http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Baboo, Joseph Paul,Park, Hyosun,Song, Jinju,Kim, Sungjin,Jo, Jeonggeun,Pham, Duong Tung,Mathew, Vinod,Xiu, Zhiliang,Kim, Jaekook Pergamon Press 2017 Electrochimica Acta Vol. No.
<P><B>Abstract</B></P> <P>The present work reports on the development of layered-type Li<I> <SUB>x</SUB> </I>(Ni<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>)O<SUB>2</SUB> (<I>x</I> =1.05 and 1.1) cathodes by a simple ambient temperature redox synthesis followed by post-heat treatments with added lithium source. The intermediate precursor (Ni<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>O<I> <SUB>y</SUB> </I>) was synthesized through redox reaction between KMnO<SUB>4</SUB>, CoCl<SUB>2</SUB> and NiCl<SUB>2</SUB> in aqueous KOH medium. Synchrotron XANES and ICP measurements were performed to confirm the changes in the oxidation states and successful control in stoichiometric ratio of ternary transition metal oxide (Ni<SUP>2+</SUP> <SUB>0.33</SUB>Co<SUP>3+</SUP> <SUB>0.35</SUB>Mn<SUP>4+</SUP> <SUB>0.32</SUB>O<I> <SUB>y</SUB> </I>) during the redox reaction. Synchrotron X-ray diffraction studies of post lithiation confirmed the formation of a well-developed layer-type hexagonal phase of α-NaFeO<SUB>2</SUB> with least cation mixing, as observed from the estimated lattice parameters (<I>a</I> =2.858Å and <I>c</I> =14.228Å), integrated intensity ratio (<I>I</I> <SUB>003</SUB>/<I>I</I> <SUB>104</SUB> =1.79), and <I>c</I>/3<I>a</I> ratio (∼1.659) values. FE-SEM images revealed loosely agglomerated particles with average diameters of 60nm in the intermediate product while the particle-size grows to a few hundred nanometers after lithiation at elevated temperatures. The electrochemical performances in the potential range of 3.0–4.3V vs. Li/Li<SUP>+</SUP> at 14 mAg<SUP>−1</SUP> indicated that reasonable specific capacities and cycle performances are registered for all the prepared cathodes. In particular, the Li<SUB>1.05</SUB>(Ni<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>)O<SUB>2</SUB> composition demonstrated the highest capacity retention value (∼99%) after 50 cycles and better rate performances (104, 91, 76, and 67 mAhg<SUP>−1</SUP>) at high current densities (229, 457, 914, and 1429 mAg<SUP>−1</SUP> respectively).</P> <P><B>Highlights</B></P> <P> <UL> <LI> LiNi<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>O<SUB>2</SUB> cathode synthesis via an ambient temperature redox reaction. </LI> <LI> The stoichiometric elemental composition is controlled by the redox synthesis. </LI> <LI> The cathode exhibits ordered layer-type structure with minimal cation mixing. </LI> <LI> The cathode exhibited reasonable electrochemical properties versus lithium. </LI> </UL> </P>
Baboo, Joseph Paul,Song, Jinju,Kim, Sungjin,Jo, Jeonggeun,Baek, Sora,Mathew, Vinod,Pham, Duong Tung,Alfaruqi, Muhammad Hilmy,Xiu, Zhiliang,Sun, Yang-Kook,Kim, Jaekook American Chemical Society 2017 Chemistry of materials Vol.29 No.16
<P>Monoclinic Li3V2(PO4)(3) (LVP) has been considered a promising cathode material for lithium-ion batteries for the past decade because of its high average potential (>4.0 V) and specific capacity (197 mAh g(-1)). In this paper, we report a new monoclinic-orthorhombic Na1.1Li2.0V2(PO4)(3)/C (NLVP/C) composite cathode synthesized from monoclinic LVP via a soft ion-exchange reaction for use in Na+/Li+ hybrid-ion batteries. High-resolution synchrotron X-ray diffraction (XRD), thermal studies, and electrochemical data confirm room temperature stabilization of the monoclinic-orthorhombic NLVP/C composite phase. Specifically, we report the application of a monoclinic-orthorhombic NLVP/C composite as cathode material in a Na half-cell. The cathode delivered initial discharge capacities of 115 and 145 mAh g(-1) at a current density of 7.14 mA g(-1) in the 2.5-4 and 2.5-4.6 V vs Na/Na+ potential windows, respectively. In the lower potential window (2.5-4 V), the composite electrode demonstrated a two-step voltage plateau during the insertion and extraction of Na+/Li+ ions. Corresponding in situ synchrotron XRD patterns recorded during initial electrochemical cycling clearly indicate a series of two-phase transitions and confirm the structural stability of the NLVP/C composite cathode during insertion and extraction of the hybrid ions. Under extended cycling, excessive storage of Na ions resulted in the gradual transformation to the orthorhombic NLVP/C symmetry due to the occupancy of Na ions in the available orthorhombic sites. Moreover, the estimated average working potential and energy density at the initial cycle for the monoclinic-orthorhombic NLVP/C composite cathode (3.47 V vs Na/Na+ and 102.5 Wh kg(-1), respectively) are higher than those of the pyro-synthesized rhombohedral Na3V2(PO4)(3) (3.36 V vs Na/Na+ and 88.5 Wh kg(-1)) cathode. Further, the cathode performance of the composite material was significantly higher than that observed with pure monoclinic LVP under the same electrochemical measurement conditions. The present study thus showcases the feasibility of using a soft ion-exchange reaction at 150 degrees C to facilitate the formation of composite phases suitable for rechargeable hybrid-ion battery applications.</P>
Paul, Baboo Joseph,Do, Giang Xuan,Mathew, Vinod,Gim, Jihyeon,Song, Jinju,Kim, Sungjin,Tung, Duong Pham,Kim, Jaekook The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.10
<P>The present study investigates on the effect of excessive Ni doping, secondary heat-treatment and their influence on the structural and electrochemical properties of LiMn<SUB>1.3</SUB>Ni<SUB>0.7</SUB>O<SUB>y</SUB> spinel samples prepared by a two-step solid state synthesis. X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), electrochemical studies and in-situ synchrotron XRD (SXRD) results acquired during electrochemical lithiation indicates that the concentration of Mn<SUP>3+</SUP> and the corresponding ordering of the spinel composition can be controlled by excessive nickel doping and secondary annealing (at 700°C). Moreover, the above characterizations also confirmed long-range cation ordering (<I>P</I>4<SUB>3</SUB>32) in addition to minor contributions from the Mn<SUP>3+</SUP> content in the secondary annealed spinel (LiMn<SUB>1.3</SUB>Ni<SUB>0.7</SUB>O<SUB>y</SUB>). More importantly, the combined effect of extended Ni-doping and secondary heat-treatment is clearly reflected as an enhancement in the rate performances of LiMn<SUB>1.3</SUB>Ni<SUB>0.7</SUB>O<SUB>y</SUB> spinel cathode at elevated current rates (discharge capacity of around 88 and 61 mAh/g at 0.457 and 0.914 A/g current densities).</P>
Paul, Baboo Joseph,Gim, Jihyeon,Baek, Sora,Kang, Jungwon,Song, Jinju,Kim, Sungjin,Kim, Jaekook American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.8
<P>Nanocrystalline LiFePO4/C has been synthesized under a very short period of time (90 sec) using a polyol-assisted microwave heating synthesis technique. The X-ray diffraction (XRD) data indicates that the rapidly synthesized materials correspond to phase pure olivine. Post-annealing of the as-prepared sample at 600 °C in argon atmosphere yields highly crystalline LiFePO4/C. The morphology of the samples studied using scanning electron microscopy (SEM) reveals the presence of secondary particles formed from aggregation of primary particles in the range of 30-50 nm. Transmission electron microscopy (TEM) images reveal a thin carbon layer coating on the surface of the primary particle. The charge/discharge studies indicate that the as-prepared and annealed LiFePO4/C samples delivered initial discharge capacities of 126 and 160 mA h g-1, respectively, with good capacity retentions at 0.05 mA cm-2 current densities. The post-annealing process indeed improves the crystallinity of the LiFePO4 nanocrystals, which enhances the electrode performance of LiFePO4/C.</P>
Pham, Duong Tung,Baboo, Joseph Paul,Song, Jinju,Kim, Sungjin,Jo, Jeonggeun,Mathew, Vinod,Alfaruqi, Muhammad Hilmy,Sambandam, Balaji,Kim, Jaekook The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.13
<P>Pyrite (FeS2) is a promising electrode material for lithium ion batteries (LIBs) because of its high natural availability, low toxicity, cost-effectiveness, high theoretical capacity (894 mA h g<SUP>−1</SUP>) and high theoretical specific energy density (1270 W h kg<SUP>−1</SUP>, 4e<SUP>−</SUP>/FeS2). Nevertheless, the use of FeS2 in electrochemical capacitors was restricted due to fast capacity fading as a result of polysulfide (S/Sn<SUP>2−</SUP>) formation during the initial electrochemical cycling. In order to avoid the formation of polysulfides, we employed the strategy of utilizing an ether based electrolyte (1.0 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/diglyme (DGM)). Herein, we introduce FeS2/C as the Faradaic electrode for a non-aqueous hybrid electrochemical capacitor (NHEC) in combination with activated carbon (AC) as a non-Faradaic electrode, and 1.0 M LiTFSI/DGM as a non-aqueous electrolyte. Specifically, FeS2/C nanoparticles have been prepared <I>via</I> the sulfidation of a room temperature synthesized Fe-based MOF (metal organic framework) precursor. The fabricated FeS2/C∥AC NHEC, operating within the chosen voltage window of 0-3.2 V, delivered energy densities in the range of 63-9 W h kg<SUP>−1</SUP> at power densities of 152-3240 W kg<SUP>−1</SUP>. Remarkable cycling stability with stable energy density retention for 2500 cycles at high power densities (729, 1186 and 3240 W kg<SUP>−1</SUP>) was observed.</P>
Özpınar Ali,Yazmış Efecan,Ali Baboo,Şahin Ali Kürşat 한국곤충학회 2020 Entomological Research Vol.50 No.12
This study has been carried out in the years of 2016–2017 to determine biological parameters of Capsodes infuscatus Brulle (Hemiptera: Miridae) on asphodel (Asphodelus aestivus Broth.) in the pastures of Canakkale, Turkey. In order to determine the population fluctuation of C. infuscatus, counting was done twice in a week on leaves, stems and flowers of plants in two different locations in the pasture. It was determined that the C. infuscatus aestivates in dried asphodel stalks as eggs. The first nymphal stages can be seen at the end of February, while adult population ends at the end of May. It was observed that both the nymphal and adult stages of C. infuscatus were feeding together on A. aestivus from March to May. In 2016, an average of 7.86%, 57.26%, 8.72% and 34.12% C. infuscatus individuals were recorded on plant, leaves, stems and flowers, respectively. In 2017, an average of 22.08%, 67.5%, 15.0% and 17.56% C. infuscatusindividuals were recorded on plant, leaves, stems and flowers, respectively. The mortality rates of C. infuscatus nymphal stages were 94.76% in grazing area and 95.77% in non‐grazing area. We concluded that C. infuscatus has potential for the biological control of A. aestivus.
Low-temperature synthesis of LiFePO <sub>4 </sub> nanocrystals by solvothermal route
Lim, Jinsub,Kang, Sung-Won,Moon, Jieh,Kim, Sungjin,Park, Hyosun,Baboo, Joseph Paul,Kim, Jaekook Springer 2012 NANOSCALE RESEARCH LETTERS Vol.7 No.1
<P>LiFePO<SUB>4 </SUB>nanocrystals were synthesized at a very low temperature of 170°C using carbon nanoparticles by a solvothermal process in a polyol medium, namely diethylene glycol without any heat treatment as a post procedure. The powder X-ray diffraction pattern of the LiFePO<SUB>4 </SUB>was indexed well to a pure orthorhombic system of olivine structure (space group: Pnma) with no undesirable impurities. The LiFePO<SUB>4 </SUB>nanocrystals synthesized at low temperature exhibited mono-dispersed and carbon-mixed plate-type LiFePO<SUB>4 </SUB>nanoparticles with average length, width, and thickness of approximately 100 to 300 nm, 100 to 200 nm, and 50 nm, respectively. It also appeared to reveal considerably enhanced electrochemical properties when compared to those of pristine LiFePO<SUB>4</SUB>. These observed results clearly indicate the effect of carbon in improving the reactivity and synthesis of LiFePO<SUB>4 </SUB>nanoparticles at a significantly lower temperature.</P>
Some summation and Laplace transformation formulas for the Gauss hypergeometric series
H. M. Srivastava,M. I. Qureshi,Chaudhary Wali Mohammad,M. S. Baboo 장전수학회 2016 Advanced Studies in Contemporary Mathematics Vol.26 No.1
The authors derive a family of three summation formulas for the Gauss hypergeometric series 2F1 and show how their summation formulas would provide the correct forms of some erroneous hypergeometric summation theorems recorded by Prudnikov et al. [3]. By means of the correct forms of these summation theorems, the Laplace transforms of Kummer’s confluent hypergeometric function 1F1 are also presented in closed forms.