This page has only limited features, please log in for full access.
A two-stage continuous process was developed for improved silica extraction from rice husk. The two-stage continuous process consists of attrition ball milling and alkaline leaching methods. To find the optimum conditions for the continuous process, the effects of alkaline leaching parameters, such as the alkaline solution type and reaction conditions, on the silica extraction yield were investigated in a batch process. The use of NaOH showed a slightly higher silica yield than KOH. The optimum reaction conditions were found to be 0.2 M, 80 °C, 3 h, and 6% (w/v) for the reaction concentration, temperature, duration time, and solid content, respectively. Attrition ball milling was used to make micron-sized rice husk particles and to improve the fluidity of the rice husk slurry. The two-stage continuous process was performed using optimum conditions as determined based on the results of the batch experiment. The two-stage continuous extraction was stably operated for 80 h with an 89% silica yield. During the operation, the solid content remained consistent at 6% (w/v). The obtained silica was characterized using inductively coupled plasma–optical emission spectrometry (ICP–OES), X-ray diffraction (XRD), and the Brunauer–Emmett–Teller (BET) method.
Ji Park; Yang Gu; Seon Park; Ee Hwang; Byoung-In Sang; Jinyoung Chun; Jin Lee. Two-Stage Continuous Process for the Extraction of Silica from Rice Husk Using Attrition Ball Milling and Alkaline Leaching Methods. Sustainability 2021, 13, 7350 .
AMA StyleJi Park, Yang Gu, Seon Park, Ee Hwang, Byoung-In Sang, Jinyoung Chun, Jin Lee. Two-Stage Continuous Process for the Extraction of Silica from Rice Husk Using Attrition Ball Milling and Alkaline Leaching Methods. Sustainability. 2021; 13 (13):7350.
Chicago/Turabian StyleJi Park; Yang Gu; Seon Park; Ee Hwang; Byoung-In Sang; Jinyoung Chun; Jin Lee. 2021. "Two-Stage Continuous Process for the Extraction of Silica from Rice Husk Using Attrition Ball Milling and Alkaline Leaching Methods." Sustainability 13, no. 13: 7350.
Silicon is considered an important industrial element, primarily owing to its use in semiconductors, which are key components of various electronic devices; thus, the development of low-cost and efficient purification silicon processes has become a research focus. In this study, we developed a new process using ammonium fluoride (NH4F) to remove residual silica (SiO2) and generate nanopores on raw silicon (Si) materials without the use of highly toxic reagents and expensive procedures. We conducted low-temperature heat treatment of raw Si with NH4F under an inert atmosphere and found that the purity of raw Si was improved to a level similar to that of raw Si treated with hydrofluoric acid solution. Moreover, through this process, the surface area of raw Si was increased by surface tearing and the formation of nanopores. We also proposed a reaction mechanism for removing residual SiO2 from raw Si through X-ray diffraction analysis and demonstrated the safety of the process by analyzing the by-products generated during the heat treatment. When the modified Si material was applied to Li-ion battery anodes, they showed improved capacity, initial coulombic efficiency, and cycle performance as compared with those using raw Si material. We expect that this new NH4F-based method will not only be used to modify various Si materials for their efficient application, but will also be used to obtain nanostructured materials that require the removal of SiO2 during synthesis.
Sung Eun Wang; Il-Seop Jang; Yun Chan Kang; Jinyoung Chun; Dae-Soo Jung. Residual silica removal and nanopore generation on industrial waste silicon using ammonium fluoride and its application to lithium-ion battery anodes. Chemical Engineering Journal 2021, 419, 129389 .
AMA StyleSung Eun Wang, Il-Seop Jang, Yun Chan Kang, Jinyoung Chun, Dae-Soo Jung. Residual silica removal and nanopore generation on industrial waste silicon using ammonium fluoride and its application to lithium-ion battery anodes. Chemical Engineering Journal. 2021; 419 ():129389.
Chicago/Turabian StyleSung Eun Wang; Il-Seop Jang; Yun Chan Kang; Jinyoung Chun; Dae-Soo Jung. 2021. "Residual silica removal and nanopore generation on industrial waste silicon using ammonium fluoride and its application to lithium-ion battery anodes." Chemical Engineering Journal 419, no. : 129389.
The parameters of the alkaline fractionation process were investigated and optimized using a statistical analysis method to simultaneously remove hemicellulose and ash from rice husk (RH) concomitantly. After the alkaline fractionation process, the residual solid contained high cellulose, and the recovery yield of hemicellulose was enhanced in the fractionated liquid hydrolyzate. The hemicellulosic sugar recovery yield (71.6%), de-ashing yield (>99%), and lignin removal (>80%) were obtained at the reaction conditions of 150 °C of temperature, 40 min of reaction time, and 6% (w/v) of NaOH concentration. Subsequently, nano-structured silica was synthesized using black liquor obtained as a by-product of this fractionation process. For the production of nano-structured silica, it was observed that the pH of a black liquor and the heat treatment temperature significantly influenced the textural properties of silica product. In addition, the two-stage bleaching of solid residue followed by colloid milling for the production of high value-added CNF with was attempted. As a result, in addition to 119 g of fermentable sugar, 143 g of high-purity (>98%) silica with a surface area of 328 m2g−1 and 273.1 g of high-functional CNF with cellulose content of 80.1% were simultaneously obtained from 1000 g of RH.
Hyun Jung; Hyun Kwak; Jinyoung Chun; Kyeong Oh. Alkaline Fractionation and Subsequent Production of Nano-Structured Silica and Cellulose Nano-Fibrils for the Comprehensive Utilization of Rice Husk. Sustainability 2021, 13, 1951 .
AMA StyleHyun Jung, Hyun Kwak, Jinyoung Chun, Kyeong Oh. Alkaline Fractionation and Subsequent Production of Nano-Structured Silica and Cellulose Nano-Fibrils for the Comprehensive Utilization of Rice Husk. Sustainability. 2021; 13 (4):1951.
Chicago/Turabian StyleHyun Jung; Hyun Kwak; Jinyoung Chun; Kyeong Oh. 2021. "Alkaline Fractionation and Subsequent Production of Nano-Structured Silica and Cellulose Nano-Fibrils for the Comprehensive Utilization of Rice Husk." Sustainability 13, no. 4: 1951.
In this study, sodium cobalt fluoride (NaCoF3)/reduced graphene oxide (NCF/rGO) nanocomposites were fabricated through a simple one-pot solvothermal process and their electrochemical performance as cathodes for Li-ion batteries (LIBs) was investigated. The NCF nanoclusters (NCs) on the composites (300–500 nm in size) were formed by the assembly of primary nanoparticles (~20 nm), which were then incorporated on the surface of rGO. This morphology provided NCF NCs with a large surface area for efficient ion diffusion and also allowed for close contact with the conductive matrix to promote rapid electron transfer. As a cathode for LIBs, the NCF/rGO electrode achieved a high reversible capacity of 465 mAh·g−1 at 20 mA·g−1 via the conversion reaction, and this enhancement represented more than five times the reversible capacity of the bare NCF electrode. Additionally, the NCF/rGO electrode exhibited both better specific capacity and cyclability within the current density testing range (from 20 to 200 mA·g−1), compared with those of the bare NCF electrode.
Jiwoong Oh; Jooyoung Jang; Eunho Lim; Changshin Jo; Jinyoung Chun. Synthesis of Sodium Cobalt Fluoride/Reduced Graphene Oxide (NaCoF3/rGO) Nanocomposites and Investigation of Their Electrochemical Properties as Cathodes for Li-Ion Batteries. Materials 2021, 14, 547 .
AMA StyleJiwoong Oh, Jooyoung Jang, Eunho Lim, Changshin Jo, Jinyoung Chun. Synthesis of Sodium Cobalt Fluoride/Reduced Graphene Oxide (NaCoF3/rGO) Nanocomposites and Investigation of Their Electrochemical Properties as Cathodes for Li-Ion Batteries. Materials. 2021; 14 (3):547.
Chicago/Turabian StyleJiwoong Oh; Jooyoung Jang; Eunho Lim; Changshin Jo; Jinyoung Chun. 2021. "Synthesis of Sodium Cobalt Fluoride/Reduced Graphene Oxide (NaCoF3/rGO) Nanocomposites and Investigation of Their Electrochemical Properties as Cathodes for Li-Ion Batteries." Materials 14, no. 3: 547.
The development of engineered silica particles by using low-cost renewable or waste resources is a key example of sustainability. Rice husks have emerged as a renewable resource for the production of engineered silica particles as well as bioenergy. This review presents a state-of-the-art process for the development of engineered silica particles from rice husks via a bottom-up process. The first part of this review focuses on the extraction of Si from rice husks through combustion and chemical reactions. The second part details the technologies for synthesizing engineered silica particles using silicate obtained from rice husks. These include technologies for the precipitation of silica particles, the control of morphological properties, and the synthesis of ordered porous silica particles. Finally, several issues that need to be resolved before this process can be commercialized are addressed for future research.
Jinyoung Chun; Jin Hyung Lee. Recent Progress on the Development of Engineered Silica Particles Derived from Rice Husk. Sustainability 2020, 12, 10683 .
AMA StyleJinyoung Chun, Jin Hyung Lee. Recent Progress on the Development of Engineered Silica Particles Derived from Rice Husk. Sustainability. 2020; 12 (24):10683.
Chicago/Turabian StyleJinyoung Chun; Jin Hyung Lee. 2020. "Recent Progress on the Development of Engineered Silica Particles Derived from Rice Husk." Sustainability 12, no. 24: 10683.
Although water, air, and other resources are abundant on earth, they have been subjected to strict environmental regulations. This is because of their limitation of availability for human consumption. In the separation industry, the membrane system was introduced to increase the amount of resources available to mankind. Experts used an easy-to-use polymeric material to design several membranes with porous structures for wastewater treatment, gas separation, and chemical removal; consequently, they succeeded in obtaining positive results. However, past polymeric membranes exhibited a chronic drawback such that it was difficult to simultaneously augment the permeate flux and improve its selectivity toward certain substances. Because of the trade-off relationship that existed between permeability and selectivity, the membrane efficiency was not very good; consequently, the cost-effectiveness was significantly hindered because there was no other alternative than to replace the membrane in order to maintain its initial characteristics steadily. This review begins with the introduction of a polymer nanocomposite (PNC) membrane that has been designed to solve the chronic problem of polymeric membranes; subsequently, the stimuli-responsive PNC membrane is elucidated, which has established itself as a popular topic among researchers in the separation industry for several decades. Furthermore, we have listed the different types and examples of stimuli-responsive PNC membranes, which can be switched by external stimuli, while discussing the future direction of the membrane separation industry.
Taegyun Kwon; Jinyoung Chun. ON/OFF Switchable Nanocomposite Membranes for Separations. Polymers 2020, 12, 2415 .
AMA StyleTaegyun Kwon, Jinyoung Chun. ON/OFF Switchable Nanocomposite Membranes for Separations. Polymers. 2020; 12 (10):2415.
Chicago/Turabian StyleTaegyun Kwon; Jinyoung Chun. 2020. "ON/OFF Switchable Nanocomposite Membranes for Separations." Polymers 12, no. 10: 2415.
We developed a facile synthetic method for the preparation of spherical mesoporous silica nanoparticles from a sodium silicate solution. Spherical mesoporous silica with an overall size of several hundreds of nanometers was obtained through a simple sol-gel process using acetic acid and polyethylene glycol (PEG) as a pH adjuster and morphology directing agent, respectively. In this method, PEG is an essential component that affects the shape of silica particles and that leads to the formation of mesopores on silica. Additionally, the size of the mesopores could be easily controlled by changing the reaction temperature. Thus, we successfully synthesized spherical silica nanoparticles with tunable mesopores ranging from 3 to 40 nm. This synthetic method can be valuable in developing customized porous silica nanoparticles using an inexpensive silica resource.
Jongkook Hwang; Jin Hyung Lee; Jinyoung Chun. Facile approach for the synthesis of spherical mesoporous silica nanoparticles from sodium silicate. Materials Letters 2020, 283, 128765 .
AMA StyleJongkook Hwang, Jin Hyung Lee, Jinyoung Chun. Facile approach for the synthesis of spherical mesoporous silica nanoparticles from sodium silicate. Materials Letters. 2020; 283 ():128765.
Chicago/Turabian StyleJongkook Hwang; Jin Hyung Lee; Jinyoung Chun. 2020. "Facile approach for the synthesis of spherical mesoporous silica nanoparticles from sodium silicate." Materials Letters 283, no. : 128765.
Jinyoung Chun; Jang H. Chun. Transition effect of under- and over-potentially deposited hydrogen and negative resistance at a poly-Rh/alkaline aqueous solution interface. International Journal of Hydrogen Energy 2019, 45, 1429 -1434.
AMA StyleJinyoung Chun, Jang H. Chun. Transition effect of under- and over-potentially deposited hydrogen and negative resistance at a poly-Rh/alkaline aqueous solution interface. International Journal of Hydrogen Energy. 2019; 45 (3):1429-1434.
Chicago/Turabian StyleJinyoung Chun; Jang H. Chun. 2019. "Transition effect of under- and over-potentially deposited hydrogen and negative resistance at a poly-Rh/alkaline aqueous solution interface." International Journal of Hydrogen Energy 45, no. 3: 1429-1434.
Rice husk is a promising abundant bioresource for the production of high value-added silica materials because it has the highest SiO2 content among all plant-based resources. In this study, ordered mesoporous silica with various pore structures are synthesized from rice husk by combining acid leaching, chemical dissolution, and co-assembly with additional surfactants. Depending upon the type of the surfactant used and the co-assembly conditions, various mesoporous silica that have controlled pore structures (mesocellular forms and hexagonal nanochannel structures), pore sizes (3–60 nm), large surface areas (297–895 m2 g−1), and pore volumes (0.81–1.77 cm3 g−1) are successfully synthesized from a sodium silicate solution, which was made from high-purity silica (99.8%) extracted from rice husk. The synthesis of high value-added silica from an abundant bioresource can open up new avenues for sustainable and environment-friendly industrial development.
Jinyoung Chun; Yang Mo Gu; Jongkook Hwang; Kyeong Keun Oh; Jin Hyung Lee. Synthesis of ordered mesoporous silica with various pore structures using high-purity silica extracted from rice husk. Journal of Industrial and Engineering Chemistry 2019, 81, 135 -143.
AMA StyleJinyoung Chun, Yang Mo Gu, Jongkook Hwang, Kyeong Keun Oh, Jin Hyung Lee. Synthesis of ordered mesoporous silica with various pore structures using high-purity silica extracted from rice husk. Journal of Industrial and Engineering Chemistry. 2019; 81 ():135-143.
Chicago/Turabian StyleJinyoung Chun; Yang Mo Gu; Jongkook Hwang; Kyeong Keun Oh; Jin Hyung Lee. 2019. "Synthesis of ordered mesoporous silica with various pore structures using high-purity silica extracted from rice husk." Journal of Industrial and Engineering Chemistry 81, no. : 135-143.
In this study, we have developed a simple, versatile, and rapid solvothermal process for the preparation of sodium metal fluoride (NaxMFy) nanopowders (NaCoF3, NaMnF3, and Na3FeF6) using a microwave digestion system. Microwave heating significantly reduces the reaction time compared to conventional heating methods. The NaxMFy nanopowders have cluster structures consisting of small primary nanoparticles, thus resulting in a large surface area of >60 m2 g−1. The effect of an essential additive is also investigated to confirm the optimal conditions for obtaining large‐surface‐area NaxMFy nanopowders without impurities. We expect that this study will promote further research into the development and application of various nanostructured NaxMFy materials. This article is protected by copyright. All rights reserved.
Jongkook Hwang; Jinyoung Chun. Microwave‐assisted solvothermal synthesis of sodium metal fluoride (Na x MF y ) nanopowders. Journal of the American Ceramic Society 2019, 102, 6475 -6479.
AMA StyleJongkook Hwang, Jinyoung Chun. Microwave‐assisted solvothermal synthesis of sodium metal fluoride (Na x MF y ) nanopowders. Journal of the American Ceramic Society. 2019; 102 (11):6475-6479.
Chicago/Turabian StyleJongkook Hwang; Jinyoung Chun. 2019. "Microwave‐assisted solvothermal synthesis of sodium metal fluoride (Na x MF y ) nanopowders." Journal of the American Ceramic Society 102, no. 11: 6475-6479.
Due to the superposition of various effects at electrocatalyst/solution interfaces, the Frumkin and Temkin adsorption isotherms of H and D are not readily determined using conventional methods. The phase-shift method is a unique electrochemical impedance spectroscopy technique for studying the linear relationship between the phase shift (90° ≥ −φ ≥ 0°) for the optimum intermediate frequency vs potential (E) behavior and the fractional coverage (0 ≤ θ ≤ 1) for adsorption vs potential (E) behavior. The Frumkin and Temkin adsorption isotherms (θ vs E) of H and D and their isotopic shifts at Pt/0.1 M LiOH (H2O, D2O) solution interfaces are determined using the phase-shift method. Over the θ range (i.e., 1 ≥ θ ≥ 0), the kinetic isotope effect (KH/D) is 3.1 to 3.5 and the standard Gibbs energy (ΔGθ0) of D is 2.8 to 3.1 kJ mol−1 greater than that of H. The bond dissociation energy for Pt−D2O is greater than that for Pt−H2O. The rate-determining steps are determined by the recombination step at low θ or E and electrochemical desorption step at high θ or E, sequentially. The isotopic shifts of the Frumkin and Temkin adsorption isotherms of H and D and related electrode kinetic effects are clearly distinguished.
Jinyoung Chun; Jang H. Chun. Isotopic Shifts of the Frumkin and Temkin Adsorption Isotherms of H and D at Pt/Alkaline Solution Interfaces: Analysis Using the Phase-Shift Method. Journal of The Electrochemical Society 2019, 166, H243 -H249.
AMA StyleJinyoung Chun, Jang H. Chun. Isotopic Shifts of the Frumkin and Temkin Adsorption Isotherms of H and D at Pt/Alkaline Solution Interfaces: Analysis Using the Phase-Shift Method. Journal of The Electrochemical Society. 2019; 166 (6):H243-H249.
Chicago/Turabian StyleJinyoung Chun; Jang H. Chun. 2019. "Isotopic Shifts of the Frumkin and Temkin Adsorption Isotherms of H and D at Pt/Alkaline Solution Interfaces: Analysis Using the Phase-Shift Method." Journal of The Electrochemical Society 166, no. 6: H243-H249.
Juyeon Kim; Jinyoung Chun; Sang-Gil Kim; Hyojun Ahn; Kwang Chul Roh. Nitrogen and Fluorine Co-doped Activated Carbon for Supercapacitors. Journal of Electrochemical Science and Technology 2017, 8, 338 -343.
AMA StyleJuyeon Kim, Jinyoung Chun, Sang-Gil Kim, Hyojun Ahn, Kwang Chul Roh. Nitrogen and Fluorine Co-doped Activated Carbon for Supercapacitors. Journal of Electrochemical Science and Technology. 2017; 8 (4):338-343.
Chicago/Turabian StyleJuyeon Kim; Jinyoung Chun; Sang-Gil Kim; Hyojun Ahn; Kwang Chul Roh. 2017. "Nitrogen and Fluorine Co-doped Activated Carbon for Supercapacitors." Journal of Electrochemical Science and Technology 8, no. 4: 338-343.
Jinyoung Chun; Changshin Jo; Eunho Lim; Kwang Chul Roh; Jinwoo Lee. Solvothermal synthesis of sodium cobalt fluoride (NaCoF3) nanoparticle clusters. Materials Letters 2017, 207, 89 -92.
AMA StyleJinyoung Chun, Changshin Jo, Eunho Lim, Kwang Chul Roh, Jinwoo Lee. Solvothermal synthesis of sodium cobalt fluoride (NaCoF3) nanoparticle clusters. Materials Letters. 2017; 207 ():89-92.
Chicago/Turabian StyleJinyoung Chun; Changshin Jo; Eunho Lim; Kwang Chul Roh; Jinwoo Lee. 2017. "Solvothermal synthesis of sodium cobalt fluoride (NaCoF3) nanoparticle clusters." Materials Letters 207, no. : 89-92.
A Li-ion hybrid supercapacitor (Li-HSC) delivering high energy within seconds (excellent rate performance) with stable cycle life is one of the most highly attractive energy storage devices.
Eunho Lim; Won-Gwang Lim; Changshin Jo; Jinyoung Chun; Mok-Hwa Kim; Kwang Chul Roh; Jinwoo Lee. Rational design of [email protected] core–shell nanoparticles as Li-ion hybrid supercapacitor anode materials. Journal of Materials Chemistry A 2017, 5, 20969 -20977.
AMA StyleEunho Lim, Won-Gwang Lim, Changshin Jo, Jinyoung Chun, Mok-Hwa Kim, Kwang Chul Roh, Jinwoo Lee. Rational design of [email protected] core–shell nanoparticles as Li-ion hybrid supercapacitor anode materials. Journal of Materials Chemistry A. 2017; 5 (39):20969-20977.
Chicago/Turabian StyleEunho Lim; Won-Gwang Lim; Changshin Jo; Jinyoung Chun; Mok-Hwa Kim; Kwang Chul Roh; Jinwoo Lee. 2017. "Rational design of [email protected] core–shell nanoparticles as Li-ion hybrid supercapacitor anode materials." Journal of Materials Chemistry A 5, no. 39: 20969-20977.
The porous carbon matrix is widely recognized to be a promising sulfur reservoir to improve the cycle life by suppressing the polysulfide dissolution in lithium sulfur batteries (LSB). Herein, we synthesized mesocellular carbon foam (MSUF-C) with bimodal mesopore (4 and 30 nm) and large pore volume (1.72 cm2/g) using MSUF silica as a template and employed it as both the sulfur reservoir and the conductive agent in the sulfur cathode. Sulfur was uniformly infiltrated into MSUF-C pores by a chemical solution deposition method (MSUF-C/S CSD) and the amount of sulfur loading was achieved as high as 73% thanks to the large pore volume with the CSD approach. MSUF-C/S CSD showed a high capacity (889 mAh/g after 100 cycles at 0.2 C), an improved rate capability (879 mAh/g at 1C and 420 mAh/g at 2C), and a good capacity retention with a fade rate of 0.16% per cycle over 100 cycles.
Tae-Gyung Jeong; Jinyong Chun; Byung-Won Cho; Jinwoo Lee; Yong-Tae Kim. Enhanced performance of sulfur-infiltrated bimodal mesoporous carbon foam by chemical solution deposition as cathode materials for lithium sulfur batteries. Scientific Reports 2017, 7, 42238 .
AMA StyleTae-Gyung Jeong, Jinyong Chun, Byung-Won Cho, Jinwoo Lee, Yong-Tae Kim. Enhanced performance of sulfur-infiltrated bimodal mesoporous carbon foam by chemical solution deposition as cathode materials for lithium sulfur batteries. Scientific Reports. 2017; 7 (1):42238.
Chicago/Turabian StyleTae-Gyung Jeong; Jinyong Chun; Byung-Won Cho; Jinwoo Lee; Yong-Tae Kim. 2017. "Enhanced performance of sulfur-infiltrated bimodal mesoporous carbon foam by chemical solution deposition as cathode materials for lithium sulfur batteries." Scientific Reports 7, no. 1: 42238.
Metal fluorides (MFx) are one of the most attractive cathode candidates for Li-ion batteries (LIBs) due to their high conversion potentials with large capacities. However, only a limited number of synthetic method, generally involving highly toxic or inaccessible reagents, currently exist, which has made it difficult to produce well-designed nanostructures suitable for cathodes; consequently, harnessing their potential cathodic properties has been a challenge. Herein, we report a new bottom-up synthetic method utilizing ammonium fluoride (NH4F) for the preparation of anhydrous MFx(CuF2, FeF3, and CoF2)/mesoporous carbon(MSU-F-C) nanocomposites, whereby a series of metal precursor nanoparticles pre-confined in mesoporous carbon were readily converted to anhydrous MFx through simple heat treatment with NH4F under solventless conditions. We demonstrate the versatility, less-toxicity, and efficiency of this synthetic method, and, using XRD analysis, propose a mechanism for the reaction. All MFx/MSU-F-C prepared in this study exhibited superior electrochemical performances, through conversion reactions, as the cathode for LIBs. Especially, FeF3/MSU-F-C maintained a capacity of 650 mAh g−1,FeF3 across 50 cycles, which is ~90% of its initial capacity. We expect that this facile synthesis method will trigger further research into the development of various nanostructured MFx for use in energy storage and other applications.
Jinyoung Chun; Changshin Jo; SunHye Sahgong; Min Gyu Kim; Eunho Lim; Dong Hyeon Kim; Jongkook Hwang; Eunae Kang; Keun Ah Ryu; Yoon Seok Jung; YoungSik Kim; Jinwoo Lee. Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride–Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes. ACS Applied Materials & Interfaces 2016, 8, 35180 -35190.
AMA StyleJinyoung Chun, Changshin Jo, SunHye Sahgong, Min Gyu Kim, Eunho Lim, Dong Hyeon Kim, Jongkook Hwang, Eunae Kang, Keun Ah Ryu, Yoon Seok Jung, YoungSik Kim, Jinwoo Lee. Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride–Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes. ACS Applied Materials & Interfaces. 2016; 8 (51):35180-35190.
Chicago/Turabian StyleJinyoung Chun; Changshin Jo; SunHye Sahgong; Min Gyu Kim; Eunho Lim; Dong Hyeon Kim; Jongkook Hwang; Eunae Kang; Keun Ah Ryu; Yoon Seok Jung; YoungSik Kim; Jinwoo Lee. 2016. "Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride–Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes." ACS Applied Materials & Interfaces 8, no. 51: 35180-35190.
A general method to synthesize mesoporous metal [email protected] macroporous graphene composite by heat-treatment of electrostatically co-assembled amine-functionalized mesoporous silica/metal oxide composite and graphene oxide, and subsequent silica removal to produce mesoporous metal oxide and N-doped macroporous graphene simultaneously is reported. Four mesoporous metal oxides (WO3−x , Co3O4, Mn2O3, and Fe3O4) are encapsulated in N-doped macroporous graphene. Used as an anode material for sodium-ion hybrid supercapacitors (Na-HSCs), mesoporous reduced tungsten [email protected] macroporous graphene (m-WO3− [email protected]) gives outstanding rate capability and stable cycle life. Ex situ analyses suggest that the electrochemical reaction mechanism of m-WO3− [email protected] is based on Na+ intercalation/de-intercalation. To the best of knowledge, this is the first report on Na+ intercalation/de-intercalation properties of WO3− x and its application to Na-HSCs.
Min Su Kim; Eunho Lim; Seongbeen Kim; Changshin Jo; Jinyoung Chun; Jinwoo Lee. General Synthesis of N-Doped Macroporous Graphene-Encapsulated Mesoporous Metal Oxides and Their Application as New Anode Materials for Sodium-Ion Hybrid Supercapacitors. Advanced Functional Materials 2016, 27, 1 .
AMA StyleMin Su Kim, Eunho Lim, Seongbeen Kim, Changshin Jo, Jinyoung Chun, Jinwoo Lee. General Synthesis of N-Doped Macroporous Graphene-Encapsulated Mesoporous Metal Oxides and Their Application as New Anode Materials for Sodium-Ion Hybrid Supercapacitors. Advanced Functional Materials. 2016; 27 (3):1.
Chicago/Turabian StyleMin Su Kim; Eunho Lim; Seongbeen Kim; Changshin Jo; Jinyoung Chun; Jinwoo Lee. 2016. "General Synthesis of N-Doped Macroporous Graphene-Encapsulated Mesoporous Metal Oxides and Their Application as New Anode Materials for Sodium-Ion Hybrid Supercapacitors." Advanced Functional Materials 27, no. 3: 1.
Sodium-ion hybrid supercapacitors (Na-HSCs) have potential for mid- to large-scale energy storage applications because of their high energy/power densities, long cycle life, and the low cost of sodium. However, one of the obstacles to developing Na-HSCs is the imbalance of kinetics from different charge storage mechanisms between the sluggish faradaic anode and the rapid non-faradaic capacitive cathode. Thus, to develop high-power Na-HSC anode materials, this paper presents the facile synthesis of nanocomposites comprising [email protected] core–shell nanoparticles ([email protected] NPs) and reduced graphene oxide (rGO), and an analysis of their electrochemical performance with respect to various weight ratios of [email protected] NPs to rGO (e.g., [email protected], [email protected]/rGO-70, -50, and -30). In a Na half-cell configuration, the [email protected]/rGO-50 shows highly reversible capacity of ≈285 mA h g−1 at 0.025 A g−1 in the potential range of 0.01–3.0 V (vs Na/Na+). In addition, the Na-HSC using the [email protected]/rGO-50 anode and activated carbon (MSP-20) cathode delivers high energy/power densities (≈76 W h kg−1 and ≈20 800 W kg−1) with a stable cycle life in the potential range of 1.0–4.3 V. The energy and power densities of the Na-HSC developed in this study are higher than those of similar Li- and Na-HSCs previously reported.
Eunho Lim; Changshin Jo; Min Su Kim; Mok-Hwa Kim; Jinyoung Chun; Haegyeom Kim; Jongnam Park; Kwang Chul Roh; Kisuk Kang; Songhun Yoon; Jinwoo Lee. High-Performance Sodium-Ion Hybrid Supercapacitor Based on [email protected] Core-Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites. Advanced Functional Materials 2016, 26, 3711 -3719.
AMA StyleEunho Lim, Changshin Jo, Min Su Kim, Mok-Hwa Kim, Jinyoung Chun, Haegyeom Kim, Jongnam Park, Kwang Chul Roh, Kisuk Kang, Songhun Yoon, Jinwoo Lee. High-Performance Sodium-Ion Hybrid Supercapacitor Based on [email protected] Core-Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites. Advanced Functional Materials. 2016; 26 (21):3711-3719.
Chicago/Turabian StyleEunho Lim; Changshin Jo; Min Su Kim; Mok-Hwa Kim; Jinyoung Chun; Haegyeom Kim; Jongnam Park; Kwang Chul Roh; Kisuk Kang; Songhun Yoon; Jinwoo Lee. 2016. "High-Performance Sodium-Ion Hybrid Supercapacitor Based on [email protected] Core-Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites." Advanced Functional Materials 26, no. 21: 3711-3719.
We demonstrated the use of iron slag as a raw material to produce highly mesoporous Si for high-performance Li-ion battery anodes.
Jinyoung Chun; Sunhyung An; Jinwoo Lee. Highly mesoporous silicon derived from waste iron slag for high performance lithium ion battery anodes. Journal of Materials Chemistry A 2015, 3, 21899 -21906.
AMA StyleJinyoung Chun, Sunhyung An, Jinwoo Lee. Highly mesoporous silicon derived from waste iron slag for high performance lithium ion battery anodes. Journal of Materials Chemistry A. 2015; 3 (43):21899-21906.
Chicago/Turabian StyleJinyoung Chun; Sunhyung An; Jinwoo Lee. 2015. "Highly mesoporous silicon derived from waste iron slag for high performance lithium ion battery anodes." Journal of Materials Chemistry A 3, no. 43: 21899-21906.
Hybrid supercapacitors (battery-supercapacitor hybrid devices, HSCs) deliver high energy within seconds (excellent rate capability) with stable cyclability. One of the key limitations in developing high-performance HSCs is imbalance in power capability between the sluggish Faradaic lithium-intercalation anode and rapid non-Faradaic capacitive cathode. To solve this problem, we synthesize [email protected] core-shell nanocyrstals ([email protected] NCs) as high-power anode materials with controlled crystalline phases (orthorhombic (T) and pseudohexagonal (TT)) via a facile one-pot synthesis method based on a water-in-oil microemulsion system. The synthesis of ideal T-Nb2O5 for fast Li(+) diffusion is simply achieved by controlling the microemulsion parameter (e.g., pH control). The [email protected] NCs shows a reversible specific capacity of ∼180 mA h g(-1) at 0.05 A g(-1) (1.1-3.0 V vs Li/Li(+)) with rapid rate capability compared to that of [email protected] and carbon shell-free Nb2O5 NCs, mainly due to synergistic effects of (i) the structural merit of T-Nb2O5 and (ii) the conductive carbon shell for high electron mobility. The highest energy (∼63 W h kg(-1)) and power (16 528 W kg(-1) achieved at ∼5 W h kg(-1)) densities within the voltage range of 1.0-3.5 V of the HSC using [email protected] anode and MSP-20 cathode are remarkable.
Eunho Lim; Changshin Jo; Haegyeom Kim; Mok-Hwa Kim; Yeongdong Mun; Jinyoung Chun; Youngjin Ye; Jongkook Hwang; Kyoung-Su Ha; Kwang Chul Roh; Kisuk Kang; Songhun Yoon; Jinwoo Lee. Facile Synthesis of [email protected] Core–Shell Nanocrystals with Controlled Crystalline Structure for High-Power Anodes in Hybrid Supercapacitors. ACS Nano 2015, 9, 7497 -7505.
AMA StyleEunho Lim, Changshin Jo, Haegyeom Kim, Mok-Hwa Kim, Yeongdong Mun, Jinyoung Chun, Youngjin Ye, Jongkook Hwang, Kyoung-Su Ha, Kwang Chul Roh, Kisuk Kang, Songhun Yoon, Jinwoo Lee. Facile Synthesis of [email protected] Core–Shell Nanocrystals with Controlled Crystalline Structure for High-Power Anodes in Hybrid Supercapacitors. ACS Nano. 2015; 9 (7):7497-7505.
Chicago/Turabian StyleEunho Lim; Changshin Jo; Haegyeom Kim; Mok-Hwa Kim; Yeongdong Mun; Jinyoung Chun; Youngjin Ye; Jongkook Hwang; Kyoung-Su Ha; Kwang Chul Roh; Kisuk Kang; Songhun Yoon; Jinwoo Lee. 2015. "Facile Synthesis of [email protected] Core–Shell Nanocrystals with Controlled Crystalline Structure for High-Power Anodes in Hybrid Supercapacitors." ACS Nano 9, no. 7: 7497-7505.