Secondary battery and battery box comprising same

Abstract

The present invention relates to a secondary battery and a battery box comprising same. The secondary battery according to one aspect of the present invention comprises: an electrode assembly extending in one direction; a cap covering one side of the electrode assembly in the direction of extension; and an exterior film surrounding the other side of the electrode assembly. The exterior film includes: an accommodation portion surrounding the electrode assembly in the circumferential direction; first and second edge portions extending from one side and the other side of the accommodation portion and overlapping each other; a first-type coupling portion provided along the one direction to couple the first and second edge portions; and a non-coupling portion extending between the first and second edge portions in a direction parallel to the first-type coupling portion. The length (L1) of the non-coupling portion may be defined by the following [Equation 1]: [Equation 1] may be C +170 < = L1, wherein L1 may be the length [mm] of the non-coupling portion, and C may be the electric capacity [Ah] of the secondary battery.

Description

Secondary battery and battery box including the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0157198 filed on November 7, 2024, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to a secondary battery and a battery box including the same, and more specifically, to a secondary battery capable of charging and discharging electrical energy and a battery box including the same.

[0005] Although secondary batteries have been applied to small-scale fields such as mobile devices and laptop computers, recently the direction of research has expanded to medium and large-scale fields, and they are widely used in fields requiring high voltage and large capacity, such as Energy Storage Systems (ESS) and Electric Vehicles (EV).

[0006] Meanwhile, as secondary batteries are utilized in various devices, the demand for their stability is increasing. To enhance the stability of secondary batteries, it is necessary to control the direction in which internal gases or flames are discharged during abnormal situations where the battery's temperature or pressure rises. This is because controlling the discharge direction of gases or flames allows for the suppression or control of thermal transfer or thermal runaway phenomena.

[0007] The present invention has been devised to solve the above problems, and the objective of the present invention is to provide a secondary battery in which the direction of discharge of internal gas or flame can be controlled, and a battery box including the same.

[0008] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art to which the present invention pertains from the description below.

[0009] According to one aspect of the present invention, a secondary battery is provided comprising: an electrode assembly extending in one direction; a cap covering one side of the extension direction of the electrode assembly; and an outer film wrapping the other side of the electrode assembly, wherein the outer film comprises: a receiving portion surrounding the electrode assembly in a circumferential direction; first and second edge portions extending from one side and the other side of the receiving portion and overlapping each other; a first type coupling portion provided along the one direction to combine the first and second edge portions; and a non-coupling portion extending in a direction parallel to the first type coupling portion between the first and second edge portions, wherein the length (L1) of the non-coupling portion is defined by the following [Formula 1].

[0010] [Equation 1] C + 170 ≤ L1

[0011] L1: Length of the above non-coupling part [mm]

[0012] C: Electric capacity of the above secondary battery [Ah]

[0013] At this time, the length (L1) of the above-mentioned non-coupling part can be defined by the following [Equation 2].

[0014] [Equation 2] L1 ≤ L2 - 40

[0015] L2: Length of the above exterior film [mm]

[0016] At this time, the length (L2) of the exterior film may be a length measured along the above one direction.

[0017] At this time, the above non-coupling portion is composed of a plurality of parts, and the plurality of non-coupling portions can be arranged along the above one direction.

[0018] At this time, the distance between adjacent non-coupling parts among the plurality of non-coupling parts may be 60 mm or more.

[0019] At this time, the first type of joint may be made of a metal material.

[0020] At this time, the first type joint can be formed by a welding process.

[0021] At this time, the exterior film may include a second type of coupling portion that extends parallel to at least one of the first type of coupling portion and the non-coupling portion and combines the first and second edge portions.

[0022] At this time, the second type coupling part may be located inside the first type coupling part.

[0023] At this time, the second type of joint may be made of a different material from the first type of joint.

[0024] At this time, the second type of joint may be made of a resin material.

[0025] At this time, the second type joint can be formed by a sealing process using heat or pressure.

[0026] At this time, the breaking force of the second type of joint may be smaller than the breaking force of the first type of joint.

[0027] At this time, the above caps are provided in pairs and can cover both sides of the electrode assembly in the extension direction.

[0028] At this time, the above cap can be combined with the above exterior film.

[0029] At this time, the electrode assembly further includes a terminal for energizing the outside, and the terminal can be coupled through the cap.

[0030] According to another aspect of the present invention, a battery box is provided comprising: a packaging; and a secondary battery accommodated in the packaging, wherein the secondary battery comprises: an electrode assembly extending in one direction; a cap covering one side of the extension direction of the electrode assembly; and an outer film covering the other side of the electrode assembly, wherein the outer film comprises: a receiving portion surrounding the electrode assembly in a circumferential direction; first and second edge portions extending from one side and the other side of the receiving portion and overlapping each other; a first type coupling portion provided along the one direction to combine the first and second edge portions; and a non-coupling portion extending in a direction parallel to the first type coupling portion between the first and second edge portions, wherein the length (L1) of the non-coupling portion is defined by the following [Formula 1].

[0031] [Equation 1] C + 170 ≤ L1

[0032] L1: Length of the above non-coupling part [mm]

[0033] C: Electric capacity of the above secondary battery [Ah]

[0034] According to one aspect of the present invention, a first type coupling part and a non-coupling part are provided along the extension direction of the electrode assembly between the first and second edge parts, and since the length of the non-coupling part is defined according to [Equation 1] below, gas or flame inside the outer film can be discharged through the non-coupling part. Through this, the direction of discharge of gas or flame can be controlled in abnormal situations, thereby improving the stability of the secondary battery. Here, [Equation 1] is C + 170 ≤ L1, where L1 is the length [mm] of the non-coupling part, and C is the electrical capacity [Ah] of the secondary battery.

[0035] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0036] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present invention, viewed from above.

[0037] FIG. 2 is a plan view of a secondary battery according to one embodiment of the present invention. In this case, the portion equipped with the first and second type coupling portions is indicated as a hatched area.

[0038] Figure 3 is an enlarged view of a portion of the cross-section according to II of Figure 1.

[0039] Figure 4 is a cross-sectional view along II-II of Figure 2.

[0040] Figure 5 is an enlarged view of part A of Figure 4.

[0041] Figure 6 is a cross-sectional view along III-III of Figure 2.

[0042] Figure 7 is an enlarged view of part B of Figure 6.

[0043] FIG. 8 is a plan view of a secondary battery according to another embodiment of the present invention. In this case, the portion equipped with the second and second type coupling portions is indicated as a hatched area.

[0044] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0045] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0046] In addition, terms or words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0047] FIG. 1 is a perspective view of a secondary battery according to an embodiment of the present invention, viewed from above. FIG. 2 is a plan view of a secondary battery according to an embodiment of the present invention. In this case, the portion equipped with the first and second type coupling portions is indicated as a hatched area. FIG. 3 is an enlarged view of a portion of the cross-section according to II of FIG. 1. FIG. 4 is a cross-sectional view according to II-II of FIG. 2. FIG. 5 is an enlarged view of portion A of FIG. 4. FIG. 6 is a cross-sectional view according to III-III of FIG. 2. FIG. 7 is an enlarged view of portion B of FIG. 6.

[0048] FIGS. 1 to 7 disclose a secondary battery according to one embodiment of the present invention. Referring to FIGS. 1 to 3, the secondary battery (1) according to one embodiment of the present invention may be a secondary battery for charging and discharging electrical energy.

[0049] To this end, a secondary battery (1) according to one embodiment of the present invention may include an electrode assembly (10). The electrode assembly (10) may be an assembly composed of an electrode and a separator. The electrode assembly (10) may be extended in a front-rear direction (X-axis direction). Hereinafter, the said direction is referred to as the length direction (or extension direction) of the electrode assembly (10), and the direction wrapping around the said direction (X-axis direction) is referred to as the circumference direction of the electrode assembly (10).

[0050] The electrode may consist of a foil-shaped current collector made of copper (Cu) or aluminum (Al) and an electrode active material layer provided on one or both sides of the current collector. The separator may be made of an insulating material. An all-solid-state may be used in place of the separator. The materials of the current collector, the electrode active material layer, and the separator are not particularly limited.

[0051] At this time, the electrodes and separators may be composed of multiple units. Some of the multiple electrodes may be positive electrodes, and the remaining parts may be negative electrodes. The multiple electrodes and separators may be stacked in one direction. The separators may be interposed between adjacent electrodes.

[0052] Such an electrode assembly (10) can be classified into a stacked type, a stacked and folding type, or a cylindrical type depending on the stacked structure or overall shape. In this embodiment, the type or shape of the electrode assembly (10) is not particularly limited as long as it can charge and discharge electrical energy.

[0053] Meanwhile, in this embodiment, the electrode assembly (10) may be provided with an electrode tab (11). The electrode tab (11) may be configured to conduct current between the electrode and the terminal (30) described later. The electrode tab (11) may extend from the electrode. The electrode tab (11) may extend parallel to the longitudinal direction (X-axis direction) of the electrode assembly (10). The electrode tab (11) may extend toward the terminal (30).

[0054] A secondary battery (1) according to one embodiment of the present invention may include a cap (20). The cap (20) may be configured to seal the electrode assembly (10) together with an outer film (40) described later. The cap (20) may be disposed on one side of the electrode assembly (10) in the extension direction (X-axis direction).

[0055] In this embodiment, the cap (20) may be configured as a pair. The pair of caps (20) may be placed on each side of the electrode assembly (10) in the extension direction (X-axis direction). The pair of caps (20) may be formed symmetrically around the electrode assembly (10).

[0056] However, as needed, a pair of caps (20) may have different shapes or structures. Alternatively, a cap (20) may be placed on one side in the extension direction (X-axis direction) of the electrode assembly (10), while another part of the outer film (40) may surround the other side. Hereinafter, when describing a secondary battery (1) according to an embodiment of the present invention, the description will be based on the cap (20) placed in front (positive direction of the X-axis) of the electrode assembly (10).

[0057] In this embodiment, the cap (20) may include a cover portion (22). The cover portion (22) may be configured to cover the front (positive direction of the X-axis) of the electrode assembly (10). The cover portion (22) may have a square plate shape. The cover portion (22) may be made of a metal or plastic material having a certain rigidity. However, the material or shape of the cover portion (22) is not particularly limited as long as it can cover one side of the electrode assembly (10).

[0058] In this embodiment, the cap (20) may include an extension portion (24). The extension portion (24) may extend from the cover portion (22) toward the electrode assembly (10). The extension portion (24) may be configured to form a combined structure of the outer film (40) and the cap (20) described later. The extension portion (24) may extend from the edge portion of the cover portion (22). The extension portion (24) may have a side wall shape having a predetermined thickness.

[0059] In this embodiment, the extension portion (24) may be provided along the edge of the cover portion (22). The extension portion (24) may surround the cover portion (22) in a circumferential direction along the edge. When viewed in the longitudinal direction (X-axis direction) of the electrode assembly (10), the extension portion (24) may have a ring shape.

[0060] In this embodiment, the extension part (24) may be connected to the cover part (22). The extension part (24) may be made of the same material as the cover part (22). Of course, if necessary, the extension part (24) may be provided separately from the cover part (22) and combined with it, or it may be made of a different material.

[0061] Additionally, the structure or shape of the extension part (24) is not particularly limited as long as it can achieve a combined structure of the cap (20) and the exterior film (40). For example, the extension part (24) may be composed of a pair and provided on the left (negative direction of the Y-axis) edge portion and the right (positive direction of the Y-axis) edge portion of the cover part (22), respectively. In this case, the cover part (22) and the extension part (24) may have an overall 'U' shape.

[0062] Meanwhile, in this embodiment, the cap (20) may include a connecting portion (26). The connecting portion (26) may be configured to connect the extension portion (24) and the outer film (40) described later. The connecting portion (26) may be made of a material that can be melted by heat or pressure. For example, the connecting portion (26) may be made of a resin such as polypropylene, but the material of the connecting portion (26) is not particularly limited.

[0063] In this embodiment, a portion of the connecting portion (26) may be provided on the outer circumference of the extension portion (24). A portion of the connecting portion (26) may have a ring shape that surrounds the outer side of the extension portion (24). The portion may be interposed between the outer film (40) and the extension portion (24) to connect them together.

[0064] Meanwhile, in this embodiment, the remaining portion of the connecting portion (26) may be provided on another portion of the extension portion (24) and / or on the outer surface of the cover portion (22). As illustrated, the remaining portion of the connecting portion (26) may cover the entire outer surface of the extension portion (24) and may be provided on the surface of the outer surface of the cover portion (22) facing the electrode assembly (10). That is, the extension portion (24) may be embedded in the connecting portion (26).

[0065] However, the area where the connecting portion (26) is provided on the outer surface of the cover portion (22) or the extension portion (24) can be appropriately modified as needed. For example, a part of the connecting portion (26) may also be provided on the surface of the outer surface of the cover portion (22) that faces the outside of the electrode assembly (10).

[0066] Referring again to FIGS. 1 to 3, a secondary battery (1) according to one embodiment of the present invention may include a terminal (30) made of a conductive material. The terminal (30) may be configured to conduct current to an electrode assembly (10) with an external load or power source. The terminal (30) may be installed on a cap (20).

[0067] In this embodiment, the terminal (30) may include a body portion (32). The body portion (32) may be coupled through the cap (20). More specifically, the body portion (32) may be coupled through the cover portion (22). One side of the body portion (32) may be exposed to the outside of the cap (20), and the other side may be exposed to the inside of the cap (20) (i.e., the side of the electrode assembly (10)).

[0068] In this embodiment, the terminal (30) may include an outer locking portion (34). The outer locking portion (34) may be provided on one side of the body portion (32). The outer locking portion (34) may have a larger cross-section than the body portion (32). As a result, the outer locking portion (32) can prevent the terminal (30) from entering excessively into the inside of the cap (20).

[0069] In this embodiment, the terminal (30) may include an inner locking portion (36). The inner locking portion (36) may be provided on the other side of the body portion (32). The inner locking portion (36) may have a larger cross-section than the body portion (32). As a result, the inner locking portion (36) can prevent the terminal (30) from falling out to the outside of the cap (20). At this time, an electrode tab (11) may be coupled to the inner locking portion (36). Through this, the electrode assembly (10) can be energized with an external load or power source.

[0070] Meanwhile, in this embodiment, the terminal (30) is described as having a rivet shape. However, the structure or shape of the terminal (30) is not particularly limited as long as it allows the electrode assembly (10) to conduct electricity to the outside.

[0071] Meanwhile, although not shown, a gasket may be provided between the cap (20) and the terminal (30) to assist in the bonding force between the terminal (30) and the cap (20), to achieve insulation between the terminal (30) and the cap (20), or to prevent leakage of the electrolyte.

[0072] Referring to FIGS. 1, FIGS. 2 and FIGS. 4 to 7, a secondary battery (1) according to one embodiment of the present invention may include an outer film (40). The outer film (40) may be configured to form a receiving space (S) together with a cap (20).

[0073] In this embodiment, an electrode assembly (10) may be placed in the receiving space (S). Accordingly, the electrode assembly (10) can be protected from external shock or contamination. Additionally, the electrolyte injected into the receiving space (S) can be prevented from leaking out.

[0074] In this embodiment, the exterior film (40) may be formed into a multilayer structure. For example, the multilayer structure of the exterior film (40) may include a surface protection layer made of a polymer and provided on the outermost layer, a sealant layer made of a polymer and provided on the innermost layer, and a gas barrier layer made of metal interposed between the surface protection layer and the sealant layer.

[0075] Here, the polymer may include polyethylene terephthalate and / or polypropylene, and the metal may include iron (Fe), chromium (Cr), manganese (Mn), nickel (Ni) and / or aluminum. However, the layer structure of the exterior film and the materials forming it may be appropriately modified as needed.

[0076] Meanwhile, in this embodiment, the outer film (40) may include a receiving portion (42). The receiving portion (42) may wrap around the electrode assembly (10) in a circumferential direction. As a result, a receiving space (S) may be formed inside the receiving portion (42).

[0077] At this time, one side of the receiving portion (42) can be combined with the cap (20). The connecting portion (26) of the cap (20) is provided between the receiving portion (42) and the extension portion (24) to combine them. Thus, the receiving space (S) can be isolated from the outside.

[0078] In this embodiment, the outer film (40) has a certain flexibility so that it can be bent by an external force. Accordingly, the receiving portion (42) can effectively respond to deformation of the electrode assembly (10). For example, the electrode assembly (10) may increase in volume during the charging and discharging process.

[0079] In this process, the receiving portion (42) may be bent in response to the deformation of the electrode assembly (10). In other words, the shape of the receiving space (S) may be deformed in response to the deformation of the electrode assembly (10). This prevents damage to the electrode assembly (10) by relieving the partial application of excessive force to the electrode assembly (10).

[0080] In contrast, since the case of a prismatic secondary battery in which the shape of the receiving space (S) is fixed cannot be deformed in response to the deformation of the electrode assembly (10), excessive force or pressure may be applied locally to the electrode assembly (10). The electrode assembly (10) may be damaged by such force or pressure.

[0081] Referring to FIGS. 2 and FIGS. 4 to 7, an outer film (40) of a secondary battery (1) according to one embodiment of the present invention may include a border portion (44). The border portion (44) may include a first border portion (44a) extending from one side of the receiving portion (42) and a second border portion (44b) extending from the other side of the receiving portion (42).

[0082] In this embodiment, the first and second edge portions (44a, 44b) may be provided along the longitudinal direction (X-axis direction) of the electrode assembly (10). The first and second edge portions (44a, 44b) may overlap each other. By the first and second edge portions (44a, 44b) being in close contact and joined together, the receiving space (S) is sealed to the periphery of the electrode assembly (10), and leakage of the electrolyte can be prevented.

[0083] Meanwhile, in this embodiment, the exterior film (40) may include a first type coupling part (46) and a non-coupling part (47). The first type coupling part (46) may be configured to combine the first and second edge parts (44a, 44b) with each other.

[0084] In this embodiment, the first type joint (46) can be formed by a welding process. For example, the first type joint (46) can be formed by laser welding performed at 600 to 700 degrees. The first type joint (46) can be formed by solidifying a predetermined metal after it has been melted.

[0085] At this time, the metal may be a part of the gas barrier layer of the exterior film. More specifically, a part of the area constituting the edge portion (44) of the exterior film (40) may have the gas barrier layer exposed for the welding.

[0086] Of course, if necessary, the welding process may be performed with a separate metal film interposed between the first and second edge portions (44a, 44b) to form the first type joint portion (46).

[0087] Meanwhile, in this embodiment, the first type coupling part (46) may be extended in the longitudinal direction (X-axis direction) of the electrode assembly (10). As a result, the periphery of the receiving space (S) may be sealed by the first type coupling part (46).

[0088] In addition, in this embodiment, the non-coupling portion (47) may be extended in the longitudinal direction (X-axis direction) of the electrode assembly (10) parallel to the first type coupling portion (46). In other words, the first type coupling portion (46) and the non-coupling portion (47) may form a single line in the said direction (X-axis direction). Alternatively, the first type coupling portion (46) may be provided in one section based on the said direction (X-axis direction), and the non-coupling portion (47) may be provided in the remaining section.

[0089] In this embodiment, the non-coupling portion (47) may be defined as a portion where the first and second edge portions (44a, 44b) are not joined to each other by the first type coupling portion (46). In the non-coupling portion (47), the first and second edge portions (44a, 44b) may be separated from each other. Alternatively, in the non-coupling portion (47), the first and second edge portions (44a, 44b) may be in contact with each other but may be in a state where they can be easily separated by an external force.

[0090] Such a non-coupling part (47) can function as a passage for gas or flames in the receiving space (S) to be discharged when an abnormal situation occurs in the secondary battery (1). That is, the discharge of gas or flames is restricted to the part of the perimeter of the receiving space (S) where the first type coupling part (46) is provided, and the discharge of gas or flames can be guided toward the non-coupling part (47). In this way, since the discharge direction of gas or flames in the secondary battery (1) can be guided toward the non-coupling part (47), high stability can be achieved.

[0091] At this time, in this embodiment, the length (L1) of the non-coupling portion (47) may be defined by the following [Equation 1]. Here, the length (L1) of the non-coupling portion (47) may be a length measured in a direction parallel to the length direction (X-axis direction) of the electrode assembly (10).

[0092] [Formula 1]

[0093] C + 170 ≤ L1

[0094] L1: Length of the above non-coupling part [mm]

[0095] C: Electric capacity of the above secondary battery [Ah]

[0096] The inventors have confirmed that if the length (L1) of the non-coupling part (47) has a length defined according to [Equation 1], the direction of discharge of gas or flame can be very effectively guided toward the non-coupling part (47).

[0097] This may be because the length (L1) of the non-coupling part (47) is extended to a sufficient length corresponding to the electrical capacity of the secondary battery (1), thereby providing sufficient space for gas or flame to be discharged, so no additional breakage occurs in the surrounding part of the non-coupling part (47).

[0098] Meanwhile, in this embodiment, the length (L1) of the non-coupling part (47) can be defined by the following [Equation 2]. In this case, the length (L2) of the outer film (40) in [Equation 2] may be the length measured in the length direction (X-axis direction) of the electrode assembly (10).

[0099] [Equation 2]

[0100] L1 ≤ L2 - 40

[0101] L1: Length of the above non-coupling part [mm]

[0102] L2: Length of the above exterior film [mm]

[0103] In this way, the non-coupling portion (47) having a length (L1) defined according to [Equation 2] can be used to secure minimum strength for the frame supporting the secondary battery (1) when the secondary battery (1) is subsequently housed in a battery pack. In other words, the secondary battery (1) can be stably supported on the frame by the first type coupling portion (46) provided on both sides in the longitudinal direction (Y-axis direction) of the non-coupling portion (47).

[0104] Meanwhile, referring again to FIG. 2 and FIG. 4 to 7, the outer film (40) of a secondary battery (1) according to one embodiment of the present invention may include a second type coupling part (48). The second type coupling part (48) may be configured to combine the first and second edge parts (44a, 44b) together with the first type coupling part (46).

[0105] In this embodiment, the second type joint (48) can be formed by a sealing process using heat or pressure. The second type joint (48) can be made of a resin material that can be solidified after being melted by heat or pressure. The sealing process can be performed at a lower temperature than the welding process that forms the first type joint (46). For example, the temperature of the sealing process can be around 200 degrees.

[0106] This second type of joint (48) can be formed by solidifying the sealant layer of the exterior film (40) after it has been partially melted. However, the process by which the second type of joint (48) is formed or the material forming it is not particularly limited as long as it can join the first and second edge portions (44a, 44b).

[0107] In this embodiment, the second type coupling part (48) may be extended in the longitudinal direction (X-axis direction) of the electrode assembly (10). The second type coupling part (48) may be parallel to the line formed by the first type coupling part (46) and the non-coupling part (47).

[0108] At this time, the second type connecting part (48) can connect the first and second edge parts (44a, 44b) together in the length direction (X-axis direction). Accordingly, the second type connecting part (48) can effectively prevent the electrolyte from leaking out of the receiving space (S).

[0109] Meanwhile, in this embodiment, the second type coupling part (48) may be located inside the first type coupling part (46). Here, the fact that the second type coupling part (48) is located inside the first type coupling part (46) may mean that the distance between the connecting part where the receiving part (42) and the edge part (44) are connected and the second type coupling part (48) is shorter than the distance between the connecting part and the first type coupling part (46) based on the circumferential direction.

[0110] This configuration may be for effective insulation between the electrode assembly (10) and the outer film (40) in the receiving space (S). More specifically, it is preferable that the inner surface of the receiving portion (42) (or the inner wall of the receiving space (S)) be provided with a configuration for insulating the electrode assembly (10) and the outer film (40). This configuration may be a sealant layer of the outer film (40).

[0111] This sealant layer can be extended from the first and second edge portions (44a, 44b) of the receiving portion (42) to the area where the second type joint portion (48) is provided. This is because the second type joint portion (48) can be made of a sealant layer that has been melted and then solidified. As a result, insulation by the sealant layer can be effectively achieved even on the periphery side of the receiving portion (42).

[0112] Contrary to the present embodiment, if the first type coupling part (46) is located inside the second type coupling part (48), the possibility of insulation breakdown on the periphery side of the receiving part (42) may be slightly higher. This is because the first type coupling part (46) may be made of metal formed by a welding process, and a part of this metal may be exposed to the receiving space (S).

[0113] Of course, if the distance between the first type coupling part (46) and the receiving part (42) is sufficient to maintain insulation, the first type coupling part (46) may be positioned inside the second type coupling part (48).

[0114] At this time, the breaking force of the second type joint (48) may be smaller than the breaking force of the first type joint (46). Here, the fact that the breaking force of the second type joint (48) is smaller than that of the first type joint (46) may mean that the second type joint (48) breaks at a lower pressure or temperature.

[0115] Generally, the second type joint (48) formed by the sealing process may have a smaller breaking force than the first type joint (46) formed by the welding process. This configuration may be intended to allow flames or gases to be guided toward the non-joint (47) side by maintaining the bonding force of the first type joint (46) even when the temperature or pressure rises to the point where the second type joint (48) breaks.

[0116] As previously explained, in a secondary battery (1) according to one embodiment of the present invention, a non-coupling portion (47) that can function as a passage for gas or flame is provided between the first and second edge portions (44a, 44b), so that the direction of discharge of gas or flame can be effectively controlled in abnormal situations.

[0117] In particular, in this embodiment, the length (L1) of the non-coupling part (47) is defined by the aforementioned [Equation 1] and / or [Equation 2], so the direction of discharge of gas or flame can be controlled more accurately.

[0118] Hereinafter, a secondary battery according to another embodiment of the present invention will be described.

[0119] FIG. 8 is a plan view of a secondary battery according to another embodiment of the present invention. In this case, the portion equipped with the first and second type coupling portions is indicated as a hatched area. At this time, the differences from the secondary battery according to the first embodiment of the present invention described above will be described in detail.

[0120] FIG. 8 discloses a secondary battery according to another embodiment of the present invention. Referring to FIG. 8, the non-coupling portion (147) of the secondary battery (101) according to another embodiment of the present invention may be composed of a plurality of portions.

[0121] In this embodiment, a plurality of non-coupling portions (147) may be arranged in the longitudinal direction (X-axis direction) of the electrode assembly. Among the plurality of non-coupling portions (147), a first type coupling portion (146) may be provided between adjacent non-coupling portions (147).

[0122] In this embodiment, the distance (d) between adjacent non-coupling parts (147) among a plurality of non-coupling parts (147) may be 60 mm or more. As a result, the first type coupling part (146) provided between adjacent non-coupling parts (147) can generate sufficient coupling force.

[0123] Therefore, additional breakage between adjacent non-connected parts (147) and the release of gas or flame in an unexpected direction can be prevented. At this time, the distance (d) may increase or decrease depending on the electrical capacity of the secondary battery (101). For example, the distance (d) may increase or decrease in proportion to the electrical capacity of the secondary battery (101).

[0124] Meanwhile, a battery box according to one embodiment of the present invention may include packaging and a secondary battery. In this case, the secondary battery may be a secondary battery (1, 101) according to the embodiment of the present invention described above (shown in FIG. 1 and FIG. 8). The secondary battery may be composed of a plurality of units.

[0125] In this embodiment, the secondary battery may be housed in a package. The package may be configured to protect the secondary battery from external shock or contamination. To this end, the package may have an enclosure shape with a predetermined space inside. However, the structure or shape of the package is not particularly limited as long as it can house and protect the secondary battery.

[0126] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0127] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0128] [Explanation of the symbol]

[0129] 1, 101: Secondary battery 10: Electrode assembly

[0130] 20: Cap 22: Cover part

[0131] 24: Extension part 26: Connection part

[0132] 30: Terminal 32: Body part

[0133] 34: Lateral catch 36: Inner catch

[0134] 40, 140: Exterior film 42: Receiving part

[0135] 44: Border section 44a: First border section

[0136] 44b: Second rim portion 46, 146: First type connecting portion

[0137] 47, 147: Non-joining part 48: Type 2 joining part

[0138] S: Accommodation space

Claims

1. Electrode assembly extended in one direction; A cap covering one side in the extension direction of the electrode assembly; and It includes an outer film that wraps the other side of the electrode assembly, and The above exterior film is, A receiving portion surrounding the above electrode assembly in a circumferential direction; First and second edge portions extending from one side and the other side of the above-mentioned receiving portion and overlapping each other; A first type coupling part provided along the above-mentioned direction to combine the first and second edge parts; and It includes a non-coupling portion extending in a direction parallel to the first type coupling portion between the first and second edge portions, and The length (L1) of the above-mentioned non-coupling portion is a secondary battery defined by the following [Formula 1]. [Equation 1] C + 170 ≤ L1 L1: Length of the above non-coupling part [mm] C: Electric capacity of the above secondary battery [Ah] 2. In Paragraph 1, The length (L1) of the above-mentioned non-coupling portion is a secondary battery defined by the following [Equation 2]. [Equation 2] L1 ≤ L2 - 40 L2: Length of the above exterior film [mm] 3. In Paragraph 2, The length (L2) of the above exterior film is a length measured along the above one direction, a secondary battery.

4. In Paragraph 1, The above non-coupling part is composed of a plurality of parts, and The above plurality of non-coupling parts are arranged along the above one direction, forming a secondary battery.

5. In Paragraph 4, A secondary battery in which the distance between adjacent non-coupled parts among the plurality of non-coupled parts is 60 mm or more.

6. In Paragraph 1, The above-mentioned first type coupling part is a secondary battery made of a metal material.

7. In Paragraph 6, The above-mentioned first type joint is a secondary battery formed by a welding process.

8. In Paragraph 1, The above exterior film is, A secondary battery comprising a second type coupling portion that extends parallel to at least one of the first type coupling portion and the non-coupling portion and combines the first and second edge portions.

9. In Paragraph 8, The above second type coupling part is a secondary battery located inside the above first type coupling part.

10. In Paragraph 8, The above second type coupling part is made of a different material from the above first type coupling part, in a secondary battery.

11. In Paragraph 8, The above-mentioned second type coupling part is a secondary battery made of a resin material.

12. In Paragraph 11, The above-mentioned second type joint is a secondary battery formed by a sealing process using heat or pressure.

13. In Paragraph 8, A secondary battery in which the breaking force of the second type of joint is smaller than the breaking force of the first type of joint.

14. In Paragraph 1, The above caps are provided in pairs and each cover both sides in the extension direction of the electrode assembly, in a secondary battery.

15. In Paragraph 1, The above cap is a secondary battery that is combined with the above exterior film.

16. In Paragraph 1, The above electrode assembly further includes a terminal for energizing the outside, and The above terminal is a secondary battery that is coupled through the above cap.

17. Packaging; and It includes a secondary battery accommodated in the above packaging, and The above secondary battery is, Electrode assembly extended in one direction; A cap covering one side in the extension direction of the electrode assembly; and It includes an outer film that wraps the other side of the electrode assembly, and The above exterior film is, A receiving portion surrounding the above electrode assembly in a circumferential direction; First and second edge portions extending from one side and the other side of the above-mentioned receiving portion and overlapping each other; A first type coupling part provided along the above-mentioned direction to combine the first and second edge parts; and It includes a non-coupling portion extending in a direction parallel to the first type coupling portion between the first and second edge portions, and The length (L1) of the above-mentioned non-coupling portion is a battery box defined by the following [Formula 1]. [Equation 1] C + 170 ≤ L1 L1: Length of the above non-coupling part [mm] C: Electric capacity of the above secondary battery [Ah]

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