Secondary batteries

Abstract

A secondary battery according to one embodiment of the present disclosure may include an electrode assembly, a support frame surrounding a part of the electrode assembly, a sheet-like exterior material that surrounds the remaining part of the electrode assembly and forms a housing space for housing the electrode assembly together with the support frame, and is coupled to the support frame such that the housing space is separated from the outside of the support frame, and electrode terminals that are electrically connected to the electrode tabs of the electrode assembly and are arranged on the sheet-like exterior material so as to be exposed to the outside of the sheet-like exterior material.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0109210 filed on August 21, 2023 and Korean Patent Application No. 10-2024-0111561 filed on August 20, 2024, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference in their entirety.

[0002] Embodiments of the present disclosure relate to secondary batteries.

Background Art

[0003] Generally, a secondary battery, unlike a primary battery that cannot be charged, means a battery that can be charged and discharged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, and electric vehicles.

[0004] Secondary batteries are classified into cylindrical batteries or prismatic batteries in which an electrode assembly is built into a cylindrical or prismatic metal can according to the shape of the battery case, and pouch-type batteries in which the electrode assembly is built into a pouch-type case made of a laminate sheet.

[0005] FIG. 1 is a diagram showing 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 laminating electrodes and a separator, and a pouch-type exterior member 20 in which the electrode assembly 2 is accommodated. Electrode tabs 15 may be respectively connected to the electrodes of the electrode assembly 2. The electrode tabs 15 may be welded to each other in a predetermined region and then welded to an electrode lead 17. The exterior member 20 includes a housing portion 21 (cup portion) for accommodating the electrode assembly 2. The housing portion 21 of the exterior member 20 may be formed of one or two recessed-shaped portions. The housing portion 21 formed of two recessed-shaped portions is illustrated in FIG. 1. Such an exterior member 20 may be manufactured by molding a pouch film. A seal portion 23 is formed by sealing around the periphery of the housing portion 21.

[0006] On the other hand, the molding depth of the cup portion formed into the pouch film was limited by the material properties of the pouch film. As a result, it was difficult to mold the cup portion deep enough to increase the battery capacity, and the selection of the material and thickness of the pouch film was also limited. As the thickness of the pouch film decreased during the molding of the cup portion, defects such as cracks were more likely to occur in the outer material. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Embodiments of this disclosure are intended to provide a secondary battery that can solve various problems that arise in the process of forming a cup portion for housing an electrode assembly. [Means for solving the problem]

[0008] In one example, the secondary battery may include an electrode assembly, a support frame surrounding a part of the electrode assembly, a sheet-like exterior material that surrounds the remaining part of the electrode assembly and forms a housing space for housing the electrode assembly together with the support frame, and is coupled to the support frame such that the housing space is separated from the outside of the support frame, and electrode terminals that are electrically connected to the electrode tabs of the electrode assembly and are arranged on the sheet-like exterior material so as to be exposed to the outside of the sheet-like exterior material.

[0009] In another example, the support frame includes a support side wall that forms an upper opening along the height direction and encloses the entire side of the electrode assembly defined along the lateral direction, with the direction in which the electrodes of the electrode assembly are stacked being the height direction and the direction perpendicular to the height direction being the lateral direction, and the sheet-like exterior material may include an exterior material 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.

[0010] In yet another example, the support frame is formed in a C-shape, where the direction in which the electrodes of the electrode assembly are stacked is the height direction, and the direction perpendicular to the height direction is the lateral direction, and it forms an upper opening along the height direction and a side opening along the lateral direction, and includes a support side wall that surrounds a part of the side surface of the electrode assembly defined along the lateral direction, and the sheet-like exterior material may include an exterior 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.

[0011] In yet another example, the support frame may be made of a plastic material, and the sheet-like exterior 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.

[0012] In yet another example, the support frame may be made of a metal material, and the sheet-like 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.

[0013] In yet another example, one surface of the support frame that is coupled to the sheet-like exterior material may be subjected to a surface treatment to improve the bonding with the sheet-like exterior material.

[0014] In yet another example, the support frame may be made of a metal material, and the sheet-like exterior material may include a metal layer that is welded to the support frame.

[0015] In yet another example, the secondary battery may further include an adhesive that is placed between the support frame and the sheet-like exterior material to bond the support frame and the sheet-like exterior material together.

[0016] In yet another example, the electrode terminal may include a terminal metal layer that is part of the metal layer of the sheet-like exterior material, which is exposed on the inner side to the inside of the housing space and electrically connected to the electrode tab, and exposed on the outer side to the outside of the sheet-like exterior material.

[0017] In yet another example, the terminal metal layer is arranged 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, and does not necessarily overlap the electrode assembly when projected in the height direction.

[0018] In yet another example, the sheet-like exterior 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.

[0019] In yet another example, the electrode terminal may include a terminal metal layer which is part of the metal layer of the sheet-like exterior material and is exposed on the inner side to the inside of the housing space and electrically connected to the electrode tab, and an exposed member which is electrically connected to the terminal metal layer and is arranged on the outer surface side of the terminal metal layer and is exposed to the outside of the sheet-like exterior material.

[0020] In yet another example, the sheet-like exterior material includes 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 exposed hole that exposes the terminal metal layer to the outside of the sheet-like exterior material, and the exposed member may include a connecting portion that is placed in the exposed hole and electrically connected to the terminal metal layer, and an extending portion that extends from the connecting portion parallel to the sheet-like exterior material on the outside of the sheet-like exterior material and overlaps the resin layer that surrounds the exposed hole.

[0021] In yet another example, the sheet-like exterior material may include an exposed hole that exposes the housing space to the outside of the sheet-like exterior material, and the electrode terminal may include an exposed member that is positioned to penetrate the exposed hole, exposed to the inside of the housing space at one end and electrically connected to the electrode tab, and exposed to the outside of the sheet-like exterior material at the other end.

[0022] In yet another example, the exposed member may include a body portion that extends in a direction orthogonal to the sheet-like exterior material and is disposed in the exposed hole, an inner extending portion that extends from an inner end portion located inside the sheet-like exterior material among both side end portions of the body portion to the outside of the exposed hole in parallel with the sheet-like exterior, and an outer extending portion that extends from an outer end portion located outside the sheet-like exterior material among both side end portions of the body portion to the outside of the exposed hole in parallel with the sheet-like exterior material.

[0023] In yet another example, a sealant layer may be disposed at least in any one of between the inner extending portion and the inner surface of the sheet-like exterior material facing it, and between the outer extending portion and the outer surface of the sheet-like exterior material facing it.

[0024] In yet another example, the exposed member may include an inner body portion at least partially exposed inside the accommodation space, and an outer body portion provided separately from the inner body portion and separably coupled to the inner body portion, with at least a part thereof exposed outside the sheet-like exterior material.

[0025] In yet another example, the electrode assembly may include 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 may be coupled to the electrode terminal so as to be separated from each other.

Advantages of the Invention

[0026] According to an embodiment of the present disclosure, since the sheet-like exterior material can be provided without forming a cup portion for accommodating the electrode assembly, the battery capacity can be easily increased by increasing the size of the support frame, the selection of the material and thickness of the sheet-like exterior material can be relatively freely made, and defects such as cracks are also less likely to occur.

[0027] Further, according to an embodiment of the present disclosure, 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 and the volume energy density of the secondary battery can be improved.

[0028] Furthermore, according to an embodiment of the present disclosure, since planar contact is possible between the support frame and the sheet-like exterior material, the support frame and the sheet-like exterior material can be strongly bonded as a whole.

Brief Description of the Drawings

[0029] [Figure 1] It is a diagram showing an example of a pouch-type secondary battery. [Figure 2] It is a perspective view showing the secondary battery according to Embodiment 1 of the present disclosure. [Figure 3] It is an exploded perspective view of the secondary battery of FIG. 2. [Figure 4] It is a cross-sectional view showing the laminated structure of the sheet-like exterior material in the secondary battery of FIG. 2. [Figure 5] It is a perspective view showing another type of secondary battery compared with the secondary battery of FIG. 2. [Figure 6] It is a cross-sectional view showing a modified example of the laminated structure of the sheet-like exterior material of FIG. 4. [Figure 7] It is a cross-sectional view taken along line A-A of the secondary battery of FIG. 2. [Figure 8] It is a cross-sectional view showing a first modified example of the secondary battery of FIG. 2. [Figure 9] It is a cross-sectional view showing a second modified example of the secondary battery of FIG. [Figure 10] It is a perspective view showing a third modified example of the secondary battery of FIG. 2. [Figure 11] It is an exploded perspective view showing the secondary battery according to Embodiment 2 of the present disclosure.

Modes for Carrying Out the Invention

[0030] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited to or restricted to the following embodiments.

[0031] In order to clearly explain the present invention, detailed descriptions of parts unrelated to the description or related prior art that may obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in each drawing, the same or similar reference numerals are assigned to components that are the same or similar throughout the specification.

[0032] Furthermore, the terms and words used in this specification and the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather should be interpreted in a manner consistent with the technical concept of the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best explain their invention.

[0033] Embodiment 1 Figure 2 is a perspective view showing a secondary battery 100 according to Embodiment 1 of this disclosure, and Figure 3 is an exploded perspective view of the secondary battery 100 of Figure 2. The secondary battery 100 according to Embodiment 1 of this disclosure may include an electrode assembly 110, a support frame 120, a sheet-like exterior material 130, and electrode terminals 140, as shown in Figures 2 and 3. The secondary battery 100 of this embodiment will be described in detail below, mainly focusing on Figure 3. Note that the contents of Embodiment 1 can also be applied to the embodiments described later, unless they conflict with each other.

[0034] electrode assembly The electrode assembly 110 may be formed by alternately stacking electrodes and a separator membrane. The electrodes may include a positive electrode and a negative electrode. The electrode assembly 110 may also include electrode tabs 111 connected to the electrodes. The electrode tabs 111 may be provided separately or as part of the current collector constituting the electrodes. If the electrode assembly 110 is an all-solid-state battery, a solid electrolyte may be provided instead of a separator membrane.

[0035] Support frame The support frame 120 may be provided to support the structure of the secondary battery 100 according to this embodiment. For this purpose, the support frame 120 may be provided to have greater rigidity than the sheet-like exterior material 130, which will be described later.

[0036] The support frame 120 may surround a portion of the electrode assembly 110. Figure 3 illustrates a support frame 120 surrounding a side surface of the electrode assembly 110, which is a portion of the electrode assembly 110. The remaining portion of the electrode assembly 110, the top and bottom surfaces, may be surrounded by a sheet-like exterior material 130. Here, the top and bottom 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 side surface of the electrode assembly 110 may be defined along the lateral direction D2, which is perpendicular to the height direction D1. The lateral direction D2 can mean various directions perpendicular to the height direction D1.

[0037] 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, and 121d, and may form an upper opening 122a on the upper side and a lower opening 122b on the lower side in the height direction D1. Furthermore, the support side wall 121 may completely surround the side surface of the electrode assembly 110. In this way, the support side wall 121 is formed in a frame shape and can completely surround the side surface of the electrode assembly 110, in addition to the upper and lower surfaces of the electrode assembly 110.

[0038] 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 shown in Figure 3. In this disclosure, the upper and lower sides or the left and right sides are relative concepts that differ depending on the viewing direction.

[0039] On the other hand, the support frame 120 may include an electrolyte injection hole 123 for injecting electrolyte into the containment space S, which will be described later. This allows for the electrolyte injection process and the degassing process after activation to be performed. For example, with the secondary battery 100 positioned so that one side 121a of the support frame 120, which is provided with the electrolyte injection hole 123, faces upward, the electrolyte can be injected into the containment space S from the electrolyte injection hole 123. In the degassing process, the discharge of internal gas from the open electrolyte injection hole 123 can be guided. After the electrolyte injection and degassing, the electrolyte injection hole 123 can be closed by sealing or welding. Alternatively, an openable and closable valve (not shown) can be installed in the electrolyte injection hole 123, allowing the electrolyte injection hole 123 to be opened only when necessary.

[0040] Conventionally, the pouch-type outer packaging consisted of a storage section for housing the electrode assembly 110 and a pocket section for housing the gas generated during activation. After the gas in the pocket section was discharged through a degassing process, the pocket section was removed. This resulted in the problem that a portion of the pouch-type outer packaging was always discarded. However, with the addition of an electrolyte injection hole 123, the electrolyte can be injected and degassed through the electrolyte injection hole 123, thus eliminating the need for the aforementioned disposal of outer packaging material.

[0041] Sheet-type exterior materials The sheet-like exterior material 130 may be a sheet including a metal layer 131a, as shown in Figure 4. Figure 4 is a cross-sectional view showing the laminated structure of the sheet-like exterior material 130 in the secondary battery 100 of Figure 2. The metal layer 131a may include an aluminum layer or a stainless steel layer.

[0042] The sheet-like exterior material 130 may be a laminate sheet further comprising a resin layer laminated on the metal layer 131a. The sheet-like exterior material 130 may also 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 is required to have high insulation and corrosion resistance, the first resin layer 131b may be formed of another resin that satisfies such requirements. The sheet-like exterior material 130 may also 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 is required to protect the secondary battery 100 and ensure insulation, the second resin layer 131c may be formed of another resin that satisfies such requirements.

[0043] As shown in Figure 3, the sheet-like exterior material 130 may surround the remaining portion of the electrode assembly 110 not enclosed by the support frame 120, forming a housing space S that accommodates the electrode assembly 110 together with the support frame 120. Figure 3 illustrates two exterior material sheets 131 and 132 that surround the upper and lower surfaces of the electrode assembly 110 not enclosed by the support frame 120, respectively, by covering the upper opening 122a and lower opening 122b formed by the support frame 120. The exterior material sheets 131 and 132 may also be exterior films. Thus, the sheet-like exterior material 130 may include two exterior material sheets 131 and 132 that cover the upper opening 122a and lower opening 122b of the support frame 120, respectively. If the support frame 120 forms only one of the upper opening 122a and lower opening 122b, the sheet-like exterior material 130 may also include only one exterior material sheet to correspond to this. The exterior material sheets 131 and 132 may include a metal layer 131a, or they may include a metal layer 131a and resin layers 131b and 131c.

[0044] The sheet-like outer covering material 130 may be coupled to the support frame 120, partitioning the housing space S that accommodates the electrode assembly 110 from the outside of the secondary battery 100. For example, when the electrode assembly 110 is positioned inside the support frame 120, if the sheet-like outer covering material 130 is coupled to the support frame 120 so as to cover the upper opening 122a and lower opening 122b of the support frame 120, the housing space S containing the electrode assembly 110 is isolated from the outside of the secondary battery 100. When the housing space S is filled with electrolyte, the sheet-like outer covering material 130 is coupled to the support frame 120 so as to seal it. This prevents leakage of the electrolyte.

[0045] On the other hand, conventionally, a cup portion for housing the electrode assembly was molded into an outer material sheet, the cup portion was sealed with another outer material sheet, and the electrode assembly was housed in a pouch-type outer material (see Figure 1). However, the molding depth of the cup portion is limited by the material properties of the pouch-type outer material, making it difficult to mold the cup portion sufficiently deep to increase battery capacity, and the selection of material and thickness of the pouch-type outer material was also limited. Furthermore, as the thickness of the pouch-type outer material decreased during the molding of the cup portion, defects such as cracks were more likely to occur in the pouch-type outer material.

[0046] In contrast, in the secondary battery 100 of this embodiment, the electrode assembly 110 is placed inside the support frame 120, and then the openings 122a and 122b of the support frame 120 are covered with a sheet-like outer material 130 that does not have a cup portion formed, thereby housing the electrode assembly 110 and avoiding the limitations and defects described above. As a result, the battery capacity can be easily increased by increasing the size of the support frame 120, the material and thickness of the sheet-like outer material 130 can be selected relatively freely, and defects such as cracks are less likely to occur.

[0047] Furthermore, as a battery that uses a sheet-like outer casing material 130 without a molded cup portion, a battery including a cover member 120' and a sheet-like outer casing material 130'', as shown in Figure 5, is also conceivable. Figure 5 is a perspective view showing another type of secondary battery in comparison to the secondary battery 100 of Figure 2. In the battery of Figure 5, the sheet-like outer casing material 130'' may form an internal space for housing the electrode assembly 110 and an outer casing opening that connects the internal space to the outside by winding or folding multiple times. The cover member 120' may be a member that covers the outer casing opening of the sheet-like outer casing material 130'' so that it is sealed.

[0048] In the case of such a battery, the sheet-like outer covering material 130'' must be bonded to the cover member 120' along its edge. To do this, it may be necessary to pressurize the sheet-like outer covering material 130'' toward the cover member 120'. However, since it is not easy to pressurize the sheet-like outer covering material 130'' toward the corner A of the cover member 120', the bond between the cover member 120' and the sheet-like outer covering material 130'' may be weak at the corner A of the cover member 120'. Such a weak bond leads to a decrease in sealing performance, and if the battery is filled with electrolyte, electrolyte leakage may occur.

[0049] In contrast, in the secondary battery 100 of this embodiment, the support frame 120 and the sheet-like exterior material 130 can be strongly bonded together overall. As shown in Figure 3, the exterior material sheets 131 and 132 of this embodiment may be bonded to the upper surface 121e or lower surface 121f of the support side wall 121. Since the exterior material sheets 131 and 132 can be brought into planar contact with the upper surface 121e or lower surface 121f of the support side wall 121 opposite to them, the exterior material sheets 131 and 132 can be uniformly pressed against the upper surface 121e or lower surface 121f of the support side wall 121, thereby forming a strong bond between the exterior material sheets 131 and 132 and the support side wall 121. Note that 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.

[0050] Connection between the support frame and the sheet-like exterior material The support frame 120 may be made of a plastic material. The sheet-like exterior material 130 may include a metal layer 131a and a resin layer 131b placed on the inner surface of the metal layer 131a, as shown in Figure 4. In this case, the support frame 120 and the resin layer 131b of the sheet-like exterior material 130 may be bonded by heat fusion. The resin layer 131b may be a layer made of polypropylene (PP). A sealant layer (not shown) may be formed on the portion of the support frame 120 that is bonded to the sheet-like exterior material 130 in order to improve the bonding with the sheet-like exterior material 130. The sealant layer may be a layer made of polypropylene (PP).

[0051] The support frame 120 may be made of a metal material. The sheet-like exterior material 130 may include a metal layer 131a and a resin layer 131b placed on the inner surface of the metal layer 131a. The sheet-like exterior material 130 may be bonded to the support frame 120 by heat fusion. One surface of the support frame 120 bonded to the sheet-like exterior material 130 may be treated to improve the bonding with the sheet-like exterior material 130. For example, one surface of the support frame 120 may be treated with a chemical treatment such as chromate treatment. Alternatively, fine irregularities may be formed on one surface of the support frame 120. The resin layer 131b of the sheet-like exterior material 130 may be a layer made of polyphthalamide (PPA), which has excellent bonding properties with metal. A sealant layer (not shown) may be formed on the portion of the support frame 120 that is bonded to the sheet-like exterior material 130. The sealant layer may be a layer made of polypropylene (PP). The support frame 120 may have a structure formed from a metal frame, or it 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 is effective in preventing external moisture from penetrating into the interior.

[0052] The metal support frame 120 may be joined to the sheet-like exterior material 130' by welding. For this purpose, the sheet-like exterior material 130' may include a metal layer 131a' that is welded to the support frame 120, as shown in Figure 6. Figure 6 is a cross-sectional view showing a modified example of the laminated structure of the sheet-like exterior material 130 of Figure 4. Here, the metal layer 131a' may include a stainless steel layer. If the resin layer 131b' on the inner surface of the metal layer 131a' interferes with welding, the resin layer 131b' formed in the portion joined to the support frame 120 may be removed, as shown in Figure 6, or the resin layer 131b' may not be formed in that portion. Alternatively, the resin layer may not be formed on the entire inner surface of the metal layer 131a'.

[0053] To improve bonding, an adhesive (not shown) may be provided between the support frame 120 and the sheet-like exterior material 130.

[0054] electrode terminal The electrode terminals 140 may be components for electrical connection to other devices. For this purpose, the electrode terminals 140 may be made of an electrically conductive material. The electrode terminals 140 may be arranged on the sheet-like exterior material 130 so as to be exposed to the outside of the sheet-like exterior material 130;131,132, as shown in Figures 3 and 7. Only a portion of the electrode terminals 140 may be exposed to the outside of the sheet-like exterior material 130. The electrode terminals 140 may be electrically connected to the electrode tabs 111 of the electrode assembly 110, as shown in Figure 7. The electrical connection may include both direct connection and indirect connection mediated by other electrically conductive members. The electrode tabs 111 may be welded to each other in a predetermined area and then connected to the electrode terminals 140 by welding. Figure 7 is a cross-sectional view of the secondary battery 100 of Figure 2 along line AA. The electrode terminals 140 may include a positive electrode terminal connected to the positive electrode tab of the electrode assembly 110 and a negative electrode terminal connected to the negative electrode tab of the electrode assembly 110.

[0055] In this embodiment, the electrode terminals 140 are arranged on the sheet-like exterior materials 130; 131, 132, thereby improving the volumetric energy density of the battery. 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 terminals 140 extend far outside the support frame 120, the required installation volume for the secondary battery 100 increases. In the case of the secondary battery 100 of this embodiment, when the secondary battery 100 is projected in the direction in which the electrodes of the electrode assembly 110 are stacked, the electrode terminals 140 do not extend far outside the support frame 120, thus minimizing the installation volume of the secondary battery 100.

[0056] On the other hand, the electrode terminal 140 may include a terminal metal layer 141 that is electrically connected to the electrode tab 111, as shown in Figure 7. The terminal metal layer 141 may be part of the metal layer 131a of the sheet-like exterior material 130. The metal layer 131a of the sheet-like exterior material 130 may be an electrically conductive metal layer, such as an aluminum layer.

[0057] The sheet-like 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. The first resin layer 131b does not have to cover the terminal metal layer 141. In this case, the terminal metal layer 141 is exposed to the inside of the housing space S on the inner surface side of the terminal metal layer 141. The terminal metal layer 141 may be electrically connected to the electrode tab 111 through such exposed portion. If the sheet-like exterior material does not include the first resin layer 131b, a portion of the metal layer of the sheet-like exterior material may be selected and connected to the electrode tab 111.

[0058] The sheet-like 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. The second resin layer 131c does not have to cover the terminal metal layer 141. In this case, the terminal metal layer 141 is exposed to the outside of the sheet-like exterior material 130 on the outer surface side of the terminal metal layer 141. The terminal metal layer 141 may be electrically connected to other devices through such exposed portions.

[0059] On the other hand, the portion of the metal layer 131a of the sheet-like exterior material 130 other than the terminal metal layer 141 does not need to be exposed to the outside of the sheet-like exterior material 130. For example, the portion of the metal layer 131a that can be exposed to the outside of the sheet-like exterior material 130 (e.g., the portion located on the far right in Figure 7) may be covered by another insulating member.

[0060] The terminal metal layer 141 may be placed on one surface of the sheet-like outer covering material 130 surrounding the upper or lower surface of the electrode assembly 110. Figure 7 illustrates a terminal metal layer 141 placed on the sheet-like outer covering 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 placed so as not to overlap the electrode assembly 110 when projected upward in the height direction D1. Figure 7 illustrates a terminal metal layer 141 placed in a space corresponding to the space between the electrode assembly 110 and the support frame 120, and not overlapping the electrode assembly 110.

[0061] As shown in Figure 3, the positive and negative electrode tabs of the electrode tabs may be connected to the electrode terminals 140 of the upper casing material 131 and the lower casing material 132, respectively. For example, in Figure 3, the right-hand tab connected to the electrode terminal 140 of the upper casing material 131 is the positive electrode tab, and the left-hand tab connected to the electrode terminal 140 of the lower casing material 132 is the negative electrode tab. For such electrical connections, the electrode terminals 140 of the upper casing material 131 and the electrode terminals 140 of the lower casing material 132 do not necessarily have to be electrically connected to each other.

[0062] On the other hand, the electrode terminal 140 can be deformed as shown in Figure 8. Figure 8 is a cross-sectional view showing a first modified example of the secondary battery 100 of Figure 2.

[0063] The electrode terminal 140' may include a terminal metal layer 141, which is part of the metal layer 131a of the sheet-like outer covering material 130. The terminal metal layer 141 may be exposed on its inner surface side to the inside of the housing space S and electrically connected to the electrode tab 111.

[0064] The electrode terminal 140' may include an exposed member 142 positioned on the outer surface side of the terminal metal layer 141 and exposed to the outside of the sheet-like 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 outward from the terminal metal layer 141 toward the sheet-like exterior material 130, electrical connection with other devices can be facilitated. 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.

[0065] To describe the sheet-like exterior material 130 in detail, the sheet-like exterior material 130 may include a metal layer 131a and a resin layer 131c that covers the outer surface of the metal layer 131a. The resin layer 131c does not need to cover the terminal metal layer 141, which is part of the metal layer 131a, in order to expose the terminal metal layer 141 to the outside of the sheet-like exterior material 130. Thus, an exposure hole H penetrating the resin layer 131c may be formed in a region of the resin layer 131c that does not cover the terminal metal layer 141. The terminal metal layer 141 may be exposed to the outside of the sheet-like exterior material 130 through the exposure hole H of the sheet-like exterior material 130.

[0066] More specifically, 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 can be placed in the exposed hole H corresponding to the exposed hole H, or in any shape that can be placed in the exposed hole H.

[0067] The exposed member 142 may include an extended portion 142b extending from the connecting portion 142a. The extended portion 142b may extend outside the sheet-like exterior material 130 parallel to the sheet-like exterior material 130 (e.g., in the left-right direction in Figure 8). In this disclosure, parallel also includes substantially parallel. The extended portion 142b may extend in this manner and overlap the resin layer 131c surrounding the exposed hole H outside the sheet-like exterior material 130. For example, the extended portion 142b may overlap the resin layer 131c outside the sheet-like exterior material 130, based on a projection in a direction perpendicular to the sheet-like exterior material 130 (the same direction in which the electrodes of the electrode assembly are stacked in Figure 8). The extended portion 142b can suppress the penetration of liquid from outside the secondary battery 100 into the interior of the secondary battery 100 through the exposed hole H. To improve such effects, the extended portion 142b may be provided so as to completely surround the resin layer 131c located along the edge of the exposed hole H. Figure 8 illustrates an extended portion 142b that extends parallel to the sheet-like exterior material 130 at the outer end of the connecting portion 142a.

[0068] On the other hand, the electrode terminal 140 can be deformed as shown in Figure 9. Figure 9 is a cross-sectional view showing a second modified example of the secondary battery 100 of Figure 2.

[0069] The electrode terminal 140'' may include an exposed member 142' positioned to penetrate the exposed hole H of the sheet-like exterior material 130. The exposed member 142' may be exposed to the inside of the housing space S at one end (see the lower end in Figure 9) and electrically connected to the electrode tab 111. The exposed member 142' may be exposed to the outside of the sheet-like exterior material 130 at the other end (see the upper end in Figure 9). In this modification, the exposed hole H of the sheet-like exterior material 130 may be formed to expose the housing space S to the outside of the sheet-like exterior material 130. For this purpose, the exposed hole H may be formed to penetrate the sheet-like exterior material 130. The exposed member 142' may be positioned in the exposed hole H of the sheet-like exterior material 130 and exposed to both the inside and outside of the secondary battery 100. The exposed member 142' may be positioned across the entire exposed hole H.

[0070] To describe the exposed member 142' in detail, the exposed member 142' may include a body portion 142a' positioned in the exposed hole H. The body portion 142a' may extend in a direction perpendicular to the sheet-like exterior material 130 (the same as the height direction, which is the direction in which the electrodes of the electrode assembly are stacked in Figure 9). In this disclosure, perpendicularity includes substantially perpendicularity. The body portion 142a' may extend in this manner and include an inner end (see the lower end in Figure 9) located inside (or exposed to the inside) of the housing space S, and an outer end (see the upper end in Figure 9) located outside (or exposed to the outside) of the sheet-like exterior material 130. The body portion 142a' may be a member formed in a shape corresponding to the cross-sectional shape of the exposed hole H and extending in the aforementioned perpendicular 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 in the exposed hole H. The body portion 142a' may also be formed of two members 142a1 and 142a2 that are separately provided and connected to each other, as shown in Figure 9.

[0071] The exposed member 142' may include an inner extension 142b1 extending from the inner end of the body portion 142a'. The inner end of the body portion 142a' may be the end of the body portion 142a' located inside the sheet-like exterior material 130. The inner extension 142b1 may extend parallel to the sheet-like exterior material 130 to the outside of the exposed hole H. For example, the inner extension 142b1 may extend parallel to the sheet-like exterior material 130 inside the sheet-like exterior material 130 (e.g., in the housing space) until it overlaps with the resin layer 131b surrounding the exposed hole H. One surface of the inner extension 142b1 facing the inner surface of the sheet-like exterior material 130 may be in close contact with the inner surface of the sheet-like exterior material 130. Such close contact can suppress the leakage of electrolyte from the inside of the secondary battery 100 to the outside of the secondary battery 100 through the exposed hole H. To prevent leakage of the electrolyte, a sealant layer (not shown) may be placed between the inner extending portion 142b1 and the inner surface of the sheet-like exterior material 130 facing it.

[0072] The exposed member 142' may include an outer extension 142b2 extending from the outer end of the body portion 142a'. The outer end of the body portion 142a' may be the end of the body portion 142a' located outside the sheet-like exterior material 130. The outer extension 142b2 may extend parallel to the sheet-like exterior material 130 to the outside of the exposed hole H. For example, the outer extension 142b2 may extend parallel to the sheet-like exterior material 130 on the outside of the sheet-like exterior material 130 until it overlaps with the resin layer 131c surrounding the exposed hole H. One surface of the outer extension 142b2 facing the outer surface of the sheet-like exterior material 130 may be in close contact with the outer surface of the sheet-like exterior material 130. Such close contact can suppress the penetration of liquid from the outside of the secondary battery 100 into the inside of the secondary battery 100 through the exposed hole H. To prevent liquid penetration, a sealant layer (not shown) may be placed between the outerly extending portion 142b2 and the outer surface of the sheet-like exterior material 130 facing it.

[0073] On the other hand, the exposed member 142' may include an inner body portion 143 and an outer body portion 144 that is detachably coupled to the inner body portion 143. Figure 9 illustrates an inner body portion 143 and an outer body portion 144 that are fitted together and have protrusions and recesses, respectively. At least a portion of the inner body portion 143 may be exposed to the inside of the sheet-like exterior material 130 (e.g., the housing space). At least a portion of the outer body portion 144 may be exposed to the outside of the sheet-like exterior material 130. The outer body portion 144 may be provided separately from the inner body portion 143. Figure 9 illustrates an inner body portion 143 including a portion 142a1 of the body portion 142a' and an inner extension portion 142b1, and an outer body portion 144 including another portion 142a2 of the body portion 142a' and an outer extension portion 142b2.

[0074] On the other hand, the electrode assembly 110 can be modified as shown in Figure 10. Figure 10 is a perspective view showing a third modified example of the secondary battery 100 of Figure 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, which has the same polarity as the first electrode tab 111a, may be coupled to the electrode terminal 140 so as to be spaced apart from each other. For example, as shown in Figure 10, the negative electrode tab 111a of the first electrode assembly 110a and the negative electrode tab 111b of the second electrode assembly 110b are both connected to the electrode terminal 140 of the lower outer casing material 132, but they may be connected to two points on the electrode terminal 140 that are spaced apart from each other.

[0075] It is also conceivable to increase the height (h) of the support frame 120 and then house multiple electrode assemblies in the housing space S. However, when connecting the electrode tabs of one electrode assembly to the electrode terminals of other electrode assemblies, the connection process between the electrode tabs and electrode terminals becomes easier than when connecting all the electrode tabs of an electrode assembly first and then further connecting them to the electrode terminals.

[0076] Embodiment 2 Figure 11 is an exploded perspective view showing a secondary battery 200 according to Embodiment 2 of this disclosure. The secondary battery 200 according to this embodiment differs from the secondary battery 100 of Embodiment 1 in its support frame and sheet-like exterior material, and these differences will be the focus of the explanation below. The contents of Embodiment 2 can also be applied to the previously described embodiments, unless otherwise contradictory.

[0077] The secondary battery 200 according to this embodiment may include an electrode assembly 110, a support frame 220, a sheet-like outer material 230, and electrode terminals 140, as shown in Figure 11.

[0078] The support frame 220 may include a support side wall 221. If the direction in which the electrodes of the electrode assembly 110 are stacked is defined as the height direction D1, and the direction perpendicular to the height direction D1 is defined as the lateral direction D2, the support side wall 221 may form an upper opening 222a along the height direction D1 and a side opening 222c along the lateral direction D2. The support side wall 221 may be formed in a C-shape overall. The support side wall 221 may form a lower opening 222b corresponding to the upper opening 222a. The support side wall 221 may surround a portion of the side surface of the electrode assembly 110. The side surface of the electrode assembly 110 may be defined along the lateral direction D2. In Figure 11, three of the four side surfaces of the electrode assembly 110 are surrounded by support side walls 221; 221a, 221b, and 221c. An electrolyte injection hole 223 may be formed on one surface 221a of the support frame 220.

[0079] The sheet-like exterior material 230 may include exterior material sheets 231 and 233 that cover the upper opening 222a and the side opening 222c formed by the support side wall 221. If the support side wall 221 also forms a lower opening 222b, the lower opening 222b may also be covered by the exterior material sheet 232. Figure 11 illustrates exterior material sheets 231, 232, and 233 that continuously cover the upper opening 222a, the side opening 222c, and the lower opening 222b. That is, exterior material sheet 231 for covering the upper opening 222a, exterior material sheet 233 for covering the side opening 222c, and exterior material sheet 232 for covering the lower opening 222b may be continuously connected to form a C-shape overall. The exterior material sheets 231, 232, and 233 may be bonded to the support side wall 221. Exterior material sheets 231, 232, and 233 may be joined to the upper surface 221e and lower surface 221f of the support side wall 221 defined along the height direction D1, and to the side surface 221g of the support side wall 221 defined along the lateral direction D2 on the side of the side opening 222c.

[0080] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs could make various modifications and alterations without departing from the essential characteristics of the present invention.

[0081] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0082] The scope of protection of this invention should be interpreted in accordance with the appended claims, and all technical ideas equivalent thereto should be interpreted as being included within the scope of the rights of this invention.

Claims

1. Electrode assembly and A support frame surrounding a part of the electrode assembly, A sheet-like exterior material is attached to the support frame so as to surround the remaining portion of the electrode assembly and form a housing space for housing the electrode assembly together with the support frame, and such that the housing space is separated from the outside of the support frame. A secondary battery comprising: electrode terminals electrically connected to electrode tabs of the electrode assembly and positioned on the sheet-like outer material so as to be exposed to the outside of the sheet-like outer material.

2. The aforementioned support frame is If the direction in which the electrodes of the electrode assembly are stacked is defined as the height direction, and the direction perpendicular to the height direction is defined as the lateral direction, then the electrode assembly includes a support side wall that forms an upper opening along the height direction and completely surrounds the side surface of the electrode assembly defined along the lateral direction, The aforementioned sheet-like exterior material is The secondary battery according to claim 1, comprising an exterior material sheet coupled to the upper surface of the support side wall defined along the height direction and covering the upper opening formed by the support side wall.

3. The aforementioned support frame is If the direction in which the electrodes of the electrode assembly are stacked is defined as the height direction, and the direction perpendicular to the height direction is defined as the lateral direction, then the electrode assembly is formed in a C-shape, forming an upper opening along the height direction and a side opening along the lateral direction, and includes a support side wall that surrounds a part of the side surface of the electrode assembly defined along the lateral direction. The aforementioned sheet-like exterior material is The secondary battery according to claim 1, comprising an exterior material sheet coupled to the support side wall and covering the upper opening and the side opening formed by the support side wall.

4. The support frame is made of plastic material, The secondary battery according to claim 1, wherein the sheet-like exterior 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. The support frame is made of a metal material, The secondary battery according to claim 1, wherein the sheet-like exterior material includes a metal layer and a resin layer disposed on the inner surface of the metal layer and bonded to the support frame.

6. On one side of the support frame which is connected to the sheet-like exterior material, The secondary battery according to claim 5, wherein a surface treatment is applied to improve the bonding with the aforementioned sheet-like exterior material.

7. The support frame is made of a metal material, The secondary battery according to claim 1, wherein the sheet-like exterior material includes a metal layer that is welded to the support frame.

8. The secondary battery according to claim 1, further comprising an adhesive disposed between the support frame and the sheet-like exterior material for bonding the support frame and the sheet-like exterior material.

9. The electrode terminals are, The secondary battery according to claim 1, wherein a portion of the metal layer of the sheet-like exterior material includes a terminal metal layer that is exposed on the inner side to the inside of the housing space and electrically connected to the electrode tab, and exposed on the outer side to the outside of the sheet-like exterior material.

10. The aforementioned terminal metal layer is The secondary battery according to claim 9, wherein the electrode is placed on one surface of the sheet-like exterior material surrounding the upper or lower surface of the electrode assembly, which is defined along the height direction in which the electrodes of the electrode assembly are stacked, and does not overlap the electrode assembly when projected in the height direction.

11. The aforementioned sheet-like exterior material is The secondary battery according to claim 9, comprising 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.

12. The electrode terminals are, A part of the metal layer of the sheet-like exterior material, which is exposed on the inner side to the inside of the housing space and electrically connected to the electrode tab, is a terminal metal layer. The secondary battery according to claim 1, 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-like exterior material.

13. The aforementioned sheet-like exterior material is The material includes 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 that exposes the terminal metal layer to the outside of the sheet-like exterior material. The exposed member is, The secondary battery according to claim 12, comprising: a connecting portion disposed in the exposed hole and electrically connected to the terminal metal layer; and an extending portion extending from the connecting portion parallel to the sheet-like exterior material on the outside of the sheet-like exterior material and overlapping the resin layer surrounding the exposed hole.

14. The aforementioned sheet-like exterior material is The aforementioned containment space includes an exposed hole that is exposed to the outside of the sheet-like exterior material, The electrode terminals are, The secondary battery according to claim 1, comprising an exposed member arranged to penetrate the exposed hole, exposed at one end to the inside of the housing space and electrically connected to the electrode tab, and exposed at the other end to the outside of the sheet-like outer material.

15. The exposed member is, A body portion extending in a direction perpendicular to the sheet-like exterior material and positioned in the exposed hole, An inner extension portion extends from the inner end of the body portion located inside the sheet-like exterior material, parallel to the sheet-like exterior, to the outside of the exposed hole, The secondary battery according to claim 14, further comprising: an outer extension portion extending parallel to the sheet-like exterior material from the outer end of the body portion located outside the sheet-like exterior material to the outside of the exposed hole.

16. The secondary battery according to claim 15, wherein a sealant layer is disposed between the inner extending portion and the inner surface of the sheet-like exterior material facing it, and between the outer extending portion and the outer surface of the sheet-like exterior material facing it.

17. The exposed member is, An inner body portion, at least a part of which is exposed to the inside of the aforementioned containment space, The secondary battery according to claim 14, comprising an outer body portion provided separately from the inner body portion and detachably coupled to the inner body portion, with at least a portion of which exposed to the outside of the sheet-like outer material.

18. The electrode assembly includes a first electrode assembly and a second electrode assembly stacked on the first electrode assembly. The secondary battery according to claim 1, wherein the first electrode tab of the first electrode assembly and the second electrode tab of the second electrode assembly, which has the same polarity as the first electrode tab, are coupled to the electrode terminals so as to be separated from each other.

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