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

Patent metadata

Field	Value
Publication number	US-12537231-B2
Application number	US-202217967614-A
Country	US
Kind code	B2
Filing date	Oct 17, 2022
Priority date	Oct 15, 2021
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

An electrode assembly having a first electrode, a second electrode, and a separator positioned between the first electrode and the second electrode. The first electrode, the second electrode, and the separator are together wound about an axis in a winding direction resulting in a plurality of winding turns. Each of the first electrode and the second electrode has a first side and a second side opposite the first side in the direction of the axis, as well as a first, electrode active material portion, coated with an electrode active material, extending from the second side in the direction of the first side, and a second, uncoated portion extending from the first side in the direction of the second side to the active material of the first portion. Additionally, the first side of the first electrode and the first side of the second electrode are divided into a plurality of segments by a cut groove, and each of the segments has a first end corresponding to the first side of either the first or the second electrode. One or more of the segments are bent in a radial direction relative to the axis, at a point below the first end of each bent segment, and the separator has a side that is positioned between the bending point of each bent segment and a boundary between the first and the second portions.

First claim

What is claimed is:

1 . An electrode assembly comprising:
a first electrode, a second electrode, and a separator between the first electrode and the second electrode, wherein the first electrode, the second electrode, and the separator are together wound about an axis in one winding direction to have a plurality of winding turns, wherein each of the first electrode and the second electrode comprises a first side and a second side opposite the first side in a direction of the axis, wherein each of the first electrode and the second electrode further comprises a first, electrode active material portion, coated with an electrode active material, extending from the second side in the direction of the first side, and a second, uncoated portion extending from the first side in the direction of the second side to the active material of the first portion, wherein the first side of the first and the second electrodes is divided into a plurality of segments by a cut groove having a predetermined length, wherein each of the segments has a first end corresponding to the first side of the first and second electrodes, wherein one or more of the segments are bent in a radial direction relative to the axis, at a point below the first end in each segment, wherein the separator has a side that is positioned between the bending point of each bent segment and a boundary between the first and the second portions, wherein the side of the separator is positioned between the bending point and a base line, or positioned below the base line in the axis direction, and wherein the base line is represented by a straight line extending in a winding direction (X) at a height corresponding to a notching valley of cut grooves dividing the plurality of segments, wherein a bent segment is a segment that is bent among the segments and a shortest bent segment is a segment that has a shortest length among the plurality of bent segments, wherein the side of the separator is located above the base line and at a distance from the base line that is no greater than 50% of the total length of the shortest bent segment, or the side of the separator is located below the base line and at a distance from the base line that is no greater than 30% of the total length of the shortest bent segment, and wherein the total length of the shortest bent segment is the length from the base line corresponding to the shortest bent segment to the first end of the shortest bent segment.

2 . The electrode assembly of claim 1 , wherein the separator is positioned such that a notching valley of each cut groove is not exposed.

3 . The electrode assembly of claim 1 , wherein a base line is represented by a straight line extending in the winding direction coincident with a notching valley of each cut grooves.

4 . The electrode assembly of claim 3 , wherein a length from the first end of each segment to the base line is variable.

5 . The electrode assembly according to claim 1 , wherein the second, uncoated portion includes a core-side uncoated portion adjacent to a core of the electrode assembly, a circumferential uncoated portion adjacent to an outer circumferential surface of the electrode assembly, and an intermediate uncoated portion interposed between the core-side uncoated portion and the circumferential uncoated portion, and at least one of the core-side uncoated portion and the circumferential uncoated portion has a relatively shorter length from the base line to the first side than the intermediate uncoated portion.

6 . The electrode assembly according to claim 5 , wherein the core-side uncoated portion has a relatively shorter length from the base line to the first side than the intermediate uncoated portion and the circumferential uncoated portion.

7 . The electrode assembly according to claim 5 , wherein the first side of the core-side uncoated portion and the base line coincide with each other.

8 . The electrode assembly according to claim 5 , wherein the core-side uncoated portion includes an uncoated portion corresponding to an innermost winding turn of the electrode assembly, and the circumferential uncoated portion includes an uncoated portion corresponding to an outermost winding turn of the electrode assembly.

9 . The electrode assembly according to claim 5 , wherein all or at least a partial region of the intermediate uncoated portion is divided into a plurality of segments.

10 . The electrode assembly according to claim 1 , wherein a distance between the bending point and the side of the separator is greater than or equal to 0.1 mm.

11 . The electrode assembly according to claim 1 , wherein the length from bending point to base line of the shortest bent segment is greater than or equal to 2 mm.

12 . The electrode assembly according to claim 1 further comprising:
at least one segment (segment A) having a height less than the shortest bent segment, otherwise the shortest bent segment is the segment having a minimum height, wherein segment height means a shortest length from the base line to the first end.

13 . The electrode assembly according to claim 5 , wherein at least a partial region of the intermediate uncoated portion is configured to have a height in the winding axis direction, which increases stepwise from the core to the outer circumference.

14 . The electrode assembly according to claim 1 , wherein at least one of segment height and segment width increases stepwise in the winding direction from the core to the outer circumference individually or in groups.

15 . The electrode assembly according to claim 1 , wherein each of the plurality of segments satisfies at least one of the following conditions: a width of 1 mm to 6 mm in the winding direction; a height of 2 mm to 10 mm in the axis direction; and a separation pitch of 0.05 mm to 1 mm in the winding direction.

16 . The electrode assembly according to claim 1 , wherein the plurality of segments satisfy a separation pitch condition of 0.05 mm to 1 mm in the winding direction, the separation pitch is defined as a distance between corners of two segments adjacent to each other, and wherein round reinforcing portions are formed to the corners of the segments adjacent to each other.

17 . The electrode assembly according to claim 1 ,
wherein the separator comprises a porous polymer substrate; and a porous coating layer located on at least one surface of the porous polymer substrate, wherein the porous coating layer comprises a plurality of inorganic particles and binder polymer.

18 . The electrode assembly according to claim 17 , wherein the inorganic particles comprise inorganic particles having a hydrophilic property.

19 . A cylindrical battery cell, comprising an electrode assembly according to claim 1 , and further comprising:
a battery can configured to accommodate the electrode assembly and electrically connected to one of the first electrode and the second electrode to have a first polarity; a sealing body configured to seal an open end of the battery can; and a terminal electrically connected to the other of the first electrode and the second electrode to have a second polarity and configured to have a surface exposed to the outside, wherein the separator comprises a porous polymer substrate; and a porous coating layer located on both surfaces of the porous polymer substrate and comprising inorganic particles and a binder polymer.

20 . A battery pack, comprising at least one battery cell according to claim 19 .

21 . A vehicle

Assignees

• Lg Energy Solution Ltd

Inventors

• Lee Myung-An
• Ryu Duk-Hyun
• Woo Jae-Young

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M50/446

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M50/107

  having curved cross-section, e.g. round or elliptic (H01M50/103, H01M50/109, H01M50/11 take precedence) · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/0587 Primary

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title