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Synthesis and characterization of Li2MnO3 nanoparticles using sol-gel technique for lithium ion battery

Chennakrishnan Sandhiya, Thangamuthu Venkatachalam, Subramaniyam Akshaya, Venkatachalam Viknesh, Venugopal Manikandan, Marudhan Raju

Materials Science Poland

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2020

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Vol. 38, No. 2

312--319

EN

Nanoparticles of Li2MnO3 were fabricated by sol-gel method using precursors of lithium acetate and manganese acetate, and citric acid as chelating agent in the stoichiometric ratio. TGA/DTA measurements of the sample in the regions of 30 °C to 176 °C, 176 °C to 422 °C and 422 °C to 462 °C were taken to identify the decomposition temperature and weight loss. The XRD analysis of the sample indicates that the synthesized material is monoclinic crystalline in nature and the calculated lattice parameters are 4.928 Å (a), 8.533 Å (b), and 9.604 Å (c). The surface morphology, particle size and elemental analysis of the samples were observed using SEM and EDAX techniques and the results confirmed the agglomeration of nanoparticles and, as expected, Li2MnO3 composition. Half cells of Li2MnO3 were assembled and tested at C/10 rate and the maximum capacity of 27 mAh/g was obtained. Charging and discharging processes that occurred at 3 V and 4 V were clearly observed from the cyclic voltammetric experiments. Stability of the electrodes was confirmed by the perfect reversibility of the anodic and cathodic peak positions observed in the cyclic voltammogram of the sample. The Li2MnO3 nanoparticles exhibit excellent properties and they are suitable for cathode materials in lithium ion batteries.

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Influence of bath temperature on microstructure and NH3 sensing properties of chemically synthesized CdO thin films

Sharma A. K., Potdar S. S., Yewale M. A., Shirgaonkar Deepak B., Pakhare K. S., Sargar B. M., Rokade M. V., Patil U. M.

Materials Science Poland

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2019

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Vol. 37, No. 1

25--32

EN

Cadmium oxide (CdO) thin films were synthesized using chemical bath deposition (CBD) method from aqueous cadmium nitrate solution. The bath temperatures were maintained at room temperature (25 °C) and at higher temperature (80 °C). The structural studies revealed that the films showed mixed phases of CdO and Cd(OH)2 with hexagonal/monoclinic crystal structure. Annealing treatment removed the hydroxide phase and the films converted into pure CdO with cubic, face centered crystal structure. SEM micrographs of as-deposited films revealed nanowire-like morphology for room temperature deposited films while nanorod-like morphology for high temperature deposited films. However, cube-like morphology was observed after air annealing. Elemental composition was confirmed by EDAX analysis. Band gap energies of the as-deposited films varied over the range of 3 eV to 3.5 eV, whereas the annealed films showed band gap energy variation in the range of 2.2 eV to 2.4 eV. The annealed films were successfully investigated for NH3 sensing at different operating temperatures and at different gas concentrations. The room temperature synthesized film showed a response of 17.3 %, whereas high temperature synthesized film showed a response of 13.5 % at 623 K upon exposure to 24 ppm of NH3.

3

Development of Electroless Ni-P Coatings on Sisal Fiber

Hemachandran R., Pugazhvadivu M., Jayabal S.

Fibres & Textiles in Eastern Europe

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2017

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Vol. 25, no. 1 (121)

32--35

EN

Improving the properties of natural fibers can be interesting from a technological point of view. Modifications can result in a high specific strength, electromagnetic interference (EMI) shielding, antistatic brush etc. Plant fiber composites would make them an option for use in components such as rifle stocks and knife handles etc. The greatest challenge would be to ensure that the components are all weather capable, but today several materials exist that have a high moisture tolerance. Moreover with proper surface coating techniques, most natural fibers materials can be toughened up to use as reinforcement. An attempt was made using a proprietary experimental set-up to coat natural fiber with electroless nickel phosphorus (ENi-P), since sisal fiber is a non-conducting material. In this article the surface morphology, ingredients and cross-section images of the modified natural fibers were characterised by a scanning electron microscope equipped with EDAX.

PL

Poprawa właściwości włókien naturalnych jest interesująca z technologicznego punktu widzenia. Wynikiem modyfikacji może być wysoka wytrzymałość, poprawa ekranowania pól elektromagnetycznych (EMI), poprawa właściwości antystatycznych itp. Powłoki niklowo-fosforowe na włóknach roślinnych umożliwiają wytworzenie różnego rodzaju kompozytów, min. o powierzchni odpornej na wilgoć. Morfologia powierzchni kompozytów była badana za pomocą SEM-EDAX.

4

Optimization of deposition temperature of SILAR Cu-rich CuInS2 thin films

Maheswari B., Dhanam M.

Materials Science Poland

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2013

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Vol. 31, No. 2

193--200

EN

CuInS2 (CIS) is studied widely as a promising absorber material for high efficient and low cost thin film solar cells. CIS thin films are prepared on soda lime glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at different deposition temperatures (40 to 70 °C). The structural, compositional and optical properties are studied with x-ray diffractometer, energy dispersive x-ray analyzer and spectrophotometer. The influence of the deposition temperature on the properties of CIS thin films is discussed in this paper in detail.

5

Identification of growth mechanism of CBD CIAS thin films from SEM analysis

Kavitha B., Dhanam M.

Materials Science Poland

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2013

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Vol. 31, No. 4

506--515

EN

Near stoichiometric and stoichiometric CuIn(1-x)Al(x)Se2 (CIAS) thin films have been prepared by chemical bath deposition (CBD) technique. X-ray diffraction (XRD) and energy dispersive x-ray analysis (EDAX) spectra have been employed to confirm the structure and composition of the prepared films. SEM analysis of near-stoichiometric and stoichiometric CIAS thin films enabled us to estimate the grain size, to identify the growth mechanism and also to visualize the surface morphology. Transmittance spectra have been employed to determine the type of transition and other optical parameters such as absorption coefficient, extinction coefficient, dielectric constant, refractive index, Sellmeier parameters and bandgap which are reported in this paper in detail.

6

Allochtoniczność pokryw pyłowych na stokach Ślęży (Przedgórze Sudeckie) w świetle analizy ich składu chemicznego w skaningowym mikroskopie elektronowym (SEM)

Woronko B., Żurawek R.

Przegląd Geologiczny

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2002

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Vol. 50, nr 6

535-540

PL

Dla rozstrzygnięcia problemu allo- bądź autochtoniczności osadów pylastych, współtworzących pokrywy stokowe Ślęży (718 m n.p.m.) na Przedgórzu Sudeckim zastosowano metodę określania składu chemicznego detektorem rentgenowskim ECON. Wobec braku minerałów z grupy krzemionki w budującym wschodni stok Ślęży gabrze oraz ich znacznym udziale (około 70%) w analizowanych próbach, reprezentujących osady z wysokości 280-508 m n.p.m., wykazano allochtoniczność osadów pyłowych. Stwierdzenie to, w połączeniu z pozycją geomorfologiczą osadów i ich cechami litologicznymi, pozwoliło na wykluczenie innych niż eoliczny procesów mogących odpowiadać za ich depozycję.

EN

Mapping of the chemical composition of the siltfraction which composes to a considerable extent the slope covers ofMt. Ślęża (718 m a.s. I.), Sudetic Foreland, SW Poland has been carried out in order to verify their alio- or autochtonism. An X-ray detector ECONhas been used. Lack of the silica minerals within the rock composing eastern slope of the Mt Ślęża, i.e. gabbro, compared with an abundant (70%) occurrence of such minerals within the samples derived from different altitudes (280-508 m a.s. I.), allowed one to state the allochtonism of the siltfraction. Taking into account both this statement and the geomorphological setting and the lithological features of the silty deposits, one can exclude all processes other than aeolian activity as potential factors of deposition of these sediments.