Electrode assembly and rechargeable battery having the same

Abstract

The invention discloses an electrode assembly and a rechargeable battery having the same. An electrode assembly includes: a first electrode assembly having a plurality of first windings of a first laminate; an intermediate portion surrounding the first electrode assembly; and a second electrode assembly surrounding the intermediate portion, the second electrode assembly having a plurality of second windings of a second laminate, in which the intermediate portion is configured to adjust a gap between the first electrode assembly and the second electrode assembly according to a pressure change.

Description

Technical Field

[0001] Embodiments relate to a rechargeable battery. More particularly, embodiments of the present disclosure relate to an electrode assembly for a cylindrical battery. Background Art

[0002] Rechargeable batteries are used for various purposes, such as powering small electronic devices such as mobile phones and laptop computers, and powering motors of transportation vehicles such as electric vehicles and hybrid vehicles. In the latter case, a battery module system combining a plurality of cylindrical rechargeable batteries may be used, and in this case, the cylindrical rechargeable battery tends to enlarge the diameter of the electrode assembly to ensure a large capacity.

[0003] As the diameter of the electrode assembly increases, during the process of high-speed winding of the separator and the electrode, the pressure applied to the center of the electrode assembly increases, and therefore the diameter of the core needs to be expanded to withstand the high pressure. However, expanding the core diameter results in a decrease in the capacity of the rechargeable battery. In addition, during charging, the volume of the electrode assembly increases, and as the diameter of the electrode assembly increases, the pressure due to expansion increases. This may cause the electrode assembly to deform or crack, which may cause an internal short circuit in the rechargeable battery. Summary of the invention

[0004] An embodiment includes an electrode assembly comprising: a first electrode assembly having a plurality of first windings of a first stack including a first electrode, a diaphragm, and a second electrode; a middle portion surrounding the first electrode assembly; and a second electrode assembly surrounding the middle portion, the second electrode assembly having a plurality of second windings of a second stack including a first electrode, a diaphragm, and a second electrode, wherein the middle portion can be configured to adjust a gap between the first electrode assembly and the second electrode assembly according to a pressure change.

[0005] The plurality of first windings of the first stack may be wrapped around a first core, the plurality of second windings of the second stack may be wrapped around a second core, and the second core may be removed at the center of the second electrode assembly, and the first electrode assembly and the middle portion may be disposed in an empty space at the center of the second electrode assembly.

[0006] The first stack may be a stacked structure having a first electrode, a first diaphragm, a second electrode and a second diaphragm, the middle part may include two diaphragms, the two diaphragms may be integrally connected to the first diaphragm and the second diaphragm included in the first stack, and the middle part may have multiple windings of the two diaphragms.

[0007] The intermediate portion may include an adhesive tape covering an end of the first laminate, and the intermediate portion may have a plurality of windings of the adhesive tape.

[0008] The plurality of first windings of the first stack may surround a first core, the middle portion may surround a second core, the plurality of second windings of the second stack may surround the middle portion, and the second core may be removed at the center of the middle portion, and the first electrode assembly may be located in the empty space at the center of the middle portion.

[0009] The second stack may be a stacked structure having a first electrode, a first diaphragm, a second electrode and a second diaphragm, the middle part may include two diaphragms integrally connected to the first diaphragm and the second diaphragm included in the second stack, and the middle part may have multiple windings of the two diaphragms.

[0010] An embodiment includes an electrode assembly, comprising: a first electrode assembly having a plurality of first windings of a first stack, the first stack including a first electrode, a separator, and a second electrode; a middle portion surrounding the first electrode assembly; and a second electrode assembly surrounding the middle portion, the second electrode assembly having a plurality of second windings of a second stack, the second stack including a first electrode, a separator, and a second electrode, the first stack and the second stack being arranged separately from each other, and the middle portion can be integrally connected to the first stack and one of the second stacks.

[0011] The first stacked body may be a stacked structure having a first electrode, a first separator, a second electrode, and a second separator, and the middle portion may include two separators integrally connected to the first separator and the second separator included in the first stacked body.

[0012] The plurality of first windings of the first laminate may surround a first core, and the intermediate portion may have a plurality of windings of the two-layer diaphragm.

[0013] The second stack may be a stacked structure having a first electrode, a first separator, a second electrode, and a second separator, and the middle portion may include two separators integrally connected to the first separator and the second separator included in the second stack.

[0014] The plurality of windings of the two-layer separator may be wrapped around a second core, the plurality of second windings of the second stack may be wrapped around the middle portion, and the second core may be removed at the center of the middle portion, and the first electrode assembly may be disposed in an empty space at the center of the middle portion.

[0015] The second electrode of each of the first stack and the second stack may include a second substrate and a second composite material layer disposed on the second substrate, and the second composite material layer of the first stack and the second composite material layer of the second stack are different in at least one of silicon content and density.

[0016] The second electrode assembly may have an N / P ratio smaller than that of the first electrode assembly.

[0017] An embodiment includes a rechargeable battery comprising: an electrode assembly; a can accommodating the electrode assembly in its internal space; and a cover plate connected to an end of an open side of the can and sealing the can, wherein the electrode assembly comprises a first electrode assembly having a plurality of windings of a first stack, a middle portion surrounding the first electrode assembly, and a second electrode assembly surrounding the middle portion and having a plurality of windings of a second stack, and wherein the middle portion is configured to adjust a gap between the first electrode assembly and the second electrode assembly according to a pressure change.

[0018] The first electrode assembly and the second electrode assembly may each include a first uncoated region extending to one side and a second uncoated region extending to the other (opposite) side, and each of the first uncoated region and the second uncoated region may be bent toward the center of the first electrode assembly, and the first uncoated region of the second electrode assembly may be in contact with the first uncoated region of the first electrode assembly, and the second uncoated region of the second electrode assembly may be in contact with the second uncoated region of the first electrode assembly.

[0019] The rechargeable battery may further include: a first current collecting plate fixed to the first uncoated area of ​​the electrode assembly; a riveted terminal installed in a terminal hole provided in the top portion of the can via an insulator and connected to the first current collecting plate; and a second current collecting plate fixed to the second uncoated area of ​​the electrode assembly and including a conductive portion in close contact with an inner wall of the can. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various features will become apparent to those skilled in the art by describing exemplary embodiments in detail with reference to the accompanying drawings, in which:

[0021] Figure 1 is a perspective view of an electrode assembly according to one or more embodiments;

[0022] Figure 2 According to one or more embodiments Figure 1 An exploded perspective view of an electrode assembly;

[0023] Figure 3 According to one or more embodiments Figure 2 A partial enlarged view of the first electrode assembly of the electrode assembly shown in ;

[0024] Figure 4 According to one or more embodiments Figure 2 A partial enlarged view of the second electrode assembly of the electrode assembly shown in ;

[0025] Figure 5 According to one or more embodiments Figure 1 A schematic cross-sectional view of a middle portion of an electrode assembly shown in FIG.

[0026] Figure 6 According to one or more embodiments Figure 5 A partial enlarged view of

[0027] Figure 7 is a partially enlarged cross-sectional view of an electrode assembly that has been subjected to an uncoated area bending process according to one or more embodiments;

[0028] Figure 8 is an exploded perspective view of an electrode assembly according to one or more embodiments;

[0029] Fig. 9 According to one or more embodiments Figure 8 A schematic cross-sectional view of a middle portion of an electrode assembly shown in FIG.

[0030] Fig.10 According to one or more embodiments Fig. 9 A partial enlarged view of

[0031] Fig.11 is a schematic cross-sectional view of a middle portion of an electrode assembly according to one or more embodiments;

[0032] Fig.12 is a perspective view of a rechargeable battery according to one or more embodiments; and

[0033] Fig.13 According to one or more embodiments Fig.12 A cross-sectional view of a rechargeable battery shown in FIG. DETAILED DESCRIPTION

[0034] Exemplary embodiments will be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey exemplary embodiments to those skilled in the art.

[0035] In the accompanying drawings, the sizes of layers and regions may be exaggerated for ease of illustration. It is also understood that if a layer is referred to as being "on" another layer or substrate, it may be directly on the other layer or substrate, or there may also be an intermediate layer. Further, it is understood that if a layer is referred to as being "below" another layer, it may be directly below, and there may also be one or more intermediate layers. In addition, it is also understood that if a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or there may also be one or more intermediate layers. The same reference numerals refer to the same elements throughout.

[0036] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. As will be appreciated by those skilled in the art, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure.

[0037] Figure 1 is a perspective view of an electrode assembly according to one or more embodiments, and Figure 2 According to one or more embodiments Figure 1 An exploded perspective view of an electrode assembly. Figure 3 According to one or more embodiments Figure 2 A partial enlarged view of the first electrode assembly of the electrode assembly shown in FIG. Figure 4 According to one or more embodiments Figure 2 A partially enlarged view of the second electrode assembly of the electrode assembly shown in .

[0038] refer to Figures 1 to 4 , the electrode assembly 100 according to one or more embodiments may include a first electrode assembly 110 in which a first laminate 210 is wound in a core form, a middle portion 120 disposed outside the first electrode assembly 110, and a second electrode assembly 130 disposed outside the middle portion 120 and in which a second laminate 220 is wound in a core form. The first laminate 210 and the second laminate 220 may be disconnected from each other instead of being connected.

[0039] The first electrode assembly 110 is formed by a strip-shaped first laminate 210 wound in a core form around a first core 140. The first laminate 210 may include a first electrode 10, a separator 30, a second electrode 20, and a separator 30 stacked sequentially, and may be wound around the first core 140, for example, five times or more. In the first laminate 210, the positions of the first electrode 10 and the second electrode 20 may be swapped. In some embodiments, the first electrode assembly 110 may have a plurality of first windings of the first laminate 210. In some embodiments, a plurality of first windings of the first laminate 210 may surround the first core 140.

[0040] The middle portion 120 may be disposed outside the first electrode assembly 110 while surrounding the first electrode assembly 110. The second electrode assembly 130 may be disposed outside the middle portion 120 while surrounding the middle portion 120. In this manner, the first electrode assembly 110, the middle portion 120, and the second electrode assembly 130 may be sequentially disposed along a radial direction centered on the first core 140.

[0041] The second electrode assembly 130 may be formed by a strip-shaped second laminate 220 wound in a core form around the second core 150, and then the second core 150 may be removed. The second laminate 220 may include a first electrode 40, a separator 60, a second electrode 50, and a separator 60 stacked sequentially, and may be wound around the second core 150, for example, five times or more. In the second laminate 220, the positions of the first electrode 40 and the second electrode 50 may be swapped. In some embodiments, the second electrode assembly 130 may have a plurality of second windings of the second laminate 220. In some embodiments, a plurality of second windings of the second laminate 220 may surround the second core 150.

[0042] The diameter d1 of the second core 150 and the inner diameter of the second electrode assembly 130 after removing the second core 150 may be slightly larger than the outer diameter d2 of the middle portion 120. After removing the second core 150 from the second electrode assembly 130, the first electrode assembly 110 and the middle portion 120 may be accommodated in the inner space of the second electrode assembly 130 (that is, the first electrode assembly 110 and the middle portion 120 may be disposed in the empty space at the center of the second electrode assembly 130) to form the electrode assembly 100 together with the second electrode assembly 130. In some embodiments, the first core 140 may be retained, or may be removed in other embodiments. The electrode assembly 100 may be accommodated in the inner space of a can to be described later together with an electrolyte solution.

[0043] The first electrode 10 of the first stack 210 and the first electrode 40 of the second stack 220 may include first substrates 11, 41, respectively, and first composite material layers 12, 42 may be disposed on the first substrates 11, 41, respectively. The first composite material layers 12, 42 may be disposed on both sides of the remaining regions of the first substrates 11, 41 except for one (upper) edge. The second electrode 20 of the first stack 210 and the second electrode 50 of the second stack 220 may include second substrates 21, 51 and second composite material layers 22, 52 disposed on the second substrates 21, 51, respectively. The second composite material layers 22, 52 may be disposed on both sides of the remaining regions of the second substrates 21, 51 except for the other (lower) edge.

[0044] In the lithium ion rechargeable battery according to one or more embodiments, the first substrate 11, 41 may include an aluminum foil, and the first composite material layer 12, 42 may include a transition metal oxide such as LiCoO2, LiNiO2, LiMn2O4, Li(NiCoMn)O2, LiFePO4, Li(NiCoMn)O2, etc., a conductive material, an adhesive, etc. The second substrate 21, 51 may include, for example, a copper foil or a nickel foil, and the second composite material layer 22, 52 may include, for example, graphite, silicon, a conductive material, and an adhesive. The first electrode 10, 40 may be referred to as a positive electrode, and the second electrode 20, 50 may be referred to as a negative electrode.

[0045] The separator 30, 60 may be made of a porous material, or may be made of a porous material with a coating provided on at least one side. The porous material may include one or more of polyethylene, polypropylene, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyester, polycarbonate, and polyimide. The coating may include an adhesive and may further include inorganic particles. The adhesive may include polyvinylidene fluoride compounds. The inorganic particles may include one or more of Al2O3, BaSO4, MgO, Mg(OH)2, SiO2, TiO2, ZnO, SnO2, NiO, and GaO. The separator 30, 60 may insulate the first electrode 10, 40 from the second electrode 20, 50 while allowing the movement of lithium ions.

[0046] Figure 5 According to one or more embodiments Figure 1 A schematic cross-sectional view of a middle portion of an electrode assembly shown in FIG. Figure 6 According to one or more embodiments Figure 5 A partial enlarged view of .

[0047] refer to Figures 1 to 6 , the middle portion 120 may be used to adjust the gap between the first electrode assembly 110 and the second electrode assembly 130. To this end, the middle portion 120 may be made of a material having ductility and elasticity. The middle portion 120 may actively change the gap between the first electrode assembly 110 and the second electrode assembly 130 by changing its thickness according to the applied pressure.

[0048] The middle part 120 may include two or more layers of diaphragms, and may include the above two or more layers of diaphragms wound one or more times. For example, the middle part 120 may include two layers of diaphragms 30a, and the two layers of diaphragms 30a may be connected, for example, integrally connected to two diaphragms 30 belonging to the first stack 210. In some embodiments, the middle part 120 may have a plurality of windings of the two layers of diaphragms 30a.

[0049] In some embodiments, the two separators 30 belonging to the first stack 210 may extend outward beyond the first electrode 10 and the second electrode 20 to form a separator 30a of the middle portion 120. The middle portion 120 may be formed of the separator 30a and has excellent electrolyte solution impregnation and rapidly changes thickness according to pressure changes, and thus is advantageous for accurately controlling the gap between the first electrode assembly 110 and the second electrode assembly 130.

[0050] The number of turns of the middle portion 120 may be, for example, between 1 and 10 times, preferably between 1 and 3 times. If the number of turns of the middle portion 120 is one or more, the middle portion 120 may surround the entire outer surface of the first electrode assembly 110. As the number of turns of the middle portion 120 increases, the gap control function becomes better, but the capacity of the electrode assembly 100 decreases. If the number of turns of the middle portion 120 is 3 or less, the capacity of the electrode assembly 100 may be increased while achieving an appropriate gap adjustment function.

[0051] Generally, rechargeable batteries tend to enlarge the diameter of the electrode assembly to ensure a large capacity. However, simply enlarging the diameter of the electrode assembly increases the pressure applied to the center of the electrode assembly during the process of high-speed winding of the laminate, so the diameter of the core can be enlarged to withstand the high pressure. However, enlarging the core diameter will result in a reduction in the capacity of the rechargeable battery.

[0052] exist Figures 1 to 6 In the electrode assembly 100, the first stack 210 and the second stack 220 are not connected to each other, but are wound around their respective cores (the first core 140 and the second core 150) separately and then combined. Therefore, the pressure generated when the second stack 220 is wound does not affect the first core 140 and the first electrode assembly 110. Therefore, Figures 1 to 6 The electrode assembly 100 may be advantageous in ensuring a large capacity by enlarging the entire diameter, and there is no capacity reduction due to the enlargement of the diameter of the first core 140 .

[0053] In addition, in a typical rechargeable battery, the electrode assembly may undergo repeated volume changes of expansion during charging and contraction during discharging due to the secondary composite material layer, and as the diameter of the electrode assembly increases, the pressure applied to the center of the electrode assembly also increases due to the expansion. Therefore, deformation such as folding or cracking may occur in the electrode assembly, which may cause an internal short circuit of the rechargeable battery.

[0054] exist Figures 1 to 6In the electrode assembly 100 of the present invention, the middle portion 120 may be disposed between the first electrode assembly 110 and the second electrode assembly 130. In the rechargeable battery, since the second electrode assembly 130 may be blocked by the can and cannot expand outward, it expands inward, and if the first core 140 exists, the first electrode assembly 110 expands outward. The middle portion 120 may shrink due to pressure generated during expansion of the first electrode assembly 110 and the second electrode assembly 130 to release pressure caused by the expansion.

[0055] Therefore, even if volume expansion occurs during charging, Figures 1 to 6 The electrode assembly 100 may also suppress the occurrence of deformation or cracking due to pressure and may effectively prevent an internal short circuit of the rechargeable battery.

[0056] In the electrode assembly 100 configured as described above, the second composite material layer 22 of the first stack 210 and the second composite material layer 52 of the second stack 220 may be manufactured to have different expansion characteristics. For example, the second composite material layer 22 of the first stack 210 and the second composite material layer 52 of the second stack 220 may be manufactured differently in at least one of silicon content and density. Generally, the silicon content and density of the second composite material layers 22, 52 may be proportional to the degree of expansion during charging.

[0057] Since the inner portion of the second electrode assembly 130 facing the middle portion 120 is not mechanically fixed to a specific portion, the inner portion of the second electrode assembly 130 may be deformed or cracked when expanding along the length direction (circumferential direction) of the second stack 220. If it is necessary to suppress the expansion along the length direction (circumferential direction) of the second stack 220, the second composite material layer 52 of the second stack 220 may have a silicon content lower than that of the second composite material layer 22 of the first stack 210, or may have a density lower than that of the second composite material layer 22 of the first stack 210.

[0058] In some embodiments, if the first core 140 is removed, the first electrode assembly 110 may have an empty space inside. In this case, if the first electrode assembly 110 expands, wrinkles or cracks may occur at the inner end of the first electrode assembly 110. If it is necessary to suppress the expansion of the first electrode assembly 110, the second composite material layer 22 of the first stack 210 may have a silicon content lower than that of the second composite material layer 52 of the second stack 220, or may have a density lower than that of the second composite material layer 52 of the second stack 220.

[0059] The difference in the silicon content of the second composite material layers 22, 52 or the density of the second composite material layers 22, 52 is not limited to the above examples, and if it is necessary to control the expansion degree of a specific part according to the position characteristics of the electrode assembly 100, the silicon content of the second composite material layers 22, 52 or the density of the second composite material layers 22, 52 can be adjusted in various ways.

[0060] In addition, in the electrode assembly 100 configured as described above, the first electrode assembly 110 and the second electrode assembly 130 may be manufactured to have different N / P ratios. The N / P ratio is the capacity of the second electrode divided by the capacity of the first electrode, and a typical rechargeable battery has an N / P ratio greater than 1. As the diameter of the electrode assembly increases to ensure a large capacity of the rechargeable battery, it is necessary to increase the N / P ratio to balance the first electrode and the second electrode at the inner edge (the edge where the winding starts) and the outer edge (the edge where the winding ends).

[0061] exist Figures 1 to 6 In the electrode assembly 100 of the present invention, the first electrode assembly 110 and the second electrode assembly 130 may be separated from each other and have their own inner and outer edges. Therefore, the second electrode assembly 130 does not need to have the same N / P ratio as that of the first electrode assembly 110, and may have an N / P ratio that is smaller than that of the first electrode assembly 110. This has the effect of reducing the amount of active material used by the entire electrode assembly 100.

[0062] Figures 1 to 6 The electrode assembly 100 may include a bent structure of the uncoated area to improve current collecting efficiency.

[0063] Figure 7 is a partially enlarged cross-sectional view of an electrode assembly that has been subjected to an uncoated region bending process according to one or more embodiments.

[0064] refer to Figure 7 , the portion of the first substrate 11, 41 of the first electrode 10, 40 not covered by the first composite material layer 12, 42 may be referred to as the first uncoated area 13, 43, and the portion of the second substrate 21, 51 of the second electrode 20, 50 not covered by the second composite material layer 22, 52 may be referred to as the second uncoated area 23, 53. In the electrode assembly 100, the first uncoated area 13, 43 and the second uncoated area 23, 53 may be disposed on opposite sides ( Figure 7 upper and lower sides).

[0065] After the first electrode assembly 110 and the middle portion 120 are accommodated in the inner space of the second electrode assembly 130, the first uncoated area 13, 43 may be bent inwardly toward the center of the first core (not shown) or the first electrode assembly 110, and thus may overlap with the adjacent first uncoated area 13, 43. The second uncoated area 23, 53 may also be bent inwardly toward the center of the first core or the first electrode assembly 110 and overlap with the adjacent second uncoated area 23, 53. A plurality of cut lines may be located in the first uncoated area 13, 43 and the second uncoated area 23, 53, so that the first uncoated area 13, 43 and the second uncoated area 23, 53 may be easily bent (e.g., where bending is required). The first uncoated area 13, 43 and the second uncoated area 23, 53 may each be overlapped and squeezed by bending to form a flat surface.

[0066] In this case, the first uncoated region 43 of the second electrode assembly 130 may contact the first uncoated region 13 of the first electrode assembly 110, and the second uncoated region 53 of the second electrode assembly 130 may contact the second uncoated region 23 of the first electrode assembly 110. In this case, the first electrode 10 of the first electrode assembly 110 and the first electrode 40 of the second electrode assembly 130 may be conductive, and the second electrode 20 of the first electrode assembly 110 and the second electrode 50 of the second electrode assembly 130 may be conductive.

[0067] Figure 8 is an exploded perspective view of an electrode assembly according to one or more embodiments, Fig. 9 According to one or more embodiments Figure 8 A schematic cross-sectional view of a middle portion of an electrode assembly shown in FIG. Fig.10 According to one or more embodiments Fig. 9 In some embodiments, in addition to the following description, the electrode assembly may have the same Figures 1 to 7 The same or similar configuration of the embodiments.

[0068] refer to Figures 8 to 10 The first electrode assembly 110 may be formed by winding the first laminate 210 around the first core 140 in a core form. The middle portion 160 and the second electrode assembly 130 may be formed by winding at least two layers of the separator 30b and the second laminate 220 around the second core 150 in a core form and then removing the second core 150.

[0069] The diameter d3 of the second core 150 and the inner diameter of the middle portion 160 after removing the second core 150 may be slightly larger than the outer diameter d4 of the first electrode assembly 110. After removing the second core 150 from the middle portion 160 and the second electrode assembly 130, the first electrode assembly 110 may be accommodated in the inner space of the middle portion 160 (that is, the first electrode assembly 110 may be in the empty space at the center of the middle portion 160), thereby forming the electrode assembly 100A together with the middle portion 160 and the second electrode assembly 130.

[0070] The middle portion 160 may be formed of two layers of diaphragms 30b, and the two layers of diaphragms 30b may be connected, for example, integrally connected, to the two diaphragms 60 belonging to the second stack 220. That is, the two diaphragms 60 belonging to the second stack 220 may extend inwardly beyond the first electrode 40 and the second electrode 50 to form the diaphragm 30b of the middle portion 160. In some embodiments, the middle portion 160 may have a plurality of windings of the two layers of diaphragms 30b.

[0071] Fig.11 is a schematic cross-sectional view of a middle portion of an electrode assembly according to one or more embodiments. In addition to the contents described below, Fig.11 The electrode assembly may have the same Figures 1 to 7 The same or similar configuration of the embodiments.

[0072] refer to Fig.11 , the middle portion 170 may include an adhesive tape, and the adhesive tape may be wound one or more times around the first electrode assembly 110. The adhesive tape may be formed of a polymer film having an adhesive material coated on the surface, for example, a film such as polyimide (PI), polyethylene terephthalate (PET), and oriented polystyrene (OPS). In some embodiments, the middle portion 170 may have a plurality of windings of the adhesive tape.

[0073] The thickness of the adhesive tape may be equal to or greater than the thickness of the separator 30 included in the first stack 210 and the separator 60 included in the second stack 220. The middle portion 170 formed by the adhesive tape may cover the outer edge (the edge where the winding ends) of the first stack 210 to prevent the first stack 210 from unwinding. Therefore, in the process of inserting the first electrode assembly 110 and the middle portion 170 into the second electrode assembly 130 from which the second core (not shown) has been removed, assembly can be facilitated.

[0074] In the above Figures 1 to 7 In the case of an embodiment of the present invention, the middle portion 120 may be connected to the first stack 210 and may be configured to be disconnected from the second stack 220. In this case, the outer edge of the middle portion 120 and the inner edge of the second stack 220 may be offset from each other. Figures 8 to 10In the embodiment of the present invention, the middle portion 160 may be connected to the second stack 220 and may be disposed to be disconnected from the first stack 210. In this case, the outer edge of the first stack 210 and the inner edge of the middle portion 160 may be offset from each other. Fig.11 In the embodiment of the present invention, the middle portion 170 may be configured to be disconnected from both the first stack 210 and the second stack 220 .

[0075] Fig.12 is a perspective view of a rechargeable battery according to one or more embodiments, and Fig.13 According to one or more embodiments Fig.12 A rechargeable battery according to one or more embodiments may include the electrode assembly in one of the above embodiments.

[0076] refer to Fig.12 and Fig.13 A rechargeable battery 300 according to one or more embodiments may include an electrode assembly 100, a can 310 accommodating the electrode assembly 100 in an inner space, and an open side (eg, Fig.13 The rechargeable battery 300 may further include a first current collecting plate 330, a second current collecting plate 340, and a riveted terminal 350.

[0077] The tank 310 may have one side (e.g., Fig.13 The can 310 may be formed in a shape that is open at the lower side in the orientation of the rechargeable battery 300 so that the electrode assembly 100 can be inserted. The can 310 may include a disc-shaped top portion 311 and a cylindrical side portion 312 connected to the edge of the top portion 311. If the orientation of the top and bottom of the rechargeable battery 300 is changed, the top portion 311 may be referred to as a bottom portion, for example. The can 310 may be made of steel, stainless steel, aluminum, or an aluminum alloy.

[0078] A terminal hole may be provided at the center of the top portion 311, and a rivet terminal 350 may be installed in the terminal hole via or through the first insulator 361. The first current collecting plate 330 may be fixed to the first uncoated region 13, 43 of the electrode assembly 100, and the second current collecting plate 340 may be fixed to the second uncoated region 23, 53 of the electrode assembly 100. The rivet terminal 350 may be combined with or coupled to the first current collecting plate 330, and may be charged to the same polarity as that of the first electrode 10, 40 by the first current collecting plate 330, and serve as a first terminal (e.g., a positive terminal).

[0079] The first insulator 361 can insulate the riveted terminal 350 from the top portion 311 and can seal the terminal hole to prevent leakage of the electrolyte solution. In some embodiments, the second insulator 362 can be disposed between the inner surface of the top portion 311 and the first current collecting plate 330 to insulate the top portion 311 from the first current collecting plate 330.

[0080] The cap plate 320 may be disposed on the outer side (e.g., the lower side) of the second current collecting plate 340, and may be coupled to the end of the side portion 312 via the third insulator 363. A notch groove 321 may be provided on the inner surface of the cap plate 320. The notch groove 321 may have a V-shaped cross-section, and may have an arc shape on a plane (if the target object is viewed from above).

[0081] The internal temperature of the rechargeable battery may increase due to various reasons such as rapid charge and discharge, external impact, and exposure to a high temperature environment, and the internal pressure may increase due to gasification of the electrolyte solution, etc. If the internal pressure of the rechargeable battery 300 increases, the cap plate 320 may be ruptured around the notch groove 321, and the internal gas may be discharged.

[0082] The side portion 312 of the can 310 may include a curling portion 313 and a crimping portion 314. The curling portion 313 may be a portion where the side portion 312 is concavely deformed toward the inside of the side portion 312, and the crimping portion 314 may be a portion where the end of the side portion 312 is vertically bent toward the inside of the side portion 312.

[0083] The edge of the cap plate 320 may be pressed between the curling portion 313 and the crimping portion 314 via the third insulator 363, and the cap plate 320 may be firmly fixed to the end of the side portion 312 by the curling portion 313 and the crimping portion 314. The cap plate 320 is insulated from the first electrode 10, 40 and the second electrode 20, 50, and may be non-electrically polar.

[0084] The second current collecting plate 340 may include a conductive portion 341 in close contact with the inner wall of the can 310 (e.g., the inner surface of the curling portion 313). The conductive portion 341 may be provided in plurality along the edge of the second current collecting plate 340. The can 310 may be charged to the same polarity as the second electrode 20, 50 through the conductive portion 341, and may be used as a second terminal (e.g., a negative terminal). The rechargeable battery 300 may be provided in plurality, and the plurality of rechargeable batteries may be connected by a bus bar (not shown) to form a battery module system.

[0085] The rechargeable battery 300 can increase the capacity by expanding the diameters of the electrode assembly 100 and the can 310, and suppress deformation or cracking due to pressure during expansion of the electrode assembly 100 by using the middle portion 120 of the electrode assembly 100, thereby preventing internal short circuits and improving long-term durability.

[0086] The present disclosure provides an electrode assembly and a rechargeable battery provided with the electrode assembly, which achieves large capacity by enlarging the diameter of the electrode assembly to prevent capacity reduction due to a core and prevents internal short circuit by suppressing deformation or cracking of the electrode assembly due to pressure during expansion.

[0087] According to the embodiment, the electrode assembly is advantageously capable of ensuring a large capacity by expanding the entire diameter due to the separate winding of the first laminate and the second laminate, and a capacity reduction due to the core does not occur. In addition, even if volume expansion occurs during charging, the electrode assembly can suppress the occurrence of deformation or cracking in the electrode assembly through the middle portion, and can effectively prevent an internal short circuit of the rechargeable battery.

[0088] While the present disclosure has been described in conjunction with what are presently considered to be practical embodiments, it is to be understood that the embodiments are not limited to those disclosed. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims.

[0089] Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for limiting purposes. In some cases, as would be apparent to one of ordinary skill in the art at the time of filing this application, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise specifically indicated. Therefore, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. An electrode assembly, comprising: a first electrode assembly having a plurality of first windings of a first stack; a middle portion surrounding the first electrode assembly; and a second electrode assembly surrounding the intermediate portion, the second electrode assembly having a plurality of second windings of a second stack, The middle portion is configured to adjust a gap between the first electrode assembly and the second electrode assembly according to a pressure change.

2. The electrode assembly according to claim 1, wherein: The plurality of first windings of the first laminated body surround a first core, The plurality of second windings of the second laminated body surround the second core, and The second core is removed from the center of the second electrode assembly, and the first electrode assembly and the middle portion are disposed in an empty space in the center of the second electrode assembly.

3. The electrode assembly according to claim 2, wherein: The first stacked body is a stacked structure having a first electrode, a first separator, a second electrode and a second separator, The middle portion includes two layers of diaphragms integrally connected to the first diaphragm and the second diaphragm included in the first stack, and The middle portion has a plurality of windings of the two-layer diaphragm.

4. The electrode assembly according to claim 2, wherein: The intermediate portion includes an adhesive tape covering an end portion of the first laminate, and The intermediate portion has a plurality of windings of the adhesive tape.

5. The electrode assembly according to claim 1, wherein: The plurality of first windings of the first laminated body surround a first core, The middle portion surrounds the second core, The plurality of second windings of the second laminate surround the intermediate portion, and The second core is removed at the center of the middle portion, and the first electrode assembly is in an empty space in the center of the middle portion.

6. The electrode assembly according to claim 5, wherein: The second stacked body is a stacked structure having a first electrode, a first separator, a second electrode and a second separator, The middle portion includes two layers of diaphragms integrally connected to the first diaphragm and the second diaphragm included in the second stack, and The middle portion has a plurality of windings of the two-layer diaphragm.

7. The electrode assembly according to claim 1, wherein: Each of the first stacked body and the second stacked body includes a first electrode, a separator, and a second electrode, The second electrode of each of the first stack and the second stack includes a second substrate and a second composite material layer disposed on the second substrate, and The second composite material layer of the first stack and the second composite material layer of the second stack are different in at least one of silicon content and density.

8. The electrode assembly according to claim 1, wherein: The second electrode assembly has an N / P ratio smaller than that of the first electrode assembly.

9. An electrode assembly, comprising: a first electrode assembly having a plurality of first windings of a first stack; a middle portion surrounding the first electrode assembly; and a second electrode assembly surrounding the intermediate portion, the second electrode assembly having a plurality of second windings of a second stack, The first stacked body and the second stacked body are disposed separately from each other, and the middle portion is integrally connected to one of the first stacked body and the second stacked body.

10. The electrode assembly according to claim 9, wherein: The first stacked body is a stacked structure having a first electrode, a first separator, a second electrode, and a second separator, and The middle portion includes two-layered diaphragms integrally connected to the first diaphragm and the second diaphragm included in the first stacked body.

11. The electrode assembly according to claim 10, wherein: The plurality of first windings of the first laminated body surround a first core, and The middle portion has a plurality of windings of the two-layer diaphragm.

12. The electrode assembly according to claim 9, wherein: The second stacked body is a stacked structure of a first electrode, a first separator, a second electrode, and a second separator, and The middle portion includes two-layered diaphragms integrally connected to the first diaphragm and the second diaphragm included in the second stack.

13. The electrode assembly according to claim 12, wherein: The plurality of windings of the two-layer diaphragm are wrapped around the second core, The plurality of second windings of the second laminate surround the intermediate portion, and The second core is removed at the center of the middle portion, and the first electrode assembly is disposed in an empty space at the center of the middle portion.

14. The electrode assembly according to claim 9, wherein: Each of the first stacked body and the second stacked body includes a first electrode, a separator, and a second electrode, The second electrode of each of the first stack and the second stack includes a second substrate and a second composite material layer disposed on the second substrate, and The second composite material layer of the first stack and the second composite material layer of the second stack are different in at least one of silicon content and density.

15. The electrode assembly according to claim 9, wherein: The second electrode assembly has an N / P ratio smaller than that of the first electrode assembly.

16. A rechargeable battery comprising: Electrode assembly; a can, accommodating the electrode assembly in its inner space; and a cover plate coupled to an end of the open side of the tank and sealing the tank, wherein the electrode assembly comprises a first electrode assembly having a plurality of windings of a first laminate, a middle portion surrounding the first electrode assembly, and a second electrode assembly surrounding the middle portion and having a plurality of windings of a second laminate, and The middle portion is configured to adjust a gap between the first electrode assembly and the second electrode assembly according to a pressure change.

17. The rechargeable battery according to claim 16, wherein: The first electrode assembly and the second electrode assembly each include a first uncoated region extending to one side and a second uncoated region extending to the other side, and each of the first uncoated region and the second uncoated region is bent toward a center of the first electrode assembly, and The first uncoated region of the second electrode assembly contacts the first uncoated region of the first electrode assembly, and the second uncoated region of the second electrode assembly contacts the second uncoated region of the first electrode assembly.

18. The rechargeable battery according to claim 17, further comprising: a first current collecting plate fixed to the first uncoated region of the electrode assembly; a riveting terminal installed in a terminal hole provided in a top portion of the can via an insulator and coupled to the first current collecting plate; and A second current collecting plate is fixed to the second uncoated region of the electrode assembly and includes a conductive portion in close contact with an inner wall of the can.

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