Papers by Keyword: Nasicon

Abstract: This study aims to analysized the effect of addition doped metal (Ti and Zn) on NASICON structure to morphology, materials structure, and electrochemical performance especially ionic conductivity properties. NASICON is a sodium super ionic conductor that it could be as solid electrolyte batteries. One of the problems that exist in the secondary battery is the low working temperature of the electrolyte, which makes it easy to explode when exposed to free air. The common electrolyte in liquid phase, so NASICON as replacement alternative. The synthesis method used is the solid-state reaction method by mixing sodium carbonate, silicon dioxide, zirconium oxide, ammonium dihydrogen phosphate, doped metal (titanium oxide and zinc oxide) and some anhydrous ethanol into a planetary ball mill, dried then calcined. Then the material is pressed to produce pellets and the sintered. The doping used varies from 0 to 5 mol% of titanium and zinc. XRD results showed that all variations in titanium doped had found rhombohedral and monoclinic. whereas in zinc doping also have those phase. The highest ionic conductivity is 7.8x10^-3 S/m on 2% mol Zinc Addition

Abstract: An alternative sensor that can be used to monitor Nitrogen Oxide (NOx) levels in the air is an electrochemical sensor type such as Sodium Super Ionic Conductor (NASICON). In this study titanium doping on zirconium was carried out to improve the electrical conductivity of NASICON. This material was synthesized using the solid state method by mixing sodium carbonate, silicon dioxide, zirconium oxide, ammonium dihydrogen phosphate, titanium dioxide and some anhydrous ethanol into the Ballmill for 12 hours, dried at 80 °C for 12 hours then calcined at 1125 °C for 12 hours with heating rate of 2 °C.min^-1. Then the material was pressed at 160 MPa to produce pellets with diameter of 10 mm and the sintering process was carried out at 1175 °C for 12 hours at a speed of 1 °C.min^-1. The doping of Titanium was varied from 0 to 6 mol%. The XRD characterization results indicate that the formed material phase was monoclinic phase and rhombohedral phase. The most optimal electrical conductivity of 5.897x10^-5 S.cm^-1 was obtained by Titanium doping of 6 mol%.

Abstract: NASICON materials can be used as the solid electrolyte component in the sensor system, because they have excellent Na⁺ conductivity. This study prepares NASICON materials by solid state reaction method, and their phase, microstructure and electrical property will be characterized by XRD, SEM and EIS. Then an amperometric NO₂ sensor is fabricated to detect NO₂ gas in the level of ppb. The sensor current signal will be studied by changing different NO₂ concentrations, employing different materials on the counter electrode and using different applied voltages when the working temperature is 150°C.

Abstract: In this work, NASICON-type disks with the formula, Na₃Zr₂Si₂PO₁₂ were prepared by non-aqueous tape casting method. The effect of the dispersant on the slurry viscosity was investigated, triethanolamine was found to be an effective dispersant for NASICON slurry. The correlation between the overall conductivity and the sintering conditions (temperature and time) for the NASICON disk was also studied. Green tapes were calcined at 900°C, 1000°C, 1100°C for 6h and 12h, respectively. Results revealed that the overall conductivity increased with the increasing of the sintering temperature and decreased with the increasing of the sintering time. The segregation of resistive monoclinic ZrO₂ phase was examined to have a negative effect on the overall conductivity. The CO₂ sensor using NASICON disk and Li₂CO₃-BaCO₃ complex thick film was fabricated and evaluated, the sensitivity was about 82.9 mV/decade at 450°C.

Abstract: Nasicon type compounds of general formula Li1..3M0.3Ti1.7 (PO4)3 (M = Al, Cr, Fe) were prepared using melt quenching method. The samples were characterized by X-ray powder diffraction and infrared spectra. Thermal stability against crystallization was evaluated by DSC curve. All the compounds crystallize in hexagonal lattice with R-3c space group. The IR spectra show the characteristic PO4 vibrations. DSC curve reveals that the Li1.3Fe0.3Ti1.7(PO4)3 glass-ceramics possesses the better thermal stability against crystallization. Conductivity studies indicate that the total conductivity is dominated by the grain boundary

Abstract: Lithium aluminium titanium phosphate (LATP) with different stoichiometric ratios according to the formula Li_1+xAl_xTi_2-x(PO₄)₃ with x = 0, 0.2, 0.4, 0.5 and 0.8 are prepared by mechanical milling method. The structural and electrical properties of the prepared samples are investigated by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and A.C Impedance Spectroscopy (IS). The XRD results showed that the sample milled for 60 hours has very low crystallinity with conductivity value of ˜10^-7 S cm^-1. The conductivity is enhanced by one order of magnitude upon sintering of the samples at 900 °C for 6 hours. This enhancement may be attributed to formation of improved grain homogeneity and contacts.

Abstract: Li₂O-Al₂O₃(La₂O₃)-TiO₂-P₂O₅ glass-ceramics were fabricated through heat-treatment of the original glass. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical workstation were employed to study the structural, morphology and electrical properties of the samples heat-treated at different temperatures. The results showed that: the glass-ceramics consist of the dominating LiTi₂(PO₄)₃ phases, trifle AlPO₄, TiO₂ and unknown phases. With the heat-treatment temperature increasing from 700 °C to 1100 °C, the structure of glass-ceramic become denser and grain grew, lithium ion conductivity increased quickly and subsequent cut down gradually. While the specimen was obtained by crystallization at 900 °C for 12 h, the total conductivity of glass-ceramic material come up to the maximum (5.85 ×10^-4 S•cm^-1) at 25 °C. This inorganic solid electrolyte has a potential application in lithium batteries or other devices.

Abstract: LiSn2P3O12 has been prepared using mechanochemical milling method and sintered at 700 °C, 800 °C, 900 °C and 1000 °C for 8 hours. All samples sintered up to 900 °C show a rhombohedral structure. However, the sample sintered at 1000 °C possessed a monoclinic structure. This is attributed to the rotation of skeleton LiSn2P3O12 as indicated by the change in the a and c parameters of the sample. The sample sintered at 700 °C shows the highest bulk conductivity of 1.65 × 10-6 S cm-1 and the lowest bulk activation energy of 0.09 eV. The grain boundary activation energy of the samples decreases with increase in sintering temperature due to enhancement in grain contacts.

Abstract: Electrophoretic deposition method was applied to prepare some solid-electrolyte thick-films of Na1+xZr2SixP3-xO12 (x = 2, 3; NASICON) and Na5DySi4O12 (NDSO) on Au-coated alumina substrates. With the ethanol-based medium, the deposition process was investigated under constant voltage mode. The concentration of the suspension and applied voltage were optimized with respect to the rate of deposition and quality of the deposit. The NASICON (Na3Zr2Si2PO12) -based solid-state ionic conductor thick-film as a host ceramic with a guest Cu+ ion has been produced as a noble phosphor thick-film by using an electrochemical ion doping method. The photoluminescence (PL) device of the NASICON:Cu+ film showed good photo-luminescent peaks near 450-500nm depending on the host materials.