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

An electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound based on a winding axis to define a core and an outer circumference,

• wherein the first electrode includes a first active material portion coated with an active material layer and a first uncoated portion not coated with an active material layer along a winding direction, at least a part of the first uncoated portion is defined as an electrode tab by itself, the first uncoated portion includes a first portion including an innermost winding turn adjacent to the core of the electrode assembly, a second portion including an outermost winding turn adjacent to the outer circumference of the electrode assembly, and a third portion interposed between the first portion and the second portion, and each of the first portion and the second portion has a smaller height than the third portion in a direction of the winding axis,
• wherein the heights of the first portion and the second portion are larger than zero,
• wherein, in the winding direction, a length of the first portion is larger than a length of the second portion,
• wherein the first portion forms more winding turns than the second portion,
• wherein at least a partial region of the third portion is divided into a plurality of segments that are independently bendable and the plurality of segments have a cut groove between segments adjacent to each other along the winding direction,
• wherein the first portion and the second portion do not have a segment which is independently bendable, and
• wherein the plurality of segments are bent inwardly towards the axis and along a radial direction of the electrode assembly thereby forming a number of overlapping layers of the first uncoated portion stacked in the direction of the winding axis.