Electrode assembly and rechargeable battery including the same

Abstract

Provided are an electrode assembly and a rechargeable battery including the same, the electrode assembly including: an assembly in which a first electrode, a separator overlapping the first electrode, and a second electrode overlapping the separator are alternately stacked; and a shape holding member at a side of the assembly where an end portion of the first electrode, an end portion of the diaphragm, and an end portion of the second electrode are exposed, where the shape holding member is a certain distance (e.g., a set or predetermined distance) from both side surfaces of the assembly at both sides around the shape holding member.

Description

Technical Field

[0001] An aspect of some embodiments of the present disclosure relates to an electrode assembly. Background Art

[0002] A rechargeable battery is a power storage system that can provide relatively excellent energy density and can convert electrical energy into chemical energy to store the converted chemical energy. Generally, in contrast to a primary battery that cannot be recharged, a rechargeable battery is rechargeable, so that the rechargeable battery can be widely used in IT devices such as smart phones, notebooks (or laptops), tablet PCs, etc.

[0003] Rechargeable batteries can be developed in various forms according to the products using them, and can be used in prismatic batteries that maintain a specific shape and pouch-type batteries made of flexible materials according to the type of case.

[0004] The pouch-type battery may have a shape in which an electrode assembly is sealed within an exterior material made of a flexible laminate material, and a case of the pouch-type battery may be relatively easily deformed by external pressure or impact compared to a prismatic battery.

[0005] After the electrode assembly is inserted into the pouch, the case of the pouch type battery may be deformed due to the discharge of gas generated by a formation process or a pressure difference between the inside and the outside of the pouch during charge and discharge of the battery.

[0006] Deformation of the shape of the bag may cause defects such as failure to install the bag in a product due to poor appearance and detachment from an attached band during packaging or manufacturing processes.

[0007] The above information disclosed in this background section is only for enhancement of understanding of the background technology and therefore, the information discussed in this background section does not necessarily constitute prior art. Summary of the invention

[0008] Aspects of some embodiments of the present disclosure relate to an electrode assembly (eg, to an electrode assembly for a rechargeable battery) and a rechargeable battery including the electrode assembly.

[0009] Aspects of some embodiments of the present disclosure include an electrode assembly that can minimize or reduce deformation of a shape of a pouch during a gas exhaust process and charge and discharge of a rechargeable battery, and a rechargeable battery including the electrode assembly.

[0010] According to some embodiments of the present disclosure, an electrode assembly includes: an assembly in which a first electrode, a separator stacked with the first electrode, and a second electrode stacked with the separator are alternately stacked; and a shape-retaining member formed at one side of the assembly where an end of the first electrode, an end of the separator, and an end of the second electrode are exposed. According to some embodiments, the shape-retaining member is at a certain distance (e.g., a set or predetermined distance) from two side surfaces of the assembly at both sides around the shape-retaining member.

[0011] According to some embodiments, the shape maintaining member may be at a distance from both side surfaces of the electrode assembly by at least ½ of the thickness of the electrode assembly.

[0012] According to some embodiments, the shape retaining member may be formed continuously along one side of the assembly.

[0013] According to some embodiments, the shape retaining member may be formed discontinuously along one side of the component.

[0014] According to some embodiments, the first electrode and the second electrode may include a first electrode tab and a second electrode tab protruding out of the separator, and the shape maintaining member may be at a region where the first electrode tab and the second electrode tab are not formed.

[0015] According to some embodiments, the diaphragm may be bent toward the center of the assembly, and the shape maintaining member may be formed on the bent diaphragm.

[0016] According to some embodiments, an end of the septum may be inserted into the shape-retaining member.

[0017] According to some embodiments, the shape retaining member may become increasingly thicker toward the center bisecting the thickness of the component, thereby having a semicircular cross-section.

[0018] According to some embodiments, the thickness of the shape maintaining member at the edge of the component may be in the range of 100 micrometers (μm) to 500 μm, and the thickness of the shape maintaining member at the center of the component may be 500 μm to 1000 μm.

[0019] According to some embodiments, the shape maintaining member may be formed to have a constant thickness.

[0020] According to some embodiments, the thickness of the shape maintaining member may be 100 μm to 500 μm.

[0021] According to some embodiments, the shape retaining member may be a photocurable adhesive.

[0022] According to some embodiments, the photocurable adhesive may be an acrylic adhesive.

[0023] If an electrode assembly is formed according to an embodiment of the present disclosure, deformation of the shape of the bag during the gas discharge process and charge and discharge of the rechargeable battery after the electrode assembly is inserted into the bag can be prevented or reduced, thereby improving the productivity of the pouch-type rechargeable battery by relatively reducing the appearance defects and detachment defects of the packaging tape attached to the package. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic exploded perspective view of a rechargeable battery according to some embodiments of the present disclosure.

[0025] Figure 2 It is shown Figure 1 A plan view of the lower surface of an electrode assembly.

[0026] Figure 3 It is along Figure 2 Cross-sectional view taken along line III-III'.

[0027] Figure 4 It is along Figure 2 A cross-sectional view of an electrode assembly according to some embodiments of the present disclosure, cut along line III-III'.

[0028] Figure 5 is a schematic diagram of an electrode assembly according to some embodiments of the present disclosure.

[0029] Figure 6 is a view for describing a method of folding a diaphragm according to some embodiments of the present disclosure.

[0030] Figures 7 to 9 is a schematic diagram of an electrode assembly according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0031] The aspects of some embodiments of the present disclosure will be described more fully below with reference to the accompanying drawings so that those skilled in the art can easily implement these embodiments. The embodiments according to the present disclosure may be modified in various different ways without departing from the spirit or scope of the embodiments according to the present disclosure.

[0032] In order to more clearly describe the aspects of the embodiments of the present disclosure, parts or portions not related to the description are omitted, and the same or similar constituent elements are represented by the same reference numerals throughout the specification. In addition, ordinal numbers such as "first", "second", "third", etc. in this specification are used to avoid confusion between constituent elements.

[0033] Hereinafter, a rechargeable battery according to some embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

[0034] Figure 1is a schematic exploded perspective view of a rechargeable battery according to some embodiments of the present disclosure, Figure 2 It is shown Figure 1 A plan view of the lower surface of the electrode assembly, Figure 3 It is along Figure 2 A cross-sectional view taken along line III-III', Figure 4 It is along Figure 2 A cross-sectional view of an electrode assembly according to some embodiments of the present disclosure, cut along line III-III'.

[0035] like Figures 1 to 3 As shown in , a rechargeable battery 1000 according to some embodiments of the present disclosure may include an electrode assembly 100 and a pouch 200 .

[0036] The electrode assembly 100 may include a first electrode 11 , a second electrode 12 , and a separator 13 between the first electrode 11 and the second electrode 12 .

[0037] The separator 13 may serve for insulation, and may be stacked in the order of the first electrode 11 , the separator 13 , the second electrode 12 , and the separator 13 .

[0038] The electrode assembly 100 may have a core shape wound around the winding axis XL in a state where the first electrode 11, the separator 13, the second electrode 12, and the separator 13 are stacked. For example, the electrode assembly 100 may be wound and then pressed flat (or pressed to be relatively flatter), and a cross section cut in a vertical direction across the winding axis XL may have an elliptical shape that is long in one direction.

[0039] According to some embodiments, in a cross-sectional view, the electrode assembly 100 may include a relatively flat or planar flat portion P and a relatively rounded curved portion R. The flat portion P may be a portion pressed after the electrode assembly 100 is wound, and the curved portion R may connect two flat portions facing each other. One turn of the electrode assembly 100 may include a pair of flat portions P facing each other and a pair of curved portions R connected to ends of the flat portion P.

[0040] The first electrode 11 may be a positive electrode and may include a substrate 2 and a positive electrode active material layer 3 formed on the substrate 2. The substrate 2 of the first electrode 11 may be aluminum. The positive electrode active material of the first electrode 11 may be a compound capable of reversibly inserting and extracting lithium (lithiated inserting compound). For example, the positive electrode active material of the first electrode 11 may use one or more of a composite oxide including lithium and a metal selected from cobalt, manganese, nickel, and a combination thereof. The content of the positive electrode active material may be in the range of 90 wt % to 98 wt % based on the total weight of the positive electrode active material layer.

[0041] The positive electrode active material layer may further include a binder and a conductive material. For example, the content of each of the binder and the conductive material may be in the range of 1 wt % to 5 wt % based on the total weight of the positive electrode active material layer.

[0042] The binder can make the positive electrode active material particles adhere well to each other, and can make the positive electrode active material adhere well to the substrate as the current collector. Representative examples of binders can include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers including ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc., but the present disclosure is not limited thereto. The conductive material can be used to provide conductivity to the electrode, and can be any electronic conductive material that does not cause chemical changes in the battery.

[0043] The second electrode 12 may be a negative electrode, and the second electrode 12 may include a substrate 5 and a negative electrode active material layer 6 formed on the substrate 5. The substrate of the second electrode 12 may be copper. The negative electrode active material of the second electrode 12 may be a carbon-based active material. The carbon-based negative electrode active material may be artificial graphite or a mixture of artificial graphite and natural graphite.

[0044] Because the crystallization characteristics of the particles in the case of using amorphous carbon active materials are more developed than the crystallization characteristics of the particles in the case of using crystalline carbon materials as artificial graphite or a mixture of artificial graphite and natural graphite as negative electrode active materials, the use of crystalline carbon materials as a mixture of artificial graphite or artificial graphite and natural graphite as negative electrode active materials can have the advantage of further improving the orientation characteristics of the carbon material in the electrode plate relative to the external magnetic field. Artificial graphite or natural graphite can have any shape such as amorphous shape, sheet shape, flake shape, spherical shape, fiber shape or a combination thereof. For example, if a mixture of artificial graphite and natural graphite is used, the mixing ratio can be in the range of 70wt%:30wt% to 95wt%:5wt%.

[0045] According to some embodiments, the negative electrode active material layer may further include a Si-based negative electrode active material, a Sn-based negative electrode active material, and LiMO x If the negative electrode active material layer includes a carbon-based negative electrode active material as a first negative electrode active material and a negative electrode active material as a second negative electrode active material, the mixing ratio of the first negative electrode active material and the second negative electrode active material may be a weight ratio of 50:50 to 99:1.

[0046] LiMOx The negative electrode active material of the type (M = metal) may be a lithium vanadium oxide.

[0047] The Si-based negative electrode active material may include Si, Si-C composite, SiO x (0 < x < 2) or Si-Q alloy (where Q is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof, and is not Si), and the Sn-based negative electrode active material may include Sn, SnO 2 or Sn-R alloy (where R is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof, and is not Sn). At least one of the foregoing materials may be mixed with SiO 2 The element Q and the element R may be selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof.

[0048] Based on the total weight of the negative electrode active material layer, the content of the negative electrode active material in the negative electrode active material layer may be in the range of 95 wt% to 99 wt%.

[0049] The negative electrode active material may include a binder and may optionally further include a conductive material. Based on the total weight of the negative electrode active material, the content of the binder in the negative electrode active material may be in the range of 1 wt% to 5 wt%. Additionally, if a conductive material is also included, 90 wt% to 98 wt% of the negative electrode active material, 1 wt% to 5 wt% of the binder, and 1 wt% to 5 wt% of the conductive material may be used.

[0050] The binder may enable the negative electrode active material particles to adhere well to each other and may enable the negative electrode active material to adhere well to the negative electrode substrate. The binder may be a non-aqueous binder, an aqueous binder, or a combination thereof.

[0051] The non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer including ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or a combination thereof.

[0052] The aqueous binder may include styrene-butadiene rubber, acrylated styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, ethylene propylene diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, acrylate resin or a combination thereof.

[0053] If an aqueous binder is used as the negative electrode binder, a cellulose compound that can impart viscosity may be further included as a thickener. The cellulose compound may be used by mixing one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and an alkali metal salt thereof. Na, K, or Li may be used as an alkali metal. The thickener may be used in an amount in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material.

[0054] The conductive material can be used to provide conductivity to the electrode, and can be any electronic conductive material that does not cause chemical changes in the battery. Examples of the conductive material can be conductive materials including the following substances: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.; metal-based materials such as metal powder or metal fiber containing copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenylene derivatives, etc.; or mixtures thereof.

[0055] For example, the BET specific surface area of ​​the negative electrode active material layer may be less than 3.0 m 2 / g, or 0.6m 2 / g to 1.2m 2 / g. The BET specific surface area of ​​the negative electrode active material layer is less than 3.0 m 2 The case of 0.1% / g can relatively improve the electrochemical life characteristics of the single cell of the battery.

[0056] BET measurement can be performed as follows: charging and discharging a lithium rechargeable battery including a negative electrode; disassembling the battery in a fully discharged state; cutting the negative electrode of the disassembled battery into a certain size; placing the cut negative electrode in a BET sample holder; and measuring the placed negative electrode using a nitrogen adsorption method.

[0057] The negative electrode may have 6 mg / cm 2 Up to 65mg / cm 2 Cross-section loading level (L / L).

[0058] The membrane 13 can be a polymer film that allows lithium ions to pass through. It can use polyethylene, polypropylene, polyvinylidene fluoride or a multilayer film of two or more layers thereof. It can use a mixed multilayer film such as a polyethylene / polypropylene double-layer membrane, a polyethylene / polypropylene / polyethylene three-layer membrane, a polypropylene / polyethylene / polypropylene three-layer membrane, etc.

[0059] For example, the shape maintaining member 20 may be formed at the lower end portion of the electrode assembly 100. According to some embodiments, the electrode tab 21 of the first electrode 11 and the electrode tab 23 of the second electrode 12 may protrude at the upper side of the electrode assembly 100, respectively, and the lower end portion may be an opposite end portion of the upper side at which the electrode tabs 21, 23 are not formed.

[0060] The separator 13 may be formed larger than the first and second electrodes 11 and 12, and may protrude more outward than upper ends of the first and second electrodes 11 and 12. Adjacent separators 13 may be spaced apart from each other due to the thickness of the first and second electrodes 11 and 12.

[0061] The shape-maintaining member 20 may be formed on a cross section of the separator 13 at the lower end portion exposed to the electrode assembly 100. In some embodiments, the shape-maintaining member 20 may flow into the gap between the separators 13 to connect the adjacent separators 13 to each other while filling the gap between the separators 13. Therefore, the separator 13 may be inserted into the shape-maintaining member 20 and fixed to the shape-maintaining member 20. For example, the lower end portion of the separator 13 may be inserted into the shape-maintaining member 20 and fixed to the shape-maintaining member 20.

[0062] The shape maintaining member 20 may have low wetting properties (or low impregnation properties) with respect to the electrolyte, may have a hardness of 90 or less to prevent the rechargeable battery from being damaged due to a drop shock of the rechargeable battery, and may have elasticity to absorb external shock.

[0063] The shape maintaining member 20 may be a photocurable adhesive. For example, the shape maintaining member 20 may be a photocurable acrylic adhesive and may have a viscosity in the range of 7,000 cPs to 30,000 cPs.

[0064] The shape maintaining member 20 may be formed at a distance from the bent portion R of the electrode assembly 100. According to some embodiments, the shape maintaining member 20 may be located at a distance D away from the bent portion R, and the distance D may be greater than or equal to the electrode assembly thickness T×1 / 2.

[0065] Compared to the flat portion P of the electrode assembly 100, the interval between the separators 13 may become wider toward the curved portion R, so that when the shape-maintaining member 20 is formed, the shape-maintaining member 20 penetrates between the separators 13 to a depth deeper than the flat portion P. Therefore, the shape-maintaining member 20 may contact the active material layers 3 and 6 of the first electrode 11 and the second electrode 12. Therefore, the shape-maintaining member 20 may be formed at a certain distance D from the curved portion R at which the interval between the separators is wide. According to some embodiments, the certain distance D may be located at a distance greater than or equal to 1 / 2 of the thickness of the electrode assembly from both side surfaces of the electrode assembly.

[0066] The width T1 of the shape maintaining member 20 may be formed to be equal to or smaller than the lower width T of the electrode assembly 100 .

[0067] The shape maintaining member 20 may be formed to have a uniform thickness (or a relatively uniform thickness) T2 so as to have a flat or planar surface. For example, the thickness T2 of the shape maintaining member 20 may be in the range of 100 μm to 500 μm.

[0068] According to some embodiments, as in Figure 4 In the electrode assembly 101, the shape retaining member 20 may be formed in a shape in which the thickness thereof becomes larger and larger toward the center portion thereof. Therefore, the cross section obtained by cutting the shape retaining member 20 may have a semicircular structure. According to some embodiments, the thickness of the edge may be in the range of 100 μm to 500 μm, the thickness T3 of the center portion may be in the range of 500 μm to 1000 μm, and may protrude outward from the edge thereof.

[0069] If the shape-maintaining member 20 is formed as in the embodiment of the present disclosure, when the electrode assembly is inserted into the bag and then the formation process (or charge / discharge process) and the process of exhausting gas from the bag are performed, the defect of the shape deformation of the bag does not occur. That is, the shape-maintaining member 20 can reduce the spacing between the electrode assembly 100 and the bag 200, and the bag 200 can be supported by the shape-maintaining member 20 so that the bag 200 maintains a constant shape. Therefore, even if pressure is applied to the bag due to the pressure difference between the inside and the outside of the bag during the process, the deformation of the outer shape of the bag can be prevented or reduced.

[0070] Return to reference Figure 1 , the electrode assembly 100 may be contained in a bag-type case (or referred to as a "bag") 200 together with the electrolyte. The bag-type case may be formed by laminating external materials, and the electrode assembly 100 may be located between the lower laminating external material 201 and the upper laminating external material 202, and then the edges of the external materials may be heat welded to seal the bag-type case.

[0071] For example, the stacked exterior materials 201 and 202 may be formed in a multilayer structure having a first insulating layer 32, a metal layer 33, and a second insulating layer 34. For example, various adhesive layers or functional layers may be further added in the multilayer structure.

[0072] The first insulating layer 32 may be formed of a material having insulating properties and thermal adhesiveness on the inner surface of the laminated external material so that the edge of the external material is thermally welded to seal the pouch-type case in a state of accommodating the electrode assembly 100. For example, the first insulating layer 32 may be formed on one surface of the metal layer 33 and may form the inner surface of the laminated external material facing the electrode assembly 100. The first insulating layer 32 may be formed of cast polypropylene (CPP) or its equivalent that does not react with the electrolyte.

[0073] Figure 5 , Figures 7 to 9 is a schematic diagram of an electrode assembly according to some embodiments of the present disclosure, Figure 6 is a view for describing a method of folding a diaphragm according to some embodiments of the present disclosure.

[0074] because Figures 5 to 9 Most of the electrode components are Figure 1 The electrode assembly is the same, so only the other parts will be described in more detail.

[0075] Figure 5 The electrode assembly 102 may be an electrode assembly having a core shape formed by winding the first electrode 11, the separator 13, and the second electrode 12. The separator 13 protruding from the first electrode 11 and the second electrode 12 may be folded toward the center of the lower surface of the electrode assembly 102.

[0076] Can be used Figure 6 The diaphragm 13 is bent by using the diaphragm fixture 700 shown in the figure, and the diaphragm fixture 700 may include a groove S in which the electrode assembly 102 is placed. The groove S may have a curved corner. Therefore, the groove S may guide the folding direction of the diaphragm 13, so that when the electrode assembly 102 is placed, the diaphragm 13 is easily bent toward the center of the electrode assembly 102.

[0077] The diaphragm jig 700 may adjust the temperature if necessary, and the diaphragm jig 700 may be a heating device in which a heating wire or the like is installed.

[0078] The separator 13 may become flexible due to heat and may become easily formed due to heat. Therefore, by heating the separator jig 700 to a certain temperature or higher to transfer heat to the separator 13, the separator 13 may be easily bent toward the inside of the electrode assembly.

[0079] If the diaphragm 13 is bent, the diaphragm 13 may be stacked to form Figure 5The relatively flat surface shown in FIG. 1 and the shape maintaining member 20 can be formed on the flat surface to form the shape maintaining member 20 having a relatively more uniform thickness.

[0080] exist Figure 1 In the embodiment, when the shape-maintaining member 20 is formed, before applying the adhesive for forming the shape-maintaining member and then curing the applied adhesive, the shape-maintaining member 20 flows into the gap between the diaphragms 13, but Figure 5 In the embodiment, the shape maintaining member 20 does not flow into the gap between the diaphragms 13 due to the curved diaphragms 13 , and thus the shape maintaining member 20 having a constant thickness (or a relatively constant thickness or a planar surface) is formed even with a small amount.

[0081] According to some embodiments, the amount of entry into the gap between the diaphragms 13 may not be constant, so that the shape-maintaining member is formed with a non-uniform thickness. Figure 5 In the embodiment, the diaphragm 13 may be bent to form a flat bottom at which the shape-retaining member is to be formed, and then the shape-retaining member may be formed on the flat bottom so that the shape-retaining member is formed with a more uniform thickness.

[0082] like Figure 7 As shown in , in the electrode assembly 103 , the first electrode 11 , the separator 13 , the second electrode 12 , and the separator 13 may be alternately stacked, and the first electrode 11 , the separator 13 , the second electrode 12 , and the separator 13 may be sheet-type materials individually separated from each other.

[0083] like Figure 7 As shown in , the stacked electrode assembly including the sheet type electrodes may expose one end of the separator 13 on all four surfaces. Therefore, the shape maintaining member 20 may be formed on the remaining three surfaces except for one surface where the electrode tabs 21 and 23 are formed.

[0084] If the shape maintaining member 20 is formed as Figure 7 In the case of the stacked electrode assembly 103 shown in FIG. 1 , the fixing tape for aligning and fixing the position of the stacked electrodes and the separator may not be used.

[0085] like Figure 8 As shown in , the shape-maintaining member 20 of the electrode assembly 104 can be formed discontinuously along the lower surface of the electrode assembly 104. The shape-maintaining member 20 according to some embodiments of the present disclosure can prevent or reduce deformation of the bag, and can maintain the bag in a constant shape during the formation process and the gas exhaust process. Even if the shape-maintaining member 20 is formed discontinuously, the shape-maintaining member can support the bag inside the bag so that the bag maintains a constant shape.

[0086] If the interval between adjacent shape-maintaining members 20 is wide, pressure may be applied to the bag corresponding to the wide interval so that the bag is deformed. Therefore, the interval between the shape-maintaining members 20 may be narrowly formed to have an interval narrower than the lower width of the electrode assembly 104, so that the bag is not deformed even if pressure is applied.

[0087] If the shape retaining member 20 is formed discontinuously, the shape retaining member 20 may be formed only in areas other than portions where phenomena such as tail detachment occur, such as tail detachment in which a portion of an electrode falls off from an electrode assembly due to misalignment when the electrode assembly is assembled.

[0088] For example, Fig. 9 As shown in , the shape maintaining member 20 may be formed only at a region other than the electrode tabs 21 and 23 located at an upper side of the electrode assembly 105 .

[0089] While the disclosure has been described in conjunction with what are presently considered to be practical embodiments, it will be understood that the disclosure is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims and their equivalents.

[0090] Description of some reference symbols 11: First electrode 12: Second electrode 13: Diaphragm 20: Shape retaining member 21, 23: Electrode terminal block 100, 101, 102, 103, 104, 105: electrode assembly 200: bag 700: Diaphragm clamp 1000: Rechargeable battery.

Claims

1. An electrode assembly, comprising: an assembly in which a first electrode, a separator stacked with the first electrode, and a second electrode stacked with the separator are alternately stacked; as well as a shape-maintaining member at one side of the assembly where an end of the first electrode, an end of the separator, and an end of the second electrode are exposed, The shape maintaining member is at a predetermined distance from two side surfaces of the component at both sides around the shape maintaining member.

2. The electrode assembly according to claim 1, wherein: The shape maintaining member is spaced apart from both side surfaces of the assembly by at least 1 / 2 of the thickness of the electrode assembly.

3. The electrode assembly according to claim 1, wherein: The shape maintaining member is continuously formed along the one side of the component.

4. The electrode assembly according to claim 1, wherein: The shape maintaining member is discontinuously formed along the one side of the component.

5. The electrode assembly according to claim 4, wherein: The first electrode includes a first electrode tab protruding out of the diaphragm, the second electrode includes a second electrode tab protruding out of the diaphragm, and the shape maintaining member is in a region where the first and second electrode tabs are not formed.

6. The electrode assembly according to claim 1, wherein: The diaphragm is bent toward the center of the assembly, and the shape maintaining member is formed on the bent diaphragm.

7. The electrode assembly according to claim 1, wherein: The end portion of the diaphragm is inserted into the shape maintaining member.

8. The electrode assembly according to claim 1, wherein: The shape-maintaining member becomes thicker toward a center that bisects the thickness of the component, thereby having a semicircular cross-section.

9. The electrode assembly according to claim 1, wherein: A thickness of the shape maintaining member at an edge of the component is in a range of 100 μm to 500 μm, and a thickness of the shape maintaining member at a center of the component is in a range of 500 μm to 1000 μm.

10. The electrode assembly according to claim 1, wherein: The shape maintaining member is formed to have a constant thickness.

11. The electrode assembly according to claim 10, wherein: The shape maintaining member has a thickness in the range of 100 μm to 500 μm.

12. The electrode assembly according to claim 1, wherein: The shape-retaining member is a photocurable adhesive.

13. The electrode assembly according to claim 12, wherein: The photocurable adhesive is an acrylic adhesive.

14. A rechargeable battery, comprising: The electrode assembly according to claim 1; as well as The bag contains the electrode assembly and the electrolyte.

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