PURPOSE: To restrict increase of internal resistance of a battery due to a charging/discharging cycle, and to lighten weight of a battery, and to improve lifetime of a battery to realize a high energy density by using a current collecting lid made of impermeable amorphous carbon or graphitic carbon to seal a container.
CONSTITUTION: A negative electrode current collecting lid 8 is provided in the upper part (negative electrode side) of a container 1 through an insulating αalumina layer 9. This α alumina layer 9 prevents short-circuiting between the negative electrode current collecting lid 8 and the container 1. As a material of the negative electrode current collecting lid 8, amorphous carbon or graphitic carbon is used. Increase of internal resistance of a battery due to a charging/ discharging cycle is thereby restricted, and lifetime of a battery can be improved. The carbon material has a small gravity, for example, at 1.5-2g/cm3 and the mechanical strength nearly equal to that of metal. Weight of a battery can be thereby lightened, and as a result, lifetime of a battery can be improved, and a high energy density is obtained.
MURAKAMI YUICHIRO
UEDA TAKASHI
TSUNEYOSHI KIKUJI
