In the field of electric power where NGK started its business, NGK, now a world's leading manufacturer of insulators, has been providing various products and systems to ensure the stable supply of electricity. Such products and systems include insulators for 1,000 kV transmission lines, arresters for protection against lightning, feeder automation systems and so on.
Making full use of fine ceramics technology which we have cultivated, and with key materials such as ion conducting ceramics, conductive ceramics and structural ceramics, and key technologies such as forming, firing, processing and evaluating, NGK is now actively entering into new fields that will become the backbone of the energy arena in the future. Mass production of NAS battery systems for large capacity power storage has already started.
And now, our development efforts are directed toward such products exploiting ceramics as solid oxide fuel cells (SOFC) and large lithium ion batteries for vehicles.
SOFC fuel cell (single cell) under development
In recent years, fuel cells have come into the spotlight as clean, high efficiency power generation systems. Among them, many people are paying attention particularly to ceramic fuel cells, or solid oxide fuel cells (SOFC). Having the highest power generation efficiency and being able to directly use other fuel than hydrogen such as natural and coal gas, SOFC is expected to realize a low-cost power generation system. While general SOFCs operate at a temperature of about 1,000°C, NGK has lowered the temperature to 600 - 800°C by enhancing the performance of ceramics used in the fuel cells, succeeding in developing highly efficient and reliable SOFC.
SOFC consists of two porous, conductive ceramic electrodes (the air and fuel electrodes) and ion conducting, ceramic electrolyte (solid electrolyte), which only conducts oxygen ions and is sandwiched between the electrodes. When air is supplied to the air side of the cell and fuel gas(e.g. gas containing hydrogen and carbon monoxide) to the opposite side; first oxygen molecules are converted into oxygen ions, then the oxygen ions move through solid electrolyte and react with hydrogen or carbon monoxide giving off water and electrons, which is the source of electrical energy.