Secondary battery and battery pack comprising same

Abstract

The present invention relates to a secondary battery. The secondary battery according to one aspect of the present invention may comprise: an electrode assembly extending in a first direction; a cap including a cover part, which is arranged at one side of the electrode assembly in the first direction, and an extension part, which extends from the cover part toward the electrode assembly; and an exterior film, which encompasses the electrode assembly and is coupled to the extension part, wherein the exterior film can include: an accommodation part that encompasses the electrode assembly in the circumferential direction; an edge part provided at one side of the accommodation part in the first direction; and a coupling part, which is provided between the accommodation part and the edge part, is coupled to the extension part, and is positioned a predetermined first distance (d1) from the reference surface facing the first direction from among outer surfaces of the cover part.

Description

Secondary battery and battery pack including the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0104155, filed August 5, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a secondary battery and a battery pack including the same, and more particularly, to a secondary battery capable of charging and discharging electric energy and a battery pack including the same.

[0005] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used not only in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in larger products requiring high output, such as electric and hybrid vehicles, as well as in power storage devices that store surplus power or renewable energy, and as backup power storage devices.

[0006] At this time, the secondary battery includes an electrode assembly in which a positive electrode, a negative electrode, and a separator are laminated, a case that accommodates the electrode assembly, and an electrode lead for conducting current between the electrode assembly and the outside. Such secondary batteries are sometimes named as cylindrical, square, or pouch-shaped depending on the structure or shape of the case. The case requires certain functions for the operation of the secondary battery. For example, it may require airtightness to prevent the electrolyte or electrode assembly inside from leaking to the outside, insulation to achieve insulation between the electrode assembly and the outside, and durability against external contamination or impact.

[0007] The present invention has been devised to solve the above problems, and the object of the present invention is to provide a secondary battery with improved confidentiality and a battery pack including the same.

[0008] Another object of the present invention is to provide a secondary battery with improved insulation and a battery pack including the same.

[0009] Another object of the present invention is to provide a secondary battery with improved durability and a battery pack including the same.

[0010] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0011] According to one aspect of the present invention, a secondary battery is provided, comprising: an electrode assembly extending in a first direction; a cap including a cover portion disposed on one side of the electrode assembly in the first direction and an extension portion extending from the cover portion toward the electrode assembly; and an outer film surrounding the electrode assembly and coupled to the extension portion, wherein the outer film includes: a receiving portion circumferentially wrapping the electrode assembly; a border portion provided on one side of the receiving portion in the first direction; and a coupling portion provided between the receiving portion and the border portion, coupled to the extension portion, and positioned at a predetermined first distance (d1) from a reference plane facing the first direction on an outer surface of the cover portion.

[0012] At this time, the first distance (d1) may be 10% or more and 55% or less of the width length (w1) that the connecting portion has in the first direction.

[0013] At this time, the border portion may be in contact with or adjacent to the outer surface of the cap.

[0014] At this time, the above-mentioned border portion may be formed as a free end so as to be able to move away from or closer to the cap.

[0015] At this time, the width length (w2) of the border portion in the first direction may be shorter than the first distance (d1).

[0016] At this time, the width length (w2) of the border portion in the first direction may be 5% or more and 50% or less of the width length (w1) of the joining portion in the first direction.

[0017] At this time, the border portion is positioned at a predetermined second distance (d2) from the reference surface, and the second distance (d2) may be 5% or more and 50% or less of the width length (w1) that the joining portion has in the first direction.

[0018] At this time, the end of the extension part can be positioned at a predetermined third distance (d3) from the connecting part.

[0019] At this time, the third distance (d3) may be 5% or more and 50% or less of the width length (w1) that the connecting portion has in the first direction.

[0020] At this time, the cover part may have a plate shape extending in a direction perpendicular to the first direction.

[0021] At this time, the extension portion may have a side wall shape extending from the edge portion of the cover portion.

[0022] At this time, the extension portion may have a ring shape extending in the circumferential direction, and the joining portion and the edge portion may be provided along the circumference of the extension portion.

[0023] At this time, the electrode assembly may further include a terminal that is exposed to the outside of the cap through the reference surface at least in part so as to conduct current between the electrode assembly and the outside.

[0024] At this time, the terminal can penetrate the cover portion.

[0025] At this time, the extension portion may include an outer extension portion; and an inner extension portion embedded inside the outer extension portion and made of a different material from the outer extension portion.

[0026] At this time, the inner cover portion may include a metal, and the outer cover portion may include a resin layer that can be melted by heat or pressure.

[0027] According to another aspect of the present invention, a battery pack is provided, comprising at least one of the aforementioned secondary batteries; and packaging for accommodating the secondary batteries.

[0028] According to one aspect of the present invention, the joint portion of the outer film and the outer surface of the cap are joined together, and a border portion is provided on one side of the joint portion, thereby preventing the cap from excessively protruding outside the outer film. This can improve the airtightness and insulation of the space enclosed by the cap and the outer film.

[0029] According to one aspect of the present invention, since the portion (e.g., resin layer) provided between the outer surface of the bonding portion and the cap by the frame portion can be minimized from being exposed to the outside, the durability and appearance of the secondary battery can be improved.

[0030] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0031] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present invention viewed from above.

[0032] Figure 2 is an exploded perspective view of a secondary battery according to one embodiment of the present invention.

[0033] Figure 3 is a cross-sectional view according to II of Figure 1.

[0034] Figure 4 is an enlarged view of part A of Figure 3.

[0035] Figure 5 is a plan view of a secondary battery according to one embodiment of the present invention viewed from above.

[0036] Preferred embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0037] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0038] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0039] Fig. 1 is a perspective view of a secondary battery according to an embodiment of the present invention, viewed from above. Fig. 2 is an exploded perspective view of a secondary battery according to an embodiment of the present invention. Fig. 3 is a cross-sectional view according to II of Fig. 1. Fig. 4 is an enlarged view of portion A of Fig. 3. Fig. 5 is a plan view of a secondary battery according to an embodiment of the present invention, viewed from above. In this case, in Fig. 5, the extension of the cap surrounded by the outer film is indicated by a dotted line, and the area corresponding to the joint portion of the outer film is indicated by a hatching.

[0040] FIGS. 1 to 5 disclose a secondary battery according to one embodiment of the present invention. Referring to FIGS. 1 and 2, a secondary battery (1) according to one embodiment of the present invention may include an electrode assembly (10). The electrode assembly (10) may be a component responsible for a charge / discharge function in a secondary battery.

[0041] To this end, the electrode assembly (10) may have a structure in which a plurality of positive electrodes, separators, and negative electrodes are sequentially stacked. The electrode assembly (10) may be collectively referred to as a cylindrical, stacked, or stack-and-folded type depending on its shape or structure. In the present embodiment, the shape or structure of the electrode assembly (10) is not particularly limited.

[0042] In this embodiment, the electrode assembly (10) can extend in the first direction (X-axis direction). In other words, the electrode assembly (10) can have a predetermined length in the first direction (X-axis direction). At this time, the direction surrounding the axis parallel to the first direction (X-axis direction) can be referred to as the circumferential direction.

[0043] Meanwhile, in the present embodiment, an electrode tab (11) may be provided on one side of the electrode assembly (10) in the first direction (X-axis direction). The electrode tab (11) may extend from the positive electrode and / or negative electrode described above. The electrode tab (11) may be electrically connected to the outside via a terminal (30) described below. The position at which the electrode tab (11) extends or is arranged is not particularly limited.

[0044] Referring to FIGS. 2 and 3, a secondary battery (1) according to one embodiment of the present invention may include a cap (20). The cap (20) may be configured to cover one side of the electrode assembly (10) in the longitudinal direction (X-axis direction).

[0045] At this time, in the present embodiment, the caps (20) may be configured as a pair. A pair of caps (20) may cover both sides of the electrode assembly (10) in the longitudinal direction (X-axis direction). However, if necessary, the cap (20) may be configured as only one, so as to cover only one side of the electrode assembly (10).

[0046] Meanwhile, the cap (20) according to one embodiment of the present invention may include a cover portion (22). The cover portion (22) may be arranged on one side of the electrode assembly (10) in the longitudinal direction (X-axis direction). The cover portion (22) may have a plate shape. In this case, the plate may extend in a direction (Y-axis direction and / or Z-axis direction) perpendicular to the longitudinal direction (X-axis direction) of the electrode assembly (10).

[0047] At this time, the cover portion (22) may include a reference surface (22a). The reference surface (22a) may be a surface of the outer surface of the cover portion (22) that faces outward along the longitudinal direction (X-axis direction) of the electrode assembly (10). In other words, the reference surface (22a) may be a surface that faces the first direction (X-axis direction).

[0048] In this embodiment, the reference plane (22a) is configured as a plane extending in a direction (Y-axis and / or Z-axis direction) perpendicular to the longitudinal direction (X-axis direction), but the reference plane (22a) is not particularly limited as long as it faces the outside of the electrode assembly (10) along the longitudinal direction (X-axis direction).

[0049] Meanwhile, according to the present embodiment, the cover portion (22) may include an inner cover portion (24) and an outer cover portion (23). The inner cover portion (24) may be a plate having a predetermined thickness.

[0050] In this embodiment, the inner cover portion (24) may be made of a material with stronger rigidity than the outer cover portion (23). For example, the inner cover portion (24) may be made of a metal such as aluminum (Al), but is not limited thereto. This may enhance the structural stability of the cap (20).

[0051] In this embodiment, the outer cover portion (23) may be configured to surround the outer surface of the inner cover portion (24). In other words, the outer cover portion (23) may have a layer structure provided with a predetermined thickness on the outer surface of the inner cover portion (24). Of course, if necessary, the outer cover portion (23) may be configured to partially cover only one area of ​​the outer surface of the inner cover portion (24).

[0052] Referring again to FIGS. 2 and 3, the cap (20) according to one embodiment of the present invention may include an extension portion (26). The extension portion (26) may be a component of the cap (20) that is coupled with an outer film (40) described later. The coupling structure of the extension portion (26) and the outer film (40) will be described later with respect to the coupling portion (44).

[0053] In the present embodiment, the extension portion (26) may extend from the cover portion (22) toward the electrode assembly (10). At this time, the extension portion (26) may have a side wall shape extending from the edge portion of the cover portion (22). As illustrated, in the present embodiment, the cover portion (22) may have a square plate shape, and the extension portion (26) may extend from each of the four sides of the cover portion (22).

[0054] At this time, the extension portion (26) may have a square ring shape when viewed in the longitudinal direction of the electrode assembly (10). Through this, the outer film (40) described later can surround the extension portion (26) in the circumferential direction. Accordingly, airtightness of the electrode assembly (10) can be achieved by the outer film (40) and the cap (20).

[0055] Meanwhile, referring to FIG. 3, in the present embodiment, the extension portion (26) may include an inner extension portion (28) and an outer extension portion (27). The inner extension portion (28) may be made of a material having stronger rigidity than the outer extension portion (27).

[0056] In this embodiment, the inner extension portion (28) may be connected to the inner cover portion (24). The inner extension portion (28) may extend from the edge portion of the inner cover portion (24) toward the electrode assembly (10). The inner extension portion (28) may be made of the same material as the inner cover portion (24).

[0057] In this embodiment, the outer extension portion (27) may be configured to surround the outer surface of the inner extension portion (28). The outer extension portion (27) may be connected to the outer cover portion (23).

[0058] Of course, if necessary, the outer extension portion (27) may be configured to cover only a portion of the outer surface of the inner extension portion (28). For example, the outer extension portion (27) may be configured to circumferentially surround the outer surface of the inner extension portion (28).

[0059] At this time, in the present embodiment, the outer extension portion (27) may include a resin layer that can be melted by heat or pressure. Accordingly, the resin layer of the outer extension portion (27) may be partially melted and combined with the outer film (40), and the electrode assembly (10) surrounded by the cap (20) and the outer film (40) may be sealed and isolated from the outside.

[0060] Of course, the aforementioned resin layer may be provided on the outer surface of the outer film (40) as needed, and a separate resin layer may not be provided on the outer surface of the extension portion (26). Alternatively, resin layers may be provided on both the outer surface of the outer film (40) and the outer surface of the extension portion (26).

[0061] As another example, the outer film (40) and the extension portion (26) may be joined by a separate bonding layer interposed therebetween. In this case, the extension portion (26) and / or the outer film (40) may not include a separate resin layer. The bonding layer may be formed of a predetermined adhesive. The adhesive may include a hydrophobic material.

[0062] Meanwhile, in this embodiment, the cover portion (22) of the cap (20) is depicted as a plate having a uniform thickness. However, the plate shape should be interpreted to include a shape in which the thickness of one portion is different from that of another portion. Furthermore, in this embodiment, the cover portion (22) of the cap (20) is described as having a plate shape. However, the shape or structure of the cover portion (22) is not particularly limited as long as it can cover one side of the electrode assembly (10).

[0063] Referring again to FIGS. 1 to 3, a secondary battery (1) according to one embodiment of the present invention may include a terminal (30). The terminal (30) is configured to conduct current through the electrode assembly (10) to the outside. For this purpose, the terminal (30) may be made of a conductive material.

[0064] In this embodiment, the terminal (30) may include a body portion (32). The body portion (32) may penetrate the cover portion (22) of the cap (20). The body portion (32) may have a cylindrical shape, but is not limited thereto.

[0065] In this embodiment, the terminal (30) may include an outer catch (34). The outer catch (34) may be provided on one side of the body (32). The one side may be a portion facing the outside of the electrode assembly (10).

[0066] At this time, the outer catch portion (34) may have a larger cross-sectional area than the body portion (32). As a result, the outer catch portion (34) may be caught on the cover portion (22). Accordingly, the terminal (30) may be restricted from moving beyond a certain distance toward the electrode assembly (10).

[0067] In the present embodiment, the terminal (30) may include an inner hook portion (36). The inner hook portion (36) may be provided on the other side of the body portion (32). The other side may be a portion facing the electrode assembly (10). An electrode tab (11) may be coupled to the inner hook portion (36). For example, the electrode tab (11) may be welded to the outer surface of the inner hook portion (36), but is not limited thereto.

[0068] At this time, the inner catch portion (36) may have a larger cross-sectional area than the body portion (32). As a result, the inner catch portion (36) may be caught on the cover portion (22). Accordingly, the terminal (30) may be restricted from moving beyond a certain distance to the outside of the electrode assembly (10).

[0069] Referring to FIGS. 2 to 5, a secondary battery (1) according to one embodiment of the present invention may include an outer film (40). The outer film (40) is configured to cover a portion of the outer surface of the electrode assembly (10) that is not covered by the cap (20).

[0070] In this embodiment, the outer film (40) may include a receiving portion (42). The receiving portion (42) may circumferentially surround the electrode assembly (10) between a pair of caps (20). In this way, the electrode assembly (10) may be entirely covered by the caps (20) and the outer film (40).

[0071] The receiving portion (42) may have a predetermined width in the first direction (or, the longitudinal direction of the electrode assembly (10)) (X-axis direction) described above. That is, the width direction of the receiving portion (42) and the longitudinal direction of the electrode assembly (10) may be parallel. The width length of the receiving portion (42) may be appropriately set in consideration of the length of the electrode assembly (10), the length of the extension portion (26), the gap between the caps (20), etc.

[0072] In this embodiment, the outer film (40) may include a joining portion (44). The joining portion (44) may be a portion that is directly joined to the extension portion (26) of the cap (20) in the outer film (40). The joining portion (44) may be provided on one side of the receiving portion (42) in the width direction (X-axis direction).

[0073] This joint (44) may be formed by partially melting and then solidifying the resin layer of the outer film (40) and the resin layer of the extension (26), or may be formed by a separate joint layer interposed therebetween. The method by which the joint (44) and the extension (26) are joined is not particularly limited.

[0074] In this embodiment, the connecting portion (44) may be provided along the edge of the receiving portion (42). In other words, the connecting portion (44) may have a ring shape when viewed in the longitudinal direction (X-axis direction) of the electrode assembly (10). Through this, airtightness between the outer film (40) and the cap (20) may be secured.

[0075] At this time, in the present embodiment, the connecting portion (44) may have a predetermined first width (w1) in the longitudinal direction (X-axis direction) of the electrode assembly (10). In the illustrated embodiment, the first width (w1) is shown to be uniform along the circumferential direction of the electrode assembly (10). However, if necessary, the first width (w1) of one section and another section may have different sizes.

[0076] Meanwhile, in the present embodiment, the coupling portion (44) may be positioned at a first distance (d1) from the reference surface (22a) in the longitudinal direction (X-axis direction) of the electrode assembly (10). The first distance (d1) may mean the distance from the reference surface (22a) to the edge of the coupling portion (44).

[0077] At this time, the above-mentioned border may be a border positioned closer to the reference plane (22a) among the borders provided on both sides in the width direction (X-axis direction). This first distance (d1) may be equal to the sum of the second width (w2) and the second distance (d2) described later.

[0078] In the present embodiment, the first distance (d1) may be 10% or more of the first width (w1). Alternatively, the first distance (d1) may be 20% or more of the first width (w1). Alternatively, the first distance (d1) may be 30% or more of the first width (w1). Meanwhile, the first distance (d1) may be 55% or less of the first width (w1). Alternatively, the first distance (d1) may be 45% or less of the first width (w1). The first distance (d1) may be 35% or less of the first width (w1). This configuration may be to secure the insulation of the secondary battery (1).

[0079] Referring to FIGS. 3 to 5, the outer film (40) of the secondary battery (1) according to one embodiment of the present invention may include a border portion (46). The border portion (46) may be configured to improve the bonding properties, insulation properties, and durability of the secondary battery (1).

[0080] In this embodiment, the border portion (46) may be provided on one side of the width direction (X-axis direction) of the coupling portion (44) and the receiving portion (42). The border portion (46) may be positioned on the opposite side of the receiving portion (42) with the coupling portion (44) therebetween. The border portion (46) may be connected to the receiving portion (42) by the coupling portion (44).

[0081] In this embodiment, the edge portion (46) may be provided along the edge of the joining portion (44). In other words, the edge portion (46) may have a ring shape when viewed in the longitudinal direction (X-axis direction) of the electrode assembly (10).

[0082] At this time, in the present embodiment, the edge portion (46) may be in contact with or adjacent to the outer surface of the cap (20). The edge portion (46) may be configured as a free end so as to be able to move away from or closer to the outer surface (20b) of the cap (20).

[0083] That is, the edge portion (46) can prevent the portion where the joint portion (44) and the cap (20) are joined from being directly exposed to the outside. More specifically, a predetermined space can be provided between the edge portion (46) and the cap (20). This space can function as a free space in which the molten resin (or adhesive) between the joint portion (44) and the extension portion (26) can flow. In other words, the resin (or adhesive) can be prevented from being directly exposed to the outside by the edge portion (46).

[0084] Through this, the appearance, insulation, and bonding properties of the present secondary battery (1) can be improved. In addition, since the resin (or adhesive) can be protected from external impact, contamination, or corrosion, the durability of the present secondary battery (1) can be improved.

[0085] Meanwhile, in the present embodiment, the border portion (46) may have a predetermined second width (w2) in the longitudinal direction (X-axis direction) of the electrode assembly (10). In the illustrated embodiment, the second width (w2) is illustrated as being uniform in the circumferential direction of the electrode assembly (10). However, if necessary, the second width (w2) may have different sizes in one section and another section.

[0086] At this time, the second width (w2) may be shorter than the first distance (d1). In other words, a portion of the outer surface of the extension (26) may be exposed to the outside without being covered by the outer film (40). This configuration can further improve the appearance, durability, bonding properties, and insulation properties of the secondary battery (1).

[0087] At this time, the second width (w2) may be 5% or more of the first width (w1). Alternatively, the second width (w2) may be 15% or more of the first width (w1). Alternatively, the second width (w2) may be 25% or more of the first width (w1). Meanwhile, the second width (w2) may be 55% or less of the first width (w1). Alternatively, the second width (w2) may be 45% or less of the first width (w1). Alternatively, the second width (w2) may be 35% or less of the first width (w1). This configuration may be intended to secure insulation, durability, and appearance of the secondary battery (1).

[0088] Referring to FIGS. 3 to 5, in the present embodiment, the edge portion (46) can be positioned at a second distance (d2) in the longitudinal direction (X-axis direction) of the electrode assembly (10) from the reference surface (22a).

[0089] This second distance (d2) may mean the distance from the reference plane (22a) to the edge of the edge portion (46). At this time, the edge may be a edge positioned closer to the reference plane (22a) among the edges provided on both sides in the width direction (X-axis direction).

[0090] At this time, the second distance (d2) may be 5% or more of the first width (w1). Alternatively, the second distance (d2) may be 15% or more of the first width (w1). Alternatively, the second distance (d2) may be 25% or more of the first width (w1). Meanwhile, the second distance (d2) may be 55% or less of the first width (w1). Alternatively, the second distance (d2) may be 45% or less of the first width (w1). Alternatively, the second distance (d2) may be 35% or less of the first width (w1). This configuration may be intended to simultaneously secure durability, insulation, and appearance of the secondary battery (1).

[0091] Referring again to FIG. 5, in one embodiment of the present invention, the connecting portion (44) and the end portion (26a) of the extension portion (26) may be positioned at a predetermined third distance (d3). Here, the third distance (d3) may be the distance from the edge of the connecting portion (44) to the end portion (26a) of the extension portion (26).

[0092] At this time, the end (26a) of the extension (26) may be an end positioned on the inside of the outer film (40), and the edge of the connecting portion (44) may be an edge positioned close to the end (26a) of the extension (26) among the edges provided on both sides in the width direction (X-axis direction).

[0093] In the present embodiment, the third distance (d3) may be 5% or more of the first width (w1). Alternatively, the third distance (d3) may be 15% or more of the first width (w1). Alternatively, the third distance (d3) may be 25% or more of the first width (w1). Meanwhile, the third distance (d3) may be 55% or less of the first width (w1). Alternatively, the third distance (d3) may be 45% or less of the first width (w1). Alternatively, the third distance (d3) may be 35% or less of the first width (w1). This configuration may be intended to simultaneously secure durability, insulation, and appearance of the secondary battery (1).

[0094] Below, a battery pack according to one embodiment of the present invention is described.

[0095] A battery pack according to one embodiment of the present invention may include at least one secondary battery and packaging for accommodating the secondary battery. In this case, the secondary battery may be a secondary battery according to one embodiment of the present invention described above.

[0096] In this embodiment, the packaging may include a housing having a body shape for accommodating a secondary battery. The housing may include at least one support frame for supporting the secondary battery.

[0097] At this time, the housing may be equipped with a bus bar for energizing the secondary battery contained within it with the outside, a vent plug for connecting the inside and outside, and the like. The structure and shape of such packaging may be appropriately modified as needed.

[0098] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0099] [Explanation of symbols]

[0100] 1: Secondary battery 10: Electrode assembly

[0101] 20: Cap 22: Cover

[0102] 26: Extension 30: Terminal

[0103] 32: Body 34: Outer hook

[0104] 36: Inner hanging part 40: Outer film

[0105] 42: Receptacle 44: Joint

[0106] 46: Border d1: First distance

[0107] d2: 2nd street d3: 3rd street

[0108] w1: first width w2: second width

Claims

1. An electrode assembly extending in the first direction; A cap including a cover portion arranged on one side of the first direction of the electrode assembly and an extension portion extending from the cover portion toward the electrode assembly; and An outer film surrounding the electrode assembly and coupled to the extension portion is included, The above outer film, A receiving portion that surrounds the electrode assembly in a circumferential direction; A border portion provided on one side of the first direction of the above-mentioned receiving portion; and A secondary battery comprising a connecting portion provided between the receiving portion and the frame portion, coupled to the extension portion, and positioned at a predetermined first distance (d1) from a reference plane facing the first direction among the outer surfaces of the cover portion.

2. In paragraph 1, A secondary battery, wherein the first distance (d1) is 10% or more and 55% or less of the width length (w1) of the connecting portion in the first direction.

3. In paragraph 1, The secondary battery, wherein the above-mentioned border is in contact with or adjacent to the outer surface of the cap.

4. In paragraph 1, A secondary battery, wherein the above-mentioned edge portion is formed as a free end that can move away from or closer to the cap.

5. In paragraph 1, A secondary battery, wherein the width length (w2) of the above-mentioned edge portion in the first direction is shorter than the first distance (d1).

6. In paragraph 5, A secondary battery, wherein the width length (w2) of the above-mentioned edge portion in the first direction is 5% or more and 50% or less of the width length (w1) of the above-mentioned joint portion in the first direction.

7. In paragraph 5, The above-mentioned border portion is positioned at a predetermined second distance (d2) from the reference surface, A secondary battery, wherein the second distance (d2) is 5% or more and 50% or less of the width length (w1) that the connecting portion has in the first direction.

8. In paragraph 1, A secondary battery, wherein the end of the extension is positioned at a predetermined third distance (d3) from the connecting portion.

9. In paragraph 8, A secondary battery, wherein the third distance (d3) is 5% or more and 50% or less of the width length (w1) that the connecting portion has in the first direction.

10. In paragraph 1, A secondary battery, wherein the cover portion has a plate shape extending in a direction perpendicular to the first direction.

11. In paragraph 10, A secondary battery, wherein the extension portion has a side wall shape extending from the edge portion of the cover portion.

12. In paragraph 11, The above extension portion has a ring shape extending in the circumferential direction, A secondary battery, wherein the above-mentioned connecting portion and the above-mentioned edge portion are provided along the perimeter of the extension portion.

13. In paragraph 1, A secondary battery further comprising a terminal, at least a portion of which is exposed to the outside of the cap through the reference surface, so as to conduct current between the electrode assembly and the outside.

14. In paragraph 13, The above terminal is a secondary battery that penetrates the cover part.

15. In paragraph 1, The above extension part, outer extension portion; and A secondary battery comprising an inner extension portion embedded within the outer extension portion and made of a different material from the outer extension portion.

16. In paragraph 15, The inner cover portion above comprises metal, A secondary battery, wherein the outer cover portion includes a resin layer that can be melted by heat or pressure.

17. At least one secondary battery according to paragraph 1; and A battery pack comprising packaging for accommodating the secondary battery.

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