Secondary battery

Abstract

A secondary battery according to an embodiment of the present document may comprise: an electrode assembly; a support frame surrounding a portion of the electrode assembly; a sheet-type exterior material which surrounds the rest of the electrode assembly to form an accommodation space for accommodating the electrode assembly, together with the support frame, and is coupled to the support frame such that the accommodation space is partitioned from the outside of the support frame; and electrode terminals electrically connected to electrode tabs of the electrode assembly and arranged to be in the sheet-type exterior material and exposed outside the sheet-type exterior material.

Description

secondary battery

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0109210, filed August 21, 2023, and Korean Patent Application No. 10-2024-0111561, filed August 20, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments of this document relate to secondary batteries.

[0005] In general, secondary batteries are batteries that can be recharged, unlike primary batteries that cannot be recharged, and are widely used in electronic devices such as cell phones, laptops, camcorders, and electric vehicles.

[0006] Secondary batteries can be classified into cylindrical or prismatic batteries in which the electrode assembly is built into a cylindrical or prismatic metal can, and pouch-type batteries in which the electrode assembly is built into a pouch-type case of a laminate sheet, depending on the shape of the battery case.

[0007] Fig. 1 is a drawing illustrating an example of a pouch-type secondary battery. The pouch-type secondary battery (1, pouch-type cell) includes an electrode assembly (2) formed by alternately stacking electrodes and separators, and a pouch-type outer case (20) in which the electrode assembly (2) is accommodated. Electrode tabs (15) may be connected to the electrodes of the electrode assembly (2), respectively. The electrode tabs (15) may be welded to each other in a predetermined region and then connected to an electrode lead (17) by welding. The outer case (20) includes a receiving portion (21; cup portion) for accommodating the electrode assembly (2). The receiving portion (21) of the outer case (20) may be formed by one or two concave-shaped portions. Fig. 1 illustrates an example of a receiving portion (21) formed by two concave-shaped portions. Such an outer case (20) may be manufactured by forming a pouch film. A sealing portion (23) is formed around the periphery of the receiving portion (21) by sealing.

[0008] Meanwhile, the depth of the cup portion formed into the pouch film is limited by the material properties of the pouch film. Consequently, it is difficult to form the cup portion deep enough to increase battery capacity, and the material and thickness of the pouch film must be selected with restrictions. As the pouch film thickness decreases during cup portion forming, defects such as cracks can easily occur in the outer packaging.

[0009] The embodiments of this document are intended to provide a secondary battery that can solve various problems that occur in the process of forming a cup portion for accommodating an electrode assembly.

[0010] In one example, a secondary battery may include an electrode assembly, a support frame surrounding a portion of the electrode assembly, a sheet-like outer covering material that surrounds the remainder of the electrode assembly to form a receiving space for accommodating the electrode assembly together with the support frame, the receiving space being separated from the exterior of the support frame, and an electrode terminal that is electrically connected to an electrode tab of the electrode assembly and is disposed on the sheet-like outer covering material so as to be exposed to the exterior of the sheet-like outer covering material.

[0011] In another example, the support frame may include a support side wall that forms an upper opening along the height direction, when the direction in which the electrodes of the electrode assembly are stacked is referred to as a height direction, and a direction orthogonal to the height direction is referred to as a side direction, and further surrounds the side surfaces of the electrode assembly defined along the side direction, and the sheet-shaped outer material may include an outer material sheet that is bonded to an upper surface of the support side wall defined along the height direction and covers the upper opening formed by the support side wall.

[0012] In another example, the support frame may be formed in a C shape, wherein the direction in which the electrodes of the electrode assembly are stacked is referred to as the height direction, and the direction perpendicular to the height direction is referred to as the side direction, and the support frame may include a support side wall that surrounds a portion of the side surfaces of the electrode assembly defined along the side direction, such that the support side wall is formed in a C shape that forms an upper opening along the height direction and also forms a side opening along the side direction, and the sheet-shaped outer material may include an outer material sheet that is bonded to the support side wall and covers the upper opening and the side opening formed by the support side wall.

[0013] In another example, the support frame may be formed of a plastic material, and the sheet-shaped outer material may include a metal layer and a resin layer disposed on the inner surface of the metal layer and fused to the support frame.

[0014] In another example, the support frame may be formed of a metal material, and the sheet-shaped exterior material may include a metal layer and a resin layer disposed on the inner surface of the metal layer and bonded to the support frame.

[0015] In another example, one surface of the support frame coupled with the sheet-like exterior material may be surface-treated to improve bonding with the sheet-like exterior material.

[0016] In another example, the support frame may be formed of a metal material, and the sheet-shaped exterior material may include a metal layer that is welded to the support frame.

[0017] In another example, the secondary battery may further include an adhesive disposed between the support frame and the sheet-like outer covering material to bond the support frame and the sheet-like outer covering material.

[0018] In another example, the electrode terminal may include a terminal metal layer as part of a metal layer of the sheet-like outer material, which is exposed to the inside of the receiving space on the inner side and electrically connected to the electrode tab, and which is exposed to the outside of the sheet-like outer material on the outer side.

[0019] In another example, the terminal metal layer may be disposed on one surface of the sheet-like outer material surrounding the upper or lower surface of the electrode assembly defined along the height direction in which the electrodes of the electrode assembly are stacked, but may not overlap the electrode assembly when projected in the height direction.

[0020] In another example, the sheet-shaped outer material may include the metal layer and a resin layer that covers at least one of the inner and outer surfaces of the metal layer, but does not cover the terminal metal layer.

[0021] In another example, the electrode terminal may include a terminal metal layer as part of a metal layer of the sheet-like outer material, the terminal metal layer being exposed from the inner side to the inner side of the receiving space and electrically connected to the electrode tab, and an exposed member electrically connected to the terminal metal layer, but disposed on the outer side of the terminal metal layer and exposed to the outer side of the sheet-like outer material.

[0022] In another example, the sheet-shaped exterior material may include the metal layer and a resin layer that covers the outer surface of the metal layer but does not cover the terminal metal layer, thereby forming an exposure hole exposing the terminal metal layer to the outside of the sheet-shaped exterior material, and the exposure member may include a connecting portion disposed in the exposure hole and electrically connected to the terminal metal layer, and an extension portion that extends parallel to the sheet-shaped exterior material from the connecting portion on the outside of the sheet-shaped exterior material and overlaps the resin layer surrounding the exposure hole.

[0023] In another example, the sheet-shaped exterior material may include an exposure hole exposing the receiving space to the outside of the sheet-shaped exterior material, and the electrode terminal may be disposed to penetrate the exposure hole, and may include an exposure member that is exposed to the inside of the receiving space at one end and electrically connected to the electrode tab, and is exposed to the outside of the sheet-shaped exterior material at the other end.

[0024] In another example, the exposure member may include a body portion that extends in a direction perpendicular to the sheet-like exterior material and is arranged in the exposure hole, an inner extension portion that extends from an inner end positioned on the inner side of the sheet-like exterior material among the ends of the body portion to the outer side of the exposure hole in parallel to the sheet-like exterior material, and an outer extension portion that extends from an outer end positioned on the outer side of the sheet-like exterior material among the ends of the body portion to the outer side of the exposure hole in parallel to the sheet-like exterior material.

[0025] In another example, a sealant layer may be disposed between the inner extension portion and the inner surface of the sheet-shaped exterior material facing it, and between the outer extension portion and the outer surface of the sheet-shaped exterior material facing it.

[0026] In another example, the exposed member may include an inner body portion, at least a portion of which is exposed to the inside of the receiving space, and an outer body portion, which is provided separately from the inner body portion and detachably connected to the inner body portion, but at least a portion of which is exposed to the outside of the sheet-like outer material.

[0027] In another example, the electrode assembly includes a first electrode assembly and a second electrode assembly laminated on the first electrode assembly, and a first electrode tab of the first electrode assembly and a second electrode tab of the second electrode assembly having the same polarity as the first electrode tab can be coupled to the electrode terminal while being spaced apart from each other.

[0028] According to one embodiment of the present document, since a sheet-shaped outer material can be prepared without forming a cup portion for accommodating an electrode assembly, the battery capacity can be easily increased by increasing the size of the support frame, the material and thickness of the sheet-shaped outer material can be selected relatively freely, and defects such as cracks can be less likely to occur.

[0029] In addition, according to one embodiment of the present document, when the secondary battery is projected in the direction in which the electrodes of the electrode assembly are stacked, the electrode terminals do not extend outside the support frame, so that the installation volume of the secondary battery can be minimized, thereby improving the volumetric energy density of the secondary battery.

[0030] Moreover, according to one embodiment of the present document, planar contact is possible between the support frame and the sheet-like exterior material, so that the support frame and the sheet-like exterior material can be strongly bonded as a whole.

[0031] Figure 1 is a drawing illustrating an example of a pouch-type secondary battery.

[0032] Figure 2 is a perspective view illustrating a secondary battery according to Example 1 of this document.

[0033] Figure 3 is an exploded perspective view of the secondary battery of Figure 2.

[0034] Fig. 4 is a cross-sectional view showing the laminated structure of the sheet-shaped outer material of the secondary battery of Fig. 2.

[0035] Figure 5 is a perspective view illustrating another type of secondary battery in contrast to the secondary battery of Figure 2.

[0036] Fig. 6 is a cross-sectional view showing a modified example of the laminated structure of the sheet-shaped exterior material of Fig. 4.

[0037] Fig. 7 is a cross-sectional view along line AA of the secondary battery of Fig. 2.

[0038] Fig. 8 is a cross-sectional view illustrating a first modified example of the secondary battery of Fig. 2.

[0039] Fig. 9 is a cross-sectional view illustrating a second modified example of the secondary battery of Fig. 2.

[0040] Fig. 10 is a perspective view illustrating a third modified example of the secondary battery of Fig. 2.

[0041] Figure 11 is an exploded perspective view illustrating a secondary battery according to Example 2 of this document.

[0042] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0043] 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.

[0044] 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.

[0045] Example 1

[0046] FIG. 2 is a perspective view illustrating a secondary battery (100) according to Embodiment 1 of the present document, and FIG. 3 is an exploded perspective view of the secondary battery (100) of FIG. 2. The secondary battery (100) according to Embodiment 1 of the present document may include an electrode assembly (110), a support frame (120), a sheet-shaped outer material (130), and an electrode terminal (140), as illustrated in FIGS. 2 and 3. Hereinafter, the secondary battery (100) of the present embodiment will be described in detail with reference to FIG. 3. For reference, the contents of Embodiment 1 may be equally applied to the embodiments described below, as long as they do not conflict with each other.

[0047] electrode assembly

[0048] The electrode assembly (110) may be formed by alternately stacking electrodes and separators. The electrodes may include a positive electrode and a negative electrode. The electrode assembly (110) may be provided with electrode tabs (111) connected to the electrodes. The electrode tabs (111) may be provided separately or may be provided as part of a current collector constituting the electrode. For reference, if the electrode assembly (110) is an all-solid-state battery, a solid electrolyte may be provided instead of a separator.

[0049] Support frame

[0050] A support frame (120) may be provided to support the structure of a secondary battery (100) according to the present embodiment. To this end, the support frame (120) may be provided to have greater rigidity than a sheet-shaped outer material (130) to be described later.

[0051] The support frame (120) may surround a portion of the electrode assembly (110). FIG. 3 illustrates a support frame (120) surrounding side surfaces of the electrode assembly (110), which is a portion of the electrode assembly (110). The upper and lower surfaces of the remaining electrode assembly (110) may be surrounded by a sheet-like outer material (130). Here, the upper and lower surfaces of the electrode assembly (110) may be defined along a height direction (D1), which is a direction in which electrodes of the electrode assembly (110) are stacked. The side surfaces of the electrode assembly (110) may be defined along a side direction (D2), which is a direction orthogonal to the height direction (D1). The side direction (D2) may refer to various directions orthogonal to the height direction (D1).

[0052] The support frame (120) may include a support side wall (121). The support side wall (121) may be a member having a predetermined thickness (t) along the lateral direction (D2) and a predetermined height (h) along the height direction (D1). The support side wall (121) may include four side walls (121a, 121b, 121c, 121d), and may form an upper opening (122a) at the upper side in the height direction (D1), and may also form a lower opening (122b) at the lower side. In addition, the support side wall (121) may entirely surround the side surfaces of the electrode assembly (110). In this way, the support side wall (121) is formed in a frame shape, and may entirely surround the side surfaces of the electrode assembly (110) in addition to the upper and lower surfaces of the electrode assembly (110).

[0053] However, the shape of the support frame (120) is not limited to the shape described above. For example, the support frame (120) may further include a support side plate (not shown) that covers the lower opening (122b). That is, the support frame (120) may be formed in a shape that forms only the upper opening (122a). Alternatively, the support side wall (121) of the support frame (120) may be formed in a curved shape rather than a straight shape as in FIG. 3. For reference, in this document, upper and lower, or left and right, are relative concepts that may vary depending on the viewing direction.

[0054] Meanwhile, the support frame (120) may include an electrolyte injection hole (123) for injecting an electrolyte into a receiving space (S) to be described later. Through this, an electrolyte injection process and a post-activation degassing process can be performed. For example, when the secondary battery (100) is placed so that one side (121a) of the support frame (120) where the electrolyte injection hole (123) is provided faces upward, the electrolyte can be injected into the receiving space (S) through the electrolyte injection hole (123). In the degassing process, the internal gas can be discharged through the open electrolyte injection hole (123). After the electrolyte injection and degassing, the electrolyte injection hole (123) can be closed by sealing or welding. Alternatively, a valve (not shown) that can be opened and closed can be installed in the electrolyte injection hole (123) so that the electrolyte injection hole (123) can be opened only when necessary.

[0055] In the past, a pouch-type outer packaging material had a storage portion for accommodating an electrode assembly (110) and a pocket portion for accommodating gas generated during activation. After the gas in the pocket portion was discharged through a degassing process, the pocket portion was removed. This resulted in a problem in that some of the pouch-type outer packaging material was always discarded. However, if an electrolyte injection hole (123) is provided, electrolyte injection and degassing can be performed through the electrolyte injection hole (123), thus preventing the above-mentioned waste of the outer packaging material.

[0056] Sheet-type exterior material

[0057] The sheet-shaped outer covering (130) may be a sheet including a metal layer (131a), as illustrated in FIG. 4. FIG. 4 is a cross-sectional view illustrating the laminated structure of the sheet-shaped outer covering (130) of the secondary battery (100) of FIG. 2. The metal layer (131a) may include a layer of aluminum or a layer of stainless steel.

[0058] The sheet-shaped exterior material (130) may be a laminate sheet further including a resin layer laminated on a metal layer (131a). The sheet-shaped exterior material (130) may include a first resin layer (131b) disposed on the inner surface of the metal layer (131a). The first resin layer (131b) may be a layer formed of polypropylene (PP). Since the first resin layer (131b) may require high insulation and corrosion resistance, the first resin layer (131b) may be formed of another resin that satisfies these requirements. The sheet-shaped exterior material (130) may include a second resin layer (131c) disposed on the outer surface of the metal layer (131a). The second resin layer (131c) may be a layer formed of polyethylene terephthalate (PET). Since the second resin layer (131c) may be required to secure protection and insulation of the secondary battery (100), the second resin layer (131c) may be formed of another resin that satisfies these requirements.

[0059] As illustrated in FIG. 3, the sheet-shaped outer covering (130) can surround the remainder of the electrode assembly (110) that is not surrounded by the support frame (120), thereby forming a receiving space (S) that accommodates the electrode assembly (110) together with the support frame (120). FIG. 3 illustrates two outer covering sheets (131, 132) that cover the upper opening (122a) and the lower opening (122b) formed by the support frame (120), respectively, to surround the upper and lower surfaces of the electrode assembly (110) that are not surrounded by the support frame (120). The outer covering sheets (131, 132) may be outer films. In this way, the sheet-shaped exterior material (130) may include two exterior material sheets (131, 132) that cover the upper opening (122a) and the lower opening (122b) of the support frame (120), respectively. If the support frame (120) forms only one of the upper opening (122a) and the lower opening (122b), the sheet-shaped exterior material (130) may also include only one exterior material sheet correspondingly. The exterior material sheets (131, 132) may include a metal layer (131a), or may include a metal layer (131a) and a resin layer (131b, 131c).

[0060] The sheet-shaped outer material (130) can be coupled to the support frame (120) to partition the accommodation space (S) for accommodating the electrode assembly (110) from the outside of the secondary battery (100). For example, when the sheet-shaped outer material (130) is coupled to the support frame (120) to cover the upper opening (122a) and the lower opening (122b) of the support frame (120) while the electrode assembly (110) is arranged on the inside of the support frame (120), the accommodation space (S) in which the electrode assembly (110) is accommodated can be separated from the outside of the secondary battery (100). When the accommodation space (S) is filled with an electrolyte, the sheet-shaped outer material (130) can be sealedly coupled to the support frame (120). This can prevent leakage of the electrolyte.

[0061] Meanwhile, conventionally, a cup portion for accommodating an electrode assembly was formed on an outer sheet, and the cup portion was sealed with another outer sheet, thereby housing the electrode assembly in a pouch-shaped outer sheet (see Fig. 1). However, the molding depth of the cup portion was limited due to the material properties of the pouch-shaped outer sheet, making it difficult to form the cup portion deeply enough to increase battery capacity, and also requiring a limited selection of materials and thickness for the pouch-shaped outer sheet. In addition, as the thickness of the pouch-shaped outer sheet decreased during the molding of the cup portion, defects such as cracks were likely to occur in the pouch-shaped outer sheet.

[0062] In contrast, in the case of the secondary battery (100) of the present embodiment, after the electrode assembly (110) is placed within the support frame (120), the electrode assembly (110) can be accommodated by covering the openings (122a, 122b) of the support frame (120) with a sheet-shaped outer material (130) without molding of the cup portion, so that the above limitations or defects may not occur. Accordingly, the battery capacity can be easily increased by increasing the size of the support frame (120), the material and thickness of the sheet-shaped outer material (130) can be selected relatively freely, and defects such as cracks may not easily occur.

[0063] However, as a battery using a sheet-shaped outer material (130) without a cup-shaped molding, a battery illustrated in FIG. 5, that is, a battery including a cover member (120') and a sheet-shaped outer material (130'') can be considered. FIG. 5 is a perspective view illustrating another type of secondary battery in contrast to the secondary battery (100) of FIG. 2. In the battery of FIG. 5, the sheet-shaped outer material (130'') can be rolled or folded multiple times to form an internal space for accommodating an electrode assembly (110) and an outer material opening for communicating the internal space with the outside. The cover member (120') can be a member that sealingly covers the outer material opening of the sheet-shaped outer material (130'').

[0064] In the case of such a battery, the sheet-shaped outer covering (130'') must be bonded to the cover member (120') along the edge of the cover member (120'). To this end, it may be necessary to press the sheet-shaped outer covering (130'') toward the cover member (120'). However, since it is not easy to press the sheet-shaped outer covering (130'') toward the corner (A) of the cover member (120'), the bond between the cover member (120') and the sheet-shaped outer covering (130'') may be weakened at the corner (A) of the cover member (120'). Since this weak bond causes a decrease in sealing properties, it may cause leakage of the electrolyte when the inside of the battery is filled with the electrolyte.

[0065] In contrast, in the secondary battery (100) of the present embodiment, the support frame (120) and the sheet-shaped outer material (130) can be strongly bonded together as a whole. As illustrated in FIG. 3, the outer material sheets (131, 132) of the present embodiment can be bonded to the upper surface (121e) or the lower surface (121f) of the support side wall (121). Since the outer material sheets (131, 132) can be brought into planar contact with the upper surface (121e) or the lower surface (121f) of the support side wall (121) facing thereto, the outer material sheets (131, 132) can be uniformly pressed together as a whole against the upper surface (121e) or the lower surface (121f) of the support side wall (121). Through this, a strong bond can be formed between the outer material sheets (131, 132) and the support side wall (121). For reference, the upper surface (121e) or lower surface (121f) of the support side wall (121) may be one surface of the support side wall (121) defined along the height direction (D1) or the opposite direction thereof.

[0066] Combination of support frame and sheet-type exterior material

[0067] The support frame (120) may be formed of a plastic material. The sheet-shaped exterior material (130) may include a metal layer (131a) and a resin layer (131b) disposed on the inner surface of the metal layer (131a), as illustrated in FIG. 4. In this case, the support frame (120) and the resin layer (131b) of the sheet-shaped exterior material (130) may be bonded together through heat fusion. The resin layer (131b) may be a layer formed of polypropylene (PP). A sealant layer (not illustrated) may be formed on a portion of the support frame (120) that is bonded to the sheet-shaped exterior material (130) to improve bonding properties with the sheet-shaped exterior material (130). The sealant layer may be a layer formed of polypropylene (PP).

[0068] The support frame (120) may be formed of a metal material. The sheet-shaped exterior material (130) may include a metal layer (131a) and a resin layer (131b) disposed on the inner surface of the metal layer (131a). The sheet-shaped exterior material (130) may be bonded to the support frame (120) through heat fusion. A surface treatment may be applied to one surface of the support frame (120) to be bonded to the sheet-shaped exterior material (130) to improve bonding properties with the sheet-shaped exterior material (130). For example, a chemical treatment such as a chromate treatment may be applied to one surface of the support frame (120). Alternatively, fine unevenness may be formed on one surface of the support frame (120). The resin layer (131b) of the sheet-shaped exterior material (130) may be a layer formed of polyphthalamide (PPA) having excellent bonding properties with metal. A sealant layer (not shown) may be formed on a portion of the support frame (120) that is coupled to the sheet-shaped exterior material (130). The sealant layer may be a layer formed of polypropylene (PP). The support frame (120) may have a structure formed of a metal frame, or may have a structure in which a sealant layer is coated or applied to a metal frame. The support frame (120) may also have a multilayer structure including a metal layer and a sealant layer laminated thereon. The metal frame or metal layer may be effective in preventing external moisture from penetrating into the interior.

[0069] The support frame (120) made of a metal material may be joined to the sheet-shaped exterior material (130') by welding. For this purpose, the sheet-shaped exterior material (130') may include a metal layer (131a') that is joined to the support frame (120) by welding, as illustrated in FIG. 6. FIG. 6 is a cross-sectional view illustrating a modified example of the laminated structure of the sheet-shaped exterior material (130) of FIG. 4. At this time, the metal layer (131a') may include a layer of stainless steel. If the resin layer (131b') on the inner surface of the metal layer (131a') interferes with welding, as illustrated in FIG. 6, the resin layer (131b') formed at the portion joined to the support frame (120) may be removed, or the resin layer (131b') may not be formed at the corresponding portion. Alternatively, the resin layer may not be formed entirely on the inner surface of the metal layer (131a').

[0070] An adhesive (not shown) may be provided between the support frame (120) and the sheet-shaped exterior material (130) to improve bonding between the support frame (120) and the sheet-shaped exterior material (130).

[0071] electrode terminal

[0072] The electrode terminal (140) may be a member for electrical connection with another device. For this purpose, the electrode terminal (140) may be made of an electrically conductive material. As illustrated in FIGS. 3 and 7, the electrode terminal (140) may be disposed on the sheet-shaped outer material (130) so as to be exposed to the outside of the sheet-shaped outer material (130; 131, 132). Only a portion of the electrode terminal (140) may be exposed to the outside of the sheet-shaped outer material (130). The electrode terminal (140) may be electrically connected to the electrode tab (111) of the electrode assembly (110), as illustrated in FIG. 7. The electrical connection may include both a direct connection and an indirect connection via another electrically conductive member. The electrode tabs (111) may be welded to each other in a predetermined area and then connected to the electrode terminal (140) by welding. Fig. 7 is a cross-sectional view along line AA of the secondary battery (100) of Fig. 2. The electrode terminal (140) may include a positive terminal connected to the positive tab of the electrode assembly (110) and a negative terminal connected to the negative tab of the electrode assembly (110).

[0073] Since the electrode terminal (140) of the present embodiment is arranged on the sheet-shaped outer material (130; 131, 132), the volumetric energy density of the battery can be improved. When the secondary battery (100) is projected in the height direction (D1), which is the direction in which the electrodes of the electrode assembly (110) are stacked, if the electrode terminal (140) extends long toward the outside of the support frame (120), the installation volume required when installing the secondary battery (100) can increase. In the case of the secondary battery (100) of the present embodiment, when the secondary battery (100) is projected in the direction in which the electrodes of the electrode assembly (110) are stacked, the electrode terminal (140) does not extend toward the outside of the support frame (120), so the installation volume of the secondary battery (100) can be minimized.

[0074] Meanwhile, the electrode terminal (140) may include a terminal metal layer (141) electrically connected to the electrode tab (111), as illustrated in FIG. 7. The terminal metal layer (141) may be a part of the metal layer (131a) of the sheet-shaped outer material (130). The metal layer (131a) of the sheet-shaped outer material (130) may be an electrically conductive metal layer, for example, a layer of aluminum.

[0075] The sheet-shaped exterior material (130) may include a first resin layer (131b) disposed on the inner surface of the metal layer (131a). The first resin layer (131b) may cover at least a portion of the inner surface of the metal layer (131a). However, the first resin layer (131b) may not cover the terminal metal layer (141). Accordingly, the terminal metal layer (141) may be exposed from the inner surface of the terminal metal layer (141) to the inner surface of the receiving space (S). The terminal metal layer (141) may be electrically connected to the electrode tab (111) through this exposed portion. When the sheet-shaped exterior material does not include the first resin layer (131b), a portion of the metal layer of the sheet-shaped exterior material may be selected and connected to the electrode tab (111).

[0076] The sheet-shaped exterior material (130) may include a second resin layer (131c) disposed on the outer surface of the metal layer (131a). The second resin layer (131c) may cover at least a portion of the outer surface of the metal layer (131a). However, the second resin layer (131c) may not cover the terminal metal layer (141). Accordingly, the terminal metal layer (141) may be exposed to the outer surface of the sheet-shaped exterior material (130) from the outer surface side of the terminal metal layer (141). The terminal metal layer (141) may be electrically connected to another device through this exposed portion.

[0077] Meanwhile, a portion of the metal layer (131a) of the sheet-shaped exterior material (130) other than the terminal metal layer (141) may not be exposed to the outside of the sheet-shaped exterior material (130). For example, a portion of the metal layer (131a) that may be exposed to the outside of the sheet-shaped exterior material (130) (e.g., a portion located at the far right in FIG. 7) may be covered by another insulating material.

[0078] The terminal metal layer (141) may be disposed on one surface of a sheet-shaped outer material (130) surrounding the upper or lower surface of the electrode assembly (110). FIG. 7 illustrates an example of a terminal metal layer (141) disposed on a sheet-shaped outer material (130) surrounding the upper surface of the electrode assembly (110). The upper and lower surfaces of the electrode assembly (110) may be defined along the height direction (D1), which is the direction in which the electrodes of the electrode assembly (110) are stacked. The terminal metal layer (141) may be disposed so as not to overlap the electrode assembly (110) when projected in the height direction (D1) above. FIG. 7 illustrates an example of a terminal metal layer (141) disposed corresponding to the space between the electrode assembly (110) and the support frame (120) and not overlapping the electrode assembly (110).

[0079] As illustrated in FIG. 3, the positive and negative tabs among the electrode tabs may be connected to the electrode terminal (140) of the upper outer casing (131) and the electrode terminal (140) of the lower outer casing (132), respectively. For example, in FIG. 3, the right tab connected to the electrode terminal (140) of the upper outer casing (131) may be viewed as the positive tab, and the left tab connected to the electrode terminal (140) of the lower outer casing (132) may be viewed as the negative tab. For such an electrical connection, the electrode terminal (140) of the upper outer casing (131) and the electrode terminal (140) of the lower outer casing (132) may not be electrically connected to each other.

[0080] Meanwhile, the electrode terminal (140) can be modified as shown in Fig. 8. Fig. 8 is a cross-sectional view illustrating a first modified example of the secondary battery (100) of Fig. 2.

[0081] The electrode terminal (140') may include a terminal metal layer (141) that is part of the metal layer (131a) of the sheet-shaped outer material (130). The terminal metal layer (141) may be exposed from the inner side of the terminal metal layer (141) to the inner side of the receiving space (S) and may be electrically connected to the electrode tab (111).

[0082] The electrode terminal (140') may include an exposed member (142) disposed on the outer surface side of the terminal metal layer (141) and exposed to the outside of the sheet-shaped exterior material (130). The exposed member (142) may be electrically connected to the terminal metal layer (141). For example, one end of the exposed member (142) may be welded to the outer surface of the terminal metal layer (141). Since the exposed member (142) protrudes further toward the outside of the sheet-shaped exterior material (130) than the terminal metal layer (141), it is easy to make an electrical connection with another device. The exposed member (142) may be provided to correspond to the entire outer surface of the terminal metal layer (141) or to correspond to a portion of the outer surface.

[0083] As described in detail with respect to the sheet-shaped exterior material (130), the sheet-shaped exterior material (130) may include a metal layer (131a) and a resin layer (131c) covering the outer surface of the metal layer (131a). The resin layer (131c) may not cover the terminal metal layer (141) so as to expose the terminal metal layer (141), which is a part of the metal layer (131a), to the outer side of the sheet-shaped exterior material (130). In this way, an exposure hole (H) penetrating the resin layer (131c) may be formed in an area of ​​the resin layer (131c) that does not cover the terminal metal layer (141). The terminal metal layer (141) may be exposed to the outer side of the sheet-shaped exterior material (130) through the exposure hole (H) of the sheet-shaped exterior material (130).

[0084] As described above with respect to the exposed member (142), the exposed member (142) may include a connecting portion (142a) that is placed in the exposed hole (H) and electrically connected to the terminal metal layer (141). The connecting portion (142a) may be formed in a shape that corresponds to the exposed hole (H) and can be placed within the exposed hole (H) or in any shape that can be placed within the exposed hole (H).

[0085] The exposed member (142) may include an extension portion (142b) extending from the connecting portion (142a). The extension portion (142b) may extend from the outside of the sheet-shaped exterior material (130) in a parallel manner to the sheet-shaped exterior material (130) (e.g., in the left-right direction of FIG. 8). In this document, parallel may also include a case where it is generally parallel. In this way, the extension portion (142b) may overlap the resin layer (131c) surrounding the exposure hole (H) on the outside of the sheet-shaped exterior material (130). For example, when projected in a direction orthogonal to the sheet-shaped exterior material (130) (the same direction in which the electrodes of the electrode assembly are laminated in FIG. 8), the extension portion (142b) may overlap the resin layer (131c) on the outside of the sheet-shaped exterior material (130). This can prevent liquid from penetrating into the interior of the secondary battery (100) through the exposure hole (H) from the outside of the secondary battery (100). To enhance this effect, the extension portion (142b) may be provided to entirely cover the resin layer (131c) positioned along the edge of the exposure hole (H). FIG. 8 illustrates an extension portion (142b) extending parallel to the sheet-shaped outer material (130) from the outer end of the connecting portion (142a).

[0086] Meanwhile, the electrode terminal (140) can be modified as shown in Fig. 9. Fig. 9 is a cross-sectional view illustrating a second modified example of the secondary battery (100) of Fig. 2.

[0087] The electrode terminal (140'') may include an exposure member (142') positioned to penetrate the exposure hole (H) of the sheet-shaped exterior material (130). The exposure member (142') may be exposed to the inside of the receiving space (S) at one end (see the lower end in FIG. 9) and may be electrically connected to the electrode tab (111). The exposure member (142') may be exposed to the outside of the sheet-shaped exterior material (130) at the other end (see the upper end in FIG. 9). In the present modified example, the exposure hole (H) of the sheet-shaped exterior material (130) may be formed to expose the receiving space (S) to the outside of the sheet-shaped exterior material (130). To this end, the exposure hole (H) may be formed to penetrate the sheet-shaped exterior material (130). The exposed member (142') may be placed in the exposed hole (H) of the sheet-shaped outer material (130) and may be exposed to both the inside and outside of the secondary battery (100). The exposed member (142') may be placed over the entire exposed hole (H).

[0088] As described in detail about the exposure member (142'), the exposure member (142') may include a body portion (142a') arranged in the exposure hole (H). The body portion (142a') may extend in a direction orthogonal to the sheet-shaped exterior material (130) (same as the height direction in which the electrodes of the electrode assembly are stacked in FIG. 9). In this document, orthogonal may also include a case in which it is generally orthogonal. In this way, the body portion (142a') may include an inner end (see the lower end in FIG. 9) located inside (or exposed inside) of the receiving space (S) and an outer end (see the upper end in FIG. 9) located outside (or exposed outside) of the sheet-shaped exterior material (130). The body portion (142a') may be a member formed in a shape corresponding to the cross-sectional shape of the exposure hole (H) and extending in the above orthogonal direction. However, the cross-sectional shape of the body portion (142a') is not limited thereto. For example, the cross-sectional shape of the body portion (142a') may be any cross-sectional shape that can be positioned within the exposure hole (H). For reference, the body portion (142a') may be formed of two members (142a1, 142a2) that are provided separately and then coupled to each other, as illustrated in FIG. 9.

[0089] The exposed member (142') may include an inner extension portion (142b1) extending from an inner end portion of the body portion (142a'). The inner end portion of the body portion (142a') may be an end of the body portion (142a') located on the inner side of the sheet-shaped exterior material (130). The inner extension portion (142b1) may extend parallel to the sheet-shaped exterior material (130) to the outer side of the exposure hole (H). For example, the inner extension portion (142b1) may extend parallel to the sheet-shaped exterior material (130) from the inner side (e.g., the receiving space) of the sheet-shaped exterior material (130) until it overlaps the resin layer (131b) surrounding the exposure hole (H). One side of the inner extension portion (142b1) facing the inner surface of the sheet-shaped exterior material (130) can be in close contact with the inner surface of the sheet-shaped exterior material (130). This close contact can prevent electrolyte from leaking from the inside of the secondary battery (100) to the outside of the secondary battery (100) through the exposure hole (H). In order to prevent electrolyte leakage, a sealant layer (not shown) can be disposed between the inner extension portion (142b1) and the inner surface of the sheet-shaped exterior material (130) facing it.

[0090] The exposed member (142') may include an outer extension portion (142b2) extending from an outer end portion of the body portion (142a'). The outer end portion of the body portion (142a') may be an end of the body portion (142a') located on the outer side of the sheet-shaped exterior material (130). The outer extension portion (142b2) may extend parallel to the sheet-shaped exterior material (130) to the outer side of the exposure hole (H). For example, the outer extension portion (142b2) may extend parallel to the sheet-shaped exterior material (130) from the outer side of the sheet-shaped exterior material (130) until it overlaps the resin layer (131c) surrounding the exposure hole (H). One side of the outer extension portion (142b2) facing the outer surface of the sheet-shaped exterior material (130) may be in close contact with the outer surface of the sheet-shaped exterior material (130). This kind of sealing can prevent liquid from penetrating into the interior of the secondary battery (100) through the exposure hole (H) from the outside of the secondary battery (100). To prevent liquid from penetrating, a sealant layer (not shown) can be placed between the outer extension portion (142b2) and the outer surface of the sheet-shaped outer material (130) facing it.

[0091] Meanwhile, the exposed member (142') may include an inner body part (143) and an outer body part (144) that is detachably coupled to the inner body part (143). FIG. 9 illustrates an inner body part (143) and an outer body part (144) that are fitted together by having protrusions and grooves, respectively. At least a portion of the inner body part (143) may be exposed to the inside of the sheet-shaped exterior material (130) (e.g., a receiving space). At least a portion of the outer body part (144) may be exposed to the outside of the sheet-shaped exterior material (130). The outer body part (144) may be provided separately from the inner body part (143). FIG. 9 illustrates an inner body portion (143) including a part (142a1) of a body portion (142a') and an inner extension portion (142b1), and an outer body portion (144) including another part (142a2) of the body portion (142a') and an outer extension portion (142b2).

[0092] Meanwhile, the electrode assembly (110) may be modified as shown in FIG. 10. FIG. 10 is a perspective view illustrating a third modified example of the secondary battery (100) of FIG. 2. The electrode assembly (110) may include a first electrode assembly (110a) and a second electrode assembly (110b). The second electrode assembly (110b) may be stacked on the first electrode assembly (110a). The first electrode tab (111a) of the first electrode assembly (110a) and the second electrode tab (111b) of the second electrode assembly (110b) having the same polarity as the first electrode tab (111a) may be coupled to the electrode terminal (140) while being spaced apart from each other. For example, as illustrated in FIG. 10, the negative tab (111a) of the first electrode assembly (110a) and the negative tab (111b) of the second electrode assembly (110b) are connected together to the electrode terminal (140) of the lower outer shell (132), but may be connected to two points of the electrode terminal (140) that are spaced apart from each other.

[0093] It may be considered to increase the height (h) of the support frame (120) and then accommodate a plurality of electrode assemblies within the accommodation space (S), and if the electrode tabs of one electrode assembly and the electrode tabs of another electrode assembly are respectively connected to the electrode terminals, the connection process between the electrode tabs and the electrode terminals may be facilitated rather than first connecting all the electrode tabs of the electrode assemblies and then connecting them to the electrode terminals again.

[0094] Example 2

[0095] Fig. 11 is an exploded perspective view illustrating a secondary battery (200) according to Embodiment 2 of the present document. The secondary battery (200) according to the present embodiment differs from the secondary battery (100) of Embodiment 1 in terms of the support frame and the sheet-shaped outer material, and thus the following description will focus on these differences. Note that the contents of Embodiment 2 may be equally applied to the aforementioned embodiments, as long as they do not conflict with each other.

[0096] A secondary battery (200) according to the present embodiment may include an electrode assembly (110), a support frame (220), a sheet-shaped outer material (230), and an electrode terminal (140), as illustrated in FIG. 11.

[0097] The support frame (220) may include a support side wall (221). When the direction in which the electrodes of the electrode assembly (110) are stacked is referred to as the height direction (D1), and the direction orthogonal to the height direction (D1) is referred to as the lateral direction (D2), the support side wall (221) may form an upper opening (222a) along the height direction (D1) and may also form a lateral opening (222c) along the lateral direction (D2). The support side wall (221) may be formed in an overall C shape. The support side wall (221) may form a lower opening (222b) corresponding to the upper opening (222a). The support side wall (221) may surround some of the side surfaces of the electrode assembly (110). The side surfaces of the electrode assembly (110) may be defined along the lateral direction (D2). In Fig. 11, three of the four sides of the electrode assembly (110) are surrounded by support side walls (221; 221a, 221b, 221c). An electrolyte injection hole (223) may be formed on one side (221a) of the support frame (220).

[0098] The sheet-shaped exterior material (230) may include exterior material sheets (231, 233) that cover an upper opening (222a) and a side opening (222c) formed by a supporting side wall (221). If the supporting side wall (221) also forms a lower opening (222b), the exterior material sheet (232) may also cover the lower opening (222b). FIG. 11 illustrates exterior material sheets (231, 232, 233) that continuously cover an upper opening (222a), a side opening (222c), and a lower opening (222b). That is, an exterior sheet (231) for covering the upper opening (222a), an exterior sheet (233) for covering the side opening (222c), and an exterior sheet (232) for covering the lower opening (222b) can be continuously connected to form an overall C-shape. The exterior sheets (231, 232, 233) can be joined to the supporting side wall (221). The exterior sheets (231, 232, 233) can be joined to the upper surface (221e) and the lower surface (221f) of the supporting side wall (221) defined along the height direction (D1), and to the side surface (221g) of the supporting side wall (221) defined on the side of the side opening (222c) along the lateral direction (D2).

[0099] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0100] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0101] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. Electrode assembly; A support frame surrounding a portion of the electrode assembly; A sheet-shaped outer covering material that surrounds the remainder of the electrode assembly and forms a receiving space for receiving the electrode assembly together with the support frame, and is joined to the support frame so that the receiving space is separated from the outside of the support frame; and A secondary battery comprising an electrode terminal electrically connected to an electrode tab of the electrode assembly and disposed on the sheet-shaped outer covering so as to be exposed to the outside of the sheet-shaped outer covering.

2. In claim 1, The above support frame, When the direction in which the electrodes of the electrode assembly are stacked is referred to as the height direction and the direction orthogonal to the height direction is referred to as the side direction, an upper opening is formed along the height direction and a supporting side wall is included that entirely surrounds the side surfaces of the electrode assembly defined along the side direction. The above sheet-shaped exterior material is, A secondary battery comprising an outer sheet that is bonded to the upper surface of the support side wall defined along the height direction and covers the upper opening formed by the support side wall.

3. In claim 1, The above support frame, When the direction in which the electrodes of the electrode assembly are stacked is referred to as the height direction and the direction orthogonal to the height direction is referred to as the side direction, a C-shaped support side wall is formed that forms an upper opening along the height direction and also forms a side opening along the side direction, and surrounds a part of the side surfaces of the electrode assembly defined along the side direction. The above sheet-shaped exterior material is, A secondary battery comprising an outer sheet that is bonded to the support side wall and covers the upper opening and the side opening formed by the support side wall.

4. In claim 1, The above support frame is formed of a plastic material, A secondary battery, wherein the sheet-shaped outer material includes a metal layer and a resin layer disposed on the inner surface of the metal layer and fused to the support frame.

5. In claim 1, The above support frame is formed of a metal material, A secondary battery, wherein the sheet-shaped outer material includes a metal layer and a resin layer arranged on the inner surface of the metal layer and bonded to the support frame.

6. In claim 5, On one side of the support frame combined with the sheet-shaped exterior material, A secondary battery having a surface treatment to improve bonding with the above sheet-shaped outer material.

7. In claim 1, The above support frame is formed of a metal material, A secondary battery, wherein the sheet-shaped outer material includes a metal layer that is welded to the support frame.

8. In claim 1, A secondary battery further comprising an adhesive disposed between the support frame and the sheet-shaped exterior material to bond the support frame and the sheet-shaped exterior material.

9. In claim 1, The above electrode terminals are, A secondary battery comprising a terminal metal layer as part of a metal layer among the sheet-shaped outer materials, the terminal metal layer being exposed to the inside of the receiving space on the inner side and electrically connected to the electrode tab, and being exposed to the outside of the sheet-shaped outer materials on the outer side.

10. In claim 9, The above terminal metal layer is, A secondary battery, which is arranged on one side of the sheet-shaped outer material surrounding the upper or lower surface of the electrode assembly defined along the height direction in which the electrodes of the electrode assembly are stacked, but does not overlap the electrode assembly when projected in the height direction.

11. In claim 9, The above sheet-shaped exterior material is, A secondary battery comprising a resin layer covering at least one of the inner and outer surfaces of the metal layer and the terminal metal layer, but not covering the terminal metal layer.

12. In claim 1, The above electrode terminals are, As part of the metal layer of the above sheet-shaped outer material, a terminal metal layer exposed from the inner side to the inner side of the receiving space and electrically connected to the electrode tab; and A secondary battery comprising an exposed member electrically connected to the terminal metal layer and disposed on the outer surface side of the terminal metal layer and exposed to the outside of the sheet-shaped outer covering material.

13. In claim 12, The above sheet-shaped exterior material is, It includes a resin layer that covers the metal layer and the outer surface of the metal layer, but does not cover the terminal metal layer, thereby forming an exposure hole that exposes the terminal metal layer to the outside of the sheet-shaped outer material. The above exposed member is, A secondary battery comprising a connecting portion arranged in the above exposure hole and electrically connected to the terminal metal layer, and an extension portion extending parallel to the sheet-shaped outer covering material from the connecting portion on the outside of the sheet-shaped outer covering material and overlapping the resin layer surrounding the exposure hole.

14. In claim 1, The above sheet-shaped exterior material is, Including an exposure hole that exposes the above-mentioned accommodation space to the outside of the sheet-shaped exterior material, The above electrode terminals are, A secondary battery comprising an exposed member disposed to penetrate the above exposure hole, exposed to the inside of the receiving space at one end and electrically connected to the electrode tab, and exposed to the outside of the sheet-shaped outer material at the other end.

15. In claim 14, The above exposed member is, A body portion extending in a direction perpendicular to the sheet-shaped exterior material and arranged in the exposure hole; An inner extension portion extending parallel to the sheet-shaped exterior from the inner end portion located on the inner side of the sheet-shaped exterior material among the ends of the body portion; and A secondary battery, comprising an outer extension portion extending parallel to the sheet-shaped outer material to the outside of the exposure hole at an outer end positioned on the outside of the sheet-shaped outer material among the ends of the body portion on both sides.

16. In claim 15, A secondary battery, wherein a sealant layer is disposed between the inner extension portion and the inner surface of the sheet-shaped outer material facing it, and between the outer extension portion and the outer surface of the sheet-shaped outer material facing it.

17. In claim 14, The above exposed member is, an inner body portion at least partially exposed to the inside of the receiving space; and A secondary battery comprising an outer body portion that is provided separately from the inner body portion and detachably coupled to the inner body portion, at least a portion of which is exposed to the outside of the sheet-shaped outer material.

18. In claim 1, The electrode assembly includes a first electrode assembly and a second electrode assembly laminated on the first electrode assembly, A secondary battery, wherein a first electrode tab of the first electrode assembly and a second electrode tab of the second electrode assembly having the same polarity as the first electrode tab are connected to the electrode terminals while being spaced apart from each other.

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