Variation Of Open Circuit Voltage Research Articles

Electrochemical studies on solid state cells with mol % 70AgI-20Ag2O-10(0.8V2O5-0.2P2O5) amorphous electrolyte and organic cathodes

The highest conducting amorphous solid electrolyte composition (mol %) 70AgI-20Ag2O-10(0.8V2O5-0.2P2O5) in the system AgI-Ag2O-V2O5-P2O5 was investigated as an electrolyte material for solid state cells with organic cathodes by studying the electrochemical properties. The variation of open circuit voltage (OCV) with temperature, current discharge and the load characteristics were determined for the cells with iodine, tetramethyl ammonium iodide and tetrabutyl ammonium iodide as cathode materials. The cell capacities were estimated from the load characteristic curves and, in general, the cells were found to have very good stability at low current discharges even at high temperatures. In addition, it was found that the silver on the working electrode is electrochemically active and can be oxidized to Ag+ ions, making the organic cathode cells rechargeable. Thus these cells find potential use in rechargeable micropower sources and uninterrupted power supplies for microelectronic circuit devices.

Electrical conductivity, TEP and dielectric studies on mol% 66.6 Agl-22.2 Ag2O-11.1 (0.8 V2O5-0.2 P2O5) electrolyte material for solid state batteries

In the superionic conducting quarternary system Agl-Ag2O-V2O5-P2O5, the best ionic conductivity was obtained for the composition 66.6% Agl-33.3% (2Ag2O-1 (V2O5-P2O5)), when the GF/GM ratio was varied from 0.20 to 5.0. Then fixing the GF/GM ratio at 0.50, the ratio of the glass formers V2O5 and P2O5 were varied and the highest conducting composition was obtained as 66.6% Agl-22.2 Ag2O-11.1% (0.8 V2O5-0.2 P2O5). A preliminary investigation using this material in the form of an electrolyte in a solid state electrochemical cell is reported. The polycrystalline and amorphous compounds were prepared from the same melt, by open air crucible melting and the rapid quenching technique. The ionic conductivity for the best conducting polycrystalline (hence referred as 66VP82P) and amorphous (66VP82G) samples was obtained as 8.3 × 10−3 and 4.2 × 10−2 Ω−1 cm−1 respectively. The electronic conductivity of the order 10−10 Ω−1 cm−1 was observed for 66VP82G and 10−8 Ω−1 cm−1 for 66VP82P samples. Thermoelectric power studies revealed that the charge carriers are the Ag+ ions, with an activation energy of 0.288eV for 66VP82G, which correlated well with the activation energy obtained from the conductivity measurements. The dielectric constant, dielectric loss and the loss tangent were calculated for both polycrystalline and glassy 66VP82 material. It was observed that the dielectric loss is more for the glassy material than the polycrystalline material. Solid state galvanic cells with 66.6% Agl-22.2% Ag2O-11.1% V2O5, 66.6% Agl-22.2%-Ag2O-11.1% P2O5 and 66.6% Agl-22.2% Ag2O-11.1% (0.8 V2O5-0.2 P2O5) (coded as 66V, 66P and 66VP82 respectively) electrolytes were constructed. Both polycrystalline and amorphous electrolyte cells were fabricated for a comparative study and the polarization effects were observed to be negligible in amorphous cells. The variation of open circuit voltage with temperature was reported and the current discharge curves indicate that the 66VP82 material has higher current capacity with high current drain when compared to 66V and 66P cells.

Transport studies on superionic AgI−Ag2O−CrO3 glasses

Glasses in the system x AgI-(1- x ) (Ag 2 O-2CrO 3 ) with 0≤ x ≤1 have been prepared and characterised by X-ray diffraction technique. Ionic and electronic conductivity studies have been carried out on all the samples in the glass forming region. On the best conducting composition, thermoelectric power studies have also been carried out. Transport number of silver ions has been found by EMF method. A typical galvanic cell was constructed with the highest conducting composition as the electrolyte and the variation of open circuit voltage with time was investigated.

Photoelectrochimie de CdIn 2S 4: Caracteristiques photoelectrochimiques de [formula omitted] aqueux

The photoelectrochemical characteristics of the CdIn 2 S 4 (n) electrolyte cell have been studied. Surface traitments enhance the short circuit current density. This phenomena has been interpreted by a decrease of the recombination of minority carriers at the electrode/electrolyte interface. The variation of open-circuit voltage up on the incident light intensity shows that the cell can be represented by the Schottky barrier model.

Thermodynamics and kinetics of lithium diffusion in V6O13

The equilibrium voltage-composition curve for LixV6O13 between x = 0 and x = 0.7 has been determined in a cell using a single crystal V6O13 cathode, polymer solid electrolyte and a lithium metal anode. Values obtained for the diffusion coefficient of lithium from galvanostatic experiments were found to vary from 10−8 to 10−9cm2S−1; however the interference of a limiting factor other than that of diffusion in V6O13 was suspected. From the variation of open circuit voltage with temperature the partial molar entropy of lithium has been determined as a function of composition. Defects in the structure of the non-stoichiometric decomposition product of NH4VO3 have been observed by high resolution electron microscopy.

Open-circuit voltage and interface study of silicon MOS solar cells

It has been recognized that an ultrathin insulator interface (oxide) between a semiconductor and a metal contact enhances the performance of an MOS solar cell over the corresponding MS structure. Also it is now recognized that a transition region of 10-20 A exists at the Si-SiO 2 interface. Because the oxide layer thickness in MOS Si solar cells is comparable to the transition region, the nonstoichiometry and pinholes associated with the ultrathin oxide layer will affect the performance of the MOS solar cell. In the present paper the nonstoichiometry of the ultrathin oxide layer is treated by varying the parameters associated with the Si-SiO x interface and the pinholes in the oxide have been treated by associating a different barrier height to the pinhole regions. The resulting theoretical model is shown to explain the experimental variation of open-circuit voltage with the oxide layer thickness.