Amara Raja Batteries Ltd.

Tirupati, India

Amara Raja Batteries Ltd.

Tirupati, India
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Vivekanandhan S.,Pondicherry University | Vivekanandhan S.,University of Guelph | Venkateswarlu M.,Amara Raja Batteries Ltd. | Carnahan D.,NanoLab, Inc. | And 4 more authors.
Ceramics International | Year: 2013

Surface modification of nanocrystalline NiFe2O4 spinel particles with amorphous SiO2 by the sol-gel process at 350 °C was demonstrated. Amorphous phase of the SiO2 layer was evaluated by X-ray diffraction technique. Structural coordination of the pristine and SiO2 coated NiFe2O4 particles as investigated by employing FTIR analysis. Thickness of the SiO2 layer was investigated through transmission electron microscopy and it was identified to be ∼10-23 nm over nanocrystalline NiFe2O4 particles. The magnetic behavior of pristine and surface modified NiFe 2O4 particles were investigated using vibrating sample magnetometer (VSM). Magnetic studies showed the retention of magnetic property of surface modified NiFe2O4 particles with the reduced saturation magnetization and coercivity compared to the pristine NiFe 2O4 particles, which is respectively due to the lower fraction of the magnetic component and the formation of interfacial structure. © 2012 Elsevier Ltd and Techna Group S.r.l.


Nallamuthu N.,Pondicherry University | Prakash I.,Pondicherry University | Satyanarayana N.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd.
Journal of Alloys and Compounds | Year: 2011

Nanocrystalline apatite type structured lanthanum silicate (La 10Si6O27) sample was synthesized by sol-gel process. Thermal behavior of the dried gel of lanthanum silicate sample was studied using TG/DTA. The structural coordination of the dried gel of lanthanum silicate, calcined at various temperatures, was identified from the observed FTIR spectral results. The observed XRD patterns of the calcined dried gel were compared with the ICDD data and confirmed the formation of crystalline lanthanum silicate phase. The average crystalline size of La10Si 6O27 was calculated using the Scherrer formula and it is found to be ∼80 nm. The observed SEM images of the lanthanum silicate indicate the formation of the spherical particles and the existence of O, Si and La in the lanthanum silicate are confirmed from the SEM-EDX spectrum. The grain and grain boundary conductivities are evaluated by analyzing the measured impedance data, using winfit software, obtained at different temperatures, of La10Si6O27 sample. Also, the observed grain and grain boundary conductivity behaviors of the La10Si 6O27 sample are analysed using brick layer model. The electrical permittivity and electrical modulus were calculated from the measured impedance data and were analyzed by fitting through the Havriliak and Negami function to describe the dielectric relaxation behavior of the nanocrystalline lanthanum silicate. © 2010 Elsevier B.V. All rights reserved.


Nageswara Rao B.,Pondicherry University | Muralidharan P.,Pondicherry Engineering College | Ramesh Kumar P.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd | Satyanarayana N.,Pondicherry University
International Journal of Electrochemical Science | Year: 2014

A rapid and efficient two-steps growth strategy has been adopted to synthesize monodisperse single-crystalline spinel LiMn2O4 nanorods. The first step is to synthesize crystalline β-MnO2 nanorods through rapid microwave hydrothermal process followed by second step as solid state reaction between β-MnO2 nanorods and LiOH.H2O to obtain pure spinel LiMn2O4 nanorods. In addition, the possible formation mechanism of the β-MnO2 and spinel LiMn2O4 nanorods was also discussed. The spinel LiMn2O4 nanorods have an average diameter of 190 nm and length of 0.8-1.3 μm. Galvanostatic battery testing shows that the spinel LiMn2O4 nanorods have delivered a stable charge and discharge capacities of 98 and 96 mAhg-1, respectively, after 50 cycles at 0.1C rate in the voltage range 3.1-4.4 V. The cathode material exhibits good electrochemical performance even at high C-rates. The developed LiMn2O4 nanorods show a higher coulombic efficiency and also good rate capability attributed to the formation of the single-crystalline spinel LiMn2O4 with nanorod morphology. © 2014 by ESG.


Padmaraj O.,Pondicherry University | Nageswara Rao B.,Pondicherry University | Jena P.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd | Satyanarayana N.,Pondicherry University
Polymer (United Kingdom) | Year: 2014

Poly(vinylidene fluoride-co-hexafluoropropylene) P(VdF-co-HFP)/magnesium aluminate (MgAl2O4) hybrid fibrous nanocomposite polymer electrolyte membranes were newly prepared by electrospinning method. The as-prepared electrospun pure and nanocomposite fibrous polymer membranes with various MgAl2O4 filler contents were characterized by X ray diffraction, differential scanning calorimetry and scanning electron microscopy techniques. The fibrous nanocomposite polymer electrolytes were prepared by soaking the electrospun membranes in 1 M LiPF6 in EC:DEC (1:1, v/v). The fibrous nanocomposite polymer electrolyte membrane with 5 wt.% of MgAl2O4 show high electrolyte uptake, enhanced ionic conductivity is found to be 2.80 × 10-3 S cm-1 at room temperature and good electrochemical stability window higher than 4.5 V. Electrochemical performance of commercial celgard 2320, fibrous pure and nanocomposite polymer electrolyte (PE, NCPE) membranes with different MgAl 2O4 filler content is evaluated in Li/celgard 2320, PE, NCPE/LiCoO2 CR 2032 coin cells at current density 0.1 C-rate. The NCPE with 5 wt.% of MgAl2O4 delivers an initial discharge capacity of 158 mAhg-1 and stable cycle performance compared with the other cells containing celgard 2320 separator and pure membrane. © 2013 Elsevier Ltd. All rights reserved.


Nallamuthu N.,Pondicherry University | Prakash I.,Pondicherry University | Satyanarayana N.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd
Materials Research Bulletin | Year: 2011

Different compositions of scheelite type nanocrystalline La doped BaMoO4 [Ba1-xLaxMoO4+x/2, where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5] samples were prepared by acrylamide assisted sol-gel combustion process. Dried gels prepared at 60 °C were heated at different temperatures and characterized using TG/DTA, XRD, FTIR and SEM-EDX techniques. From XRD patterns, crystalline phases for La doped BaMoO4 samples were confirmed and their average crystallite sizes were calculated using Scherrer's formula and it was found to be less than 80 nm. Structure and thermal behavior of scheelite type nanocrystalline La doped BaMoO4 samples were identified respectively using FTIR and TG/DTA measurements. Microstructure and existence of O, La, Ba and Mo elements in the La doped BaMoO4 samples were obtained from SEM-EDX and HRTEMtechniques. The 'd' spacing values were obtained for different (h k l) planes and were well matched with the standard BaMoO4. (h k l) values for different directions of planes were assigned for the observed HRTEM images and were matched with standard BaMoO4. Grain and grain boundary conductivities were evaluated by analyzing the impedance data, using the Winfit software, measured at different temperatures. © 2010 Elsevier Ltd. All rights reserved.


Padmaraj O.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd | Satyanarayana N.,Pondicherry University
Ceramics International | Year: 2015

Nanocrystalline spinel type magnesium aluminate (MgAl2O4) ceramic material was synthesized by gel-combustion method. The structural, microstructural, morphology, electrical and dielectric properties of the prepared spinel type MgAl2O4 ceramic material were studied by different techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), surface area analyzer (BET) and impedance spectroscopy. The X-ray diffraction pattern and IR spectrum of magnesium aluminate material confirm the formation of impurity free nanocrystalline phase with spinel structure. The specific surface area calculated from the 1/[W((Po/P)-1)] vs relative pressure (P/Po) plot of the annealed MgAl2O4 powder is found to be 162.704 m2/g. The temperature dependent conductivity of nanocrystalline MgAl2O4 pellet was studied and the conductivity of nanocrystalline MgAl2O4 pellet at 573 K is found to be 4.9213×10-13 S cm-1. The activation energies were evaluated from log σT vs 1000/T plot of the observed two different temperature dependent conductivity regions of the nanocrystalline MgAl2O4 sample and are found to be E1=0.1828 eV (<503 K) and E2=0.8791 eV (>503 K). © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.


Padmaraj O.,Pondicherry University | Rao B.N.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd. | Satyanarayana N.,Pondicherry University
Journal of Physical Chemistry B | Year: 2015

Novel hybrid (organic/inorganic) electrospun nanocomposite polymer blend electrolyte fibrous membranes with the composition poly(vinylidene difluoride-co-hexafluoropropylene) [P(VdF-co-HFP)]/poly(methyl methacrylate) [P(MMA)]/magnesium aluminate (MgAl2O4)/LiPF6 were prepared by the electrospinning technique. All of the prepared electrospun P(VdF-co-HFP), PMMA blend [90% P(VdF-co-HFP)/10% PMMA], and nanocomposite polymer blend [90% P(VdF-co-HFP)/10% PMMA/x wt % MgAl2O4 (x = 2, 4, 6, and 8)] fibrous membranes were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The fibrous nanocomposite separator-cum-polymer blend electrolyte membranes were obtained by soaking the nanocomposite polymer blend membranes in an electrolyte solution containing 1 M LiPF6 in ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1, v/v). The newly developed fibrous nanocomposite polymer blend electrolyte [90% P(VdF-co-HFP)/10% PMMA/6 wt % MgAl2O4/LiPF6] membrane showed a low crystallinity, low average fiber diameter, high thermal stability, high electrolyte uptake, high conductivity (2.60 × 10-3 S cm-1) at room temperature, and good potential stability above 4.5 V. The best properties of the fibrous nanocomposite polymer blend electrolyte (NCPBE) membrane with a 6 wt % MgAl2O4 filler content was used for the fabrication of a Li/NCPBE/LiCoO2 CR 2032 coin cell. The electrochemical performance of the fabricated CR 2032 cell was evaluated at a current density of 0.1 C-rate. The fabricated CR 2032 cell lithium battery using the newly developed NCPBE membrane delivered an initial discharge capacity of 166 mAh g-1 and a stable cycle performance. © 2015 American Chemical Society.


Indhrajothi R.,Pondicherry University | Prakash I.,SASTRA University | Venkateswarlu M.,Amara Raja Batteries Ltd | Satyanarayana N.,Pondicherry University
RSC Advances | Year: 2014

Mesoporous copper ferrite (CuFe2O4) nanoparticles were prepared by citric acid and urea assisted combustion process. The local chemical modification obtained through addition of acid and base to the synthesis process, modifies the combustion reaction and it affects the crystalline phase, pore size and surface area of CuFe2O4 nanoparticles. The effect of grain boundary surfaces with different pore sizes on the electrical properties was explained using impedance spectroscopy results, and it was also reflected in the battery performance. The CR 2032 coin cells were fabricated using mesoporous CuFe2O4 nanoparticles with polyvinylidene difluoride (PVdF)/sodium alginate as binders; moreover, the effect of PVdF and alginate binders on the battery performance and coulombic efficiency were analyzed and were correlated to the area covered under oxidation and reduction cycles of cyclic voltammetry. CR 2032 coin cells were fabricated using mesoporous CuFe2O4 raw, acid and base samples with alginate binder and cycled at 1C rate to obtain the effect of crystallite size and surface area on the battery performance. The addition of alginate binder and its good adhesive nature improves the battery performance and retains the capacity for longer cycles. © 2014 the Partner Organisations.


Balusamy T.,Indian National Metallurgical Laboratory | Balusamy T.,Amara Raja Batteries Ltd | Venkateswarlu M.,Amara Raja Batteries Ltd | Murthy K.S.N.,Amara Raja Batteries Ltd | And 3 more authors.
International Journal of Electrochemical Science | Year: 2014

The influence of surface mechanical attrition treatment (SMAT) on the mechanical and electrochemical properties of Pb-Sn alloys is presented. SMAT induced plastic deformation of the Pb-Sn alloy to a depth of ~ 43 μm from the top surface and enabled the formation of a graded layer structure. In spite the increase in average surface roughness (Ra) from 0.40 to 2.42 μm, the uniform dimple-like features generated on the surface of the Pb-Sn alloy helped to improve the interfacial characteristics of active material and grid. SMAT has also enabled a marginal increase in hardness of the Pb-Sn alloy. The electrochemical behavior of the Pb-Sn and treated alloy was evaluated by employing potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The ability of the treated surface to induce passivation offered an increase in corrosion resistance. The current density of the redox reaction profile suggests good charge-discharge characteristics of the SMATed Pb-Sn alloy. © 2014 by ESG.


Padmaraj O.,Pondicherry University | Venkateswarlu M.,Amara Raja Batteries Ltd. | Satyanarayana N.,Pondicherry University
RSC Advances | Year: 2016

Electrospun pure and hybrid nanocomposite PMMA blend fibrous electrolyte membranes with various x wt% of ZnAl2O4, (x = 2, 4, 6 and 8) ceramic fillers were prepared by an electrospinning technique. All the prepared electrospun pure P(VdF-co-HFP), PMMA blend [90% P(VdF-co-HFP)/10% PMMA] and nanocomposite PMMA blend [90% P(VdF-co-HFP)/10% PMMA/x wt% ZnAl2O4, (x = 2, 4, 6 and 8)] fibrous membranes were characterized systematically using X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy. The activated separator-cum-nanocomposite PMMA blend fibrous electrolyte membranes were obtained by soaking in an organic liquid electrolyte solution containing 1 M LiPF6 in EC : DEC (1 : 1, v/v). The newly developed novel nanocomposite PMMA blend fibrous electrolyte [90% P(VdF-co-HFP)/10% PMMA/6 wt% ZnAl2O4/LiPF6] membrane showed low crystallinity, high thermal stability, low average fiber diameter, high electrolyte uptake, high conductivity (4.135 × 10-3 S cm-1) at room temperature and good potential stability above 4.5 V. The optimized best composition of nanocomposite PMMA blend fibrous electrolyte membranes with 6 wt% ZnAl2O4 filler content is used for the fabrication of a (Li/NCPBE/LiCoO2) CR 2032 coin type lithium cell. The fabricated CR 2032 lithium coin cell containing the newly developed nanocomposite polymer blend electrolyte (NCPBE) membrane delivers an initial discharge capacity of 157 mA h g-1 and also exhibits stable cycle performance at a current density of 0.1C rate at room temperature. © The Royal Society of Chemistry 2016.

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