MoO3/V2O5 hybrid nanobilayers are successfully prepared by the sol–gel method with a spin- coating technique followed by heat -treatment at 350 °C in order to achieve a good crystallinity. The ...composition, morphology, and microstructure of the nanobilayers are characterized by a scanning electron microscope (SEM) and X-ray diffractometer (XRD) that revealed the a grain size of around 20–30 nm, and belonging to the monoclinic phase. The samples show good reversibility in the cyclic voltammetry studies and exhibit an excellent response to the visible transmittance. The electrochromic (EC) window displayed an optical transmittance changes (ΔT) of 22.65% and 31.4% at 550 and 700 nm, respectively, with the rapid response time of about 8.2 s for coloration and 6.3 s for bleaching. The advantages, such as large optical transmittance changes, rapid electrochromism control speed, and excellent cycle durability, demonstrated in the electrochromic cell proves the potential application of MoO3/V2O5 hybrid nanobilayers in electrochromic devices.
Thermal management has become one of the crucial factors in designing electronic equipment and therefore creating composites with high thermal conductivity is necessary. In this work, a new insight ...on hybrid filler strategy is proposed to enhance the thermal conductivity in Thermoplastic polyurethanes (TPU). Firstly, spherical aluminium oxide/hexagonal boron nitride (ABN) functional hybrid fillers are synthesized by the spray drying process. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Our results demonstrate that the incorporation of spherical hybrid ABN filler assists in the formation of a three-dimensional continuous heat conduction structure that enhances the thermal conductivity of the neat thermoplastic TPU matrix. Hence, we present a valuable method for preparing the thermal interface materials (TIMs) with high thermal conductivity, and this method can also be applied to large-scale manufacturing.
Abstract
In the archetypal lithium-rich cathode compound Li
1.2
Ni
0.13
Co
0.13
Mn
0.54
O
2
, a major part of the capacity is contributed from the anionic (O
2−/−
) reversible redox couple and is ...accompanied by the transition metal ions migration with a detrimental voltage fade. A better understanding of these mutual interactions demands for a new model that helps to unfold the occurrences of voltage fade in lithium-rich system. Here we present an alternative approach, a cationic reaction dominated lithium-rich material Li
1.083
Ni
0.333
Co
0.083
Mn
0.5
O
2
, with reduced lithium content to modify the initial band structure, hence ~80% and ~20% of capacity are contributed by cationic and anionic redox couples, individually. A 400 cycle test with 85% capacity retention depicts the capacity loss mainly arises from the metal ions dissolution. The voltage fade usually from Mn
4+
/Mn
3+
and/or O
n−
/O
2−
reduction at around 2.5/3.0 V seen in the typical lithium-rich materials is completely eliminated in the cationic dominated cathode material.
Thermal management has become one of the crucial factors in designing electronic equipment and therefore creating composites with high thermal conductivity is necessary. In this work, a new insight ...on hybrid filler strategy is proposed to enhance the thermal conductivity in Thermoplastic polyurethanes (TPU). Firstly, spherical aluminium oxide/hexagonal boron nitride (ABN) functional hybrid fillers are synthesized by the spray drying process. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Then, ABN/TPU thermally conductive composite material is produced by melt mixing and hot pressing. Our results demonstrate that the incorporation of spherical hybrid ABN filler assists in the formation of a three-dimensional continuous heat conduction structure that enhances the thermal conductivity of the neat thermoplastic TPU matrix. Hence, we present a valuable method for preparing the thermal interface materials (TIMs) with high thermal conductivity, and this method can also be applied to large-scale manufacturing.
MoO
/V
O
hybrid nanobilayers are successfully prepared by the sol-gel method with a spin- coating technique followed by heat -treatment at 350 °C in order to achieve a good crystallinity. The ...composition, morphology, and microstructure of the nanobilayers are characterized by a scanning electron microscope (SEM) and X-ray diffractometer (XRD) that revealed the a grain size of around 20-30 nm, and belonging to the monoclinic phase. The samples show good reversibility in the cyclic voltammetry studies and exhibit an excellent response to the visible transmittance. The electrochromic (EC) window displayed an optical transmittance changes (Δ
) of 22.65% and 31.4% at 550 and 700 nm, respectively, with the rapid response time of about 8.2 s for coloration and 6.3 s for bleaching. The advantages, such as large optical transmittance changes, rapid electrochromism control speed, and excellent cycle durability, demonstrated in the electrochromic cell proves the potential application of MoO
/V
O
hybrid nanobilayers in electrochromic devices.
Silicon-based anode materials are gaining popularity in lithium-ion battery research due to their high theoretical specific capacity compared to the conventional graphite anode. However, the ...commercialization of silicon-based anode materials has been hampered by their limited electronic conductivity and significant volume expansion. To address these challenges, our strategy was conducted to prepare porous silicon@carbon (p-Si@C) nanocomposites as an anode material using a simple aqueous solution method. In this work, nitrogen-containing p-phenylenediamine was chosen as the carbon source for synthesizing the nanostructured p-Si@C composites. The excellent electrochemical performance can be achieved, with over 100 cycles, a specific capacity of 624 mAh g–1, and a high Coulombic efficiency of 97.2%. These promising results were attributed to efficient Li-ion transport and low volume expansion, which are confirmed by the distribution function of relaxation time plots coupled with impedance spectroscopy technique, followed by the calculation of the expansion rate obtained from the SEM cross-sectional image. Hence, our work not only clearly provides a simple yet valuable method for the preparation of nanostructured silicon-based anode material with good electrochemical performance but also demonstrates its potential for industrial battery-grade development.
The high capacity cathode materials with charge voltage above 4.5 V are widely being developed. To reduce surface reactivity at high voltage, Al2O3 and pullulan are used for coating on the ...Li(Li0.08Ni0.34Co0.08Mn0.5)O2 surface and are characterized by electrochemical analysis. Charge/discharge and electrochemical results reveal that the organic coating sustains in high voltage cycles. Ionic conductivity of surface coating plays a key role in the battery performance.
Al2O3 and pullulan coatings on the Li(Li0.08Ni0.34Co0.08Mn0.5)O2 oxide surface are applied and characterized by electrochemical analysis. Charge/discharge and electrochemical results display the organic coating sustained in high voltage cycles. Ionic conductivity of surface coating plays a key role for battery performance.
Abstract
The high capacity cathode materials with charge voltage above 4.5 V are widely being developed. To reduce surface reactivity at high voltage, Al
2
O
3
and pullulan are used for coating on ...the Li(Li
0.08
Ni
0.34
Co
0.08
Mn
0.5
)O
2
surface and are characterized by electrochemical analysis. Charge/discharge and electrochemical results reveal that the organic coating sustains in high voltage cycles. Ionic conductivity of surface coating plays a key role in the battery performance.
博士
國立暨南國際大學
應用化學系
106
This work primarily focuses on two important high energy density materials that have potential to meet the demands of the next generation technologies in satiating the need for ...energy. One belonging to the family of Ni-Co-Mn with rich lithium and manganese and the other is vanadium pentoxide. A lithium- and manganese-rich Li-Ni-Co-Mn-O cathode material Li(Li0.08Ni0.34Co0.8Mn0.5)O2, a combination of traditional battery components with a unique stoichiometry is prepared via co-precipitation method. XRD studies show the material is a single phase with C 2/m space group that falls in the monoclinic crystal system which upon electrochemical activation, goes through an irreversible phase transformation to R -3m which is stable throughout the electrochemical reactions. ICP-OES confirms the right stoichiometry. Electrochemical analysis through cyclic voltammetry and charge/discharge studies revealed the stability of the material during electrochemical reactions is tremendous. The output capacity achievable was around 205 mAh/g in the voltage range 2.2 to 4.6 V both in coin cells and full cells as well and an excellent cyclability with less than 5 % decay in the capacity after 50 cycles of charge/discharge in the case of full cell.
As an alternative to the conventional materials, V2O5 was selected and the main emphasis was on solving the irreversible phase transition problem. Two organic compounds, urea and melamine were introduced into the layers of V2O5 as structure stabilizing agents during the phase transitions. Room temperature one step synthesis route delivered Urea/V2O5 nanowires and melamine/V2O5 nanorods. The melamine/V2O5 revealed a self-assembled single phase hybrid with P-1 space group belonging to the triclinic crystal system.
Melamine was successful in acting as a stabilizing agent, while urea failed in serving the purpose. The hydrogen bonds between the V2O5 layers and melamine molecules assisted in preventing the puckering problem during the discharge processes at lower voltage making the phase transition reversible. A substantial specific capacity of 184 mAh/g was possible at the voltage range 1.9 to 3.4 V, very close to the theoretical capacity with two moles of lithium insertion per molecule. It showed a considerable cyclability with the retention of more than 85 % of its initial capacity when the coin cell was run for 100 cycles.
GPR40 (Free fatty acid receptor 1) has emerged as an important therapeutic target for diabetes. Several studies have demonstrated the association of comorbid psychiatric conditions with decreased n-3 ...polyunsaturated fatty acids, which may act as an agonist for GPR40. In this study, we for the first time provide evidence of reduced GPR40 signaling in the hippocampus and cortex which may be a critical underlying mechanism mediating cognitive deficits in diabesity (diabetes and obesity together). Specifically, we showed decreased GPR40 and brain-derived neurotrophic factor (BDNF) expression in the brain regions of high-fat-diet-induced obese and db/db mice. Next, we demonstrated that chronic treatment with docosahexaenoic acid (DHA) or the synthetic GPR40 agonist, GW9508, significantly alleviates cognitive functions in mice, which correlates with increased BDNF expression in the hippocampus. This supports the hypothesis that DHA improves cognitive function in diabesity via GPR40 agonism. We also showed that DHA specifically activates GPR40 and modulates BDNF expression in primary cortical neurons mediated by the extracellular receptor kinase (ERK) and P38-mitogen-activated protein kinase (MAPK) pathways. Finally, the central nervous system (CNS)-specific blockade of GPR40 signaling abrogated the memory potentiating effects of DHA, and induction of BDNF expression in the hippocampus. Thus, we provided evidence that DHA stimulation of GPR40 mediate some of DHA's beneficial effects in metabolic syndrome and identify GPR40 as a viable therapeutic target for the treatment of CNS-related comorbidities associated with diabesity.
•Decreased brain expression of GPR40 and BDNF in a mouse model of diabesity.•Increased DHA-mediated GPR40 signaling in the brain restores cognitive functions in diabesity.•DHA specifically activates GPR40 in primary cortical neurons.•DHA-induced GPR40 signaling increases expression of BDNF via ERK and P38-MAPK pathways in primary cortical neurons.
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