Electrode assembly, battery, and battery pack and vehicle including the same

An electrode assembly comprising:

• a first electrode;
• a second electrode;
• and
• a separator interposed between the first electrode and the second electrode, the first electrode, the second electrode and the separator wound about a winding axis in a winding direction to define a core and an outer circumference of the electrode assembly,
• wherein the first electrode includes a first active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with an active material layer and exposed beyond the separator,
• wherein the first uncoated portion includes a first portion adjacent to the core of the electrode assembly, a second portion adjacent to the outer circumference of the electrode assembly, and a third portion between the first portion and the second portion,
• wherein the third portion includes a plurality of segments spaced apart along the winding direction, the plurality of segments being defined by a plurality cut grooves along a direction of the winding axis, and
• wherein a height of the first portion is relatively lower than a height of the uncoated portion at a bottom of one of the cut grooves.