Graduate School of Science and Engineering Science of Environment and Mathematical Modeling

<1> Rechargeable Metal Hydride/Air Battery

Energy storage and supply system linked to renewable energies such as solar and wind powers is one of the most important infrastructures to reduce CO2 emission in generation and consumption of electric energy, and a secondary battery is the key technology of electric energy storage and supply. Advanced battery development beyond lithium ion secondary batteries (LIB) has been carried out by academia and industries in past decades, in which a high energy density (ED) beyond LIB is required, which means electric energy to store per unit volume or weight of a battery is high. Materials needed for high energy density are mostly chosen from more reactive ones than lithium in combination with flammable solvents for the electrolyte, although high energy density storage devices should keep themselves safe and environmentally friendly.

<2> Highly Sensitive and Selective Ion Sensor

Compositional analysis of blood and urine is important for illness diagnosis and health management, and electrochemical (EC) ion sensors are one of the useful devices for them. EC sensors have a potential of rapid, highly sensitive, and highly selective detection and quantification, which strongly depends on the material and structure of the detecting electrode. Our laboratory has been developing smart electrodes for such ion sensors and has demonstrated to be able to quantify hydrogen phosphate and hydrogen carbonate in blood with the smart electrode comprising amorphous mixed oxides. The smart electrode has shown a linearity between the concentration and the oxidation current density of the ions over 4 digits of concentration range (Figs. 3). The smart electrode is also appropriate to ion sensing of those ions in environmental water.