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Yun Chan Kang - One of the best experts on this subject based on the ideXlab platform.
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Nickel vanadate microspheres with numerous nanocavities synthesized by Spray Drying Process as an anode material for Li-ion batteries
Journal of Alloys and Compounds, 2019Co-Authors: Jinsung Park, Jung Sang Cho, Yun Chan KangAbstract:Abstract For use in next-generation energy storage applications, including electric vehicles, capacity and cycle life of lithium ion batteries need further improvement. Moreover, to achieve fast lithiation kinetics of the electrode materials, high power density and quick charging ability are necessary. Nickel vanadate (Ni3V2O8) microsphere with tens of nanocavities is one of candidates for anode materials suitable for lithium ion batteries. The synthesis of microspheres is possible by a pilot-scale Spray Drying Process and facile one-step oxidation heat treatment. Dextrin, which is present in the microspheres after Spray Drying Process, plays a key role in the formation of nanocavities. Oxidation at different temperatures yields carbon composite microspheres with nanocavities and hierarchical Ni3V2O8 microspheres with nanocavities. The nanocavities facilitate electrolyte contact with the electrode material and alleviate volume change during lithiation/delithiation. The merits of the nanocavities in the Ni3V2O8 microspheres enable a high discharge capacity of 1045 mA h g−1 for the 2nd cycle at 1 A g−1 and long cycle life. Furthermore, Ni3V2O8 microspheres deliver a high discharge capacity of 612 mA h g−1 at a high current density of 6 A g−1.
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electrochemical properties of yolk shell structured znfe2o4 powders prepared by a simple Spray Drying Process as anode material for lithium ion battery
Scientific Reports, 2015Co-Authors: Jong Min Won, Seung Ho Choi, Young Jun Hong, You Na Ko, Yun Chan KangAbstract:ZnFe2O4 yolk–shell powders were prepared by applying a simple Spray-Drying Process. Dextrin was used as a Drying additive and carbon source material, and thus played a key role in the preparation of the powders. The combustion of precursor powders consisting of zinc and iron salts and dextrin obtained by a Spray-Drying Process produced the yolk–shell-structured ZnFe2O4 powders even at a low post-treatment temperature of 350°C. The ZnFe2O4 powders prepared from the Spray solution without dextrin had a filled and pockmarked structure. The initial discharge capacities of the ZnFe2O4 yolk–shell and filled powders post-treated at 450°C at a current density of 500 mA g−1 were 1226 and 993 mA h g−1, respectively, and the corresponding initial Coulombic efficiencies were 74 and 58%. The discharge capacities of the ZnFe2O4 powders with yolk–shell and filled structures post-treated at 450°C after 200 cycles were 862 and 332 mA h g−1, respectively. The ZnFe2O4 yolk–shell powders with high structural stability during cycling had superior electrochemical properties to those of the powders with filled structure.
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Characteristics of precursor powders of a nickel-rich cathode material prepared by a Spray Drying Process using water-soluble metal salts
RSC Adv., 2014Co-Authors: Gi Dae Park, Yun Chan KangAbstract:The electrochemical properties of LiNi0.8Co0.15Al0.05O2 as a cathode material prepared by a simple Spray Drying Process are investigated. Citric acid, which is used as the chelating agent, enables the production of the lithium-containing precursor powders with uniform compositions from the water-soluble metal salts by a Spray Drying Process. The post-treatment of the precursor powders under an atmosphere of oxygen results in a cathode material in the form of a powder with good electrochemical properties. The composition of the powders is determined by inductively coupled plasma analysis to be Li1.05Ni0.81Co0.15Al0.04O2. The discharge capacities of the powders post-treated at 750 °C after the 1st and 100th cycles are 188 and 178 mA h g−1, respectively. The simple Spray Drying Process is successfully applied to the preparation of precursors of the cathode material with complex compositions. The electrochemical properties of the micron sized LiNi0.8Co0.15Al0.05O2 aggregates with a filled morphology prepared from the precursor powders obtained by the Spray Drying Process are also investigated. The aggregated powders obtained by the second Spray Drying Process show a discharge capacity of 161 mA h g−1 after 100 cycles.
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Electrochemical properties of micron-sized, spherical, meso- and macro-porous Co3O4 and CoO-carbon composite powders prepared by a two-step Spray Drying Process.
Nanoscale, 2014Co-Authors: Jung Hyun Kim, Yun Chan KangAbstract:Micron-sized, spherical, meso- and macro-porous Co3O4 and CoO–carbon composite powders were prepared via a simple two-step Spray Drying Process. The CoO–carbon composite powders, in which homogeneous mixing of the metal oxide and carbon components was achieved using the first Spray Drying Process, were wet milled to produce the slurry for the second Spray Drying Process. Co3O4 and CoO–carbon composite powders with mean particle sizes of 4.4 and 4.7 μm were respectively obtained by Spray-Drying the slurry after post-treatment at 400 °C under air and nitrogen atmospheres. Meso- and macro-pores were uniformly distributed inside the Co3O4 and CoO–carbon composite powders. The CoO–carbon composite powders exhibited discharge capacities of 882 and 855 mA h g−1 at a high constant current density of 1400 mA g−1 for the 2nd and 100th cycles. The discharge capacities of the Co3O4 powders at the 2nd and 100th cycles were 970 and 644 mA h g−1. With stepwise increment in the current density from 500 to 5000 mA g−1, the discharge capacities of the CoO–carbon composite powders decreased slightly from 985 to 698 mA h g−1. The superior rate and cycling performances of the CoO–carbon composite powders are ascribed to their meso- and macro-porous structures and carbon components.
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kilogram scale production of sno2 yolk shell powders by a Spray Drying Process using dextrin as carbon source and Drying additive
Chemistry: A European Journal, 2014Co-Authors: Seung Ho Choi, Yun Chan KangAbstract:A simple and general method for the large-scale production of yolk-shell powders with various compositions by a Spray-Drying Process is reported. Metal salt/dextrin composite powders with a spherical and dense structure were obtained by Spray Drying and transformed into yolk-shell powders by simple combustion in air. Dextrin plays a key role in the preparation of precursor powders for fabricating yolk-shell powders by Spray Drying. Droplets containing metal salts and dextrin show good Drying characteristics even in a severe environment of high humidity. Sucrose, glucose, and polyvinylpyrrolidone are widely used as carbon sources in the preparation of metal oxide/carbon composite powders; however, they are not appropriate for large-scale Spray-Drying Processes because of their caramelization properties and adherence to the surface of the Spray dryer. SnO2 yolk-shell powders were studied as the first target material in the Spray-Drying Process. Combustion of tin oxalate/dextrin composite powders at 600 °C in air produced single-shelled SnO2 yolk-shell powders with the configuration SnO2 @void@SnO2 . The SnO2 yolk-shell powders prepared by the simple Spray-Drying Process showed superior electrochemical properties, even at high current densities. The discharge capacities of the SnO2 yolk-shell powders at a current density of 2000 mA g(-1) were 645 and 570 mA h g(-1) for the second and 100th cycles, respectively; the corresponding capacity retention measured for the second cycle was 88 %.
Seung Ho Choi - One of the best experts on this subject based on the ideXlab platform.
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electrochemical properties of yolk shell structured znfe2o4 powders prepared by a simple Spray Drying Process as anode material for lithium ion battery
Scientific Reports, 2015Co-Authors: Jong Min Won, Seung Ho Choi, Young Jun Hong, You Na Ko, Yun Chan KangAbstract:ZnFe2O4 yolk–shell powders were prepared by applying a simple Spray-Drying Process. Dextrin was used as a Drying additive and carbon source material, and thus played a key role in the preparation of the powders. The combustion of precursor powders consisting of zinc and iron salts and dextrin obtained by a Spray-Drying Process produced the yolk–shell-structured ZnFe2O4 powders even at a low post-treatment temperature of 350°C. The ZnFe2O4 powders prepared from the Spray solution without dextrin had a filled and pockmarked structure. The initial discharge capacities of the ZnFe2O4 yolk–shell and filled powders post-treated at 450°C at a current density of 500 mA g−1 were 1226 and 993 mA h g−1, respectively, and the corresponding initial Coulombic efficiencies were 74 and 58%. The discharge capacities of the ZnFe2O4 powders with yolk–shell and filled structures post-treated at 450°C after 200 cycles were 862 and 332 mA h g−1, respectively. The ZnFe2O4 yolk–shell powders with high structural stability during cycling had superior electrochemical properties to those of the powders with filled structure.
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kilogram scale production of sno2 yolk shell powders by a Spray Drying Process using dextrin as carbon source and Drying additive
Chemistry: A European Journal, 2014Co-Authors: Seung Ho Choi, Yun Chan KangAbstract:A simple and general method for the large-scale production of yolk-shell powders with various compositions by a Spray-Drying Process is reported. Metal salt/dextrin composite powders with a spherical and dense structure were obtained by Spray Drying and transformed into yolk-shell powders by simple combustion in air. Dextrin plays a key role in the preparation of precursor powders for fabricating yolk-shell powders by Spray Drying. Droplets containing metal salts and dextrin show good Drying characteristics even in a severe environment of high humidity. Sucrose, glucose, and polyvinylpyrrolidone are widely used as carbon sources in the preparation of metal oxide/carbon composite powders; however, they are not appropriate for large-scale Spray-Drying Processes because of their caramelization properties and adherence to the surface of the Spray dryer. SnO2 yolk-shell powders were studied as the first target material in the Spray-Drying Process. Combustion of tin oxalate/dextrin composite powders at 600 °C in air produced single-shelled SnO2 yolk-shell powders with the configuration SnO2 @void@SnO2 . The SnO2 yolk-shell powders prepared by the simple Spray-Drying Process showed superior electrochemical properties, even at high current densities. The discharge capacities of the SnO2 yolk-shell powders at a current density of 2000 mA g(-1) were 645 and 570 mA h g(-1) for the second and 100th cycles, respectively; the corresponding capacity retention measured for the second cycle was 88 %.
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Kilogram‐Scale Production of SnO2 Yolk–Shell Powders by a Spray‐Drying Process Using Dextrin as Carbon Source and Drying Additive
Chemistry (Weinheim an der Bergstrasse Germany), 2014Co-Authors: Seung Ho Choi, Yun Chan KangAbstract:A simple and general method for the large-scale production of yolk-shell powders with various compositions by a Spray-Drying Process is reported. Metal salt/dextrin composite powders with a spherical and dense structure were obtained by Spray Drying and transformed into yolk-shell powders by simple combustion in air. Dextrin plays a key role in the preparation of precursor powders for fabricating yolk-shell powders by Spray Drying. Droplets containing metal salts and dextrin show good Drying characteristics even in a severe environment of high humidity. Sucrose, glucose, and polyvinylpyrrolidone are widely used as carbon sources in the preparation of metal oxide/carbon composite powders; however, they are not appropriate for large-scale Spray-Drying Processes because of their caramelization properties and adherence to the surface of the Spray dryer. SnO2 yolk-shell powders were studied as the first target material in the Spray-Drying Process. Combustion of tin oxalate/dextrin composite powders at 600 °C in air produced single-shelled SnO2 yolk-shell powders with the configuration SnO2 @void@SnO2 . The SnO2 yolk-shell powders prepared by the simple Spray-Drying Process showed superior electrochemical properties, even at high current densities. The discharge capacities of the SnO2 yolk-shell powders at a current density of 2000 mA g(-1) were 645 and 570 mA h g(-1) for the second and 100th cycles, respectively; the corresponding capacity retention measured for the second cycle was 88 %.
Muhammet Dervisoglu - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Spray Drying Process parameters for kefir powder using response surface methodology
LWT - Food Science and Technology, 2015Co-Authors: Ilyas Atalar, Muhammet DervisogluAbstract:Abstract In this study response surface methodology (RSM) was used to optimize the Spray Drying Process conditions for production of kefir powder. Influence of inlet air temperature (120–180 °C), feed temperature (4–30 °C) and pump rate (20–40%) on the survival rates of microorganisms, outlet temperature, moisture content and water activity were assessed after Drying and modeled by RSM. A lab-scale Spray dryer (Mini Spray Dryer B–290, Switzerland) was used to carry out the Drying experiments which are planned according to Central Composite Rotatable Design (CCRD). Inlet temperature was found as the main factor that effects the all responses statistically significant ( p
Jong Min Won - One of the best experts on this subject based on the ideXlab platform.
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electrochemical properties of yolk shell structured znfe2o4 powders prepared by a simple Spray Drying Process as anode material for lithium ion battery
Scientific Reports, 2015Co-Authors: Jong Min Won, Seung Ho Choi, Young Jun Hong, You Na Ko, Yun Chan KangAbstract:ZnFe2O4 yolk–shell powders were prepared by applying a simple Spray-Drying Process. Dextrin was used as a Drying additive and carbon source material, and thus played a key role in the preparation of the powders. The combustion of precursor powders consisting of zinc and iron salts and dextrin obtained by a Spray-Drying Process produced the yolk–shell-structured ZnFe2O4 powders even at a low post-treatment temperature of 350°C. The ZnFe2O4 powders prepared from the Spray solution without dextrin had a filled and pockmarked structure. The initial discharge capacities of the ZnFe2O4 yolk–shell and filled powders post-treated at 450°C at a current density of 500 mA g−1 were 1226 and 993 mA h g−1, respectively, and the corresponding initial Coulombic efficiencies were 74 and 58%. The discharge capacities of the ZnFe2O4 powders with yolk–shell and filled structures post-treated at 450°C after 200 cycles were 862 and 332 mA h g−1, respectively. The ZnFe2O4 yolk–shell powders with high structural stability during cycling had superior electrochemical properties to those of the powders with filled structure.
M A Garciaalvarado - One of the best experts on this subject based on the ideXlab platform.
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optimization of brewer s yeast Spray Drying Process
Journal of Food Engineering, 2005Co-Authors: Guadalupe Lunasolano, M A Salgadocervantes, G C Rodriguezjimenes, M A GarciaalvaradoAbstract:Abstract A combination of simulation with experimental treatments of Spray Drying Process were developed in order to minimize the energy resources required to obtain a production of Spray dried brewer’s yeast at given viability and moisture. The Drying was optimized by combining a few affected experiments with a 1.2 m3 Spray dryer. Cost function, viability, output moisture and production, were related with Process variables, both empirically and by simulation with a non-linear space state reported in literature. Both results were represented with response surface models (RSM). The empirical results state that the optimal operation was at 1 g grits (g yeast solids)−1, 319 s−1, Spray rotor velocity, and 60 °C in output air. At these conditions it was obtained 6.86 kg of dried yeast h−1, with a viability of 1.26 × 106 cfu g−1, and 55.5 cost $ kg−1 of product. Simulation results states optimal conditions at initial product moisture of 0.84 g g−1, 214 °C at input air, 202 kg dry air h−1, and 9.56 kg dry product h−1. At these conditions the simulator predicts 10 kg dried yeast per hour with a viability of 1.00 × 106 cfu g−1, and 26.7 cost kg−1 of product.