Kohki Tamura

Phosphoric Acid Absorption and Performance of Gas Diffusion Electrode

The relationship between acid absorption of the catalyst layer and performance of the gas diffusion electrode in a phosphoric acid fuel cell is investigated, together with the size of pores available for the cathode and anode reactions. The electrode was made from a carbon-supported platinum catalyst and a polytetrafluoroethylene dispersion spread (with a subsequent heating) on a porous carbon substrate. It was found that a nonionic surfactant contained in the dispersion enhanced acid absorption. An analysis of the pore volume and pore distribution indicated that pores from 0.2 to 10 microns in diameter are available for the electrode reactions. 7 references.

Exhaust Gas Compositions and Fuel Efficiencies of Hydrazine‐Air Fuel Cells

High fuel efficiency and clean exhaust gas are the two most important requirements in hydrazine-air fuel cells. Four anodes of sintered nickel plaque were studied for these purposes, each one containing either cobalt, nickel, palladium, silver, or platinum as a catalyst. Exhaust gases were determined with a gas chromatograph, the consumption of hydrazine in the anolyte was analyzed chemically, and fuel efficiencies and unreacted product gases were evaluated based on these data. Consequently with the silver catalyzed electrode, 97 percent fuel efficiency was attained at 50 mA/cm/sup 2/ at 25/sup 0/C.

Large-scale development of lithium batteries for electric vehicles and electric power storage applications

Abstract In Japan there was a dramatic increase in the production of lithium secondary batteries which reached a value of 210 billion yen in 1997. There are signs that this trend is increasing. These lithium batteries are presently used as small portable power sources. For these uses there has been a broadening in the research and development of lithium batteries. At the same time, advances in the research of large type lithium batteries for electric vehicles and dispersed-type electric power storage systems have been conducted on a grand scale by Japanese universities, government research laboratories and private companies. The level of activity in the research and development of lithium batteries in Japan is apparent by the state of related patent applications and number of papers presented at meetings held in Japan. LIBES is at the center of the research and development into large-type lithium batteries in Japan. Hitachi, and Shin-Kobe Electric Machinery, as members of LIBES, are carrying out the research and development of large-type lithium batteries for electric-power storage. In FY1997, the 250 W h cells, made of 10 wt.% silver–graphite anodes and spinel-type manganese oxide cathodes, which were connected together and stacked in a series of eight to make a 2 kW h module, produced desirable results and showed the prospects for good safety.