Electrode assembly of rechargeable battery

Abstract

An electrode assembly of a rechargeable battery is provided. The electrode assembly of the rechargeable battery includes an electrode plate of a positive electrode and an electrode plate of a negative electrode on both surfaces of a separator. The electrode plate may include an electrode substrate, a first active material layer on a first surface of the electrode substrate, and a second active material layer on a second surface of the electrode substrate. At least one of the electrode plates includes a first laminated tape and a second laminated tape attached to the first active material layer, an end portion of the electrode substrate, and the second active material. The first laminated tape forms a first adhesion portion, the second laminated tape forms a second adhesion portion, and an end portion of the first adhesion portion on the first active material layer and an end portion of the second adhesion portion on the second active material layer are spaced apart from each other in the winding direction.

Description

Technical Field

[0001] The present disclosure relates to an electrode assembly for a rechargeable battery including a laminated tape. Background Art

[0002] Unlike primary batteries, rechargeable batteries are batteries capable of being repeatedly charged and discharged. Small-capacity rechargeable batteries are used in portable small electronic devices (such as mobile phones, laptop computers, and video cameras). Large-capacity and high-density rechargeable batteries are used as a power source or energy storage for driving motors of hybrid vehicles or electric vehicles.

[0003] A rechargeable battery includes an electrode assembly for charging current and discharging current, a case or pouch for accommodating the electrode assembly and an electrolyte, and electrode terminals connected to the electrode assembly and led out from the case or pouch.

[0004] The electrode assembly may be formed into a core type formed by winding electrode plates and a separator. The winding process is a process of manufacturing a core by winding a negative electrode substrate, a positive electrode substrate, and a separator during the production of a cylindrical rechargeable battery.

[0005] If contact occurs between the positive electrode substrate and the negative electrode substrate in a rechargeable battery, there is a possibility of short circuit and fire. Therefore, in order to prevent fire caused by contact between the positive electrode substrate and the negative electrode substrate, the substrate is cut and a laminated tape is attached to the end. The step of attaching the laminated tape is included in the winding process of the rechargeable battery.

[0006] In the laminated tape process, the laminated tape is attached to the front end and the end of the core, and then the laminated tape is cut to produce a pattern. The laminated tape is configured to prevent short circuit due to deformation of the front end of the positive electrode.

[0007] The above information disclosed in this background art section is only for enhancing the understanding of the background of the invention, and thus it may include information that does not constitute the prior art. Summary of the Invention

[0008] The present disclosure relates to various embodiments of an electrode assembly for a rechargeable battery capable of preventing short circuit caused by deformation of a positive electrode substrate and a negative electrode substrate. The present disclosure also relates to various embodiments of an electrode assembly for a rechargeable battery configured to reduce the possibility of cracks occurring at the positive electrode substrate and / or the negative electrode substrate due to the thickness of the laminated tape.

[0009] The electrode assembly of a rechargeable battery includes an electrode plate of a positive electrode, an electrode plate of a negative electrode, and a separator between the electrode plate of the positive electrode and the electrode plate of the negative electrode. Each of the electrode plates may include: an electrode substrate; a first active material layer on a first surface of the electrode substrate; and a second active material layer on a second surface of the electrode substrate. At least one of the electrode plate of the positive electrode and the electrode plate of the negative electrode may further include a laminated tape attached to the first active material layer, an end portion of the electrode substrate, and the second active material layer. The laminated tape may form attachment portions on the first active material layer and the second active material layer respectively in a wound central portion of the electrode assembly, and end portions of the attachment portion on the first active material layer and the attachment portion on the second active material layer may be spaced apart from each other in a winding direction of the electrode assembly.

[0010] The electrode substrate, the first active material layer, and the second active material layer may be a positive electrode, and the first attachment portion may be longer than the second attachment portion by a first length.

[0011] The electrode substrate may further include an uncoated portion, the first laminated tape and the second laminated tape may be attached to the uncoated portion and may include a first extended attachment portion extending from an end portion of the uncoated portion, and the first extended attachment portion may not correspond to an end portion of the first active material layer of the negative electrode.

[0012] The first extended attachment portion and the first length may be located on opposite sides of the electrode assembly in a diameter direction.

[0013] The electrode substrate, the first active material layer, and the second active material layer may be a negative electrode, and the third attachment portion may be shorter than the fourth attachment portion by a second length.

[0014] The electrode substrate may further include an uncoated portion, and the first laminated tape and the second laminated tape are attached to the uncoated portion and may include a second extended attachment portion extending from an end portion of the uncoated portion.

[0015] The second extended attachment portion and the second length may be located on opposite sides of the electrode assembly in a diameter direction.

[0016] The electrode substrate, the first active material layer, and the second active material layer may be a positive electrode, the first attachment portion may be longer than the second attachment portion by a first length, the electrode substrate, the first active material layer, and the first active material layer may be a negative electrode, and the third attachment portion may be shorter than the fourth attachment portion by a second length.

[0017] The electrode substrate of the negative electrode may further include an uncoated portion. The first laminated tape and the second laminated tape of the negative electrode may be attached to the uncoated portion of the electrode substrate of the negative electrode and include a second extended attachment portion extending from the end of the uncoated portion of the electrode substrate of the negative electrode. The second extended attachment portion and the second length may be located on opposite sides of the electrode assembly in the diametrical direction. The electrode substrate of the positive electrode may further include an uncoated portion. The first laminated tape and the second laminated tape of the positive electrode may be attached to the uncoated portion of the electrode substrate of the positive electrode and may include a first extended attachment portion extending from the end of the uncoated portion of the electrode substrate of the positive electrode. And the first extended attachment portion and the first length may be located on opposite sides of the electrode assembly in the diametrical direction.

[0018] The electrode substrate, the first active material layer, and the second active material layer may be the positive electrode and have the same cross-section, and the first attachment portion may be longer than the second attachment portion by an eleventh length.

[0019] The first laminated tape and the second laminated tape may further include a first extended attachment portion attached to each other and extending from the ends of the first active material layer and the second active material layer, and the first extended attachment portion and the eleventh length may be located on opposite sides of the electrode assembly in the diametrical direction.

[0020] The electrode substrate, the first active material layer, and the second active material layer may be the negative electrode and have the same cross-section, and the third attachment portion may be shorter than the fourth attachment portion by a twelfth length.

[0021] The first laminated tape and the second laminated tape may further include a second extended attachment portion extending from the ends of the first active material layer and the second active material layer, and the second extended attachment portion and the twelfth length may be located on opposite sides of the electrode assembly in the diametrical direction.

[0022] The electrode substrate, the first active material layer, and the second active material layer may be the positive electrode and have the same cross-section, the first attachment portion may be longer than the second attachment portion by an eleventh length; the electrode substrate, the first active material layer, and the second active material layer may be the negative electrode and have the same cross-section, and the third attachment portion may be shorter than the fourth attachment portion by a twelfth length.

[0023] The first laminated tape and the second laminated tape of the positive electrode may further include a first extended attachment portion extending from the ends of the first active material layer and the second active material layer. The first extended attachment portion and the eleventh length may be located on opposite sides of the electrode assembly in the diametrical direction. The first laminated tape and the second laminated tape of the negative electrode may further include a second extended attachment portion that may extend from the ends of the first active material layer and the second active material layer, and the second extended attachment portion and the twelfth length may be located on opposite sides of the electrode assembly in the diametrical direction.

[0024] According to an embodiment, since the ends of the first attachment portion of the first lamination tape and the ends of the second attachment portion of the second lamination tape are spaced apart from each other in the winding direction, short circuits caused by deformation of the positive electrode substrate and the negative electrode substrate can be prevented (or at least mitigated).

[0025] According to an embodiment, when short circuits are prevented by the first lamination tape and the second lamination tape, the length difference between the first lamination tape and the second lamination tape can minimize (or at least reduce) the thickness difference caused in the winding diameter direction, and thus cracks occurring in the first active material layer and the second active material layer of the electrode assembly after winding can be prevented (or at least mitigated). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As will be recognized by those skilled in the art, the described embodiments can be modified in various different ways, all without departing from the spirit or scope of the present disclosure. The drawings and the description are to be regarded as illustrative rather than restrictive. Throughout the specification, the same reference numerals denote the same elements.

[0027] Figure 1 is a perspective view of an electrode assembly of a rechargeable battery according to a first embodiment of the present disclosure.

[0028] Figure 2 is applied to Figure 1 a cross-sectional view of the electrode plate before cutting.

[0029] Figure 3 is a cross-sectional view during the process of attaching and cutting the first lamination tape and the second lamination tape to the electrode plate.

[0030] Figure 4 is Figure 3 a cross-sectional view in a state where the first lamination tape and the second lamination tape in

[0031] Figure 5 is a cross-sectional view of a state where a first lamination tape and a second lamination tape according to a second embodiment of the present disclosure are attached to an electrode plate applied to an electrode assembly of a rechargeable battery.

[0032] Figure 6 is a cross-sectional view during the process of attaching and cutting the first lamination tape and the second lamination tape to the electrode plate applied to the electrode assembly of the rechargeable battery according to a third embodiment of the present disclosure.

[0033] Figure 7 is Figure 6 a cross-sectional view in a state where the first lamination tape and the second lamination tape in

[0034] Figure 8 is a perspective view of an electrode assembly of a rechargeable battery according to a fourth embodiment of the present disclosure.

[0035] Figure 9 is Figure 8 a partial cross-sectional view of the electrode assembly.

[0036] Figure 10 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a fifth embodiment of the present disclosure.

[0037] Figure 11 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a sixth embodiment of the present disclosure.

[0038] Figure 12 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a seventh embodiment of the present disclosure.

[0039] Figure 13 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to an eighth embodiment of the present disclosure.

[0040] Figure 14 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a ninth embodiment of the present disclosure. Detailed Description

[0041] Type A Electrode Assembly Figure 1 is a perspective view of an electrode assembly of a rechargeable battery according to a first embodiment of the present disclosure. Referring to Figure 1 , the electrode assembly of the rechargeable battery 1 of the first embodiment is configured to be charged and discharged, and can be formed into a jelly-roll type by stacking and winding two separators S and electrode plates E of a negative electrode and an electrode plate E of a positive electrode.

[0042] In one or more embodiments, the electrode assembly is housed in a case together with an electrolyte solution, an opening of the case is closed and sealed by a cover plate, and electrode terminals are led out of the cover plate, thereby forming a rechargeable battery.

[0043] In one or more embodiments, the electrode plate E of the positive electrode can be formed by coating a positive electrode active material on two surfaces of an electrode substrate 10 formed of aluminum (Al) foil (see Figure 2 ), and the electrode plate E of the negative electrode can be formed by coating a negative electrode active material on two surfaces of an electrode substrate 10 formed of copper (Cu) foil.

[0044] Figure 2 is a cross-sectional view of an electrode plate before cutting applied to Figure 1 the electrode plate. Figure 3It is a cross-sectional view during the process of attaching and cutting the first laminated tape and the second laminated tape to the electrode plate.

[0045] Referring to Figures 1 to 3 , the electrode plate E may include a first active material layer 21 and a second active material layer 22 on opposite surfaces of the electrode substrate 10 which is a thin metal plate. The electrode substrate 10 may include a first surface on the outer side in the diameter direction or the radial direction in the wound state and a second surface on the inner side in the diameter direction or the radial direction. The first active material layer 21 may be formed on the first surface, and the second active material layer 22 may be formed on the second surface.

[0046] In addition, the electrode plate E may include an uncoated portion 11 where the first active material layer 21 and the second active material layer 22 are not applied, thereby exposing the electrode substrate 10 along the winding direction. The uncoated portion 11 of the electrode plate E may be formed at the starting point and the ending point of the winding direction of the electrode assembly and in the middle of both ends, but in the first embodiment, the uncoated portion is formed at the center of both ends.

[0047] The tabs T of the negative electrode and the positive electrode are connected to the uncoated portion 11 of the electrode substrate 10. The tabs T of the negative electrode and the positive electrode may be led out through at least the first side among the two ends in the winding axis direction of the electrode assembly, and in this embodiment, are led out through the two ends in the winding axis direction. The uncoated portion 11 and the tab T are insulated by the laminated tape 40.

[0048] The electrode plate E may include a first laminated tape 41 and a second laminated tape 42 attached to the starting point and the ending point of the winding direction. In one or more embodiments, the first laminated tape 41 is attached to the end of the first active material layer 21 through the first adhesive layer 411 (see Figure 3 ). The second laminated tape 42 is attached to the end of the second active material layer 22 through the second adhesive layer 421 (see Figure 3 ).

[0049] Figure 4 It is a cross-sectional view depicting Figure 3 the structure after the first laminated tape 41 and the second laminated tape 42 in Figure 4 are cut. Referring to

[0050] , the first laminated tape 41 and the second laminated tape 42 may be attached to each other at the outer boundary of the cross-section of the first active material layer 21, the second active material layer 22, and the electrode substrate 10.

[0050] In one or more embodiments, the mutually attached first laminated tape 41 and second laminated tape 42 may further include protrusions 43 (i.e., 412 or 422 respectively) that protrude beyond the ends of the electrode substrate 10. The protrusions 43 (i.e., 412 or 422) of the first laminated tape 41 and the second laminated tape 42 can prevent short circuits caused by deformation of the electrode substrate 10.

[0051] In addition, in one or more embodiments, the first lamination tape 41 and the second lamination tape 42 may further include first non - adhesive portions 44 that are separated from each other at the outer boundaries of the first active material layer 21 and the second active material layer 22. Thus, the first non - adhesive portions 44 of the first lamination tape 41 and the second lamination tape 42 can prevent short - circuits due to deformation of the electrode substrate 10 caused by the first adhesive layer 411 and the second adhesive layer 421.

[0052] The first non - adhesive portion 44 can be cut by a cutter 50 to form two different electrode plates E. Two electrode plates E can be manufactured by one cutting process, and the first non - adhesive portion 44 can be disposed (located) on the first side of each electrode plate E.

[0053] In the first embodiment, the electrode substrate 10, the first active material layer 21, and the second active material layer 22 may form a cross - section at the same position. The first adhesive layer 411 of the first lamination tape 41 and the second adhesive layer 421 of the second lamination tape 42 may form a main adhesive portion 451 on the first active material layer 21 and the second active material layer 22, and may also form an outer - boundary adhesive portion 452 at the outer boundaries of the cross - sections of the first active material layer 21 and the second active material layer 22 and adhere to each other.

[0054] The first non - adhesive portions 44 formed as the first lamination tape 41 and the second lamination tape 42 may be formed to be separated from each other outside the outer - boundary adhesive portion 452. Thus, due to the first non - adhesive portions 44 of the first lamination tape 41 and the second lamination tape 42, the first adhesive layer 411 and the second adhesive layer 421 can be minimized, and thus, the life of the cutter 50 used to cut the first lamination tape 41 and the second lamination tape 42 can be extended (i.e., the cutter does not pierce the adhesive portions 451, 452, which extends the service life of the cutter 50).

[0055] Hereinafter, embodiments of the present disclosure will be described. Compared with the first embodiment, the description of the same structure is omitted, and the description of the different structures is described.

[0056] Figure 5 is a cross - sectional view showing a first lamination tape and a second lamination tape attached to an electrode plate of an electrode assembly applied to a rechargeable battery according to a second embodiment of the present disclosure. Referring to Figure 5 , in the electrode plate E2 of the electrode assembly of the rechargeable battery according to the second embodiment, the first lamination tape 61 and the second lamination tape 62 may form second non - adhesive portions 46 (i.e., 612 or 622, respectively) that are separated from each other on the first active material layer 21 and the second active material layer 22.

[0057] The second non - adhesive portions 46 (i.e., 612 or 622) of the first pressure - sensitive tape 61 and the second pressure - sensitive tape 62 can prevent cracks from occurring at the ends of the first pressure - sensitive tape 61 and the second pressure - sensitive tape 62 during charging and discharging of the rechargeable battery.

[0058] That is, since the electrode plate E2 becomes thicker due to the first adhesive layer 411 and the second adhesive layer 421, internal stress is generated at the starting point and the ending point of the electrode plate E2 during winding, which may cause cracks. And since the electrode plate E2 is fixed by the first adhesive layer 411 and the second adhesive layer 421, the movement of the first active material layer 21 and the second active material layer 22 is restricted or prevented, which may cause cracks.

[0059] However, the second non - adhesive portions 46 (i.e., 612 or 622) from which the first adhesive layer 411 and the second adhesive layer 421 are removed or omitted can reduce the internal stress at the ends of the first pressure - sensitive tape 61 and the second pressure - sensitive tape 62, and enable the relative movement of the first active material layer 21 and the second active material layer 22. Therefore, the active material layer can not be stretched, thus preventing the occurrence of cracks.

[0060] Figure 6 is a cross - sectional view during the process of attaching and cutting the first pressure - sensitive tape and the second pressure - sensitive tape on the electrode plate of the electrode assembly applied to a rechargeable battery according to the third embodiment of the present disclosure. Figure 7 is Figure 6 a cross - sectional view of the state after the first pressure - sensitive tape and the second pressure - sensitive tape in

[0061] Referring to Figure 6 and Figure 7 , in the electrode plate E3 of the electrode assembly of the rechargeable battery according to the third embodiment, the electrode substrate 12 can extend beyond the first active material layer 23 and the second active material layer 24 on the electrode substrate 12. Therefore, the electrode substrate 12 can include an uncoated portion 13.

[0062] The first active material layer 23 can be formed on the first surface of the electrode substrate 12 except along the uncoated portion 13, and the second active material layer 24 can be formed on the second surface of the electrode substrate 12 except along the uncoated portion 13. The first active material layer 23 and the second active material layer 24 can be offset from each other in the cross - section. In one or more embodiments, the uncoated portion 13 is formed shorter on the second surface than on the first surface.

[0063] The first pressure - sensitive tape 71 can be attached to the first surface of the electrode substrate 12 through the first adhesive layer 711, and the second pressure - sensitive tape 72 can be attached to the second surface of the electrode substrate 12 through the second adhesive layer 721.

[0064] In addition, the first lamination tape 71 and the second lamination tape 72 may further include third non-bonding portions 74 (i.e., 712 or 722, respectively) that are separated from each other at the outer boundaries of the first active material layer 23 and the second active material layer 24. Thus, the third non-bonding portions 74 (i.e., 712 or 722) of the first lamination tape 71 and the second lamination tape 72 can prevent (or at least mitigate) crack defects in the electrode substrate 12 caused by the first bonding layer 711 and the second bonding layer 721.

[0065] The third non-bonding portions 74 (i.e., 712 or 722) can be cut by a knife 50 to form two different electrode plates E3. Two electrode plates E3 can be manufactured by one cutting process, and the third non-bonding portions 74 (i.e., 712 or 722) can be provided on the first side of each electrode plate E3.

[0066] The third non-bonding portions 74 (i.e., 712 or 722) formed as the first lamination tape 71 and the second lamination tape 72 can be separated from each other outside the bonding portion 752. In one or more embodiments, due to the first bonding layer 711 and the second bonding layer 721, the bonding portion 752 may have a different cross-section from the first active material layer 23 and the second active material layer 24, but the present disclosure is not limited thereto.

[0067] Thus, due to the third non-bonding portions 74 (i.e., 712 or 722) of the first lamination tape 71 and the second lamination tape 72, the first bonding layer 711 and the second bonding layer 721 can be minimized (or at least reduced), and thus, the life of the knife 50 used for cutting the first lamination tape 71 and the second lamination tape 72 can be extended.

[0068] The first lamination tape 71 and the second lamination tape 72 may form fourth non-bonding portions 76 (i.e., 713 or 723) that are separated from each other on the first active material layer 23 and the second active material layer 24.

[0069] The fourth non-bonding portions 76 (i.e., 713 or 723) of the first lamination tape 71 and the second lamination tape 72 can reduce the winding curvature of the electrode assembly by reducing the thicknesses of the starting point and the ending point of the electrode assembly, thereby reducing the occurrence of cracks. Thus, cracks occurring at the ends of the first lamination tape 71 and the second lamination tape 72 during charging and discharging of the rechargeable battery can be prevented (or at least mitigated).

[0070] That is to say, since the electrode plate E3 becomes thicker due to the first adhesive layer 711 and the second adhesive layer 721, internal stress is generated at the starting point and the ending point of the electrode plate E3 during winding, which may cause cracks. Also, since the electrode plate E3 is fixed by the first adhesive layer 711 and the second adhesive layer 721, the movement of the first active material layer 23 and the second active material layer 24 is restricted or prevented, which may also cause cracks.

[0071] However, the fourth non - adhesive portion 76 (i.e., 713 or 723) from which the first adhesive layer 711 and the second adhesive layer 721 are removed or omitted can reduce the internal stress at the ends of the first lamination belt 71 and the second lamination belt 72, and enable relative movement of the first active material layer 23 and the second active material layer 24. Therefore, the active material layer can be not stretched, thus preventing the occurrence of cracks.

[0072] Type B electrode assembly Figure 8 is a perspective view of an electrode assembly of a rechargeable battery according to a fourth embodiment of the present disclosure. Figure 9 is Figure 8 a partial cross - sectional view of the electrode assembly. Referring to Figure 8 and Figure 9 , the electrode assembly 5 of the rechargeable battery according to the fourth embodiment is configured to be charged and discharged, and can be formed into a jelly - roll type by stacking and winding two separator sheets S and electrode plates of the negative electrode E41 and the positive electrode E42. For convenience, the separator sheet S is omitted in Figure 9 .

[0073] The electrode assembly is accommodated in a case together with an electrolyte solution. The opening of the case is closed and sealed by a cover plate, and electrode terminals are led out of the cover plate, thereby forming a rechargeable battery.

[0074] In one or more embodiments, the electrode plate of the positive electrode E42 can be formed by coating a positive electrode active material on two surfaces of an electrode substrate 420 formed of aluminum (Al) foil. In addition, the electrode plate of the negative electrode E41 can be formed by coating a negative electrode active material on two surfaces of an electrode substrate 410 formed of copper (Cu) foil.

[0075] The electrode plate of the negative electrode E41 may include a first active material layer 121 and a second active material layer 122, and the electrode plate of the positive electrode E42 may include a first active material layer 221 and a second active material layer 222. The active materials are respectively applied to two surfaces of the electrode substrates 410 and 420 formed as thin metal plates.

[0076] In the negative electrode E41 and the positive electrode E42, the electrode substrates 410 and 420 in a wound state may respectively include a first surface located on the outer side in the diameter direction or the radial direction and a second surface located on the inner side in the diameter direction or the radial direction. The first active material layers 121 and 221 may be respectively formed on the first surfaces of the electrode substrates 410 and 420, and the second active material layers 122 and 222 may be respectively formed on the second surfaces of the electrode substrates 410 and 420.

[0077] In addition, the electrode plates of the negative electrode E41 and the positive electrode E42 may respectively include uncoated portions 131 and 132 that are not coated with the first active material layers 121 and 221 or the second active material layers 122 and 222, thereby exposing the electrode substrates 410 and 420 along the winding direction. The uncoated portion 131 of the negative electrode E41 and the uncoated portion 132 of the positive electrode E42 may be respectively formed at the starting point and the ending point of the winding direction of the electrode assembly and in the middle of both ends. However, in the fourth embodiment, the uncoated portions 131 and 132 are formed at the starting point of the winding direction.

[0078] In the fourth embodiment, the electrode plate of the positive electrode E42 may include a first laminated tape 541 and a second laminated tape 542 attached to the starting point of the winding direction. That is, the first laminated tape 541 may be attached to the first surface of the uncoated portion 132 at the end of the first active material layer 221. The second laminated tape 542 may be attached to the second surface of the uncoated portion 132 at the end of the second active material layer 222.

[0079] The first laminated tape 541 and the second laminated tape 542 respectively attached to the first surface and the second surface of the uncoated portion 132 can prevent a short circuit caused by deformation of the electrode substrate 410 of the negative electrode E41 and the electrode substrate 420 of the positive electrode E42.

[0080] In the winding center portion of the electrode assembly 5, the first laminated tape 541 may form a first attachment portion (outer layer portion) located on the first active material layer 221, and the second laminated tape 542 may form a second attachment portion (inner layer portion) located on the second active material layer 222. The first active material layer 221 is positioned outward in the radial direction, and the second active material layer 222 is positioned inward in the radial direction.

[0081] The end of the first attachment portion formed by the first laminating tape 541 on the first active material layer 221 and the end of the second attachment portion formed by the second laminating tape 542 on the second active material layer 222 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminating tape 541 is longer than the second attachment portion (i.e., the inner side) formed by the second laminating tape 542 by a first length L1 (the arc length in the winding direction).

[0082] The difference in the first length L1 can minimize the thickness difference in the diameter direction after winding caused by the first laminating tape 541 and the second laminating tape 542. Therefore, cracks occurring in the first active material layer 221 and the second active material layer 222 of the electrode assembly 5 after winding can be prevented (or at least alleviated).

[0083] The first laminating tape 541 and the second laminating tape 542 can be respectively attached to the first surface and the second surface of the uncoated portion 132, and further include a first extended attachment portion 543 attached to the first laminating tape 541 and the second laminating tape 542 by further extending from the end of the uncoated portion 132. The first extended attachment portion 543 can further prevent (or alleviate) a short circuit due to the deformation of the electrode substrate 410 of the negative electrode E41 and the electrode substrate 420 of the positive electrode E42. The first extended attachment portion 543 does not correspond to the end of the first active material layer 121 of the negative electrode E41. Therefore, the occurrence of cracks in the first active material layer 121 that may be caused by the first extended attachment portion 543 can be prevented (or at least alleviated).

[0084] In addition, the first extended attachment portion 543 and the first length L1 can be located on opposite sides of the electrode assembly 5 in the diameter direction. Therefore, the occurrence of cracks due to the thickness difference can be further prevented.

[0085] Figure 10 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a fifth embodiment of the present disclosure. Referring to Figure 10 , in the electrode assembly 6 of the rechargeable battery according to the fifth embodiment, the electrode plate of the negative electrode E51 may include a first laminating tape 641 and a second laminating tape 642 attached to the starting point in the winding direction. That is, the first laminating tape 641 can be attached to the first surface of the uncoated portion 131 at the end of the first active material layer 121. The second laminating tape 642 can be attached to the second surface of the uncoated portion 131 at the end of the second active material layer 122.

[0086] The first laminating tape 641 and the second laminating tape 642 respectively attached to the first surface and the second surface of the uncoated portion 131 can prevent a short circuit due to the deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 520 of the positive electrode E52.

[0087] In the winding center portion of the electrode assembly 6, the first laminated tape 641 may form a first attachment portion (outer layer portion) located on the first active material layer 121, and the second laminated tape 642 may form a second attachment portion (inner layer portion) located on the second active material layer 122. The first laminated tape 641 is positioned outward in the radial direction, and the second laminated tape 642 is positioned inward in the radial direction.

[0088] The end of the first attachment portion formed by the first laminated tape 641 on the first active material layer 121 and the end of the second attachment portion formed by the second laminated tape 642 on the second active material layer 122 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminated tape 641 may be shorter than the second attachment portion (i.e., the inner side) formed by the second laminated tape 642 by a second length L2.

[0089] The difference in the second length L2 can minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first laminated tape 641 and the second laminated tape 642. Therefore, cracks can be prevented (or at least mitigated) from occurring in the first active material layer 121 and the second active material layer 122 of the electrode assembly 6 after winding.

[0090] The first laminated tape 641 and the second laminated tape 642 may be attached to the first surface and the second surface of the uncoated portion 131, respectively, and further include a second extended attachment portion 643 attached to the first laminated tape 641 and the second laminated tape 642 by further extending from the end of the uncoated portion 131. The second extended attachment portion 643 can further prevent short circuits due to deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 520 of the positive electrode E52.

[0091] In addition, the second extended attachment portion 643 and the second length L2 may be located on opposite sides of the electrode assembly 6 in the diameter direction. Therefore, the occurrence of cracks due to the thickness difference can be further prevented.

[0092] Figure 11 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a sixth embodiment of the present disclosure. Referring to Figure 11 , in the electrode assembly 7 of the rechargeable battery according to the sixth embodiment, the electrode plate of the positive electrode E42 may include a first laminated tape 541 and a second laminated tape 542 attached to the starting point of the winding direction. That is, the first laminated tape 541 may be attached to the first surface of the uncoated portion 132 at the end of the first active material layer 221. The second laminated tape 542 may be attached to the second surface of the uncoated portion 132 at the end of the second active material layer 222.

[0093] The first lamination tape 541 and the second lamination tape 542 respectively attached to the first surface and the second surface of the uncoated portion 132 can prevent a short circuit due to deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 420 of the positive electrode E42.

[0094] In the winding center portion of the electrode assembly 7, the first lamination tape 541 can form a first attachment portion (outer layer portion) located on the first active material layer 221, and the second lamination tape 542 can form a second attachment portion (inner layer portion) located on the second active material layer 222. The first lamination tape 541 is positioned outward in the radial direction, and the second lamination tape 542 is positioned inward in the radial direction.

[0095] The end of the first attachment portion formed by the first lamination tape 541 on the first active material layer 221 and the end of the second attachment portion formed by the second lamination tape 542 on the second active material layer 222 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first lamination tape 541 is longer than the second attachment portion (i.e., the inner side) formed by the second lamination tape 542 by a first length L1.

[0096] The difference in the first length L1 can minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first lamination tape 541 and the second lamination tape 542. Therefore, cracks occurring in the first active material layer 221 and the second active material layer 222 of the electrode assembly 7 after winding can be prevented (or at least alleviated).

[0097] The first lamination tape 541 and the second lamination tape 542 can be respectively attached to the first surface and the second surface of the uncoated portion 132, and further include a first extended attachment portion 543 attached to the first lamination tape 541 and the second lamination tape by further extending from the end of the uncoated portion 132. The first extended attachment portion 543 can further prevent (or alleviate) a short circuit due to deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 420 of the positive electrode E42. The first extended attachment portion 543 does not correspond to the end of the first active material layer 121 of the negative electrode E51. Therefore, the occurrence of cracks in the first active material layer 121 that may be caused by the first extended attachment portion 543 can be prevented (or at least alleviated).

[0098] In addition, the first extended attachment portion 543 and the first length L1 can be located on opposite sides of the electrode assembly 7 in the diameter direction. Therefore, the occurrence of cracks due to the thickness difference can be further prevented (or alleviated).

[0099] The electrode plate of the negative electrode E51 may include a first laminated tape 641 and a second laminated tape 642 attached to the starting point of the winding direction. That is, the first laminated tape 641 may be attached to the first surface of the uncoated portion 131 at the end of the first active material layer 121. The second laminated tape 642 may be attached to the second surface of the uncoated portion 131 at the end of the second active material layer 122.

[0100] The first laminated tape 641 and the second laminated tape 642 attached to the first surface and the second surface of the uncoated portion 131 may prevent (or at least mitigate) a short circuit due to the deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 420 of the positive electrode E42.

[0101] In the winding center portion of the electrode assembly 7, the first laminated tape 641 may form a first attachment portion (outer layer portion) located on the first active material layer 121, and the second laminated tape 642 may form a second attachment portion (inner layer portion) located on the second active material layer 122. The first laminated tape 641 is positioned outward in the radial direction, and the second laminated tape 642 is positioned inward in the radial direction.

[0102] The end of the first attachment portion formed by the first laminated tape 641 on the first active material layer 121 and the end of the second attachment portion formed by the second laminated tape 642 on the second active material layer 122 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminated tape 641 is shorter than the second attachment portion (i.e., the inner side) formed by the second laminated tape 642 by a second length L2.

[0103] The difference in the second length L2 may minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first laminated tape 641 and the second laminated tape 642. Therefore, cracks can be prevented (or at least mitigated) from occurring in the first active material layer 121 and the second active material layer 122 of the electrode assembly 7 after winding.

[0104] The first laminated tape 641 and the second laminated tape 642 may be respectively attached to the first surface and the second surface of the uncoated portion 131, and further include a second extended attachment portion 643 formed by attaching to the first laminated tape 641 and the second laminated tape 642 by further extending from the end of the uncoated portion 131. The second extended attachment portion 643 may further prevent (or mitigate) a short circuit due to the deformation of the electrode substrate 510 of the negative electrode E51 and the electrode substrate 420 of the positive electrode E42.

[0105] In addition, the second extended attachment portion 643 and the second length L2 may be located on opposite sides in the diameter direction of the electrode assembly 7. Therefore, the occurrence of cracks due to the thickness difference can be further prevented (or mitigated).

[0106] Figure 12 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a seventh embodiment of the present disclosure. Referring to Figure 12 , in the electrode assembly 8 of the rechargeable battery according to the seventh embodiment, the electrode plate of the positive electrode E44 may include a first laminated tape 551 and a second laminated tape 552 attached to the starting point of the winding direction.

[0107] That is, the first laminated tape 551 may be attached to the first active material layer 221 and further extend from the end of the first active material layer 221. The second laminated tape 552 may be attached to the second active material layer 222 and further extend from the end of the second active material layer 222. The first laminated tape 551 and the second laminated tape 552 that further extend may also include a first extended attachment portion 843 formed by attaching to each other.

[0108] The first extended attachment portion 843 of the first laminated tape 551 and the second laminated tape 552 respectively attached to the first active material layer 221 and the second active material layer 222 may prevent (or at least mitigate) a short circuit according to the deformation of the electrode substrate 430 of the negative electrode E43 and the electrode substrate 440 of the positive electrode E44.

[0109] In the winding center portion of the electrode assembly 8, the first laminated tape 551 may form a first attachment portion (outer layer portion) located on the first active material layer 221, and the second laminated tape 552 may form a second attachment portion (inner layer portion) located on the second active material layer 222. The first laminated tape 551 is positioned outward in the radial direction, and the second laminated tape 552 is positioned inward in the radial direction.

[0110] The end of the first attachment portion formed by the first laminated tape 551 on the first active material layer 221 and the end of the second attachment portion formed by the second laminated tape 552 on the second active material layer 222 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminated tape 551 is longer than the second attachment portion (i.e., the inner side) formed by the second laminated tape 552 by an eleventh length L11.

[0111] The difference in the eleventh length L11 may minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first laminated tape 551 and the second laminated tape 552. Therefore, cracks in the first active material layer 221 and the second active material layer 222 of the electrode assembly 8 after winding can be prevented (or at least mitigated).

[0112] In addition, the first extended attachment portion 843 and the eleventh length L11 may be located on opposite sides of the electrode assembly 8 in the diametrical direction, and thus, the occurrence of cracks due to the thickness difference can be further prevented (or at least mitigated).

[0113] Figure 13 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to an eighth embodiment of the present disclosure. Referring to Figure 13 , in the electrode assembly 9 of the rechargeable battery of the eighth embodiment, the electrode plate of the negative electrode E53 may include a first laminated tape 651 and a second laminated tape 652 attached to the starting point in the winding direction.

[0114] That is, the first laminated tape 651 may be attached to the first active material layer 121 and further extend from the end of the first active material layer 121. The second laminated tape 652 may be attached to the second active material layer 122 and further extend from the end of the second active material layer 122. The further extended first laminated tape 651 and second laminated tape 652 may also include a second extended attachment portion 943 formed by attaching to each other.

[0115] The second extended attachment portion 943 of the first laminated tape 651 and the second laminated tape 652 respectively attached to the first active material layer 121 and the second active material layer 122 can prevent (or at least mitigate) a short circuit according to the deformation of the electrode substrate 430 of the negative electrode E53 and the electrode substrate 440 of the positive electrode E54.

[0116] In the winding center portion of the electrode assembly 9, the first laminated tape 651 may form a first attachment portion (outer portion) located on the first active material layer 121, and the second laminated tape 652 may form a second attachment portion (inner portion) located on the second active material layer 122. The first laminated tape 651 is positioned outward in the radial direction, and the second laminated tape 652 is positioned inward in the radial direction.

[0117] The ends of the first attachment portion formed by the first laminated tape 651 on the first active material layer 121 and the ends of the second attachment portion formed by the second laminated tape 652 on the second active material layer 122 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminated tape 651 may be formed shorter than the second attachment portion (i.e., the inner side) formed by the second laminated tape 652 by a twelfth length L12.

[0118] The difference in the twelfth length L12 can minimize (or at least reduce) the thickness difference in the diametrical direction after winding due to the first laminated tape 651 and the second laminated tape 652, and thus, the occurrence of cracks in the first active material layer 121 and the second active material layer 122 of the electrode assembly 9 after winding can be prevented (or at least mitigated).

[0119] In addition, the second extended attachment portion 943 and the twelfth length L12 may be located on diametrically opposite sides of the electrode assembly 9, and thus, the occurrence of cracks due to thickness differences can be further prevented (or at least mitigated).

[0120] Figure 14 is a partial cross-sectional view of an electrode assembly of a rechargeable battery according to a ninth embodiment of the present disclosure. Referring to Figure 14 , in the electrode assembly 4 of the rechargeable battery of the ninth embodiment, the electrode plate of the positive electrode E44 may include a first laminated tape 551 and a second laminated tape 552 attached to the starting point in the winding direction.

[0121] That is, the first laminated tape 551 may be attached to the first active material layer 221 and further extend from the end of the first active material layer 221. The second laminated tape 552 may be attached to the second active material layer 222 and further extend from the end of the second active material layer 222. The first laminated tape 551 and the second laminated tape 552 may further include a first extended attachment portion 843 by attaching to each other.

[0122] The first extended attachment portion 843 of the first laminated tape 551 and the second laminated tape 552 respectively attached to the first active material layer 221 and the second active material layer 222 can prevent (or at least mitigate) a short circuit according to the deformation of the electrode substrate 430 of the negative electrode E53 and the electrode substrate 440 of the positive electrode E44.

[0123] In the winding center portion of the electrode assembly 4, the first laminated tape 551 may form a first attachment portion (outer layer portion) located on the first active material layer 221, and the second laminated tape 552 may form a second attachment portion (inner layer portion) located on the second active material layer 222. The first laminated tape 551 is positioned outward in the radial direction, and the second laminated tape 552 is positioned inward in the radial direction.

[0124] The end of the first attachment portion formed by the first laminated tape 551 on the first active material layer 221 and the end of the second attachment portion formed by the second laminated tape 552 on the second active material layer 222 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first laminated tape 551 is longer than the second attachment portion (i.e., the inner side) formed by the second laminated tape 552 by an eleventh length L11.

[0125] The eleventh length L11 can minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first pressure belt 551 and the second pressure belt 552. Therefore, cracks in the first active material layer 221 and the second active material layer 222 of the electrode assembly 4 after winding can be prevented (or at least alleviated).

[0126] In addition, the first extended attachment portion 843 and the eleventh length L11 can be located on opposite sides of the electrode assembly 4 in the diameter direction. Therefore, the occurrence of cracks caused by the thickness difference can be further prevented (or at least alleviated).

[0127] In the electrode assembly 4 of the rechargeable battery according to the ninth embodiment, the electrode plate of the negative electrode E53 may include a first pressure belt 651 and a second pressure belt 652 attached to the starting point of the winding direction.

[0128] That is, the first pressure belt 651 can be attached to the first active material layer 121 and further extend from the end of the first active material layer 121. The second pressure belt 652 can be attached to the second active material layer 122 and further extend from the end of the second active material layer 122. The first pressure belt 651 and the second pressure belt 652 may further include a second extended attachment portion 943 by attaching to each other.

[0129] The second extended attachment portions 943 of the first pressure belt 651 and the second pressure belt 652 respectively attached to the first active material layer 121 and the second active material layer 122 can prevent (or at least alleviate) a short circuit according to the deformation of the electrode substrate 430 of the negative electrode E53 and the electrode substrate 440 of the positive electrode E44.

[0130] In the winding center portion of the electrode assembly 4, the first pressure belt 651 can form a first attachment portion (outer layer portion) located on the first active material layer 121, and the second pressure belt 652 can form a second attachment portion (inner layer portion) located on the second active material layer 122. The first pressure belt 651 is positioned outward in the radial direction, and the second pressure belt 652 is positioned inward in the radial direction.

[0131] The ends of the first attachment portion formed by the first pressure belt 651 on the first active material layer 121 and the ends of the second attachment portion formed by the second pressure belt 652 on the second active material layer 122 are spaced apart from each other. The first attachment portion (i.e., the outer side) formed by the first pressure belt 651 may be shorter than the second attachment portion (i.e., the inner side) formed by the second pressure belt 652 by the twelfth length L12.

[0132] The twelfth length L12 can minimize (or at least reduce) the thickness difference in the diameter direction after winding caused by the first laminated tape 651 and the second laminated tape 652. Therefore, cracks in the first active material layer 121 and the second active material layer 122 of the electrode assembly 4 after winding can be prevented (or at least alleviated).

[0133] In addition, the second extended attachment portion 943 and the twelfth length L12 can be located on opposite sides of the electrode assembly 4 in the diameter direction. Therefore, the occurrence of cracks caused by the thickness difference can be further prevented (or at least alleviated).

[0134] Although the present disclosure has been described in connection with presently considered practical embodiments, it will be understood that the disclosure is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0135] Symbolic Explanation 4, 5, 6, 7, 8, 9: Electrode assembly 121, 221: First active material layer 122, 222: Second active material layer 131, 132: Uncoated portion 410: Electrode substrate (negative electrode) 420: Electrode substrate (positive electrode) 430, 440: Electrode substrate 541: First laminated tape 542: Second laminated tape 543: First extended attachment portion 551: First laminated tape 552: Second laminated tape 641: First laminated tape 642: Second laminated tape 643: Second extended attachment portion 651: First laminated tape 652: Second laminated tape 843: First extended attachment portion 943: Second extended attachment portion E41: Negative electrode (electrode plate) E42: Positive electrode (electrode plate) E43: Negative electrode E44: Positive electrode E51: Negative electrode E52: Positive electrode E53: Negative electrode E54: Positive electrode L1: First length L2: Second length L11: Eleventh length L12: Twelfth length S: Separator T: Tab.

Claims

1. An electrode assembly for a rechargeable battery, the electrode assembly comprising an electrode plate of a positive electrode, an electrode plate of a negative electrode, and a separator between the electrode plate of the positive electrode and the electrode plate of the negative electrode, Among them, Each of the electrode plate of the positive electrode and the electrode plate of the negative electrode includes: An electrode substrate; A first active material layer on a first surface of the electrode substrate; and A second active material layer on a second surface of the electrode substrate; Wherein at least one of the electrode plate of the positive electrode and the electrode plate of the negative electrode further includes a laminated tape attached to the first active material layer, an end portion of the electrode substrate, and the second active material layer, Wherein the laminated tape forms attachment portions located on the first active material layer and the second active material layer respectively in a winding center portion of the electrode assembly, and Wherein an end portion of the attachment portion on the first active material layer and an end portion of the attachment portion on the second active material layer are spaced apart from each other in a winding direction of the electrode assembly.

2. The electrode assembly according to claim 1, wherein: The electrode plate of the positive electrode includes a laminated tape, and the laminated tape includes a first laminated tape and a second laminated tape; The first laminated tape forms a first attachment portion located on the first active material layer of the electrode plate of the positive electrode in a winding center portion of the electrode assembly; The second laminated tape forms a second attachment portion located on the second active material layer of the electrode plate of the positive electrode in a winding center portion of the electrode assembly; And The first attachment portion is longer than the second attachment portion by a first length.

3. The electrode assembly according to claim 2, wherein: The electrode substrate of the electrode plate of the positive electrode further includes an uncoated portion; The first laminated tape and the second laminated tape are attached to the uncoated portion; The first laminated tape and the second laminated tape include first extended attachment portions extending from an end portion of the uncoated portion; And The first extended attachment portion does not correspond to an end portion of the first active material layer of the electrode plate of the negative electrode.

4. The electrode assembly according to claim 3, wherein, The first extended attachment portion and the first length are located on opposite sides of the electrode assembly in a diameter direction.

5. The electrode assembly according to claim 1, wherein: The electrode plate of the negative electrode includes a laminated tape, and the laminated tape includes a third laminated tape and a fourth laminated tape; The third laminated tape forms a third attachment portion located on the first active material layer of the electrode plate of the negative electrode in a winding center portion of the electrode assembly; The fourth laminated tape forms a fourth attachment portion located on the second active material layer of the electrode plate of the negative electrode in a winding center portion of the electrode assembly; And The third attachment portion is shorter than the fourth attachment portion by a second length.

6. The electrode assembly according to claim 5, wherein: The electrode substrate of the electrode plate of the negative electrode further includes an uncoated portion; The third laminated tape and the fourth laminated tape are attached to the uncoated portion; and The third laminated tape and the fourth laminated tape include second extended attachment portions extending from an end portion of the uncoated portion.

7. The electrode assembly according to claim 6, wherein, The second extended attachment portion and the second length are located on opposite sides of the electrode assembly in a diameter direction.

8. The electrode assembly according to claim 1, wherein: Both the electrode plate of the positive electrode and the electrode plate of the negative electrode include laminated tapes. The laminated tape of the electrode plate of the positive electrode includes a first laminated tape and a second laminated tape, and the laminated tape of the electrode plate of the negative electrode includes a third laminated tape and a fourth laminated tape; The first pressing belt forms a first attachment portion on the first active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly; The second pressing belt forms a second attachment portion on the second active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly; The first attachment portion is longer than the second attachment portion by a first length; The third pressing belt forms a third attachment portion on the first active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; The fourth pressing belt forms a fourth attachment portion on the second active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; And The third attachment portion is shorter than the fourth attachment portion by a second length.

9. The electrode assembly according to claim 8, wherein: The electrode substrate of the electrode plate of the negative electrode further includes an uncoated portion; The third pressing belt and the fourth pressing belt are attached to the uncoated portion of the electrode substrate of the electrode plate of the negative electrode; The third pressing belt and the fourth pressing belt include second extended attachment portions extending from the ends of the uncoated portion of the electrode substrate of the electrode plate of the negative electrode; The second extended attachment portions and the second length are located on opposite sides in the diameter direction of the electrode assembly; The electrode substrate of the electrode plate of the positive electrode further includes an uncoated portion; The first pressing belt and the second pressing belt are attached to the uncoated portion of the electrode substrate of the electrode plate of the positive electrode; The first pressing belt and the second pressing belt include first extended attachment portions extending from the ends of the uncoated portion of the electrode substrate of the electrode plate of the positive electrode; And The first extended attachment portions and the first length are located on opposite sides in the diameter direction of the electrode assembly.

10. The electrode assembly according to claim 1, wherein: The electrode plate of the positive electrode includes pressing belts, and the pressing belts include the first pressing belt and the second pressing belt; The electrode substrate, the first active material layer, and the second active material layer of the electrode plate of the positive electrode have the same cross-section; The first pressing belt forms a first attachment portion on the first active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly; The second pressing belt forms a second attachment portion on the second active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly; And The first attachment portion is longer than the second attachment portion by an eleventh length.

11. The electrode assembly according to claim 10, wherein: The first pressing belt and the second pressing belt are attached to each other and further include first extended attachment portions extending from the ends of the first active material layer and the second active material layer; And The first extended attachment portions and the eleventh length are located on opposite sides in the diameter direction of the electrode assembly.

12. The electrode assembly according to claim 1, wherein: The electrode plate of the negative electrode includes pressing belts, and the pressing belts include the third pressing belt and the fourth pressing belt; The electrode substrate, the first active material layer, and the second active material layer of the electrode plate of the negative electrode have the same cross-section; The third pressing belt forms a third attachment portion on the first active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; The fourth lamination belt forms a fourth attachment portion on the second active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; And The third attachment portion is shorter than the fourth attachment portion by a twelfth length.

13. The electrode assembly according to claim 12, wherein: The third lamination belt and the fourth lamination belt are attached to each other, and further include a second extended attachment portion extending from the ends of the first active material layer and the second active material layer; And The second extended attachment portion and the twelfth length are located on opposite sides of the electrode assembly in the diameter direction.

14. The electrode assembly according to claim 1, wherein: The electrode plate of the positive electrode and the electrode plate of the negative electrode both include lamination belts. The lamination belts of the electrode plate of the positive electrode include a first lamination belt and a second lamination belt, and the lamination belts of the electrode plate of the negative electrode include a third lamination belt and a fourth lamination belt; The electrode substrate, the first active material layer, and the second active material layer of the electrode plate of the positive electrode have the same cross-section; The first lamination belt forms a first attachment portion on the first active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly; The second lamination belt forms a second attachment portion on the second active material layer of the electrode plate of the positive electrode in the winding center portion of the electrode assembly The first attachment portion is longer than the second attachment portion by an eleventh length; The electrode substrate, the first active material layer, and the second active material layer of the electrode plate of the negative electrode have the same cross-section; The third lamination belt forms a third attachment portion on the first active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; The fourth lamination belt forms a fourth attachment portion on the second active material layer of the electrode plate of the negative electrode in the winding center portion of the electrode assembly; And The third attachment portion is shorter than the fourth attachment portion by a twelfth length.

15. The electrode assembly according to claim 14, wherein: The first lamination belt and the second lamination belt are attached to each other, and further include a first extended attachment portion extending from the ends of the first active material layer and the second active material layer; The first extended attachment portion and the eleventh length are located on opposite sides of the electrode assembly in the diameter direction; The third lamination belt and the fourth lamination belt are attached to each other, and further include a second extended attachment portion extending from the ends of the first active material layer and the second active material layer; And The second extended attachment portion and the twelfth length are located on opposite sides of the electrode assembly in the diameter direction.

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