Secondary battery and device including the same

Abstract

A secondary battery according to various embodiments may include: an electrode assembly including a plurality of electrodes, an electrode tab extending from at least one of the plurality of electrodes, and a separator interposed between the plurality of electrodes; an electrode lead electrically connected to the electrode tab; and a protection part covering at least a part of the plurality of electrodes, at least a part of the electrode tab, and a part of the electrode lead, in which at least a part of the protection part is formed of an insulating material, and the insulating material is contracted by a predetermined energy source. Other embodiments are also possible.

Description

Technical Field

[0001] This disclosure relates to secondary batteries and devices including such secondary batteries. Background Technology

[0002] Secondary batteries can be charged and discharged, and are therefore widely used in mobile devices such as digital cameras, mobile phones, and laptops, and have recently gained particular attention as an energy source for electric vehicles, energy storage systems (ESS), and the like. Meanwhile, due to the high capacity and high output power required by electric vehicles or ESS, medium and large battery devices, such as battery modules containing multiple secondary batteries within a housing, or battery packs equipped with multiple battery modules, are widely utilized.

[0003] Meanwhile, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-metal hydride batteries are commonly used as existing secondary batteries, and there is a growing trend towards the use of lithium-ion batteries. For lithium-ion batteries, the electrodes can be manufactured primarily using the following methods: copper foil, aluminum foil, etc., are used as metal current collectors for each of the positive and negative electrodes, and negative electrode active materials or positive electrode active materials are stacked on their two surfaces.

[0004] Furthermore, in contrast, in next-generation batteries such as lithium-sulfur batteries (Li-S batteries) or lithium-metal batteries (Li-metal batteries), the negative electrode can be made of lithium metal instead of being equipped with a separate current collector. In this case, since lithium has lower mechanical strength than the metal current collectors of existing negative electrodes, there is a risk that the welded parts of the electrodes may easily deform or break during the manufacturing process or use of the secondary battery. Summary of the Invention

[0005] Technical goals

[0006] While the post-processing method of attaching the welded portions that serve as the connection points for electrode leads and electrode tabs by wrapping tape around their areas is considered an existing way to improve durability, this tape-attachment method has the potential to cause a chemical reaction between the tape and the electrolyte, which could thereby degrade battery performance, and also presents the problem of complex manufacturing processes.

[0007] Furthermore, even if only the welded portion is reinforced with tape, the portion of the electrode tab extending from the end of the electrode may not be protected, making it difficult to completely resolve the disconnection problem between the welded portion and the electrode (which is a relatively vulnerable point).

[0008] Technical solution

[0009] According to various exemplary embodiments of the present disclosure, a secondary battery is provided, the secondary battery comprising: an electrode assembly including a plurality of electrodes, an electrode tab extending from at least one of the plurality of electrodes, and a separator interposed between the plurality of electrodes; an electrode lead electrically connected to the electrode tab; and a protective portion configured to cover at least a portion of the plurality of electrodes, at least a portion of the electrode tab, and a portion of the electrode lead, wherein at least a portion of the protective portion may be formed of an insulating material capable of contracting through a predetermined energy source.

[0010] According to an example embodiment, at least a portion of the plurality of electrodes covered by the protective portion, at least a portion of the electrode tabs, and a portion of the electrode leads may form a continuous region or an overlapping region.

[0011] According to an example embodiment, the secondary battery may further include a battery housing, in which the electrode assembly and the protective portion are housed, and a sealing portion is formed at the edge of the battery housing, and the protective portion may be spaced apart from the sealing portion of the battery housing.

[0012] According to an example embodiment, the protective portion may include a first protective portion and a second protective portion, the first protective portion being configured to cover the bonding area of ​​the electrode tab and the electrode lead, the second protective portion being configured to cover at least a portion of one of the plurality of electrodes, and the area of ​​the one of the plurality of electrodes covered by the second protective portion may be less than or equal to one-quarter of the area of ​​the one of the plurality of electrodes.

[0013] According to an example embodiment, at least a portion of the protective portion may include a first layer and a second layer configured to be stacked, and the first layer and the second layer may be formed of different materials from each other.

[0014] According to an example embodiment, the electrode leads of the secondary battery may further include an insulating member in a region, and the protective portion may be spaced apart from the insulating member by a predetermined gap.

[0015] According to an example embodiment, the energy source may include a laser.

[0016] According to an example embodiment, the electrode tabs and the electrode leads can be electrically connected to each other via the energy source.

[0017] According to an example embodiment, the protection portion of the secondary battery may include a first protection portion and a second protection portion, and the second protection portion may be configured to cover at least a portion of the plurality of electrodes and at least a portion of the electrode tabs, and the first protection portion may be configured to cover at least a portion of the second protection portion, at least a portion of the electrode tabs and a portion of the electrode leads, and may be formed of an insulating material that can be contracted by the predetermined energy source.

[0018] According to various exemplary embodiments of this disclosure, a secondary battery is provided, the secondary battery comprising: an electrode assembly including a plurality of electrodes, an electrode tab extending from at least one of the plurality of electrodes, and a separator interposed between the plurality of electrodes; a battery housing in which the electrode assembly is housed and a sealing portion is formed at an edge of the battery housing; and electrode leads electrically connected to the electrode tab, at least a portion of the electrode leads protruding beyond the battery housing, wherein the electrode tab and the electrode leads can be joined together by laser welding, and the joined portion can be covered by an insulating material that shrinks into close contact by the laser welding.

[0019] According to various exemplary embodiments of this disclosure, an apparatus including a secondary battery according to the various exemplary embodiments described above is provided.

[0020] Effects of the present invention

[0021] According to various exemplary embodiments of this disclosure, the durability and stability of a secondary battery can be ensured by covering the relatively fragile and durable parts of the secondary battery with a separate protective portion of plastic material, so that the electrode tabs will not easily break off even when subjected to external impact.

[0022] Furthermore, the protective element can be easily installed in the secondary battery in a simple way, thus replacing the existing cumbersome tape application method.

[0023] In addition, it can effectively protect not only the welded part that serves as the point where the electrode leads and electrode tabs are joined in the secondary battery, but also the electrode tab part that extends from the end of the electrode.

[0024] In addition, the operation of installing the protection unit in the secondary battery and the operation of welding electrode leads and electrode tabs can be performed simultaneously, thereby simplifying the manufacturing process and reducing manufacturing costs.

[0025] Furthermore, by stacking two or more layers made of different materials to form a protective layer, the protective layer can be easily installed and the waterproof, moisture-proof and electrical insulation properties of the area to be protected can be easily ensured. Attached Figure Description

[0026] Figure 1 This is a schematic exploded perspective view of a secondary battery 10 according to an exemplary embodiment of the present disclosure.

[0027] Figure 2a This is a schematic front view showing the state of the secondary battery 10 before the protection unit is installed, according to an exemplary embodiment of the present disclosure.

[0028] Figure 2b This is a schematic side view showing the state of the secondary battery 10 before the protection unit is installed, according to an exemplary embodiment of the present disclosure.

[0029] Figures 3a to 3c This is a schematic front view illustrating a protective portion installed in a secondary battery 10 according to various exemplary embodiments of the present disclosure.

[0030] Figure 4a It corresponds to Figure 3a A schematic side view of the secondary battery 10.

[0031] Figure 4b It corresponds to Figure 3c A schematic side view of the secondary battery 10.

[0032] Figures 5a to 5d This is a schematic front view illustrating a protective portion installed in a secondary battery 10 according to various exemplary embodiments of the present disclosure. Detailed Implementation

[0033] Before describing this disclosure in detail, the words and terms used in the specification and claims should not be construed as limited to their general or dictionary meanings, but rather interpreted as having meanings and concepts consistent with the technical concept of this disclosure, provided that the inventor can appropriately define the concepts of these terms to best interpret his or her own invention. Therefore, the exemplary embodiments described in the specification and the constructions shown in the accompanying drawings are merely preferred exemplary embodiments of this disclosure and do not fully cover the technical concept of this disclosure. Therefore, it should be understood that various alternatives, equivalents, and modifications may exist at the time of filing this application.

[0034] The same reference numerals or symbols in each of the accompanying figures may refer to parts or elements that perform substantially the same function. For ease of description and understanding, the same reference numerals or symbols may be used to describe different exemplary embodiments. In other words, even if elements with the same reference numerals are shown in multiple figures, not all of the multiple figures represent a single exemplary embodiment.

[0035] In the following description, unless the context explicitly defines otherwise, singular expressions include plural expressions. It should be understood that terms such as “including or comprising” and “forming or constituting” are intended to indicate the presence of features, numbers, steps, operations, elements, components or combinations thereof described in the specification, and are not intended to pre-exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, components or combinations thereof.

[0036] In addition, the terms such as upper side, upper part, above, lower side, lower part, below, side surface, front surface and back surface in the following text are relative to the direction shown in the figure, and may be expressed differently when the direction of the corresponding object changes.

[0037] Furthermore, terms including ordinal numbers such as "first" and "second" can be used to distinguish elements in the specification and claims. These ordinal numbers can be used to distinguish elements that are the same or similar to each other, and the use of ordinal numbers does not limit the meaning of the terms. As an example, the order of use, arrangement, etc., of elements combined with ordinal numbers should not be construed as being limited by that ordinal number. In some cases, each ordinal number can also be used by substituting it for another.

[0038] In the following description, exemplary embodiments of the present disclosure are illustrated with reference to the accompanying drawings. However, the present disclosure is not limited to the described exemplary embodiments. For example, those skilled in the art who understand the concept of the present disclosure may propose other exemplary embodiments that are also within the scope of the concept of the present disclosure by adding, changing, or deleting elements (including those within the scope of the concept of the present disclosure). For clarity, the shapes, sizes, etc., of the elements in the drawings may be exaggerated.

[0039] Figure 1 This is a schematic exploded perspective view of a secondary battery 10 according to an exemplary embodiment of the present disclosure. Figure 2a and Figure 2b This illustrates the installation of a protective element (e.g., in a secondary battery 10) according to an exemplary embodiment of the present disclosure. Figure 3c or Figure 5d First Protection Section 200 and Figure 5d A schematic front view and a schematic side view of the second protective section 300 in its previous state. Figure 2a and Figure 2b For ease of description, the casing of the secondary battery 10 is omitted (e.g.,Figure 1 The shell 50).

[0040] refer to Figures 1 to 2b The secondary battery 10 according to various example embodiments may include an electrode assembly 100 and a battery casing 50 therein housing the electrode assembly 100.

[0041] According to various example embodiments, the electrode assembly 100 may include a plurality of electrodes, electrode tabs 110 (e.g., positive electrode tab 110a and negative electrode tab 110b) extending from at least one of the plurality of electrodes, and a diaphragm inserted between the plurality of electrodes.

[0042] The plurality of electrodes may consist of positive and negative electrodes, and may have a structure in which, for example, a positive electrode, a separator, and a negative electrode are stacked in sequence.

[0043] In an example embodiment, the negative electrode may include a negative electrode current collector and a negative electrode active material stacked on the negative electrode current collector. For example, the negative electrode may be formed by applying a mixture comprising at least a negative electrode active material, a conductive material, and a binder to a negative electrode current collector formed of a material such as a copper alloy.

[0044] Meanwhile, in another example embodiment, the negative electrode may also be composed of a single lithium metal sheet, instead of having separate negative electrode current collectors and negative electrode active materials. The lithium metal sheet is a flat sheet component made of lithium metal (lithium or an alloy of lithium), and the negative electrode and the negative electrode tab 110b formed as extending from the end of the negative electrode may be entirely composed of lithium metal in a single form.

[0045] When the negative electrode is implemented as a single unit composed of lithium metal sheets as described above, the negative electrode current collector formed of nickel (Ni), aluminum (Al), copper (Cu), etc., can be omitted from the negative electrode, which can help reduce the weight of the secondary battery 10 and provide advantages in terms of high energy density. However, when the negative electrode is composed only of lithium metal, there may be a problem that the possibility of physical damage may increase during the manufacturing process or use due to the soft properties of lithium (in other words, the nature of lithium's low mechanical strength). According to various exemplary embodiments of this disclosure, by using a protective part (e.g., Figure 3c First protection section 200 or Figure 5d The protective parts 200 and 300 are applied to the negative electrode, which has a high probability of physical damage, and can effectively protect the negative electrode, thus easily solving the above-mentioned problems.

[0046] In an example embodiment, the positive electrode may include a positive electrode current collector and a positive electrode active material stacked on the positive electrode current collector. For example, the positive electrode can be formed by applying a mixture comprising at least a positive electrode active material, a conductive material, and a binder to a positive electrode current collector formed of a material such as an aluminum alloy. For example, the positive electrode active material may be composed of lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a compound or mixture containing one or more of the above materials. As another example, sulfur-based materials having SS bonds can also be used as positive electrode active materials.

[0047] Simultaneously, each separator of insulating material can be inserted between the positive and negative electrodes. The separator can be configured not only to prevent electrical short circuits between the electrodes but also to be impregnated with electrolyte, allowing ions to pass through. For example, the separator can be formed of a porous polymer membrane or a porous nonwoven fabric. However, the separators used in secondary batteries according to various exemplary embodiments of this disclosure are not necessarily limited to the materials described above, and various materials commonly used in secondary batteries can also be used.

[0048] According to various example embodiments, the electrode tab 110 may include a positive electrode tab 110a extending from the end of the positive electrode and a negative electrode tab 110b extending from the end of the negative electrode. The electrode tab 110 may be electrically connected to electrode leads 120, which serve as terminals in the secondary battery 1. For example, the positive electrode tab 110a may be formed of aluminum (Al), and the negative electrode tab 110b may be formed of copper (Cu) or lithium (Li).

[0049] In various example embodiments, the secondary battery 10 may include a unidirectional secondary battery and a bidirectional secondary battery, wherein the unidirectional secondary battery has a configuration in which the positive electrode tab 110a and the negative electrode tab 110b of the electrode tabs 110 extend in the same direction, and the bidirectional secondary battery has a configuration in which the positive electrode tab 110a and the negative electrode tab 110b extend in opposite directions. Compared to a unidirectional secondary battery, a bidirectional secondary battery typically requires more space and may therefore have a lower energy density. In contrast, while a unidirectional secondary battery can have a relatively high energy density, given that the positive electrode tab 110a and the negative electrode tab 110b are formed in the same direction, there is a possibility of short-circuit problems due to lithium dendrites that may grow from the negative electrode and contact the positive electrode tab 110a during charging and discharging of the battery. However, in the secondary battery 10 according to various example embodiments of the present disclosure, since the positive electrode tab 110a and the negative electrode tab 110b can be physically separated and electrically isolated by the protective portion, the above-mentioned problems can be effectively prevented even if a bidirectional secondary battery structure is applied.

[0050] Meanwhile, the secondary battery 10 may include electrode leads 120 electrically connected to the electrode assembly 100 (e.g., electrode tabs 110 of the electrode assembly 100).

[0051] Electrode leads 120 may include a positive lead 120a and a negative lead 120b. For example, the positive lead 120a may be electrically connected to a positive electrode tab 110a extending from the positive electrode, and the negative lead 120b may be electrically connected to a negative electrode tab 110b extending from the negative electrode. For this purpose, electrode leads 120 may be formed of a conductive metallic material. For example, electrode leads 120 may be formed of at least one of nickel, copper, nickel-plated copper, and aluminum.

[0052] Electrode leads 120 and electrode tabs 110 can be electrically connected via various welding methods, including ultrasonic welding; however, physical fastening methods such as rivets can also be used. Meanwhile, when the secondary battery 10 includes the protective portion (e.g., in the example embodiments of this disclosure)... Figure 3c , Figure 4b and Figure 5d When the first protective part 200 is used, the electrode lead 120 and the electrode tab 110 can also be welded by applying a laser to the protective part, and in this case, the protective part can also be fixed to the welding part while being welded by laser irradiation.

[0053] In various example embodiments, the insulating member 140 may be placed at the region of the electrode lead 120 (e.g., the region corresponding to the seal 150). For example, the insulating member 140 may be formed of a material having insulating and adhesive properties (e.g., a thermoplastic resin). The insulating member 140 may be integrated into the seal 150 of the housing 30 while surrounding a portion of the electrode lead 120, and thus ensures electrical insulation between the electrode lead 120 and the housing 30. Furthermore, the insulating member 140 may seal the housing 30 at the region corresponding to the portion of the electrode lead 120 that protrudes from the interior to the exterior of the housing 30, and simultaneously serve as a buffer against damage to the electrode lead 120 caused by the seal 150.

[0054] The housing 50 may include a receiving portion 170 and a sealing portion 150. The receiving portion 170 is an internal space that can accommodate the electrode assembly 100, and the sealing portion 150 is a region sealed to shield the electrode assembly 100 in at least a portion of the edge of the receiving portion 170. For example, the housing 50 may be formed by connecting an upper housing 52 and a lower housing 54. For example, the upper housing 520 and the lower housing 54 may be connected to each other at the area of ​​the sealing portion 150 by pressing or thermal bonding, thereby preventing external foreign matter or moisture from flowing into the electrode assembly 100 placed in the receiving portion 170.

[0055] The housing 50 may include, for example, a pouch-shaped housing formed of a soft material (e.g., an aluminum laminate). However, the various exemplary embodiments of this disclosure are not limited to such a pouch-shaped housing, and may also include a can-shaped (or rectangular) housing or a cylindrical housing made of a metallic material such as aluminum, and depending on each housing type, various types such as stacked electrode assemblies or coiled electrode assemblies may be applied to the electrode assembly 100.

[0056] Figures 3a to 3c This is a schematic front view illustrating a protective portion installed in a secondary battery 10 according to various exemplary embodiments of the present disclosure.

[0057] Figure 4a and Figure 4b They correspond to respectively Figure 3a and Figure 3c A schematic side view of the secondary battery 10. Meanwhile, for ease of description, the casing (e.g., Figure 1 The shell 50) can be understood as being in Figures 3a to 4b Each of the diagrams is omitted.

[0058] refer to Figures 3a to 4b The secondary battery 10 according to various example embodiments may include a first protective portion 200 for protecting at least a portion of the electrode leads 120 (e.g., positive electrode lead 120a and negative electrode lead 120b) and at least a portion of the electrode tabs 110 (e.g., positive electrode tab 110a and negative electrode tab 110b).

[0059] In various example embodiments, the first protective portion 200 can shrink to make close contact with a portion of the electrode lead 120 and a portion of the electrode tab 110 when irradiated by heat, ultraviolet (UV), ultrasound, laser, etc., and can be formed of a material having electrical insulation and flame retardant properties. For example, the first protective portion 200 can be formed of at least one of polyolefin-based polymers (e.g., chlorinated polyolefins and cross-linked polyolefins), fluorinated resins (e.g., fluorinated elastomers and fluorinated polymers), cross-linked polyvinylidene fluoride, cross-linked polyether block amide (PEBA), cross-linked elastomers, polyethylene / polyester composites, silicone rubber, elastomers, polytetrafluoroethylene (PTFE), and polyvinyl chloride (PVC).

[0060] For example, in various exemplary embodiments of this disclosure, the first protective portion 200 may be positioned to surround a region including at least the outer surface of the overlapping portion of the electrode lead 120 and the electrode tab 110, such as... Figure 3a and Figure 4aAs shown in the diagram, the first protective portion 200 may have a tubular shape to surround the area to be protected corresponding to each of the positive electrode tabs 110a and 110b. For example, the first protective portion 200 may have a tubular shape before shrinking, with an inner diameter larger than the actual diameter of the overlapping portion of the electrode lead 120 and the electrode tab 110 to be protected. Meanwhile, the electrode lead 120 and the electrode tab 110 may be in a state where they are not joined together by welding or the like.

[0061] Subsequently, as Figure 3b As shown, in various example embodiments, a predetermined energy source for causing the first protection section 200 to contract can be applied to the first protection section 200.

[0062] For example, in an exemplary embodiment, during the manufacture of the secondary battery 10, a laser can be used as an energy source to cause the first protective portion 200 to contract. In this case, since the overlapping portion of the electrode leads 120 and electrode tabs 110 is irradiated by the laser, the electrode leads 120 and electrode tabs 110 can be bonded together. Simultaneously, energy can also be applied to the first protective portion 200 surrounding the outer surface of the overlapping portion of the electrode leads 120 and electrode tabs 110, and when contracted, the first protective portion 200 can be fixed in close contact with the protective portion (in other words, the overlapping portion of the electrode leads 120 and electrode tabs 110), such as... Figure 3c and Figure 4b As shown in the illustration. In other words, in the various exemplary embodiments of this disclosure, since the outer surface is surrounded by the first protective portion 200 and then irradiated by laser in a state where the electrode leads 120 and electrode tabs 110 are not joined, the welding operation of the electrode leads 120 and electrode tabs 110 and the fixing operation of the first protective portion 200 can be performed simultaneously.

[0063] Since the first protective part 200 covers the connection portion of the electrode lead 120 and the electrode tab 110 on its outer surface as described above, it can prevent the joint from peeling or tearing, thus improving the safety of the secondary battery 10.

[0064] For example, the length of the enclosing region of the first protective portion 200 may be longer than the length of the bonding region between the electrode tab 110 and the electrode lead 120, so as to cover the entire area of ​​the portion where the electrode tab 110 and the electrode lead 120 are bonded together (in other words, the welded portion). For example, the first protective portion 200 may have a length of 1 mm to 4 mm longer than the bonding region, and for example, when the bonding region between the electrode tab 110 and the electrode lead 120 has a length of about 3 mm, the first protective portion 200 may have a length of about 4 mm to 7 mm.

[0065] Meanwhile, in the secondary battery 10 according to other example embodiments, in addition to lasers, UV, heat, ultrasound, etc., can also be used as energy sources for retracting the first protective section 200. For example, in some cases, the first protective section 200 is positioned such as Figure 3a Before the state shown, welding operations can be performed on the electrode leads 120 and the electrode tabs 110, and in this case, the energy source for shrinking the first protective part 200 is not limited to a laser.

[0066] In an example embodiment, the first protective portion 200 may be positioned to be spaced apart from the insulating member 140 formed in a region of the electrode lead 120 by a predetermined gap, which can prevent the insulating member 140 from acting as an obstacle during the sealing process.

[0067] Meanwhile, the first protective portion 200 applied to the secondary battery 10 according to various example embodiments can also be constructed in the form of a stack of two or more layers with different properties. When the first protective portion 200 has a stack of two or more layers, for example, the inner layer can be formed of a material with excellent shrinkage properties, and the outer layer can be formed of a material with excellent waterproof, moisture-proof and / or electrical insulation properties.

[0068] Figures 5a to 5d This is a schematic front view illustrating a protective portion installed in a secondary battery 10 according to various exemplary embodiments of the present disclosure.

[0069] refer to Figure 5a The secondary battery 10 according to various example embodiments may include a second protective portion 300 for integrally covering the electrodes (e.g., positive and negative electrodes) and electrode tabs 110 (e.g., positive electrode tab 110a and negative electrode tab 110b) extending from each electrode.

[0070] In an example embodiment, the second protective portion 300 may have a shape that includes two holes on one side corresponding to each electrode tab 110 (in other words, positive electrode tab 110a and negative electrode tab 110b) and a large hole on the other side corresponding to the body portion of the electrode, so as to integrally cover a portion of the electrode and a portion of the electrode tab 110 extending from the end of the electrode.

[0071] For example, the second protective portion 300 can be formed from at least one material selected from polypropylene (PP) or polyethylene (PE). However, it is not limited to these materials; various polymeric plastic materials with stiffness and weight characteristics to protect the ends of the electrodes can be used. As an example, the second protective portion 300 can also be formed from a plastic material that has the property of shrinking upon contact with an energy source such as heat, similar to the first protective portion 200. As another example, the second protective portion 300 can also be formed from a material that has properties harder than the first protective portion 200, although this material does not have heat-shrinkage properties.

[0072] Meanwhile, in the example embodiment, the second protective portion 300 can be secured to the electrode assembly 100 by a separate component such as a clip, while covering a portion of the electrode and a portion of the electrode tab 110 extending from the end of the electrode. Alternatively, the second protective portion 300 can be indirectly secured to the electrode assembly 100 when the first protective portion 200 connected thereto is secured to the bonding area.

[0073] Meanwhile, the area (or length) of the portion of the body portion surrounding the electrode in the second protective part 300 can be configured to cover only about one-quarter of the entire area (or length) of the body portion of the electrode that is less than or equal to the entire area (or length) of the body portion of the electrode.

[0074] Therefore, it can effectively protect the points that are vulnerable to external impact after the welding part in the secondary battery 10 (in other words, the part extending from the end of the electrode to the electrode tab 110), and can prevent energy efficiency degradation caused by increasing the weight of the auxiliary material due to unnecessarily covering the part that is not easily affected by external impact (e.g., the lower end of the body of the electrode).

[0075] refer to Figures 5b to 5d In another example embodiment, the secondary battery 10 may further include each of the second protection portion 300 and the first protection portion 200.

[0076] For example, such as Figure 5b and Figure 5c As shown, with the second protective portion 300 covering a portion of the electrodes of the secondary battery 10 and a portion of the electrode tabs 110, the first protective portion 200 can be positioned to include at least a portion of the second protective portion 300 and the overlapping portion of the electrode tabs 110 and the electrode leads 120. Then, an energy source can be applied to cause the first protective portion 200 to retract. Therefore, the first protective portion 200 can be fixed in close contact with the covered area, such as the portion of the second protective portion 300 and the overlapping portion of the electrode tabs 110 and the electrode leads 120. And thus, the second protective portion 300 can also be indirectly fixed to a predetermined portion of the electrode assembly 100, such as the electrode tabs 110.

[0077] In order to achieve the effect of fixing the second protective part 300 as described above and the close contact and fixing of the first protective part 200, according to the example embodiment of this disclosure, at least some portions of the area protected by the first protective part 200 and the second protective part 300 in the secondary battery 10 may overlap.

[0078] Meanwhile, when a laser is used as the energy source to retract the first protective portion 200, it has the advantage that the first protective portion 200 and the second protective portion 300 can be fixed. Furthermore, welding can be performed by laser irradiation to combine the electrode lead 120 with the electrode tab 110. However, the energy source for retracting the first protective portion 200 is not limited to this laser. For example, in the exemplary embodiment, welding of the electrode lead 120 and the electrode tab 110 can be performed after the second protective portion 300 covers the portion of the electrode and the portion of the electrode tab 110. Then, after the first protective portion 200 covers the portion of the second protective portion 300 and the welded portion, various energy sources such as heat and UV can be used to fix the first protective portion 200 (and the second protective portion 300 can be fixed by fixing the first protective portion 200).

[0079] In various exemplary embodiments of this disclosure, the secondary battery 10 can be charged and discharged, and may include a pouch-type secondary battery, a rectangular secondary battery, or a cylindrical secondary battery. The pouch-type secondary battery has a structure in which electrode assemblies are housed within a flexible pouch; in the rectangular secondary battery, the electrode assemblies are housed within a rectangular housing with predetermined rigidity; and in the cylindrical secondary battery, the electrode assemblies are housed within a cylindrical housing. While a pouch-type secondary battery has been described in this specification in relation to a secondary battery in a form stacked in one direction, this is merely an exemplary description, and the various exemplary embodiments of this disclosure are not limited to this pouch-type secondary battery.

[0080] The secondary battery 10 and the battery module or battery pack including the secondary battery according to various exemplary embodiments of the present disclosure can be applied to various devices. For example, the secondary battery 10 according to various exemplary embodiments of the present disclosure can be applied to devices including vehicles such as electric bicycles, electric vehicles and hybrid vehicles, but is not limited thereto, and can be applied to various types of devices that can use the secondary battery 10.

[0081] At the same time, although terms indicating directions such as up and down are used in this specification, it will be apparent to those skilled in the art that these terms are merely for ease of description and may vary depending on the position of the corresponding object, the position of the observer, etc.

[0082] While various exemplary embodiments of the present disclosure have been described in detail above, the scope of the disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the technical concept of the present disclosure as defined by the appended claims. Furthermore, the foregoing exemplary embodiments can be implemented with some elements removed, and each exemplary embodiment can be implemented in combination with each other.

Claims

1. A secondary battery, comprising: An electrode assembly, the electrode assembly including a plurality of electrodes, an electrode tab extending from at least one of the plurality of electrodes, and a diaphragm inserted between the plurality of electrodes; Electrode leads, which are electrically connected to the electrode tabs; as well as A protective portion, configured to cover at least a portion of the plurality of electrodes, at least a portion of the electrode tabs, and a portion of the electrode leads. At least a portion of the protective portion is formed of an insulating material that can be contracted by a predetermined energy source.

2. The secondary battery according to claim 1, It also includes a battery housing, in which the electrode assembly and the protective portion are housed, and a sealing portion is formed at the edge of the battery housing. in, The protective portion is spaced apart from the sealing portion of the battery casing.

3. The secondary battery according to claim 1, in, The protection unit includes: A first protective portion, configured to cover the junction area between the electrode tab and the electrode lead; and The second protective portion is configured to cover at least a portion of one of the plurality of electrodes, and Wherein, the area of ​​one of the plurality of electrodes covered by the second protective part is less than or equal to one-quarter of the area of ​​the one of the plurality of electrodes.

4. The secondary battery according to claim 1, in, The at least portion of the plurality of electrodes covered by the protective portion, the at least portion of the electrode tabs, and the portion of the electrode leads form a continuous or overlapping region.

5. The secondary battery according to claim 1, in, The at least portion of the protective portion includes a first layer and a second layer configured to be stacked, and The first layer and the second layer are formed of different materials.

6. The secondary battery according to claim 1, in, The electrode leads also include an insulating component located in a region, and The protective part is spaced apart from the insulating member by a predetermined gap.

7. The secondary battery according to claim 1, in, The energy source includes a laser.

8. The secondary battery according to claim 1, in, The protection section includes a first protection section and a second protection section. The second protective portion is configured to cover at least a portion of the plurality of electrodes and at least a portion of the electrode tabs, and The first protective portion is configured to cover at least a portion of the second protective portion, at least a portion of the electrode tab, and a portion of the electrode lead, and is formed of an insulating material that can be contracted by the predetermined energy source.

9. The secondary battery according to claim 1, in, The electrode tabs and the electrode leads are electrically connected to each other through the energy source.

10. A secondary battery, comprising: An electrode assembly comprising a plurality of electrodes, an electrode tab extending from at least one of the plurality of electrodes, and a diaphragm inserted between the plurality of electrodes; A battery housing in which the electrode assembly is housed and a sealing portion is formed at the edge of the battery housing; as well as Electrode leads, which are electrically connected to the electrode tabs, and at least a portion of the electrode leads protruding beyond the battery casing. The electrode tabs and the electrode leads are joined together by laser welding, and the joined portion is covered by an insulating material that shrinks into close contact through the laser welding.

11. An apparatus comprising a secondary battery according to any one of claims 1-10.

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