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.
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:Sungchul Choi, Janghyeok Yoon, Kwangsoo Kim, Jae Yeol Lee, and Cheol-Han Kim
Electrolyte Membrane (PEM) technology in Proton Exchange Membrane Fuel Cells (PEMFCs) in “ Case study: polymerelectrolyte membrane in PEMFCs ” section. Finally, this paper finishes with concluding remarks and directions for further study in “ Concluding
Authors:Irina Petreanu, Daniela Ebrasu, Claudia Sisu, and Mihai Varlam
Polymerelectrolyte fuel cells (PEMFCs) are electrochemical devices able to convert chemical energy of hydrogen and other small compounds (methanol) to electrical energy. The capacity to produce a high power
Authors:J. Cruz-Pinto, M. Silva, M. Smith, and C. Silva
Differential thermal analysis, optical microscopy and ionic conductivity studies have been carried out on polymer electrolyte
films prepared by deposition of solutions of neodymium trifluoromethanesulphonate and poly(ethylene oxide). A wide range of
electrolyte concentrations were examined and a partial pseudo-equilibrium phase diagram of the system was determined. From
the results obtained it is evident that the presence of relatively high concentrations of ionic guest species in the polymer
host results in an inhibition of the growth of crystalline material (polymer spherulites or a polymer—salt coordination complex).
The combination of an Ir/Pt PEM electrolyzer with a 1 L flow-through gas proportional counter was characterized for the quantification
of tritium in water. The goal of the detection system is to quantify at concentrations below the Environmental Protection
Agency (EPA) primary drinking water standard (740 Bq/L) with minimal expendables. The detector operating voltage, efficiency,
background count rate of the passively shielded counter were measured in order to calculate the minimum detectable concentration
of the detection system. The electrolyzer fractionation factor βe value deduced from the measurement of gas phase activity concentrations generated from tritium aqueous standards was found
in good agreement with literature values.
Authors:Y. Ogata, Y. Sakuma, N. Ohtani, and M. Kotaka
A tritium separation from heavy water by electrolysis using a solid polymer electrode layer was specified. The cathode was made of stainless steel or nickel. The electrolysis was performed for 1 hour at 5, 10, 20, and 30 °C. Using a palladium catalyst, generated hydrogen and oxygen gases were recombined, which was collected with a cold trap. The activities of the samples were measured by a liquid scintillation counter. The apparent tritium separation factors of the heavy and light water at 20 °C were 2 and 12, respectively.
Aqueous tritium enrichment parameters of a commercially available Iridium/Platinum (Ir/Pt) polymer electrolyte membrane (PEM)
cell were determined after electrolysis of tritium aqueous standards, and compared to those of a conventional Nickel/Iron
(Ni/Fe) electrochemical cell. Lower aqueous enrichment is seen in the Ir/Pt PEM electrolyzer in comparison to the conventional
Ni/Fe electrolytic cell. This is explained by the values found for the PEM cell fractionation factor βIr/Pt and electrolytic fractionation factor βeIr/Pt values determined to be 4.7 ± 0.3 (βNi/Fe = 26), and 6.6 ± 0.7 (βeNi/Fe = 37), respectively. A direct consequence of the Ir/Pt βe value is the richer tritium gas phase produced relative to the conventional cell, which is advantageous for direct reduction
of HTO to HT gas.