Electrode assembly with improved electrolyte impregnation property, and battery, 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 being wound in a winding direction about a winding axis to define a core and an outer circumference of the electrode assembly,

• wherein the first electrode includes an active material portion coated with an active material layer and a first non-coated portion not coated with the active material layer along the winding direction,
• wherein the first non-coated portion includes a plurality of impregnation slits extending along a circumferential direction of the electrode assembly,
• wherein longitudinal extension lines of impregnation slits adjacent to each other along the circumferential direction do not overlap each other, and
• wherein lengths of the impregnation slits in the circumferential direction gradually increases from the core toward the outer circumference of the electrode assembly.

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 being wound in a winding direction about a winding axis to define a core and an outer circumference of the electrode assembly,

• wherein the first electrode includes an active material portion coated with an active material layer and a first non-coated portion not coated with the active material layer along the winding direction,
• wherein the first non-coated portion includes a plurality of impregnation slits extending along a circumferential direction of the electrode assembly,
• wherein longitudinal extension lines of impregnation slits adjacent to each other along the circumferential direction do not overlap each other, and
• wherein the plurality of impregnation slits are inclined at a predetermined angle with respect to a line extending along the circumferential direction.

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 being wound in a winding direction about a winding axis to define a core and an outer circumference of the electrode assembly,

• wherein the first electrode includes an active material portion coated with an active material layer and a first non-coated portion not coated with the active material layer along the winding direction,
• wherein the first non-coated portion includes a plurality of impregnation slits extending along a circumferential direction of the electrode assembly,
• wherein longitudinal extension lines of impregnation slits adjacent to each other along the circumferential direction do not overlap each other, and
• wherein the first non-coated portion has a plurality of fragments spaced apart from each other along the circumferential direction of the electrode assembly and partitioned by a plurality of cutting lines having a predetermined depth from an end of the non-coated portion.