Jelly-roll type battery unit and winding method thereof and lithium secondary battery comprising the same

摘要

A jelly-roll type battery unit, a winding method thereof and a lithium secondary battery comprising the battery unit include a first electrode plate having a first electrode current collector with a first electrode tab and a first electrode active material layer coated on at least one surface of the first electrode current collector, a second electrode plate having a second electrode current collector with a second electrode tab and a second electrode active material layer coated on at least one surface of the second electrode current collector, and a separator that is interposed between the first electrode plate and the second electrode plate, wherein the electrode tab is incorporated into the electrode current collector in an area of either the first or the second electrode plate where the corresponding electrode active material layer is not coated. Since an electrode tab is formed by cutting a portion of an electrode current collector and folding upward, deformation of a jelly-roll type battery unit is prevented.

主权项

1. A battery unit comprising:
a first electrode plate having a first electrode current collector with a first electrode tab, and a first electrode active material layer coated on at least one surface of the first electrode current collector; a second electrode plate having a second electrode current collector with a second electrode tab, and a second electrode active material layer coated on at least one surface of the second electrode current collector; a separator that is interposed between the first electrode plate and the second electrode plate; and an insulating tape adhered to inner and outer surfaces of the first electrode tab, wherein, the first electrode tab is formed by folding a cut portion of an uncoated area of the first electrode current collector toward an upper edge thereof, the cut portion is defined by a portion of a lower edge of the first electrode current collector, a portion of a side edge of the first electrode current collector that extends from the lower edge, a cut that begins at the lower edge and extends along more than half of a width of the first electrode current collector, and a fold extending from the side edge to the cut, the insulating tape comprises a cut tape portion and a straight tape portion, the cut tape portion is between the first electrode tab and the first electrode current collector and is folded with the cut portion, and the first electrode tab extends past the upper edge of the first electrode current collector, is disposed at substantially the center of the battery unit, at an innermost layer of the battery unit, and partially overlaps and faces the second electrode tab.