http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Thirunakaran, R.,Kim, Taewhan,Yoon, Won-Sub Elsevier 2016 Particuology Vol.24 No.-
<P>Multi-doped spinels, namely LiMn2O4 and LiZnxHoyMn2-x-yO4 (x=0.10-0.18; y=0.02-0.10), for use as cathode materials for lithium-ion rechargeable batteries were synthesized via sol-gel method, using lauric acid as the chelating agent, to obtain micron-sized particles. The physical properties of the synthesized samples were investigated using differential thermal analysis, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, energy-dispersive X-ray analysis, and electrochemical methods. XRD showed that LiMn2O4 and LiZnxHoyMn2-x-yO4 have high degrees of crystallinity and good phase purities. The SEM images of LiMn2O4 showed an ice-cube morphology with particles of size 1 mu m. Charge-discharge studies showed that undoped LiMn2O4 delivered the discharge capacity of 124 mA h/g with coulombic efficiency of 95% during the first cycle, whereas doped spinels delivered discharge capacities of 125, 120, and 127 mA h/g in the first cycle with coulombic efficiencies of 96%, 91%, and 91%, respectively. (C) 2015 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.</P>
Thirunakaran, R.,Lew, G.H.,Yoon, W.S. Elsevier Sequoia 2016 Journal of Electroanalytical Chemistry Vol.767 No.-
<P>LiMn2O4 and LiCuxAlyMn2-x-yO4 (x = 0.50; y = 0.05-0.50) powders have been synthesized via sol-gel method for the first time using Margaric acid as chelating agent. The synthesized samples have been used to physical and electrochemical characterization such as thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQJdE). XRD patterns of LiMn2O4 and LiCuxAlyMn2-x-yO4 confirm high degree of crystallinity with better phase purity of synthesized materials. FESEM images of parent LiMn2O4 depict the most of the particles that are in 0.5 mu m while LiCu0.5Al0.05Mn1.45O4 powders exhibiting ice-cube surface morphology with good agglomerated less particle size of 50 nm. TEM images of spinel LiMn2O4 and LiCu0.5Al0.05Mn1.45O4 corroborate that all the synthesized particles are nano-sized with uniform spherical and cloudy particle morphology. LiMn2O4 samples calcined at 850 degrees C deliver the high discharge capacity of 130 mA h g(-1) in the first cycle while LiCu0.5Al0.05Mn1.45O4 samples deliver 120 mA h g(-1) during the first cycle. Inter alia all the dopant compositions investigated, LiCu0.5Al0.05Mn1.45O4 delivers the stable cycling performance of 119 and 115 mA h g(-1) in the 5th and 10th cycle with low capacity fade of 0.1 and 0.1 mA h g(-1) cycle(-1) corresponding to columbic efficiency of 99 and 99%. (C) 2016 Published by Elsevier B.V.</P>
Thirunakaran, R.,Lew, Gil Hwan,Yoon, Won-Sub Elsevier 2016 Powder technology Vol.301 No.-
<P><B>Abstract</B></P> <P>LiMn<SUB>2</SUB>O<SUB>4</SUB> and LiCr<SUB>x</SUB>Mg<SUB>y</SUB>Mn<SUB>2-x-y</SUB>O<SUB>4</SUB> (x=0.50; y=0.05–0.50) powders are synthesized via sol-gel method for the first time using Cerotic acid as chelating agent. The synthesized spinel samples have been subjected to physical and electrochemical characterization viz., thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQ/dE). XRD finger print patterns of LiMn<SUB>2</SUB>O<SUB>4</SUB> and LiCr<SUB>x</SUB>Mg<SUB>y</SUB>Mn<SUB>2-x-y</SUB>O<SUB>4</SUB> ratifies the high degree of crystallinity with single phase compound. FESEM image of undoped pristine spinel clearly depicts uniform spherical surface morphology with an average particle size of 0.5μm while LiCr<SUB>0.5</SUB>Mg<SUB>0.05</SUB>Mn<SUB>1.45</SUB>O<SUB>4</SUB> samples depicting the cabbage morphology somewhat large good agglomerated particles of 200nm.</P> <P>TEM images of LiMn<SUB>2</SUB>O<SUB>4</SUB> and LiCr<SUB>0.5</SUB>Mg<SUB>0.05</SUB>Mn<SUB>1.45</SUB>O<SUB>4</SUB> particles depict that the synthesized particles are nano-sized (100nm) with spherical morphology and cloudy agglomerated particle size of 200nm. Charge-discharge studies of LiMn<SUB>2</SUB>O<SUB>4</SUB> samples calcined at 850°C deliver the high discharge capacity of 130mAhg<SUP>−1</SUP> corresponds to 94% columbic efficiency during the first cycle, while LiCr<SUB>0.5</SUB>Mg<SUB>0.05</SUB>Mn<SUB>1.45</SUB>O<SUB>4</SUB> delivering 123mAhg<SUP>−1</SUP> corresponds to 81% columbic efficiency in the first cycle. Inter alia, all four dopant compositions investigated, LiCr<SUB>0.5</SUB>Mg<SUB>0.05</SUB>Mn<SUB>1.45</SUB>O<SUB>4</SUB> delivers the maximum discharge capacity of 119, 114mAhg<SUP>−1</SUP> in 5th and 10th cycle with a low capacity fade of 0.1, 0.1 mAh g<SUP>−1</SUP> cycle<SUP>−1</SUP> and columbic efficiency of 99, 99%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel Cerotic acid assisted sol–gel synthesis of LiMn<SUB>2</SUB>O<SUB>4</SUB> and LiCr<SUB>x</SUB>Mg<SUB>y</SUB>Mn<SUB>2-x-y</SUB>O<SUB>4</SUB>. </LI> <LI> XRD patterns of LiMn<SUB>2</SUB>O<SUB>4</SUB> and LiCr<SUB>x</SUB>Mg<SUB>y</SUB>Mn<SUB>2-x-y</SUB>O<SUB>4</SUB> shows high degree of crystallinity. </LI> <LI> SEM images of LiMn<SUB>2</SUB>O show spherical morphology with particle size (0.5μm). </LI> <LI> TEM images of LiCr<SUB>0.5</SUB>Mg<SUB>0.05</SUB>Mn<SUB>1.45</SUB>O<SUB>4</SUB> depicts agglomerated particle size of 200nm. </LI> <LI> LiMn<SUB>2</SUB>O<SUB>4</SUB> calcined at 850°C deliver the high discharge capacity of 130mAhg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>LiCr<SUB>0.50</SUB>Mn<SUB>1.50</SUB>O<SUB>4</SUB>.</P> <P>[DISPLAY OMISSION]</P>
V. Aravindan,P. Vickramana,A. Sivashanmugam,R. Thirunakaran,S. Gopukumar 한국물리학회 2013 Current Applied Physics Vol.13 No.1
This paper describes the physico-chemical and electrochemical properties of polyvinylidenefluoridehexafluoropropylene (PVdF-HFP) membranes (GPM) prepared by phase inversion technique. Nanocomposite polymer membranes (NCPM) are also prepared by the same technique using AlO(OH)n nanoparticles. The prepared GPM and NCPM are gelled with liquid electrolyte containing three different salts namely, lithium bis(oxalate)borate, lithium fluoroalkylphosphate and lithium difluoro(oxalato) borate. Prepared membranes were subjected to various physico-chemical characterizations likely, mechanical stability, ionic conductivity, morphological studies, surface area and thermal analysis. Electrochemical chemical properties of membranes are evaluated in half-cell configurations (Li/NCPM or GPM/LiFePO4) at room temperature conditions. Galvanostatic cycling profiles clearly indicates the improved performance of chelato borate based anions i.e. BOB and DFOB when compared to fluoroalkyl group (FAP).