Rechargeable lithium ion button cell battery

摘要

A rechargeable lithium ion button cell battery having a sealed housing comprises an inner casing and an outer casing, both casings have at least one flat area as top or bottom of the battery, and a round or oval sidewall vertically formed to the flat area. An insulation gasket is positioned between the sidewalls, and the outer casing opening is mechanically crimped to complete the seal of the battery. Inside the sealed housing the anode and cathode electrodes are spiral wound with separator to be a round or oval roll. A roll axis is vertical to the flat area of the casings. The two electrodes are tapered in width to fully utilize the inner space. The electrodes comprise current collectors of metal foils coated with lithium-intercalating active materials, leaving small area of uncoated metal foils as conductor tabs for connecting the electrodes to the casings.

主权项

1. A rechargeable lithium ion button cell battery comprising:
a sealed housing comprising an inner casing and an outer casing, both casings having at least one flat area as top or bottom of the battery, a round or oval sidewall vertically formed to the flat area, and a round or oval insulation gasket having a footing rim and positioning between the sidewalls, the footing rim covering an opening end of an inner casing sidewall; an outer casing sidewall is crimped together with the gasket against the inner casing to seal the battery, wherein the housing contains electrolyte; a first electrode and a second electrode inside the sealed housing being spiral wound with a separator to be a round or oval roll, wherein a roll axis is vertical to the flat areas of the casings; wherein both electrodes have one small area not coated with active materials, and exposed metals at the areas act as conductor tabs to connect the electrodes with the casings respectively; wherein the electrodes are tapered in width on coated areas thereof, wider at a center of the spiral wound roll and narrower at a rim of the spiral wound roll, and the width of the wider end is 0.1 mm to 3 mm greater than the width of the narrower end.