Authors:Y. Kato, K. Hasumi, S. Yokoyama, T. Yabe, H. Ikuta, Y. Uchimoto, and M. Wakihara
We have focused on the poly(ethylene glycol) (PEG)-borate ester as a new type plasticizer for solid polymer electrolyte for
lithium ion secondary battery. Adding the PEG-borate ester into the electrolyte shows the increase in the ionic conductivity
of the polymer electrolyte. By measuring the glass-transition temperature of the polymer electrolytes with DSC, it is found
that the increase in ionic conductivity of the polymer electrolyte is due to the increase in ionic mobility. By investigating
the temperature dependence of the ionic conductivity of the polymer electrolytes using William-Landel-Ferry type equation,
we considered that the PEG-borate ester does not have any influence for dissociation of Li-salt.
Positron annihilation lifetime spectra and ionic conductivity have been measured for poly(etherurethane)-LiClO4 as a function of temperature. The effects of Li salt on glas transition free volume and ionic conductivity have been discussed. A correlation between fractional free volume and ionic conductivity was first experimentally confirmed by using the free volume theory.
Authors:A. Hamzaoui, K. Ben-Saâd, M. Férid, and A. M’Nif
The formation of a new sulfate compound K4H2(SO4)3 is obtained by evaporation at 25C of an aqueous solution, which was
formed by a mixture of K2SO4
and H2SO4. The characterization
of this solid is carried out by X-ray diffraction, thermal and infrared analyzes.
The heat treatment was carried out in interval 25–700C; the end
product of the thermal evolution is K2SO4.
The vibration bands relating to SO4 and OH groups were
highlighted by the infrared spectroscopy.Moreover, one study of ionic conductivity
on this solid compound was carried out according to the temperature in interval
25–80C. Its activation energy is 0.47 eV. The X-ray intensities
collection obtained on a monocrystal of K4H2(SO4)3
gives the following cell parameters: a=7.035(5), b=19.751(4), c=23.466(2)
Pure and several Cu2O-doped binary lithium borate glasses have been prepared and annealed.
Extensive measurements of the temperature-dependence of DC electrical conductivity were made on these samples and the corresponding
activation energies of conduction were evaluated in each case. The results obtained are discussed in detail. They indicate
that the phenomena of the formation of BO3 triangles and a mixed alkali metal effect appear.
Authors:Dhruthiman R. Mantheni, M. P. K. Maheswaram, Hany F. Sobhi, Naullage Indika Perera, Alan T. Riga, M. Ellen Matthews, and K. Alexander
continuation of the ionicconductivity as a function of temperature in the premelt phase.
DEA (TA Instruments 2970) was used to determine electrical conductivity profiles. A single surface gold ceramic electrode ( Fig. 1 ) was calibrated by the
Authors:Agata Górniak, Alina Wojakowska, Stanisława Plińska, and E. Krzyżak
Electrical conductivity of solid systems AgX-MX2 (where M=Cd, Co, Zn and X=Cl, Br) were measured in a large range of temperature and compositions. Activation energies and conductivity values vs. composition are presented and discussed in relation to phase equilibria in the respective systems. Maximum of the conductivity
value and stabilization of the activation energy have been found for silver halides doped heavily with divalent cation e.g.
in the systems forming solid solutions on the silver halide side. Disorder in AgBr on the approach to melting, expected to
be higher than in AgCl, has been shown by means of original DSC curves presented for both halides.
Relations are demonstrated between the conductivity, phase structure and thermal history of some solid polymeric electrolytes. The results obtained for systems based on commercially available polymers, e.g. (ethylene oxide), and for specially synthesized materials are presented. Special emphasis is placed on the correlation between the crystallinity, glass transition temperature, melting temperature and conduction properties of the polymeric electrolytes.
Authors:A. Caneiro, L. Mogni, N. Grunbaum, and F. Prado
Oxide mixed conductors exhibiting both electronic and ionicconductivity have attracted much attention in the last years due to their potential application in high temperature electrochemical devices such as
Authors:T. Mori, T. Ikegami, H. Yamamura, and T. Atake
Y2O3 has a crystal structure of c-type rare-earth oxide. Y2O3 does not show an oxide ionic conductivity. On the other hand, CeO2 based oxide is one of the most interesting of the fluorite oxides since the ionic conductivity of it is higher than that of yttria-stabilized zirconia. However, CeO2 based oxides are partially reduced and develop electronic conductivity under reduced atmosphere.In this study, the effective index for the improvement of ionic conductivity in Y2O3 and CeO2 systems was defined using ionic radii from the viewpoint of crystallography. The utility of this effective index on some electrical properties was investigated.
Authors:Toshiyuki Mori, John Drennan, Yarong Wang, Ji-Guang Li, and Takayasu Ikegami
Doped ceria (CeO2) compounds are fluorite type oxides that show oxygen ionic conductivity higher than yttria stabilized zirconia, in oxidizing
atmosphere. In order to improve the conductivity, the effective index was suggested to maximize the oxygen ionic conductivity
in doped CeO2 based oxides. In addition, the true microstructure of doped CeO2 was observed at atomic scale for conclusion of conduction mechanism. Doped CeO2 had small domains (10-50 nm) with ordered structure in a grain. It is found that the electrolytic properties strongly depended
on the nano-structural feature at atomic scale in doped CeO2 electrolyte.