Humidity Driven Transition from Insulator to Ionic Conductor in Portland Cement

This work aims to assess ionic conduction in anhydrous cement particles and hydrated cement pastes with aging periods of 5–25 days. When a cement sample was humidified (relative humidity = 100%) over the range of 50–100 °C, it exhibited bulk conductivities of 10−3–10−2 S cm−1, regardless of the hydration level, whereas the interfacial conductivities varied in the range of 10−7–10−3 S cm−1, depending on the structural defects or conduction pathways of the sample. Both the bulk and interfacial conductivities were increased to 0.01 S cm−1 or higher at 100 °C, although the sample required previous moistening with water mist. The major charge carrier in the sample was determined to be hydroxide ions, and the total ion transport number was approximately 1. Exposing the sample to a mixture of carbon dioxide and water vapor caused a decrease in the bulk and interfacial conductivities; however, the bulk conductivity was returned to the initial value by treatment with an acid.

Controlling mixed conductivity in Na1/2Bi1/2TiO3 using A-site non-stoichiometry and Nb-donor doping

Bi-excess and Nb-doping can both be used to fine-tune the Na0.5Bi0.5TiO3 oxygen-ion transport number from near zero to one.

Summary of Lithium-Ion Battery Polymer Electrolytes

Polymer electrolyte is a good ion conductor in lithium-ion battery with an excellent performance in conductivity, ion mobility and ion transport number. Some researches show strengthening mechanisms of polymer electrolyte membranes correlated with macromolecules group weight of PEGDME such as concentration of compounded Li+ salt. Ion transport in glassy polymer electrolytes including polymer backbones with same mesogenic chains can affect amorphous structure and relaxation at ambient temperature. In addition, singe crystal structure polymer electrolytes have various internal microstructures and external properties such as conductivity and charge or discharge stability in electrochemical that correlating with layers of ion diffusion and forming.

Conductivity dependence on oxygen partial pressure and transport number measurements of La2Mo2O9

Transport number measurements and impedance spectroscopy in controlled temperature and atmosphere were used to investigate the electrical properties of La2Mo2O9 sintered samples. These samples were prepared from nanocrystalline La2Mo2O9 powders as obtained from a new soft chemistry route involving the polymerisation of acrylamide. By means of the electromotive force method measurements, the sintered compound was found mainly oxygen conductor in the range of 400 °C-800 °C with oxide-ion transport number greater than 0.99. The effect of the oxygen partial pressure on the electrical conductivity of La2Mo2O9 was investigated by impedance spectroscopy from 1 to 10−22 atm, showing a highly stable conduction properties up to 10−17 atm at 800 °C.