scholarly journals Three-Dimensional Porous Ti3C2Tx-NiO Composite Electrodes with Enhanced Electrochemical Performance for Supercapacitors

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 188 ◽  
Author(s):  
Kaicheng Zhang ◽  
Guobing Ying ◽  
Lu Liu ◽  
Fengchen Ma ◽  
Lin Su ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Freeze Drying ◽  
Three Dimensional ◽  
Electrochemical Capacitor ◽  
Cycling Performance ◽  
Composite Electrodes ◽  
Growth Trend ◽  
Porous Networks ◽  
Dimensional Network ◽  
Enhanced Electrochemical Performance

Ti3C2Tx and Ti3C2Tx-NiO composites with three-dimensional (3D) porous networks were successfully fabricated via vacuum freeze-drying. The microstructure, absorption, and electrochemical properties of the developed composites were investigated. Nickel oxide (NiO) nanoparticles could be evenly distributed on the three-dimensional network of three-dimensional Ti3C2Tx using solution processing. When employed as electrochemical capacitor electrodes in 1 M environmentally friendly sodium sulfate, Na2SO4, solution, the three-dimensional porous Ti3C2Tx-NiO composite electrodes exhibited considerable volume specific capacitance as compared to three-dimensional porous Ti3C2Tx. The three-dimensional porous Ti3C2Tx-NiO composite delivered a remarkable cycling performance with a capacitance retention of up to 114% over 2500 cycles. The growth trend of the capacitance with NiO content shows that nickel oxide plays a crucial role in the composite electrodes. These results present a roadmap for the development of convenient and economical supercapacitors in consideration with the possibilities of morphological control and the extensibility of the process.

scholarly journals Whey Proteins Isolate-Based Biopolymeric Combinations to Microencapsulate Supercritical Fluid Extracted Oleoresins from Sea Buckthorn Pomace

2021 ◽  
Vol 14 (12) ◽  
pp. 1217
Author(s):  
Liliana Mihalcea ◽  
Iuliana Aprodu ◽  
Loredana Dumitrașcu ◽  
Elena Iulia Cucolea ◽  
George-Mădălin Dănilă ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Freeze Drying ◽  
Palmitoleic Acid ◽  
Whey Proteins ◽  
Three Dimensional ◽  
Sea Buckthorn ◽  
Complex Coacervation ◽  
Total Carotenoids ◽  
Dimensional Network ◽  
Ic50 Value

In this study, high-value, carotenoid-rich oleoresin obtained by supercritical carbon dioxide (SFE-CO2) extraction was used to develop five variants of microencapsulated delivery system, based on whey proteins isolate (WPI), in combination with inulin (I), pectin (P) or lactose (L). The WPI:I and WPI:L variants were also obtained by conjugation via Maillard reaction. The microencapsulation of the SFE-CO2 sea buckthorn pomace oleoresin was performed by emulsion, complex coacervation and freeze-drying, which allowed for the obtaining of five powders, with different phytochemicals profile. The WPI:I conjugate showed the highest level of total carotenoids, whereas the counterpart WPI:L showed the highest content in linoleic acid (46 ± 1 mg/g) and palmitoleic acid (20.0 ± 0.5 mg/g). The β-tocopherol and β-sitosterol were identified in all variants, with the highest content in the conjugated WPI:L variant. Both WPI:L and WPI:I conjugate samples presented similar IC50 value for inhibitory activity against pancreatic lipase and α-amylase; the highest activity was observed for the conjugated WPI:I. The WPI:P combination allowed the highest release of carotenoids in the gastro-intestinal environment. All the powders exhibited poor flowing properties, whereas water activity (aw) ranged from 0.084 ± 0.03 to 0.241 ± 0.003, suggesting that all variants are stable during storage. In case of solubility, significant differences were noticed between non-heated and glycated samples, with the highest value for the WPI:I and the lowest for glycated WPI:I. The structural analysis revealed the presence of finer spherosomes in WPI:I and WPI:L, with a reduced clustering capacity, whereas the particles in the conjugated samples were more uniform and aggregated into a three-dimensional network.

scholarly journals Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Katarzyna Lota ◽  
Agnieszka Sierczynska ◽  
Grzegorz Lota
Keyword(s):  
Nickel Oxide ◽  
Active Carbon ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Negative Electrode ◽  
Electrochemical Capacitor ◽  
Carbon Composite ◽  
Electrochemical Performances ◽  
Composite Electrodes ◽  
Asymmetric Configuration

In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘Cin the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD). The morphology of the composites was observed by SEM. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied in addition to the properties of electrode consisting of separate active carbon and nickel oxide only. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy. The composites were tested in 6 M KOH aqueous electrolyte using two- and three-electrode Swagelok systems. The results showed that adding only a few percent of nickel oxide to active carbon provided the highest value of capacity. It is the confirmation of the fact that such an amount of nickel oxide is optimal to take advantage of both components of the composite, which additionally can be a good solution as a negative electrode in asymmetric configuration of electrode materials in an electrochemical capacitor.

scholarly journals The Polymer Binders for the Electrodes of Lithium Batteries Part 2. Synthetic and Natural Polymers

2020 ◽  
Vol 20 (4) ◽  
pp. 175-205
Author(s):  
Aigul S. Istomina ◽  
◽  
Olga V. Bushkova ◽  
Keyword(s):  
Three Dimensional ◽  
Synthetic Polymers ◽  
Water Soluble ◽  
Self Healing ◽  
Composite Electrodes ◽  
Natural Polymers ◽  
Power Characteristics ◽  
Polymer Binders ◽  
Dimensional Network ◽  
Cross Links

The second part of the review describes the prospects of using alternative polymer binders for composite electrodes of lithium electrochemical systems. Possible options having been taken into account, the most popular commercially-available synthetic polymers with functional group (the ones forming aqueous solutions or dispersions predominantly) and water-soluble polymers of natural origin are considered. The versatility of such materials is their distinctive feature. The availability of salt forms for natural and synthetic polymers, many of which are polyelectrolytes, makes it possible to significantly affect the ion transfer in the composite electrode mass, reducing the polarization of the electrodes and improving the power characteristics of batteries. The ability to form “artificial SEI” and / or form a three-dimensional network with self-healing cross-links between macromolecules allows long-term safe cycling, the latter being especially important for active materials with very large volume changes during lithium intercalation / deintercalation (e.g. silicon).

Fabrication of amorphous carbon-coated NiO nanofibers for electrochemical capacitor applications

2014 ◽  
Vol 2 (10) ◽  
pp. 3364-3371 ◽  
Author(s):  
Dong Hoon Shin ◽  
Jun Seop Lee ◽  
Jaemoon Jun ◽  
Jyongsik Jang
Keyword(s):  
Nickel Oxide ◽  
Amorphous Carbon ◽  
Electrochemical Property ◽  
Vapor Deposition ◽  
Electrochemical Capacitor ◽  
Cycling Performance ◽  
Carbon Coated

Amorphous carbon-coated nickel oxide nanofibers (NiC NFs) were fabricated by vapor deposition polymerization and carbonization. The NiC NFs showed a higher electrochemical property and a longer cycling performance than pristine NiO NFs.

scholarly journals Preparation and characterization of poly (3-hydroxy-butyrate-co-4-hydroxybutyrate)/porous cellulose aerogel biocomposites

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4748-4759
Author(s):  
Fen Yin ◽  
Xuejiao Zhang ◽  
Dongna Li ◽  
Xiaojun Ma
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Practical Application ◽  
Elongation At Break ◽  
Cellulose Aerogel ◽  
Dimensional Network

A green biocomposite of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and cellulose aerogels was developed. Cellulose gel was prepared from NaOH/urea aqueous solution, and subsequent regenerating by Na2SO4 solution and freeze-drying resulted in porous cellulose aerogels. The P34HB/cellulose aerogel biocomposite was fabricated by immersion of porous cellulose in a polymer solution and hot-pressing. The morphology, crystallization, thermal, mechanical, and barrier properties (H2O) of biocomposite were investigated. The cellulose aerogels matrix exhibited a three-dimensional network structure with porosity and a wide pore size distribution, contributing to the change of the glass transition temperature and cold crystallization temperature of biocomposites. Compared with cellulose aerogels, the tensile strength and elongation at break of biocomposites were increased by as much as 48% and 25.1%, respectively. Moreover, biocomposites demonstrated an increased contact angle and water vapor permeability coefficient compared with the cellulose aerogel. The results revealed the potential of P34HB/cellulose aerogel biocomposites for practical application as packaging materials.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

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