Electrode assembly, battery cell comprising electrode assembly and power supply

Abstract

The invention provides an electrode assembly, a battery cell comprising the electrode assembly and a power supply. An electrode assembly according to one embodiment of the present disclosure includes: a first electrode plate wound about a winding axis and including a first uncoated portion not coated with a first electrode active material; a second electrode plate wound around the winding axis and including a second uncoated portion on which a second electrode active material is not coated; a diaphragm disposed between the first electrode plate and the second electrode plate; and a plurality of segmented sheets formed in at least one of the first uncoated portion and the second uncoated portion, the plurality of segmented sheets being arranged such that at least one base angle changes in a winding direction.

Description

Technical Field

[0001] This disclosure relates to an electrode assembly, a battery cell including the electrode assembly, and a power supply. Background Technology

[0002] Unlike primary batteries, secondary batteries offer the convenience of being both charged and discharged, making them a popular choice as a power source for various mobile devices and electric vehicles. Because of their rechargeable and discharge capabilities, secondary batteries can be used in various fields, including digital cameras, mobile phones, laptops, hybrid vehicles, electric vehicles, and energy storage systems (ESS).

[0003] Such a secondary battery may include a battery cell, which houses an electrode assembly formed by stacking or winding positive electrode plates, negative electrode plates, and a separator inside a casing. Multiple cells may be stacked along a predetermined direction and housed in a battery module or battery pack.

[0004] On the other hand, in a cylindrical cell with a cylindrical housing, the electrode assembly can be wound and housed within the housing after the positive electrode plate, negative electrode plate, and separator are stacked.

[0005] The uncoated portions of the positive electrode plate and the uncoated portions of the negative electrode plate can be notched at predetermined intervals to form flags, and these flags can be connected to the current collector in a bent-to-center state. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] According to one aspect of this disclosure, the area of ​​overlap between multiple segments that are adjacent to each other in the winding direction can be minimized.

[0008] According to one aspect of this disclosure, welding efficiency between multiple segment pieces and current collectors can be increased.

[0009] The electrode assembly, battery cell including the electrode assembly, and power supply disclosed herein can be widely used in electric vehicles, battery charging stations, and other green technology fields such as solar power generation and wind power generation that utilize batteries. Furthermore, the electrode assembly, battery cell including the electrode assembly, and power supply disclosed herein can be used in eco-friendly electric vehicles and hybrid vehicles to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0010] (II) Technical Solution

[0011] An electrode assembly according to an embodiment of the present disclosure may include: a first electrode plate wound around a winding shaft and including a first uncoated portion uncoated with a first electrode active material; a second electrode plate wound around the winding shaft and including a second uncoated portion uncoated with a second electrode active material; a diaphragm disposed between the first electrode plate and the second electrode plate; and a plurality of segmented pieces formed in at least one of the first uncoated portion and the second uncoated portion, the plurality of segmented pieces being arranged such that at least one bottom corner changes along the winding direction.

[0012] According to one embodiment, the proportion of the plurality of segmented pieces overlapping each other along the winding direction may be less than or equal to 5%.

[0013] According to one embodiment, each of the plurality of segmented pieces may be trapezoidal in shape.

[0014] According to one embodiment, at least one of the first uncoated portion and the second uncoated portion may further include a portion in which the plurality of segmented pieces are not formed, i.e., an ungrooved portion. With the winding direction as a reference, the ungrooved portion may be disposed adjacent to either a starting end portion including an end portion near the winding shaft or a terminal end portion including an end portion furthest from the winding shaft.

[0015] According to one embodiment, with the winding direction as a reference, the size of the bottom angle of the plurality of segment pieces can gradually increase toward the terminal portion including the end furthest from the winding axis.

[0016] According to one embodiment, with the winding direction as a reference, the size of the bottom corner of the plurality of segmented pieces can be uniformly increased toward the terminal portion.

[0017] According to one embodiment, the bottom angle (α) of the nth segment of the plurality of segmented pieces, starting from the beginning end near the end of the winding shaft, is... n ) satisfies the following formula, N is the total number of the multiple segments, n is a natural number greater than 1 and less than or equal to N, and α eIt is the bottom corner (α) of the Nth set end segment piece. N ), and α s It can be the bottom corner (α1) of the first set starting segment piece.

[0018] According to one embodiment, the plurality of segmented pieces are in the shape of an equilateral trapezoid, and the base angle (α) of the starting segmented piece is... s ) satisfies the following formula, However, w s r is the width of the initial segment piece. o It is the shortest radius from the winding shaft to the first electrode plate or the second electrode plate, and θ s It can be the winding angle to the starting segment piece, where t is the thickness when one turn is made.

[0019] According to one embodiment, the winding angle θ of the initial segment piece s Satisfy the following formula, , l s It is the winding length from the beginning end to the starting segment piece, and b s It can be the winding thickness to the starting segment piece.

[0020] According to one embodiment, the plurality of segmented pieces are in the shape of an equilateral trapezoid, and the base angle (α) of the end segmented piece is... e ) satisfies the following formula, w e r is the width of the end segment piece. o θ is the shortest radius from the winding shaft to the first electrode plate or the second electrode plate. e It is the winding angle to the end segment, and t can be the thickness when one turn is wound.

[0021] According to one embodiment, the winding angle θ of the end segment piece e Satisfy the following formula, , l e It is the winding length of the segmented piece from the beginning end to the end end, and b e It can be the winding thickness of the segmented piece wound to the end.

[0022] According to one embodiment, the width of the plurality of segmented pieces can be uniformly increased outward in the winding direction.

[0023] According to one embodiment, the width (w) of the segment piece arranged from the nth segment on the winding axis among the plurality of segment pieces... n ) satisfies the following formula, However, N is the number of the plurality of segments, and n is a natural number greater than 1 and less than or equal to N. eIt is the width of the Nth set end segment piece, and w s It can be the width of the first segment to be set.

[0024] According to one embodiment, the center angle of the plurality of segmented pieces can be uniformly reduced outwards in the winding direction.

[0025] According to one embodiment, the central angle (Ø) of the nth segment of the plurality of segmented pieces located from the winding shaft is... n ) satisfies the following formula, N is the number of the plurality of segments, and n is a natural number greater than 1 and less than or equal to N. e It is the center angle of the Nth set end segment piece, and Ø s It can be the center angle of the first set starting segment.

[0026] According to one embodiment, the base angle of each of the plurality of segment pieces may include a first base angle located near the winding shaft and a second base angle located further away from the winding shaft than the first base angle, and the plurality of segment pieces may be a right trapezoid in which either the first base angle or the second base angle is a right angle.

[0027] According to one embodiment, the base angles of the plurality of segmented pieces may include a first base angle located near the winding shaft and a second base angle located further away from the winding shaft than the first base angle. The plurality of segmented pieces may be in the form of an isosceles trapezoid where either the first base angle or the second base angle is an obtuse angle and the two hypotenuses are of different sizes.

[0028] According to one embodiment, at least one of the plurality of segment pieces may have a rounded corner on the edge near the top edge of the winding shaft.

[0029] According to one embodiment, the proportion of the areas of the plurality of segment pieces overlapping each other along the winding direction can be greater than 0, and the width of the overlap between adjacent segment pieces can be constant from the outer side of the winding axis.

[0030] According to one embodiment, the plurality of segmented pieces may be configured to be connected to each other along at least one oblique edge along the winding direction.

[0031] According to one embodiment, the proportion of the areas of the plurality of segment pieces that are adjacent and overlap each other along the winding direction can be less than 0, and the width of the gap between the plurality of segment pieces that are adjacent to each other can be constant from the outside of the winding axis.

[0032] A battery cell according to an embodiment of the present disclosure may include: an electrode assembly including a first electrode plate and a second electrode plate, wound around a winding shaft; a can housing the electrode assembly and having at least one opening; a cover assembly attached to the can to close the opening; and a current collector electrically connected to the electrode assembly, wherein at least one of the first electrode plate and the second electrode plate may include a plurality of segmented pieces bent toward the winding shaft to form one side of the electrode assembly, the plurality of segmented pieces being configured such that at least one bottom angle changes in a direction away from the winding shaft.

[0033] A power supply according to an embodiment of the present disclosure may include: at least one battery cell, the battery cell including an electrode assembly; and a housing for housing the battery cell, the electrode assembly including: a first electrode plate wound around a winding shaft and including a first uncoated portion uncoated with a first electrode active material; a second electrode plate wound around the winding shaft and including a second uncoated portion uncoated with a second electrode active material; and a plurality of segmented pieces formed in at least one of the first uncoated portion or the second uncoated portion, the plurality of segmented pieces being arranged such that at least one bottom corner changes along the winding direction.

[0034] The above describes a solution based on this disclosure, but it is exemplary and any addition of other configurations not mentioned should be understood as belonging to this disclosure.

[0035] These and other features and characteristics of this disclosure, as well as the operation and function of related structural elements, component combinations, and manufacturing economics, will become clearer when taken in conjunction with the accompanying drawings and the following description and appended claims. All drawings form part of this specification, wherein like reference numerals denote corresponding components in the drawings. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to define the scope of the subject matter disclosed.

[0036] (III) Beneficial Effects

[0037] According to one embodiment of this disclosure, the flatness between multiple segment pieces can be improved.

[0038] According to one embodiment of this disclosure, the area of ​​overlap between multiple segment pieces can be minimized.

[0039] According to one embodiment of this disclosure, welding efficiency between multiple segment pieces and current collectors can be increased. Attached Figure Description

[0040] Figure 1 This is a perspective view of a battery cell according to an embodiment of the present disclosure.

[0041] Figure 2 This is an exploded view of a battery cell according to an embodiment of the present disclosure.

[0042] Figure 3 This is a schematic diagram showing an electrode assembly wound according to an embodiment of the present disclosure.

[0043] Figure 4 This is a schematic diagram showing the electrode plate of an electrode assembly according to an embodiment of the present disclosure unfolded.

[0044] Figure 5a These are plan views and partial cross-sectional views of an electrode assembly according to an embodiment of the present disclosure.

[0045] Figure 5b for Figure 5a The diagram of A is a diagram showing the case where the overlapping area of ​​the segments is greater than 0.

[0046] Figure 5c for Figure 5a The diagram of A is a diagram showing the case where the overlapping area of ​​the segments is equal to 0.

[0047] Figure 5d for Figure 5a The diagram of A is a diagram showing the case where the overlapping area of ​​the segments is less than 0.

[0048] Figure 6 This is a schematic diagram showing the electrode assembly of this disclosure being wound up.

[0049] Figure 7a This is a schematic diagram showing the arrangement of segmented sheets in the inner winding portion of the electrode assembly.

[0050] Figure 7b This is a schematic diagram showing the state of the inner circumference being wound.

[0051] Figure 8a This is a schematic diagram showing the arrangement of segmented plates in the wound periphery of the electrode assembly.

[0052] Figure 8b This is a schematic diagram showing the state of the winding around the outer periphery.

[0053] Figure 9 This is a schematic diagram showing the arrangement of segmented sheets in the middle of the winding of the electrode assembly.

[0054] Figure 10 This is a schematic diagram comparing the inner segment, the middle segment, and the outer segment.

[0055] Figure 11 This is a schematic diagram comparing the inner segment, the middle segment, and the outer segment with the winding shaft as the reference.

[0056] Figure 12aThis is a diagram showing one side of the segmented piece formed at a right angle. Figure 12b This is a diagram showing the other side of the segment piece formed at a right angle.

[0057] Figure 13a This is a diagram showing one side of the segmented piece formed at an acute angle. Figure 13b This is a diagram showing the other side of the segmented piece formed at an obtuse angle.

[0058] Figure 14 This is a diagram showing the edges of the segmented pieces formed with rounded corners.

[0059] Figure 15 This is an example diagram of a power supply according to an embodiment of the present disclosure.

[0060] Explanation of reference numerals in the attached figures:

[0061] 1: Cell 10: Electrode Assembly

[0062] 11: Electrode plate 12: Diaphragm

[0063] 13: First electrode plate; 131: First coating section

[0064] 132: First uncoated area; 133: First grooved area

[0065] 14: Second electrode plate; 141: Second coating section

[0066] 142: Second uncoated area; 143: Second grooved area

[0067] 15: Segmented piece 16: Grooved section

[0068] 17: Ungrooved section; 20: Shell

[0069] 21: Can 23: Lid assembly

[0070] 25: Electrode terminal 271: First collector board

[0071] 273: Second collector board

[0072] 50: Power supply 51: Casing

[0073] 511: First cover 512: Second cover Detailed Implementation

[0074] Before describing the embodiments in detail, it should be noted that the terms or words used in the following description and claims should not be construed as limited to their general or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical ideas of this disclosure, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0075] The same reference numerals or symbols used in each figure indicate parts or components that perform substantially the same function. For ease of explanation and understanding, the same reference numerals or symbols may also be used in different embodiments.

[0076] In the following description, unless the context clearly indicates otherwise, singular expressions include plural expressions. Terms such as “comprising” or “constituting” should be understood as being intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, rather than precluding the presence or additional possibilities of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0077] Additionally, it should be noted that in the following descriptions, terms such as top, upper, lower, side, front, and back are based on the direction shown in the diagram. If the direction of the corresponding object changes, it can be described in a different way.

[0078] Furthermore, in the following description and claims, terms including ordinal numbers such as "first" and "second" may be used to distinguish components. These ordinal numbers are used to distinguish identical or similar components, and the meaning of the terms should not be interpreted restrictively by using these ordinal numbers. As an example, the order of use or arrangement of components combined with these ordinal numbers should not be interpreted restrictively by these ordinal numbers. The ordinal numbers may also be used interchangeably as needed.

[0079] The present disclosure will now be described in detail with reference to the accompanying drawings.

[0080] Figure 1 This is a perspective view of a battery cell according to an embodiment of the present disclosure. Figure 2 This is an exploded view of a battery cell according to an embodiment of the present disclosure.

[0081] According to this disclosure, an electrode assembly 10, a battery cell 1, and a power supply can be provided. (See also...) Figure 1 and Figure 2 According to one embodiment of the present disclosure, the battery cell 1 may include an electrode assembly 10, a housing 20 housing the electrode assembly 10, and electrode terminals 25 exposed from the housing 20.

[0082] On the other hand, the battery cell 1 disclosed herein can be a secondary battery. For example, the battery cell 1 can be a lithium secondary battery, but is not limited thereto. For example, the battery cell 1 can be a nickel-cadmium battery, a nickel-metal hydride battery, or a nickel-metal hydride battery capable of being charged and discharged.

[0083] The housing 20 can be any of the following: pouch type, prismatic type, or cylindrical type. For example, as shown in the figure, the cell 1 of this disclosure can be a cylindrical cell in which the housing 20 housing the electrode assembly 10 is cylindrical, but it is not necessarily limited to this. According to one embodiment, the electrode assembly 10 can be wound around a winding axis and housed in the housing 20.

[0084] The housing 20 can internally house the electrode assembly 10. For electrical rigidity, the housing 20 can be made of a metallic material such as aluminum or stainless steel. However, this disclosure does not limit the material of the housing 20. The housing 20 may include a can 21 with an opening formed on at least one side and a lid assembly 23 for closing the can 21.

[0085] According to one embodiment, a terminal hole 215 for mounting electrode terminals 25 may be formed on one side of the can 21, and an opening (not shown) for mounting the cover assembly 23 may be formed on the other side. The terminal hole 215 may be formed on the upper surface 21a of the can. However, the upper surface here does not necessarily mean the top, but should be interpreted as including the side of the can 21 without an opening. According to one embodiment, a first electrode of the electrode assembly 10 is electrically connected to the electrode terminal 25, and a second electrode is electrically connected to either the can 21 or the cover assembly 23. The first electrode may be either a positive electrode or a negative electrode, and the second electrode may be an electrode with the opposite polarity to the first electrode.

[0086] According to one embodiment, the cap assembly 23 may be disposed at the opening of the can 21 and face the electrode terminal 25 across the electrode assembly 10.

[0087] Furthermore, the battery cell 1 disclosed herein may further include current collectors 271 and 273 for electrical connection with the electrode assembly 10. Current collectors 271 and 273 may comprise conductive materials such as metal. Current collectors 271 and 273 may be electrically connected to the electrode assembly 10. According to one embodiment, current collectors 271 and 273 may include a first current collector 271 facing one side 10a of the electrode assembly 10 and a second current collector 273 facing the other side 10b of the electrode assembly 10.

[0088] According to one embodiment, the first current collector 271 can contact and be electrically connected to one side 10a of the electrode assembly 10. For example, the first current collector 271 can be welded by means of laser or the like while in contact with said side 10a. Similarly, the second current collector 273 can contact and be electrically connected to the other side 10b of the electrode assembly 10. For example, the second current collector 273 can be welded by means of laser or the like while in contact with said other side 10b.

[0089] Electrode terminals 25 may be disposed in terminal holes 215 of the can 21. Electrode terminals 25 may contain conductive material and be electrically connected to an external power source. According to one embodiment, electrode terminals 25 may be electrically connected to a first current collector 271.

[0090] Figure 3 This is a schematic diagram showing an electrode assembly wound according to an embodiment of the present disclosure.

[0091] Reference Figure 3 The electrode assembly 10 disclosed herein may include a plurality of electrode plates 11 and a diaphragm 12 disposed therebetween. According to one embodiment, the plurality of electrode plates 11 may be provided as a jelly-roll electrode assembly wound with reference to a winding shaft. According to one embodiment, the electrode assembly 10 may be wound and housed within a canister 21 in a state where the first electrode plate 13, the diaphragm 12, the second electrode plate 14, and the diaphragm 12 are alternately stacked.

[0092] The electrode plate 11 may include a first electrode plate 13 having a first polarity and a second electrode plate 14 having a second polarity. According to one embodiment, either the first electrode plate 13 or the second electrode plate 14 may be a positive electrode (Cathode) and the other may be a negative electrode (Anode).

[0093] According to this disclosure, the wide surfaces of the first electrode plate 13 and the second electrode plate 14 are faced and stacked, and a diaphragm 12 can be inserted between them. The diaphragm 12 can be disposed between the first electrode plate 13 and the second electrode plate 14 to prevent electrical short circuits and to facilitate ion flow. As an example, the diaphragm 12 may comprise a porous polymer membrane or a porous nonwoven fabric.

[0094] The first electrode plate 13 may include a first electrode current collector and a first coating portion 131 on which a first electrode active material is coated. According to one embodiment, the first electrode plate 13 may include the portion coated with the first electrode active material, i.e., the first coating portion 131, and a portion not coated with the first electrode active material, i.e., a first uncoated portion 132. The first uncoated portion 132 is the portion not coated with the first electrode active material and may be the portion where the first electrode current collector is exposed. The first uncoated portion 132 may serve as a channel for electrical connection with adjacent components.

[0095] The second electrode plate 14 may include a second electrode current collector and a second coating portion 142 on which a second electrode active material is coated. According to one embodiment, the second electrode plate 14 may include a portion coated with the second electrode active material, namely the second coating portion 141, and a portion uncoated with the second electrode active material, namely the second uncoated portion 142. The second uncoated portion 142 is the portion without the second electrode active material coating and may be the portion where the second electrode current collector is exposed. The second uncoated portion 142 may serve as a channel for electrical connection with adjacent components.

[0096] The electrode assembly 10 disclosed herein may include a plurality of segmented pieces 15 formed by slotting uncoated portions 132 and 142 in a predetermined shape. Each segmented piece 15 may include a plurality of first segmented pieces 15a formed by slotting the first uncoated portion 132 in a predetermined shape and a plurality of second segmented pieces 15b formed by slotting the second uncoated portion 142 in a predetermined shape. According to one embodiment, the plurality of first segmented pieces 15a may be bent toward a winding shaft to form one side 10a of the electrode assembly 10, and the plurality of second segmented pieces 15b may be bent toward a winding shaft to form the other side 10b of the electrode assembly 10. According to one embodiment, the plurality of first segmented pieces 15a may be electrically connected to a first current collector 271, and the plurality of second segmented pieces 15b may be electrically connected to a second current collector 273.

[0097] Hereinafter, if referred to as segmented piece 15, it can be interpreted as a first segmented piece 15a formed on the first electrode plate 13 and / or a second segmented piece 15b formed on the second electrode plate 14.

[0098] On the other hand, although the description is based on the case where the segmented piece 15 is formed simultaneously on the first electrode plate 13 and the second electrode plate 14, this disclosure is not limited thereto, and it is acceptable even if it is formed on only one of them.

[0099] The segmented pieces will be described in detail below with reference to the accompanying drawings.

[0100] Figure 4 This is a schematic diagram showing the electrode plate of an electrode assembly according to an embodiment of the present disclosure unfolded. Figure 4 The first electrode plate 13 is shown to be deployed. Although Figure 4 The explanation is based on the first electrode plate 13, but this is only for convenience. The second electrode plate 14 should also be explained in the same way.

[0101] Reference Figure 4 In the first electrode plate 13, the end in the inner direction D1 can be referred to as the starting port (SP), and the end in the outer direction D2 can be referred to as the ending port (EP). Although the accompanying drawings are described with reference to the first electrode plate 13, the starting port (SP) and the ending port (EP) are terms used to describe the relative positions with respect to the winding shaft, and are not limited to the configuration of the first electrode plate 13. They can be used in any structure of the electrode assembly 10.

[0102] The first electrode plate 13 may include a plurality of segmented pieces 15. According to one embodiment, the segmented pieces 15 may be trapezoidal in shape by slotting the uncoated portion 132 through the slotted portion 16. According to one embodiment of the present disclosure, the plurality of segmented pieces 15 may be configured to uniformly change shape from the beginning end sp to the end end ep.

[0103] Multiple segment pieces 15 may include the starting segment piece 15 located closest to the beginning end sp. s The end segment 15 is located closest to the terminal part ep. e and the initial segment 15 s and end segment 15 e Multiple intermediate segments 15 n .

[0104] The subscripts of the reference numerals are used to indicate the order in which the multiple segment pieces 15 are arranged, starting from the beginning sp. For example, in the multiple segment pieces 15 1, 2, 3… In the middle, the initial segment 15 s It can be represented by 151, with the end segment 15. e It can be made up of 15 N This indicates that the segments set between them can be composed of 15 n The expression is: N can be the total number of segments 15, and n is a natural number greater than 1 and less than N, which can represent the segment 15 set in the middle.

[0105] For example, when the number of segments 15 is 10 (N=10), the initial segment 15 s It can be represented by 151, with the middle segment being 15. n It can be made up of 15 2, 3…9 This indicates that the end segment 15 e It can be made up of 15 10 express.

[0106] According to this disclosure, it can be configured to be segmented from the inside 15 s Segmented piece 15 outwards s The directional interior angle can be gradually changed. For example, according to one embodiment of this disclosure, it may include: a first electrode plate 13, for winding around the shaft O (see reference). Figure 6 The first electrode plate 13 is wound around the winding shaft O and includes a first uncoated portion 132 without the first electrode active material; a second electrode plate 14 is wound around the winding shaft O and includes a second uncoated portion 142 without the second electrode active material; a diaphragm 12 is disposed between the first electrode plate 13 and the second electrode plate 14; and a plurality of segmented pieces 15 are formed in at least one of the first uncoated portion 132 and the second uncoated portion 142, and the plurality of segmented pieces 15 can be arranged such that at least one bottom corner changes along the winding direction WD.

[0107] According to one embodiment, the bottom corner of the segment piece 15 can gradually increase from the beginning end sp to the end end ep. Additionally, according to another embodiment, the width W of the segment piece 15 can gradually increase from the beginning end sp to the end end ep.

[0108] Additionally, according to one embodiment, the first electrode plate 13 may include an unnotched portion 17 where no segments 15 are formed. The unnotched portion 17 may be formed adjacent to either the beginning end sp or the end end ep. For example, according to one embodiment of this disclosure, at least one of the first uncoated portion 132 and the second uncoated portion 142 includes a portion where no plurality of segments 15 are formed, i.e., the unnotched portion 17, and with reference to the winding direction WD (or circumferential direction), the unnotched portion 17 may be disposed adjacent to either the end closest to the winding axis O, i.e., the beginning end sp, or the end furthest from the winding axis, i.e., the end end ep.

[0109] Although the accompanying drawings show that the ungrooved portion 17 is formed simultaneously at both the beginning end sp and the end end ep, this disclosure is not limited thereto. The ungrooved portion 17 can refer to the portion where the uncoated portions 132 and 142 are not formed, that is, the portion where the segmented piece 15 is not provided. In addition, in this disclosure, the area where the segmented piece 15 is formed can be referred to as the notching area 133 and 143. That is, the first notching area 133 can refer to the area on the uncoated portion 132 of the first electrode plate 13 where the segmented piece 15 is formed, and the second notching area 143 can refer to the area on the uncoated portion 142 of the second electrode plate 14 where the segmented piece 15 is formed.

[0110] On the other hand, the interior angle of this disclosure can represent the inner angle of the vertex where two sides of the segment piece 15 formed by the polygon intersect. Additionally, the bottom angle of this disclosure, which represents the angle of the bottom edge of the segment piece 15, can represent the angle of the vertex of the bottom edge of the segment piece 15. For example, as... Figure 4 As shown, when the segment piece 15 is trapezoidal, the side facing the coating portions 131 and 141 can be called the bottom edge of the segment piece 15, and the side facing it (or, facing the winding shaft) can be called the top edge. In this disclosure, for ease of understanding, "α" is used to denote the bottom angle of the segment piece 15. However, this disclosure is not limited to changing the angle of the bottom angle α, but can also change the top angle (the interior angle of the top edge). That is, in this disclosure, "interior angle" can mean at least one angle including the top angle and the bottom angle of the segment piece 15. This disclosure focuses on describing the structure of changing the bottom angle α of the segment piece 15.

[0111] Additionally, as follows Figure 12a As explained, the interior angles of segment 15 may include the base angle of the vertex on the starting end sp side, i.e., the first base angle α, and the base angle on the ending end ep side, i.e., the second base angle β. Figure 4 For ease of understanding, the case where the segmented piece 15 is an equilateral trapezoid is taken as an example, and the first base angle α is called the base angle. However, as mentioned above, the base angle of this disclosure is not limited to this.

[0112] Figure 5a These are plan views and partial cross-sectional views of an electrode assembly according to an embodiment of the present disclosure. Figure 5b for Figure 5a The diagram for A illustrates the case where the overlapping area of ​​the segments is greater than 0. Figure 5c for Figure 5a The diagram for A illustrates the case where the overlapping area of ​​the segments is equal to 0. Figure 5d for Figure 5a The diagram of A is a diagram showing the case where the overlapping area of ​​the segments is less than 0.

[0113] Referring to FIG5, the electrode assembly 10 may have a central CT that is wound around the center in the winding direction WD and is hollow inside. According to one embodiment, a plurality of segmented tabs (electrode tabs) 15 may be bent toward the central CT and overlapped to form the connection surfaces 10a, 10b of the electrode assembly 10. The bent plurality of segmented tabs 15, i.e., the connection surfaces 10a, 10b, may be electrically connected by welding current collectors 271, 273.

[0114] On the other hand, the flatness of the connecting surfaces 10a and 10b may differ depending on the area of ​​the regions where the multiple segment pieces 15 overlap each other along the winding direction WD. According to this disclosure, the area of ​​overlap between the multiple segment pieces 15 along the winding direction WD can be removed or minimized. For example, the nth segment piece 15 among the multiple segment pieces 15... n Segment 15 adjacent to the winding direction WD n+1 15 n-1 The overlapping area between them can be non-existent or minimized.

[0115] Wherein, the absence or minimization of overlapping area refers to the area s overlapping along the winding direction (refer to...). Figures 5b to 5d The proportion is less than or equal to 5%. This will be explained in detail later.

[0116] Additionally, according to one embodiment, an ungrooved portion 17 can be formed near the center CT. See again... Figure 4 In the electrode plate 11, since the ungrooved portion 17 near the starting end sp is formed at a predetermined distance l0, the segmented piece 15 can be omitted on the corresponding diameter and thickness b0. Thus, as shown, it is possible to prevent the segmented piece 15 from rolling into the inner side of the central CT. However, this disclosure is not limited to the presence or absence of the ungrooved portion 17, or its length and diameter.

[0117] According to one embodiment of this disclosure, the overlap of multiple segment pieces along the winding direction WD can be prevented or minimized. For example, multiple segment pieces 15 adjacent to each other along the winding direction can avoid overlapping or minimize the overlapping area. This improves the flatness of the connection surfaces 10a, 10b of the electrode assembly 10 and increases the welding efficiency with the current collectors 271, 273. On the other hand, the "winding direction WD" refers to the direction in which the electrode assembly 10 is wound around the winding axis, and can be called the "circumferential direction." Furthermore, "overlapping along the winding direction" can mean that any one of the multiple segment pieces 15 overlaps with another segment piece 15 that is adjacent to it along the winding direction WD or the circumferential direction. For example, according to one embodiment of this disclosure, the overlap of the nth segment piece 15, i.e., the intermediate segment piece 15, can be prevented or minimized. n With adjacent segment 15 n+1 15 n-1 Overlap along the winding direction WD.

[0118] Reference Figures 5b to 5d, as described above, the ratio of the overlapping area s between the segmented pieces 15 may not exist or be minimized. According to one embodiment, the overlapping area s between multiple segmented pieces 15 adjacent to each other in the winding direction WD may be less than or equal to 5%. When the overlapping area s exceeds 5%, a step difference may occur between the multiple segmented pieces 15 due to the overlapping area s, which may reduce the welding efficiency with the current collector plates 271 and 273. Only from the aspects of welding efficiency and manufacturing performance, the overlapping area s between the segmented pieces 15 is preferably 0 or less, but in actual manufacturing processes, considering assembly tolerances, etc., the overlapping area may be formed to be greater than 0.

[0119] The present disclosure designs the arrangement of the size, width, etc. of the segmented pieces 15 through the mathematical formula described later, to remove (s≤0) or minimize (0<s≤5%) the overlapping area, so that the overlapping area between adjacent segmented pieces 15 is only 5% or less, thereby enabling smooth contact with the current collector plates 271 and 273. That is, according to the present disclosure, by reducing the step difference between the overlapping region and the non-overlapping region of the segmented pieces 15 along the winding direction WD, welding can be uniformly formed.

[0120] Among them, the "ratio of the overlapping area s" may represent the proportion of the overlapping area s with an adjacent another segmented piece 15 in the area of one segmented piece 15. In addition, "the ratio of the overlapping area s is less than or equal to 5%" may refer to the case including the overlapping area s being less than or equal to 5% (refer to Figure 5b ), the case where the hypotenuses of the trapezoids are in contact with each other and the overlapping area s is 0 (refer to Figure 5c ), and the case where they are formed without overlapping so that the overlapping area s is less than 0 (refer to Figure 5d ). Among them, "the overlapping area s is less than 0" may indicate that adjacent segmented pieces 15 are separated from each other.

[0121] More specifically, referring to Figure 5b , according to one embodiment of the present disclosure, the ratio of the overlapping area s between multiple segmented pieces 15 of the electrode assembly 10 along the winding direction WD may be greater than 0 (s>0). Among them, according to one embodiment, the size of the overlapping width db between segmented pieces 15 adjacent to each other in the winding direction may be constant from the winding axis O to the outside. The overlapping width db is the distance of overlap between adjacent segmented pieces 15. For example, it may represent the size of the overlapping base. In addition, according to one embodiment, in this case (s>0), the size of the overlapping area s may also be constant from the winding axis O to the outside. Among them, the overlapping width db may represent the distance of the hypotenuse between two adjacent segmented pieces 15.

[0122] In addition, referring to Figure 5cThe plurality of segmented pieces 15 can be configured such that at least one of their inclined edges is connected to each other along the winding direction WD. That is, the inclined edge of any one of the plurality of segmented pieces 15 can be configured to contact the inclined edge of another adjacent segmented piece 15 along the winding direction WD. Thus, when the plurality of segmented pieces 15 are wound, one side 10a of the electrode assembly 10 can be formed flat.

[0123] Additionally, refer to Figure 5d According to one embodiment of the present disclosure, the proportion of overlapping areas s of the plurality of segment pieces 15 along the winding direction WD of the electrode assembly 10 can be less than 0 (s < 0). That is, adjacent segment pieces 15 can be spaced apart from each other. In one embodiment, the width du of the gap between adjacent segment pieces 15 along the winding direction WD can be constant from the winding axis O outwards. The gap width du is the distance between adjacent segment pieces 15, for example, it can represent the size between their top edges. Additionally, according to one embodiment, in this case (s < 0), the size of the non-overlapping areas s can also be constant from the winding axis O outwards. That is, the area of ​​the gap between adjacent segment pieces 15 can be constant.

[0124] According to this disclosure, when the mathematical formula described later is satisfied, the plurality of segmented pieces 15 can be made to not overlap each other or to minimize the area of ​​overlap along the winding direction. A detailed description will follow with reference to the accompanying drawings.

[0125] Figure 6 This is a schematic diagram showing the electrode assembly of this disclosure being wound up.

[0126] Reference Figure 6 The electrode assembly 10 can be wound around the winding axis O. Referring to the attached figure, the radius r from the winding axis O to any winding point can be obtained by the following mathematical formula.

[0127] [Mathematical Expression 1]

[0128]

[0129] Where r0 is the shortest distance (core radius) between the winding shaft O and the electrode assembly 10, and b is the winding thickness of the electrode assembly 10, which is the radius from the shortest distance to the corresponding winding point. Alternatively, as stated in the mathematical formula, b = nt. Where n is the number of times the winding reaches the corresponding winding point, and t can represent the thickness of the electrode assembly per winding. That is, t can be obtained from the thickness of each component of the electrode assembly 10. As an example, t can be the thickness of the first electrode plate 13 + the thickness of the second electrode plate 14 + 2 × the thickness of the diaphragm 12. For example, t represents the "thickness of the electrode assembly 10 itself," which can be a value determined by the number and thickness of the first electrode plate 13, the second electrode plate 14, and the diaphragm 12, respectively.

[0130] Furthermore, the winding length l from the starting end sp of the electrode assembly 10 to the arbitrary location can be obtained by integrating the following mathematical formula with the winding angle θ to obtain the length l of the arc from the starting end sp to the arbitrary location.

[0131] [Mathematical Expression 2]

[0132]

[0133] Where θ can represent the winding angle rad from the starting end sp to the arbitrary location.

[0134] The structure of segment 15 will now be described in detail using mathematical formulas 1 and 2.

[0135] Figure 7a This is a schematic diagram showing the arrangement of segmented plates in the inner winding portion of the electrode assembly. Figure 7b This is a schematic diagram showing the state of winding the inner circumference. Figure 8a This is a schematic diagram showing the arrangement of segmented plates in the wound periphery of the electrode assembly. Figure 8b This is a schematic diagram showing the state of winding around the outer perimeter. Figure 9 This is a schematic diagram showing the arrangement of segmented sheets in the middle of the winding of the electrode assembly.

[0136] For example, Figure 7a and Figure 7b The segmented piece 15 of the inner winding portion is schematically shown. Figure 8a and Figure 8b The segmented piece 15 of the outer winding portion is schematically shown. Figure 9 The segmented pieces 15 of the intermediate winding between them are shown schematically.

[0137] According to one embodiment of this disclosure, the plurality of segment pieces 15 may be trapezoidal in shape. The term "trapezoid" as used in this disclosure can refer to a quadrilateral including the parallel top and bottom sides of the segment pieces 15. Specifically, "trapezoid" can mean at least one of the following: an "isosceles trapezoid" (where the lengths of the two hypotenuses of the non-parallel top and bottom sides are equal), a "scalene trapezoid" (where the lengths or angles of the two hypotenuses are different), or a "right trapezoid" (where any one of the base angles is a right angle). In this disclosure, for ease of understanding, Figures 4 to 11 The example given is that segment 15 is an equilateral trapezoid, but this disclosure is not limited to this; it can be set as follows: Figure 12a and Figure 12b A right trapezoid or such Figure 13a and Figure 13b An isosceles trapezoid.

[0138] Additionally, according to one embodiment, the heights of the multiple segment pieces 15 may be the same. However, this is merely an example, and this disclosure is not necessarily limited thereto.

[0139] In addition, refer to Figure 4 Multiple segment pieces 15 can be provided with N pieces between the beginning end sp on the side of the winding shaft O or the center CT and the far end ep, based on the winding direction WD.

[0140] Reference Figure 7a and Figure 7b This illustrates the initial segment 15, which is the segment closest to the beginning end sp among a plurality of segment segments 15. s The bottom corner. Starting segment 15 s The first segment 15 formed among multiple segmented segments 15 with its starting end sp as a reference can be represented by 151. Hereinafter, it will be referred to as the starting segment 15. s Related elements are indicated by the subscript "s".

[0141] Reference Figure 7a , Figure 7b And mathematical formula 2, from the initial end sp to the initial segment 15 s winding distance l s It can be obtained from the following mathematical formula.

[0142] [Mathematical Expression 3]

[0143]

[0144] Where, θ s From the beginning end sp winding to the beginning segment 15 sThe winding angle in rad, r s From the central axis to the starting segment 15 s The radius, and b s This represents the distance from the shortest distance r0 to the starting segment 15. s The thickness can be determined by n. s ∙t is obtained. Where, n s It is wound onto the starting segment 15 s The number of windings, t can be the thickness of the electrode assembly 10 mentioned above. On the other hand, when the ungrooved portion 17 is formed at the beginning end sp, l s It can be the length l of the ungrooved portion 17 formed at the beginning end sp. sp The value of θ. On the other hand, the winding angle θ s It is represented by polar coordinates from the beginning end sp to the starting segment 15. s The winding length on one side can be expressed in radians. In one embodiment, when the ungrooved portion 17 is formed at the starting end sp, the winding angle θ s It can be greater than or equal to 2π. On the other hand, the mathematical formula 3 is rearranged as follows with respect to the winding angle θ. s Related formulas.

[0145] [Mathematical Expression 4]

[0146] (where d) s >0)

[0147] Wherein, due to θ s 2 Since θ > 0 and the mathematical expression is in the form of a quadratic equation, the radical formula can be used to obtain θ as follows: s The solution.

[0148] [Mathematical Expression 5]

[0149]

[0150] On the other hand, refer to Figure 7a and Figure 7b Assuming that segment 15 is an equilateral trapezoid, the sum of the base angles of the base sides of the inner segment 15e is 2α. s It can be π-Ø s That is, any base angle α of the bottom edge of the inner segment 15e. s It can be Among them, Ø s It can be the central angle or circumferential angle of the inner segment 15 with the central axis O as the reference.

[0151] Ø sIt can be achieved by dividing the inner part of the circle into segments with a ratio of 15 (c) relative to the entire circle. s :w s =2π:Ø s Formula, by As shown in the figure. Where, c s It is the circumference of the inner segmented piece formed by 15s, w s It is the width of the bottom edge of the inner segment piece 15s. On the other hand, c s It can be derived from 2πr s As shown in the figure. Where, r s It is the diameter from the central axis to the inner segment 15s.

[0152] Combining the above formulas, a base angle α can be obtained as follows: s .

[0153] [Mathematical Expression 6]

[0154]

[0155] On the other hand, according to one embodiment of this disclosure, the segmented pieces 15 can be spaced apart from each other, thus allowing the angles to form smaller inequalities. That is, it is possible to satisfy... Substituting mathematical expression 5 into mathematical expression 6, ultimately, for any base angle α... s It can be obtained from the following mathematical formula.

[0156] [Mathematical Expression 7]

[0157]

[0158] Where, r s The radius r represents the distance from the central axis O to the inner segment (electrode tab) over a period of 15 seconds. o It is the core radius, n s This can represent the number of times the inner segment 15s is wound. For example, when the initial end sp does not have an ungrooved portion 17, due to n s =1, therefore it can be r s =r o +t.

[0159] 15 intermediate segments n and end segment 15 e The winding angle θ n θ e and base angle α n α e Similarly, it can be obtained through mathematical formulas 1 through 6. That is, for ease of understanding, the above explanations and mathematical formulas are presented in the starting segment 15. sThe description is provided for reference only, but this disclosure is not limited thereto; the above description can be applied to all multiple segment pieces 15. That is, the above description can be applied to intermediate segment pieces 15. n and end segment 15 e .

[0160] For example, refer to Figure 8a , Figure 8b And the above mathematical expressions 1 to 7, with end segment 15 e base angle α e It can also be obtained from the following mathematical formula.

[0161] [Mathematical Expression 8]

[0162]

[0163] However, among them, b e Indicates the segmented piece 15 at the end. e Total winding thickness e This can be represented up to the end segment 15 e The winding length.

[0164] [Mathematical Expression 9]

[0165]

[0166] However, among them, w e Indicates end segment 15 e Width, θ e This can represent the winding from the initial end sp to the final segment 15. e The winding angle is rad. On the other hand, according to one embodiment of this disclosure, the segmented pieces 15 can be spaced apart from each other, so the angle can form a smaller inequality relationship. That is, it can satisfy... .

[0167] When substituting mathematical expression 8 into mathematical expression 9, the final end segment piece 15 is obtained. e base angle α s It can be obtained from the following mathematical formula.

[0168] [Mathematical Expression 10]

[0169]

[0170] On the other hand, when there is no unslotted portion 17 close to the terminal portion ep, it can be r e =Radius R of electrode assembly 10.

[0171] Additionally, refer to Figure 9 The segment 15 is set in the middle. nIt can also be obtained through the following mathematical formula, just like the mathematical formulas mentioned above.

[0172] [Mathematical Expression 11]

[0173]

[0174] Among them, w n It is the nth segment 15 n width, b n It is wound up to the nth segment 15 n thickness, l n It can be from the beginning sp to the nth segment 15 n The winding length.

[0175] Figure 10 This is a schematic diagram comparing the inner segment, the middle segment, and the outer segment. Figure 11 This is a schematic diagram comparing the inner segment, the middle segment, and the outer segment with the winding shaft as the reference.

[0176] Reference Figure 10 and Figure 11 According to one embodiment of the present disclosure, a plurality of segmented pieces 15 may be configured to change angle and / or width from the beginning end sp to the end end ep.

[0177] According to one embodiment of this disclosure, segments can be arranged from the starting segment 15 s To the end segment 15 e The base angle α gradually increases. For example, the base angle α can increase uniformly. For example, the base angle α of the nth segment 15... n It can be obtained from the following mathematical formula.

[0178] [Mathematical Expression 12]

[0179]

[0180] Where N is the total number of segments 15, n is any natural number greater than 1 and less than or equal to N, and α e It is the Nth set end segment piece 15 e The base angle, and α s It can be the first set starting segment 15 s The bottom corner.

[0181] Furthermore, according to one embodiment of this disclosure, the center angles Ø of a plurality of segment pieces 15 can be arranged to gradually decrease towards the outer side D2 of the winding direction WD. For example, the center angles Ø can decrease uniformly. For example, the center angle Ø of the nth segment piece 15 can be obtained by the following mathematical formula.

[0182] [Mathematical Expression 13]

[0183]

[0184] Where N is the total number of segments 15, and n is any natural number greater than 1 and less than or equal to N. e It is the Nth set end segment piece 15 e The central angle, and Ø s It can be the first set starting segment 15 s The central angle.

[0185] Furthermore, according to one embodiment of this disclosure, the width w of the segment pieces 15 can be arranged to gradually increase. For example, the width w of the segment piece 15 can be uniformly increased towards the outer side D2 of the winding direction WD. For example, the width w of the nth segment piece 15 can be obtained by the following mathematical formula.

[0186] [Mathematical Expression 14]

[0187]

[0188] Where N is the total number of segments 15, n is any natural number greater than 1 and less than or equal to N, and w e It is the Nth set end segment piece 15 e The width, and w s It can be the first set starting segment 15 s The width.

[0189] On the other hand, assuming that the segmented piece 15 is trapezoidal, the width w of the segmented piece (electrode tab) 15 referred to here can represent at least one of the top edge near the winding shaft O or the bottom edge near the uncoated portions 132, 142. Although the width w in the figures is described with reference to the bottom edge, this disclosure is not limited thereto, and the mathematical formula 11 can also be applied to the top edge of the segmented piece 15.

[0190] Figure 12a This is a diagram showing one side of the segmented piece formed at a right angle. Figure 12b This is a diagram showing the other side of the segment piece formed at a right angle. Figure 13a This is a diagram showing one side of the segmented piece formed at an acute angle. Figure 13b This is a diagram showing the other side of the segmented piece formed at an obtuse angle. Figures 12a to 13b An embodiment is schematically shown where the segmented piece (electrode tab) 15 is not an equilateral trapezoid. That is, the details are omitted. Figures 1 to 11 The description is repeated within the scope of the description.

[0191] Reference Figure 12aAccording to one embodiment, each of the plurality of segmented pieces 15 can be a right-angled trapezoid with a base angle α that is right-angled in the inner direction D1. Additionally, referring to... Figure 12b According to one embodiment, each of the plurality of segmented pieces 15 can be in the shape of a right trapezoid with a base angle β set in the outer direction D2.

[0192] That is, according to one embodiment of this disclosure, each of the plurality of segment pieces 15 can be a right-angled trapezoidal shape formed by either the base angle α of the inner side D1 and the base angle β of the outer side D2 in the winding direction WD. For example, the base angle of each of the plurality of segment pieces 15 may include a first base angle α near the beginning end sp and a second base angle β near the end end ep, and can be a trapezoidal in which the first base angle α or the second base angle β is a right angle.

[0193] Reference Figure 13a According to one embodiment, each of the plurality of segmented pieces 15 can be in the shape of a trapezoid with an acute base angle α in the inner direction D1 and an obtuse base angle β in the outer direction D2. Additionally, referring to... Figure 13b According to one embodiment, each of the plurality of segmented pieces 15 can be in the shape of a trapezoid with an obtuse base angle α set in the inner direction D1 and an acute base angle β set in the outer direction D2.

[0194] That is, according to one embodiment of this disclosure, each of the plurality of segment pieces 15 can be an obtuse angle formed by either the base angle α of the inner side D1 or the base angle β of the outer side D2 in the winding direction WD. For example, the base angle of each of the plurality of segment pieces 15 can include a first base angle α near the winding axis O and a second base angle β set further away from the first base angle, and can be an irregular trapezoid with the first base angle α or the second base angle β being an obtuse angle and the two hypotenuses having different sizes.

[0195] On the other hand, according to this disclosure, regardless of the shape of the segment piece 15, the sum of the base angles of the base edge can be obtained by the following mathematical formula.

[0196] [Mathematical Expression 15]

[0197]

[0198] In addition, Figures 12a to 13b In the embodiments, it is also possible to set at least one of the bottom corner α, the center corner Ø, or the width w of the segment 15 to increase uniformly.

[0199] Figure 14 This is a diagram showing the edges of the segmented pieces formed with rounded corners.

[0200] Reference Figure 14According to one embodiment of the present disclosure, at least one of the plurality of segment pieces 15 may be formed with a rounded corner portion 15R. That is, at least one of the plurality of segment pieces 15 may be formed such that the edge portion of the top edge facing the center CT is rounded.

[0201] According to one embodiment, at least one of the plurality of segment pieces 15 may have a rounded corner 15R formed on the edge near the top edge of the winding shaft O. The rounded corner 15R may be formed at the edge of the top edge of the segment piece 15 with a predetermined curvature.

[0202] When multiple segment pieces 15 are formed in the uncoated portions 132 and 142 by laser grooving, the rounded corner portion 15R can prevent the grooving speed of the laser from decreasing at the edge of the top edge of the segment piece 15.

[0203] Figure 15 This is an example diagram of a power supply 50 according to an embodiment of the present disclosure.

[0204] omission and Figures 1 to 14 The description is repeated within the scope of the description.

[0205] According to one embodiment of this disclosure, the power source 50 may include at least one battery cell 1. The power source 50 of this disclosure may represent at least one battery module, battery pack, or energy storage device (ESS). Figures 1 to 14 The power supply source for cell 1 is described in the diagram.

[0206] According to one embodiment of this disclosure, the power supply 50 may include at least one battery cell 1 having electrode assemblies 10 and a housing 51 housing the battery cell 1. The battery cell 1 may include… Figures 1 to 14 Explain the meaning of cell 1.

[0207] For example, according to one embodiment, the power supply 50 may include a housing 51, the housing 51 including a first cover 511 for accommodating at least one battery cell 1 and a second cover 512 covering the first cover 511. That is, as long as it can accommodate... Figures 1 to 14 The battery cell 1 described herein belongs to the power supply 50 disclosed herein.

[0208] The various embodiments of this disclosure have been described in detail above, but the scope of this disclosure is not limited thereto. It will be apparent to those skilled in the art that various modifications and changes can be made without departing from the technical concept of this disclosure as set forth in the claims. In the above embodiments, some components may be deleted, or the embodiments may be combined with each other.

[0209] The above description is merely an example of applying the principles of this disclosure, and other configurations may be included without departing from the scope of this disclosure.

[0210] While embodiments or aspects have been described by way of example for illustrative purposes, it should be understood that such details are for illustrative purposes only, and this disclosure is not limited to the disclosed embodiments or aspects, but rather is intended to cover modifications and equivalents within the spirit and scope of the claims. Furthermore, it should be understood that this disclosure contemplates that, to the extent possible, one or more features of any embodiment or aspect may be combined with one or more features of any other embodiment or aspect.

Claims

1. An electrode assembly, comprising: The first electrode plate is wound around a winding shaft and includes a first uncoated portion that is not coated with the first electrode active material. The second electrode plate is wound around the winding shaft and includes a second uncoated portion that is not coated with the second electrode active material; A diaphragm is disposed between the first electrode plate and the second electrode plate; as well as Multiple segmented pieces are formed in at least one of the first uncoated portion and the second uncoated portion. The multiple segmented pieces are arranged such that at least one bottom corner changes along the winding direction.

2. The electrode assembly according to claim 1, wherein, The proportion of overlap between the multiple segmented pieces along the winding direction is less than or equal to 5%.

3. The electrode assembly according to claim 1, wherein, Each of the plurality of segment pieces comprises a trapezoidal shape.

4. The electrode assembly according to any one of claims 1 to 3, wherein, At least one of the first uncoated portion and the second uncoated portion further includes an ungrooved portion, which is the portion where the plurality of segmented pieces are not formed. With the winding direction as a reference, the ungrooved portion is arranged adjacent to either the starting end portion, which includes the end portion close to the winding shaft, or the ending portion, which includes the end portion furthest from the winding shaft.

5. The electrode assembly according to any one of claims 1 to 3, wherein, With the winding direction as a reference, the size of the bottom angle of the plurality of segment pieces gradually increases towards the terminal portion, including the end furthest from the winding axis.

6. The electrode assembly according to claim 5, wherein, With the winding direction as a reference, the size of the bottom angle of the plurality of segmented pieces increases uniformly toward the terminal portion.

7. The electrode assembly according to claim 6, wherein, The bottom angle (α) of the nth segment of the plurality of segment pieces, starting from the beginning end near the end of the winding shaft. n ) satisfies the following formula, Where N is the total number of the plurality of segments, n is a natural number greater than 1 and less than or equal to N, and α e It is the bottom corner (α) of the Nth set end segment piece. N ), α s It is the bottom corner (α1) of the first set starting segment piece.

8. The electrode assembly according to claim 7, wherein, The multiple segmented pieces are in the shape of an equilateral trapezoid. The bottom angle (α) of the starting segment piece s ) satisfies the following formula, Among them, w s r is the width of the initial segment piece. o θ is the shortest radius from the winding shaft to the first electrode plate or the second electrode plate. s It is the winding angle to the starting segment piece, and t is the thickness when one turn is made.

9. The electrode assembly according to claim 8, wherein, The winding angle θ of the initial segment s Satisfy the following formula, Among them, l s b is the winding length from the beginning end to the starting segment piece. s It is the winding thickness to the starting segment piece.

10. The electrode assembly according to claim 7, wherein, The multiple segmented pieces are in the shape of an equilateral trapezoid. The bottom angle (α) of the end segment piece e ) satisfies the following formula, Among them, w e r is the width of the end segment piece. o θ is the shortest radius from the winding shaft to the first electrode plate or the second electrode plate. e It is the winding angle to the end segment piece, and t is the thickness when one turn is wound.

11. The electrode assembly of claim 10, wherein, The winding angle θ of the end segment piece e Satisfy the following formula, Among them, l e b is the winding length of the segmented piece from the beginning to the end. e It is the winding thickness of the segmented piece wound to the end.

12. The electrode assembly according to any one of claims 1 to 3, wherein, The width of the plurality of segmented pieces increases uniformly outward in the winding direction.

13. The electrode assembly according to claim 12, wherein, The width (w) of the segment from the nth segment set on the winding axis among the plurality of segments n ) satisfies the following formula, Where N is the number of the plurality of segments, n is a natural number greater than 1 and less than or equal to N, and w e It is the width of the Nth set end segment, w s It is the width of the first set starting segment.

14. The electrode assembly according to any one of claims 1 to 3, wherein, The center angles of the multiple segmented pieces decrease uniformly outwards in the winding direction.

15. The electrode assembly of claim 14, wherein, The nth segment of the plurality of segments is located at the center angle (Ø) of the nth segment on the winding axis. n ) satisfies the following formula, Where N is the number of the plurality of segments, and n is a natural number greater than 1 and less than or equal to N. e It is the center angle of the Nth set end segment piece, Ø s It is the center angle of the first set starting segment piece.

16. The electrode assembly according to claim 1, wherein, The bottom corner of each of the plurality of segment pieces includes a first bottom corner located close to the winding shaft and a second bottom corner located further away from the winding shaft than the first bottom corner. The plurality of segmented pieces are right trapezoids in the shape of either the first base angle or the second base angle being a right angle.

17. The electrode assembly according to any one of claims 1 to 3, wherein, The bottom corners of the plurality of segmented pieces include a first bottom corner located close to the winding shaft and a second bottom corner located further away from the winding shaft than the first bottom corner. The plurality of segmented pieces are scalene trapezoids in the form of either the first or the second base angle being an obtuse angle, and the two hypotenuses having different sizes.

18. The electrode assembly according to any one of claims 1 to 3, wherein, The proportion of the overlapping area of ​​the plurality of segmented pieces along the winding direction is greater than 0. The width of the overlap between adjacent segments is constant from the outer side of the winding axis.

19. The electrode assembly according to any one of claims 1 to 3, wherein, The plurality of segmented pieces are arranged such that at least one oblique edge is connected to each other along the winding direction.

20. The electrode assembly according to any one of claims 1 to 3, wherein, The proportion of the areas of the multiple segmented pieces that are adjacent and overlap along the winding direction is less than 0. The width of the gaps between the plurality of adjacent segments is constant from the outer side of the winding axis.

21. The electrode assembly according to any one of claims 1 to 3, wherein, At least one edge of at least one of the plurality of segment pieces has a rounded corner.

22. A secondary battery, comprising: An electrode assembly, including a first electrode plate and a second electrode plate, is wound around a winding shaft as the center; A container that houses the electrode assembly and has at least one opening; A lid assembly, fitted to the can, to close the opening; and The current collector is electrically connected to the electrode assembly. At least one of the first electrode plate and the second electrode plate includes a plurality of segmented pieces bent toward the winding shaft to form one side of the electrode assembly. The plurality of segmented pieces are configured such that at least one bottom corner changes in a direction away from the winding axis.

23. A power supply, comprising: At least one battery cell, the battery cell including an electrode assembly; as well as The casing houses the battery cell. The electrode assembly includes: The first electrode plate is wound around a winding shaft and includes a first uncoated portion that is not coated with the first electrode active material. The second electrode plate is wound around the winding shaft and includes a second uncoated portion that is not coated with the second electrode active material; and Multiple segmented pieces are formed in at least one of the first uncoated portion and the second uncoated portion. The multiple segmented pieces are arranged such that at least one bottom corner changes along the winding direction.

Images