechargeable Mg batteries
- 2020
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Ingår i: Nano select. - : John Wiley & Sons. - 2688-4011. ; 1:1, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Rechargeable magnesium batteries (RMBs) have gained increasing attention owing to its high volumetric capacity, crust abundance, and safety from dendrite-free characteristic. However, the lack of development of high-performance cathode materials with long cycling stability and satisfactory capacity has greatly restricted the development of RMBs. Herein, a self-supported, current collector-free and soft electrode is prepared with delaminated Ti3C2 (d-Ti3C2) and Li4Ti5O12 nanosheets by simple vacuum filtration as flexible cathode in RMBs. Fabricated into a full cell with hybrid AlCl3/MgCl2/Mg(TFSI)2 electrolyte and Mg anode (a thin Mg foil with thickness of 50 μm), the flexible cathode shows high initial specific capacity of 320 mAh g−1 at 20 mA g−1, excellent cycling stability (good retention even after 1000 cycles) and outstanding rate performance. Detailed mechanistic studies reveal that introduction of d-Ti3C2 provide fast transport paths for electrons and Mg2+. The enlarged layer spacing of composited d-Ti3C2 accounts for significant increment in capacity. Benefiting from above-mentioned advantages, the best performance among Ti-based electrode materials is realized and make wearable devices powered by RMBs possible, thus circumventing the safety issues of lithium batteries.
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