Ionics
The present paper reports the reactivity between TiO2 and oxygen and the related charge transfer at 298 and 1,073 K. The studies were performed using work function measurements. It was found that oxidation of TiO2 at 1,073 K and p(O2) = 75 kPa, initially standardized at 1,173 K and p(O2) = 10 Pa, results in work function changes that are consistent with the theoretical model of the charge transfer...
A solid polymer electrolyte (SPE) film consisting of poly(ethylene oxide) (PEO) with magnesium chloride as electrolytic salt and B2O3 as the filler has been prepared by solution casting technique. The polymeric film was flexible and self-standing with proper mechanical strength and studied for application in a solid-state rechargeable magnesium battery. The interactions between the filler and PEO...
Alkaline polymer electrolytes (ASPE) have been prepared by using poly(vinyl alcohol) (PVA) polymer and which different weight percentages of potassium hydroxide (KOH), ceramic filler (α-Al2O3), and propylene carbonate (PC) have been added. The pure PVA/H2O weight ratio (1.00:1.49), the PVA/KOH/H2O (1.00:0.67:2.22), the PVA/KOH/α-Al2O3/H2O (1.00:0.67:0.09:7.56), and PVA/KOH/α-Al2O3/PC/H2O (1.00:0.67:0...
Electrical conductivity, differential scanning calorimetry, and X-ray diffraction measurements were performed on a pentacesium trihydrogen tetrasulfate, Cs5H3(SO4)4, crystal. The transition entropy at a superionic phase transition and the activation energy of proton migrations in the superionic phase were determined to be 58.2 J K−1 mol−1 and 0.48 eV, respectively. The crystal structure of Cs5H3(SO...
A PtSn/C electrocatalyst with a Pt–Sn molar ratio of 50:50 and A PtSnNi/C electrocatalyst with a Pt–Sn–Ni molar ratio of 50:40:10 were prepared by alcohol-reduction process using ethylene glycol as solvent and reducing agent. The electrocatalysts were characterized by energy dispersive X-ray, X-ray diffraction, and cyclic voltammetry. The electro-oxidation of ethylene glycol was studied by cyclic...
A low-temperature all-solid-state thermal method has been developed to synthesize electrolytes like LiAsF6, LiPF6 and allied lithium-based fluoro-chemicals useful for lithium secondary cells. This developed procedure is simple and environmentally friendly compared with the existing procedures, which are poisonous and hazardous to health due to the use of obnoxious gases or liquids like F2, AsF3, PF...
We have calculated the electronic states of AgX and CuX (X = Cl, Br, I) by using the DV-Xα method. The density of states (DOS) and the bond overlap populations (BOP) of AgX and CuX are calculated by assuming the several model clusters with the nearest, second, and third-neighbor atoms. The cluster-size variations of DOS and BOP are discussed from the viewpoint of the chemical bond between the neighboring...
Ce(1−x)Gd/Sm x O2−δ (x = 0.05–0.2, GDC/SDC) nanometric powder was prepared by glycine-nitrates combustion synthesis, by strictly following uniformity in the preparation route. The thermochemical properties of the obtained precursor were studied by TGA/DTA. Crystallization of the fluorite phase occurred on heating at 800 °C or higher temperature. The grain size of calcined powder was found to be about...
A novel process was proposed to synthesize the pyrolytic polyacrylonitrile (PAN)/SnCl2 composite anode material for Li-ion batteries. The preparation started with the dissolution of PAN and SnCl2 in dimethylformamide (DMF), followed by drying of the solution and pyrolysis of the dried mixture of PAN and SnCl2 at 300 °C, leading to homogenous dispersal of SnCl2 in pyrolytic PAN, which becomes conducting...
The introduction of Co, Al, and Ti into LiMn2O4 cathode powders has been studied in this work. The substitution of 25% Mn with either of these metals is expected to improve the cycle ability of the cathode, while the Jahn–Teller effect is suppressed. The solid-state reaction method is used in order to produce the cathode materials, which are prepared at 750 or 800 °C. The materials are characterized...
The effect of thickness of oxide-sensing electrode (SE) on NO2 sensitivity of the planar sensor based on yttria-stabilized zirconia (YSZ) was examined at high temperatures. The sensitivity of the sensor increased with decreasing thickness of SE, and the highest sensitivity was obtained by using the thinnest layer of Cr2O3–SE (2.7 μm) at 700 °C. In the case of NiO–SE, the highest sensitivity was observed...
Multiple ion-doped lithium manganese oxides LiCrxNixMn2-2xO4-zFz (0 < x ≤ 0.25, z = 0.05, 0.1) with a spinel structure and space group Fd $$ \overline{3} $$ m were prepared by using the co-precipitation procedure carried out in water–alcohol solvent using adipic acid as the chelating agent. The electrochemical measurements indicated that the charge/discharge capacities of the samples prepared...
LiCo0.5Fe0.5O2 was prepared by sol–gel method. The sample had spinel, cubic and hexagonal phases up to 873 K and a single hexagonal phase above 1,073 K. The magnetic properties were studied at room temperature and at 77 K. The large coercivities observed for the samples annealed at 1,073 and 1,273 K show that these samples do not exhibit a simple antiferromagnetic ordering. From the Mössbauer and...
To evaluate the exchange current I o of the oxygen electrode reaction at the O2 strontium-doped lanthanum manganite (LSM)/yttria stabilized zirconia (YSZ) composite/YSZ interface, the variation of the current I vs overvoltage η is measured at low cathodic and anodic polarizations (−50 to 30 mV). A linear behavior is observed within this potential domain with a unique slope. Taking into account of...
The ion transport mechanism in solid electrolyte LiI(C3H5NO)2 (J Am Chem Soc 127:6394, 2005) was investigated using first-principles molecular dynamics simulation. Both atomic and electronic structures and ion diffusion dynamics indicate that LiI(C3H5NO)2 is a unique Iodine ion conductor. This conclusion is opposite to the common intuition that the diffusion should be more favorable for Li+ ions due...
Electrical noise associated with ion transport (termed as “ionic noise”) has been measured at different temperatures, using a lock-in amplifier and dynamic signal analyzer for a polymer electrolyte PEO:NH4I and its CdS dispersed composite. The ionic noise suddenly increases as the polymer passes through its phase transition at T g and T m. The T g-peak in the noise measurement appears more clearly...
Microstructural characterization of thin films of 5 mol% gadolinia doped ceria films deposited by pulsed laser ablation in the energy range 100–600 mJ/pulse has been investigated, as deposited films were found to be nanocrystalline with preferred orientation. X-ray diffraction analysis revealed that the size of the nanocrystals of doped ceria does not vary significantly with increasing laser energy,...
This study was aimed to synthesize a ceramic electrolyte of BaCe0.76Zr0.19Yb0.05O2.975 using acetate and chloride precursors. The transparent sol was stable for more than 10 months but only 3 months for the gel. The dried gel was characterized using thermogravimetric analysis/differential scanning calorimetry, particle analyzer, X-ray diffraction (XRD), and scanning electron microscopy/dispersive...
Thermal properties of 15-mol% gadolinia doped ceria thin films (Ce0.85Gd0.15 O1.925) prepared by pulsed laser ablation on silicon substrates in the temperature range 473–973 K are presented. Thermal diffusivities and thermal conductivities were evaluated using photoacoustic spectroscopy. The influence of grain size on thermal properties of the films as a function of deposition temperature is studied...