Pouch-type battery cell

Abstract

A pouch-type battery cell according to an embodiment of the present invention includes an electrode assembly that may be accommodated between a first case and a second case. The pouch-type battery cell may include: a cup portion formed in the first case and / or the second case and accommodating the electrode assembly; a folded portion in which an edge portion of the first housing surrounds an edge portion of the second housing such that a discharge flow path is formed between the edge portion of the first housing and the edge portion of the second housing; a sealing portion formed in the folded portion; and an exhaust portion through which the cup portion and the discharge flow path communicate when the internal pressure of the cup portion increases.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Korean Patent Application No. 10-2023-0048247 filed on April 12, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0067111 filed on May 24, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a pouch-type battery cell. Background Art

[0004] In recent years, secondary batteries have attracted considerable attention as a power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), etc., which have been developed to solve restrictions caused by existing gasoline and diesel vehicles using fossil fuels, such as air pollution.

[0005] Although one, two, three or four secondary batteries are generally used in small mobile devices, in medium and large devices such as electric vehicles, since the vehicles require high power and large capacity, battery modules in which multiple secondary batteries are electrically connected to each other or battery packs in which multiple battery modules are electrically connected to each other are used.

[0006] Among currently commercialized secondary batteries, lithium secondary batteries are the most popular. Lithium secondary batteries are categorized into can, prismatic, and pouch types based on the shape of their exterior materials. Among these secondary batteries, pouch-type batteries are widely used in medium- and large-sized battery modules due to their high energy density and ease of stacking.

[0007] At the same time, as demand for high-energy secondary battery modules installed in vehicles increases, customer demand for battery safety is also increasing. That is, when secondary batteries have high energy density, there may be stability risks (for example, the risk of battery ignition or explosion).

[0008] Generally, a pouch-type battery cell has a structure in which an electrode assembly is accommodated in a pouch-type battery case, and a sealing portion is formed on an edge of the battery case.

[0009] When a battery cell exceeds its critical temperature due to abnormal heating, for example, the temperature and internal pressure can rapidly rise, potentially leading to an explosion. Consequently, heat propagation (TP) can occur to other nearby cells. Therefore, to prevent or sufficiently delay TP, gases generated in the battery cell due to abnormal heating, for example, need to be discharged in a specific direction in advance. Summary of the Invention

[0010] Technical issues

[0011] An aspect of the present invention provides a pouch-type battery cell configured to discharge gas in a preset direction when internal pressure of a cup portion accommodating an electrode assembly increases.

[0012] Technical Solutions

[0013] According to one aspect of the present invention, a pouch-type battery cell is provided, in which an electrode assembly can be accommodated between a first shell and a second shell. The pouch-type battery cell may include: a cup-shaped portion disposed in at least one of the first shell or the second shell and configured to accommodate the electrode assembly; a folded portion in which an edge portion of the first shell surrounds an edge portion of the second shell, such that a vent is provided between the edge portions of the first shell and the second shell; a sealing portion disposed on the folded portion; and a vent portion, wherein a portion of the folded portion is less tightly sealed than the sealing portion or is not sealed, such that when the internal pressure of the cup increases, the cup and the vent communicate with each other.

[0014] A sealing portion and a vent portion may be disposed between the cup portion and the discharge passage.

[0015] The folding portion may include a first facing portion configured to face one surface of the edge portion of the second housing; a second facing portion configured to face the other surface of the edge portion of the second housing; and a connecting portion configured to connect the first facing portion to the second facing portion and bend or curve to be spaced a predetermined distance from an end of the edge portion of the second housing. The discharge passage may be disposed in the connecting portion.

[0016] A thickness of the connection portion in a direction parallel to a thickness of the edge portion of the second case may be greater than a sum of a thickness of the first facing portion, a thickness of the edge portion of the second case, and a thickness of the second facing portion.

[0017] A width of the discharge passage in a direction parallel to a thickness of the edge portion of the second housing may be greater than the thickness of the edge portion of the second housing.

[0018] The connecting portion may include a curved surface convex outward.

[0019] The sealing portion may be provided by sealing the first facing portion and the second facing portion with an edge portion of the second housing.

[0020] The vent portion may be provided by weakly sealing or not sealing the first facing portion and the edge portion of the second housing to each other.

[0021] The drainage channel may extend along the full length or width of the cup and have at least one open end.

[0022] A plurality of exhaust portions may be provided along the peripheries of the first housing and the second housing.

[0023] Both the folded portion and the vent portion may be provided in a plurality, wherein the plurality of folded portions may include: a first folded portion extending along the entire length of the cup-shaped portion; and a second folded portion extending along the entire width of the cup-shaped portion. The plurality of vent portions may include: a first vent portion, which is provided outside the long side of the cup-shaped portion and is configured such that when the internal pressure of the cup-shaped portion increases, the exhaust passages in the cup-shaped portion and the first folded portion communicate with each other; and a second vent portion, which is provided outside the short side of the cup-shaped portion and is configured such that when the internal pressure of the cup-shaped portion increases, the exhaust passages in the cup-shaped portion and the second folded portion communicate with each other.

[0024] According to another aspect of the present invention, a pouch-type battery cell is provided, in which an electrode assembly can be accommodated between a first shell and a second shell. The pouch-type battery cell may include: a cup-shaped portion disposed in at least one of the first shell or the second shell and configured to accommodate the electrode assembly; a folded portion in which an edge portion of the first shell surrounds an edge portion of the second shell, such that a discharge passage is provided between the edge portions of the first shell and the second shell; a sealing portion disposed on the folded portion; and a gas discharge member disposed between the cup-shaped portion and the discharge passage and made of a material through which gas can pass.

[0025] The gas discharge member may comprise a hygroscopic material.

[0026] An inner end portion of the gas discharge member may be exposed inside the cup portion.

[0027] An outer end portion of the gas discharge member may be exposed to the interior of the discharge passage.

[0028] An outer end portion of the gas discharge member protrudes further than a terminal end portion of the edge portion of the second housing.

[0029] The folding portion may include a first facing portion configured to face one surface of the edge portion of the second housing; a second facing portion configured to face the other surface of the edge portion of the second housing; and a connecting portion configured to connect the first facing portion to the second facing portion and bend or curve to be spaced a predetermined distance from an end of the edge portion of the second housing. The discharge passage may be disposed in the connecting portion.

[0030] The gas discharge member may be disposed between the first facing portion and an edge portion of the second housing.

[0031] The gas discharging member may be provided in plural numbers along the circumferences of the first housing and the second housing.

[0032] Beneficial effects

[0033] Therefore, when the internal pressure of the cup-shaped portion containing the electrode assembly increases, the gas in the cup-shaped portion can pass through the exhaust portion and the exhaust channel in the folded portion in sequence and then be discharged. Therefore, the gas can be discharged in a predetermined direction to prevent the pouch-type battery cell from exploding and also prevent heat propagation (TP) to other battery cells near the pouch-type battery cell caused by the explosion.

[0034] In addition, the discharge channel can be simply and easily realized only by the folded portion without requiring a separate device or an additional sealing process.

[0035] In addition, there can be an advantage in that the length, number, and position of the exhaust portion can be adjusted to easily and appropriately design the flow rate of the gas exhaust.

[0036] Furthermore, when the internal pressure of the cup-shaped portion housing the electrode assembly increases, the gas in the cup-shaped portion can sequentially pass through the gas discharge member and the discharge channel in the folded portion and then be discharged. The gas can be discharged without a physical opening, and thus, the internal pressure of the cup-shaped portion can be maintained at an appropriate level, and the pouch-type battery cell can be used continuously.

[0037] In addition, effects that are obvious to those skilled in the art can be predicted according to the configuration of the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The following drawings attached to this specification illustrate embodiments of the present invention and are used to further understand the technical spirit of the present invention together with the detailed description, and therefore, the present invention should not be interpreted as being limited to the drawings.

[0039] Figure 1 is a perspective view illustrating a case and an electrode assembly of a pouch-type battery cell according to a first embodiment of the present invention.

[0040] Figure 2 is a plan view of a pouch-type battery cell according to a first embodiment of the present invention;

[0041] Figure 3 It is along Figure 2 A partial cross-sectional view taken along line AA'.

[0042] Figure 4 It is along Figure 2A partial cross-sectional view taken along line BB'.

[0043] Figure 5 It's a picture Figure 3 and Figure 4 A diagram of a modified example of the illustrated connection portion.

[0044] Figure 6 is a plan view illustrating a pouch-type battery cell according to a second embodiment of the present invention.

[0045] Figure 7 It is along Figure 6 A partial cross-sectional view taken along line CC'.

[0046] Figure 8 is a plan view of a pouch-type battery cell according to a third embodiment of the present invention.

[0047] Figure 9 is a plan view of a pouch-type battery cell according to a fourth embodiment of the present invention.

[0048] Figure 10 It is along Figure 9 A partial cross-sectional view taken along line D-D'. DETAILED DESCRIPTION

[0049] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in several different forms and is not limited or restricted by the following examples.

[0050] In order to clearly explain the present invention, details that are generally not relevant to the present invention or related known technologies that may unnecessarily obscure the main points of the present invention have been omitted. Reference numerals are added to the components in each of the accompanying drawings. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

[0051] Figure 1 is a perspective view illustrating a case and an electrode assembly of a pouch-type battery cell according to a first embodiment of the present invention, Figure 2 is a plan view of a pouch-type battery cell according to a first embodiment of the present invention, Figure 3 It is along Figure 2 A partial cross-sectional view taken along line AA', and Figure 4 It is along Figure 2 A partial cross-sectional view taken along line BB'.

[0052] According to the first embodiment, the pouch-type battery cell 10 may include a pair of cases 100 and an electrode assembly 200. In more detail, the pouch-type battery cell 10 may be manufactured by accommodating the electrode assembly 200 between a first case 100A and a second case 100B.

[0053] The first case 100A and the second case 100B may be sealed together with the electrode assembly 200 and the electrolyte therein to constitute the pouch-type battery cell 10 .

[0054] The electrode assembly 200 may include a positive electrode, a negative electrode, and a separator, which is disposed between the positive electrode and the negative electrode to insulate the positive electrode and the negative electrode from each other. The type of electrode assembly 200 is not limited. For example, the electrode assembly 200 may be a stacked electrode assembly in which the positive electrode and the negative electrode are alternately stacked, wherein the separator is located between the positive electrode and the negative electrode. As another example, the electrode assembly 200 may be a wound electrode assembly in which a sheet-like positive electrode and a negative electrode are wound together, wherein the separator is located between the positive electrode and the negative electrode.

[0055] A combination of the first case 100A and the second case 100B provides an accommodation space for accommodating the electrode assembly 200 and may have a pouch shape as a whole.

[0056] One side portion of the first housing 100A and one side portion of the second housing 100B may be connected to each other, and the connected portion may constitute the folding region 103. That is, the pair of housings 100 may be integrally formed along the folding region 103. However, in other examples, the first housing 100A and the second housing 100B may be provided as separate components that are subsequently sealed together.

[0057] Each of the housings 100 may include a first resin layer defining an innermost layer, a second resin layer defining an outermost layer, and a metal layer between the first and second resin layers. That is, each of the housings 100 may be manufactured by molding a laminate film including the first resin layer, the second resin layer, and the metal layer.

[0058] The first resin layer constituting the innermost layer may be in direct contact with or adjacent to the electrode assembly 200 and the electrolyte. Therefore, the first resin layer may be formed of a material having high insulation properties and high corrosion resistance. For example, the first resin layer may include a polypropylene (PP) material. However, the first resin layer is not limited thereto, and those skilled in the art may appropriately select the material of the first resin layer.

[0059] The second resin layer constituting the outermost layer can electrically insulate the electrode assembly 200 from the outside while protecting the pouch-type battery cell 10 from friction and collision with external objects. For example, the second resin layer can include polyethylene terephthalate (PET) material. However, the second resin layer is not limited thereto, and those skilled in the art can appropriately select the material of the second resin layer.

[0060] Furthermore, at least one of the first resin layer or the second resin layer may be provided as a structure including two or more layers to improve moldability and adhesiveness.

[0061] The metal layer can ensure the mechanical strength of the housing 100, prevent external gas or moisture from entering, and prevent leakage of the electrolyte. The metal layer may include aluminum (Al) or stainless steel (STS) material. However, the metal layer is not limited thereto, and those skilled in the art can appropriately select the material of the metal layer.

[0062] The pouch-type battery cell 10 may include a cup 110 provided in at least one of the first case 100A or the second case 100B, the cup 110 being used to accommodate the electrode assembly 200 .

[0063] The cup portion 110 may be recessed to a predetermined depth by drawing a laminate film defining a base material of the housing 100 .

[0064] like Figure 1 As shown, each of the first housing 100A and the second housing 100B may be provided with a cup-shaped portion 110. In this example, the electrode assembly 200 may be accommodated in the accommodation space defined by the pair of cup-shaped portions 110. However, the present invention is not limited thereto, and the cup-shaped portion 110 may alternatively be provided in only one of the first housing 100A or the second housing 100B. In other words, the housing excluding the cup-shaped portion 110 may be flat.

[0065] Each of the first and second shells 100A, 100B may include an edge portion 120 disposed around the cup-shaped portion 110. The edge portion 120 may also be referred to as a platform portion. The edge portion 120 of the first and second shells 100A, 100B may be placed in contact with each other and sealed together, thereby sealing the electrode assembly 200 inside the first and second shells 100A, 100B.

[0066] When the first and second housings 100A, 100B are integrally provided with the folding region 103, the folding region 103 can be folded so that the edge portions 120 of the first and second housings 100A, 100B contact each other. In this case, the contacting edge portions 120 define three sides of the pouch-type battery cell 10, and the folding region 103 can define the remaining side. Therefore, the sealing portion 150, which will be described later, can be arranged on three sides of the pouch-type battery cell 10.

[0067] The pouch-type battery cell 10 may include a folded portion 130 in which the edge portion 120 of the first case 100A surrounds the edge portion 120 of the second case 100B such that a discharge passage 140 is provided between the edge portions 120 of the first and second cases 100A and 100B.

[0068] The edge portion 120 of the first housing 100A may be folded, bent, or curved to constitute the folded portion 130. In more detail, to form the folded portion 130, the edge portion 120 of the first housing 100A may be folded to be spaced apart from the end of the edge portion 120 of the second housing 100B by a predetermined distance.

[0069] The folded portion 130 may extend along the entire length or width of the cup-shaped portion 110 .

[0070] At least one folding portion 130, preferably a plurality of folding portions, may be provided. Figure 2 As shown, the folding portions 130 may be arranged on three of the four sides of the pouch-type battery cell 10, excluding the folding region 103. In this case, the plurality of folding portions 130 include a first folding portion 130A extending along the entire length of the cup-shaped portion 110 and a second folding portion 130B extending along the entire width of the cup-shaped portion 110.

[0071] However, the present invention is not limited thereto, and the folding portion 130 may also be disposed only on one or more of the three side portions.

[0072] To form the folding portion 130, the edge portion 120 of the first housing 100A may be wider than the edge portion 120 of the second housing 100B. In more detail, the edge portion 120 of the first housing 100A may be longer than the edge portion 120 of the second housing 100B in full length and / or full width.

[0073] Reference Figure 1, a first line L1 and a second line L2 are shown on the edge portion 120 of the first housing 100A to illustrate exemplary lines corresponding to the ends of the edge portion 120 of the second housing 100B. The first line L1 may be parallel to the full length direction of the pouch-type battery cell 10, and the second line L2 may be parallel to the full width direction of the pouch-type battery cell 10.

[0074] The corner where the first line L1 and the second line L2 overlap each other may be doubly folded at an edge portion of the first housing 100A. Alternatively, the corner may be cut into a suitable shape by those skilled in the art.

[0075] For more details, refer to Figure 3 or Figure 4 The folding portion 130 may include a first facing portion 131 facing one surface of the edge portion 120 of the second shell 100B, a second facing portion 132 facing the other surface of the edge portion 120 of the second shell 100B, and a connecting portion 133 connecting the first facing portion 131 to the second facing portion 132.

[0076] The first facing portion 131 may be in contact with one surface of the edge portion 120 of the second housing 100B. The second facing portion 132 may be in contact with the other surface of the edge portion 120 of the second housing 100B.

[0077] The connection portion 133 may be folded, bent, or curved to be spaced a predetermined distance from the end of the edge portion 120 of the second housing 100B. Due to the above configuration, the exhaust passage 140 may be provided in the connection portion 133. When the internal pressure of the cup-shaped portion 110 increases, the gas generated in the cup-shaped portion may be discharged to the outside of the pouch-type battery cell 10 by sequentially passing through the vent 160 and the exhaust passage 140, which will be described later.

[0078] The cross-sectional shape of the discharge passage 140 may be determined by the shape of the connection portion 133. For example, the connection portion 133 may include a curved surface convex outward. In this case, a portion of the cross-sectional shape of the discharge passage 140 may be substantially rounded.

[0079] The first and second facing portions 131 and 132 may overlap each other in a thickness direction of the edge portion 120 of the second housing 100B. The first and second facing portions 131 and 132 may be coupled to the edge portion 120 of the second housing 100B by a sealing portion 150 to be described later.

[0080] The connection portion 133 extends in a direction parallel to the thickness of the edge portion 120 of the second housing 100B (see FIG. Figure 3The thickness t2 of the connecting portion 133 (in the vertical direction of the second housing 100B) can be greater than the sum t1 of the thickness of the first facing portion 131, the thickness of the edge portion 120 of the second housing 100B, and the thickness of the second facing portion 132. That is, the thickness t2 of the connecting portion 133 can be greater than the thickness of the sealing portion 150. In other words, the connecting portion 133 can be configured to protrude more than the combination of the first facing portion 131 and the second facing portion 132 in the thickness direction.

[0081] The exhaust passage 140 extends in a direction parallel to the thickness of the edge portion 120 of the second housing 100B (see FIG. Figure 4 The width W in the vertical direction of the second shell 100B may be greater than the thickness t0 of the edge portion 120 of the second shell 100B.

[0082] Due to the above configuration, the cross-sectional area of ​​the discharge passage may be sufficiently large, and gas may be smoothly discharged through the discharge passage 140 .

[0083] The exhaust passage 140 may extend along the entire length or width of the cup-shaped portion 110, and at least one end, preferably both ends, of the exhaust passage 140 may be open. The open end of the exhaust passage 140 may serve as an outlet for exhaust gas. Figure 2 The indicated arrows schematically indicate that the gas is discharged from one end of the discharge channel 140 in each folded portion 130. Therefore, there is no need to provide a separate outlet in the folded portion 130.

[0084] like Figure 2 As shown, the sealing portion 150 may be disposed on the folded portion 130 and be elongated along the folded portion 130 .

[0085] The sealing portion 150 may be formed in various ways. For example, the sealing portion 150 may be formed by heat fusion, laser welding, ultrasonic welding, or resistance welding.

[0086] More specifically, the sealing portion 150 may be disposed between the cup portion 110 and the discharge passage 140. Thus, the sealing portion 150 may separate the inner space of the cup portion 110 from the discharge passage 140.

[0087] Reference Figure 3, the sealing portion 150 may be provided by sealing the first facing portion 131 and the second facing portion 132 with the edge portion 120 of the second shell 100B. In more detail, the sealing portion 150 may include a first sealing portion 151 and a second sealing portion 152, the edge portion 120 of the second shell 100B and the first facing portion 131 being sealed on the first sealing portion 151, and the edge portion 120 and the second facing portion 132 of the second shell 100B being sealed on the second sealing portion 152. That is, the sealing portion 150 may be provided as a double sealing portion on the folding portion 130 and have a high sealing strength.

[0088] The pouch-type battery cell 10 may include a vent 160 disposed between the cup 110 and the drain duct 140. Vent 160 may be formed by sealing a portion of the folded portion 130 weaker than the seal 150. This seal ruptures when the internal pressure of the cup 110 increases, placing the cup 110 and drain duct 140 in communication with each other. Alternatively, vent 160 may be unsealed. In either case, the cup 110 can selectively communicate with the drain duct.

[0089] In more detail, the vent 160 may be provided by slightly sealing the first facing portion 131 and the edge portion 120 of the second housing 100B or leaving the region unsealed.

[0090] The vent portion 160 may overlap the second sealing portion 152 in a thickness direction of the edge portion 120 of the second housing 100B.

[0091] When the first facing portion 131 and the edge portion 120 of the second housing 100B are weakly sealed with each other to provide the vent 160 , the sealing strength of the vent 160 may be lower than that of each of the first and second sealing portions 151 and 152 .

[0092] like Figure 4 As shown, when the first facing portion 131 and the edge portion 120 of the second housing 100B are not sealed to provide the vent 160, if the internal pressure of the cup 110 increases, the space between the first facing portion 131 and the edge portion 120 of the second housing 100B may expand to generate a gap g. Therefore, the gas in the cup 110 may flow into the vent channel 140 through the gap g.

[0093] Alternatively, when the first facing portion 131 and the edge portion 120 of the second housing 100B are weakly sealed to provide the vent 160, if the internal pressure of the cup 110 increases, the space between the first facing portion 131 and the edge portion 120 of the second housing 100B may expand to break the weak seal and generate a gap g. As a result, the gas in the cup 110 may flow into the vent passage 140 through the gap g.

[0094] At least one exhaust portion 160 , preferably a plurality of exhaust portions 160 , may be provided along the periphery of the first housing 100A and the second housing 100B.

[0095] At least one vent portion 160 may be provided on each folding portion 130. For example, when the plurality of folding portions 130 include a first folding portion 130A and a second folding portion 130B, the plurality of vent portions 160 may include a first vent portion 160A arranged along a length side of the edge portion 120 and a second vent portion 160B arranged along a width side of the edge portion 120.

[0096] When the internal pressure of the cup 110 increases, the first vent 160A may allow the exhaust passage 140 in the first folded portion 130A to communicate with the cup 110 , and the second vent 160B may allow the exhaust passage 140 in the second folded portion 130B to communicate with the cup 110 .

[0097] However, a plurality of vents 160 may be provided on a single folded portion 130 .

[0098] The pouch-type battery cell 10 has the advantage that the approximate flow rate of gas discharged from the cup portion 110 can be easily designed by adjusting the length, number, position, etc. of the vent portion 160 .

[0099] Figure 5 It's a picture Figure 3 and Figure 4 A diagram of a modified example of the illustrated connection portion.

[0100] The connection portion 133' according to the modified example may define a discharge passage 140'. The discharge passage 140' is parallel to the thickness of the edge portion 120 of the second housing 100B (refer to FIG. Figure 5 The width in the vertical direction of the second shell 100B may be equal to or similar to the thickness t0 of the edge portion 120 of the second shell 100B.

[0101] In order to ensure a sufficiently wide cross-sectional area of ​​the exhaust passage 140', the exhaust passage 140' is parallel to the thickness of the edge portion 120 of the second housing 100B (refer to FIG. Figure 5The width W' of the discharge passage 140' in the horizontal direction (in the horizontal direction) may be greater than the thickness t0 of the edge portion 120 of the second housing 100B. Preferably, the width W' of the discharge passage 140' may be twice or more the thickness t0 of the edge portion 120 of the second housing 100B.

[0102] The connection portion 133' may define a polygonal discharge passage 140' that does not include a curved surface. However, the connection portion 133' is not limited thereto, and like the first embodiment, the connection portion 133' may have a curved surface.

[0103] Figure 6 is a plan view illustrating a pouch-type battery cell according to a second embodiment of the present invention, and Figure 7 It is along Figure 6 A partial cross-sectional view taken along line CC'.

[0104] In the pouch-type battery cell 10 a according to the second embodiment, one or more of three side portions except the folding region 103 may be provided with a folding portion 130 , and each of the other side portions may be provided with an auxiliary folding portion 170 .

[0105] The auxiliary folding portion 170 may be provided by folding the edge portion 120 of the first housing 100A to surround the edge portion 120 of the second housing 100B so as not to form a discharge passage. That is, the auxiliary folding portion 170 may be folded, bent, or curved at a position adjacent to or in contact with the distal end of the edge portion 120 of the second housing 100B.

[0106] Similar to the folding portion 130, the auxiliary folding portion 170 may include a first facing portion 171 facing one surface of the edge portion 120 of the second housing 100B, a second facing portion 172 facing the other surface of the edge portion 120 of the second housing 100B, and a connecting portion 173 connecting the first facing portion 171 to the second facing portion 172. The connecting portion 173 may be folded, bent, or curved in contact with or adjacent to a distal end portion of the edge portion 120 of the second housing 100B.

[0107] The sealing portion 150 may be arranged on the auxiliary folding portion 170. The sealing portion 150 may be provided by sealing the first facing portion 171 and the second facing portion 172 with the edge portion 120 of the second shell 100B. More specifically, the sealing portion 150 may include a first sealing portion 151 and a second sealing portion 152, the edge portion 120 of the second shell 100B and the first facing portion 171 being sealed on the first sealing portion 151, and the edge portion 120 and the second facing portion 172 of the second shell 100B being sealed on the second sealing portion 152. That is, the sealing portion 150 may be provided on the auxiliary folding portion 170 as a double sealing portion and a higher sealing strength.

[0108] The auxiliary folded portion 170 may be provided compactly compared to the folded portion 130. Therefore, by providing the auxiliary folded portion 170 instead of the folded portion 130 at a portion where the exhaust passage 140 does not need to be formed, the energy density of the pouch-type battery cell 10a may be improved.

[0109] Figure 8 is a plan view of a pouch-type battery cell according to a third embodiment of the present invention.

[0110] The pouch-type battery cell 10b according to the third embodiment can be manufactured by sealing a first housing 100A and a second housing 100B. The first housing 100A and the second housing 100B are not integrally connected but provided as separate components. The edge portion 120 of the first housing 100A and the edge portion 120 of the second housing 100B can contact each other and then be sealed together to define the four sides of the pouch-type battery cell 10b. Therefore, the sealing portion 150 can be arranged on the four sides of the pouch-type battery cell 10b.

[0111] The folding portion 130 may be disposed on at least one of the four sides of the pouch-type battery cell 10. Figure 8 As shown, the folds 130 may be arranged on opposite sides with the cup 110 positioned between them, and the folds 130 may be arranged in pairs, parallel to each other. As another example, the folds 130 may be arranged on each of the four sides of the pouch-type battery cell 10. As described above, at least one vent 160 may be arranged on each fold 130.

[0112] Figure 9 is a plan view of a pouch-type battery cell according to a fourth embodiment of the present invention, and Figure 10 It is along Figure 9 A partial cross-sectional view taken along line D-D'.

[0113] Hereinafter, contents repeated with the aforementioned embodiment will be omitted, and differences will be mainly described.

[0114] The pouch-type battery cell 10c according to the fourth embodiment may include a gas discharging member 180 disposed on the folded portion 130 and between the cup portion 110 and the discharge channel 140. The gas discharging member 180 may replace the vent 160 of the aforementioned first embodiment.

[0115] The gas discharge member 180 may be disposed between the cup 110 and the discharge passage 140. The gas discharge member 180 may be disposed between the first facing portion 131 of the folding portion 130 and the edge portion 120 of the second housing 100B.

[0116] The gas discharging member 180 may overlap the second sealing portion 152 in a thickness direction of the edge portion 120 of the second housing 100B.

[0117] The gas discharging member 180 may be made of a gas-permeable material. Therefore, when the internal pressure of the cup 110 increases, the gas in the cup 110 may be discharged to the discharge passage 140 through the gas discharging member 180 .

[0118] The inner end of the gas discharging member 180 may be disposed within the cup-shaped portion 110. The outer end of the gas discharging member 180 may be disposed within the discharge passage 140. The width of the gas discharging member 180 may be wider than the width of the sealing portion 150, particularly the second sealing portion 152. Therefore, the gas generated in the cup-shaped portion 110 may be smoothly discharged to the discharge passage 140 through the gas discharging member 180.

[0119] Preferably, the outer end of the gas exhaust member 180 may protrude further than the terminal end of the edge portion 120 of the second housing 100B. Therefore, the gas passing through the gas exhaust member 180 may not only be discharged in the width direction ( Figure 10 The horizontal direction in the middle) can also be discharged along the surface direction ( Figure 10 That is, the gas can be discharged smoothly into the discharge channel 140.

[0120] The length L of the gas discharging member 180 may be appropriately adjusted according to the gas discharging amount required by the pouch type battery cell 10c and the gas permeability of the gas discharging member 180. The length of the gas discharging member 180 may refer to a direction parallel to the length of the sealing portion 150.

[0121] The gas discharging member 180 may be made of a material having a higher melting point than the first resin layer (eg, PP layer) forming the innermost layer of the case 100. In addition, the gas discharging member 180 may be formed of a material that does not react with the electrolyte.

[0122] For example, the gas discharging member 180 may include an adhesive including at least one of an olefin-based resin, an acrylic resin, or a fluorine-based resin. For example, the olefin-based resin may be polypropylene (PP), polyethylene (PE), or polyvinylidene fluoride (PVDF). The fluorine-based resin may be polytetrafluoroethylene (PTFE) or polyvinylidene fluoride.

[0123] Due to the gas discharge member, gas may be discharged without a physical opening, and thus, the internal pressure of the cup 110 may be maintained at an appropriate level and the pouch-type battery cell 10 c may be continuously used.

[0124] The gas discharging member 180 may further include a hygroscopic material to improve gas permeability while minimizing moisture permeability. That is, the gas discharging member 180 may include a getter material. For example, the hygroscopic material may be calcium oxide (CaO), barium oxide (BaO), lithium chloride (LiCl), silicon dioxide (SiO2), calcium (Ca), barium (Ba), etc., but is not limited thereto, and any material that reacts with H2O may be used.

[0125] Since moisture outside the pouch-type battery cell 10 c is removed by reacting with the hygroscopic material of the gas discharge member 180 , it is possible to prevent moisture from penetrating into the inside of the cup 110 .

[0126] The gas exhaust member 180 may be provided in the form of a film. However, the gas exhaust member 180 is not limited thereto, and a resin containing the aforementioned adhesive and / or hygroscopic material may be applied to at least one of the first facing portion 131 or the edge portion 120 of the second housing 100B by any known coating method to provide the gas exhaust member 180.

[0127] The bonding strength of the gas discharging member 180 with the first facing portion 131 and / or the edge portion 120 of the second housing 100B may be smaller than that of the sealing portion 150 , particularly, the second sealing portion 152 .

[0128] As the internal pressure of the cup 110 increases, interfaces between the first facing portion 131 and / or the edge portion 120 of the second housing 100B and the gas discharging member 180 may gradually separate from each other.

[0129] In addition, when the internal pressure of the cup 110 is very high, the interfaces between the first facing portion 131 and / or the edge portion 120 of the second housing 100B and the gas discharge member 180 may be completely separated from each other, thereby forming a passage through which gas is discharged, similar to Figure 4Therefore, gas can be discharged quickly and the safety of the pouch-type battery cell 10c can be improved.

[0130] Reference Figure 9 At least one gas discharge member 180 , preferably a plurality of gas discharge members 180 , may be provided along the periphery of the first housing 100A and the second housing 100B.

[0131] At least one gas exhaust member 180 may be provided in each folding portion 130. For example, when the plurality of folding portions 130 include a first folding portion 130A and a second folding portion 130B, the plurality of gas exhaust members 180 may include a first gas exhaust member 180A disposed along a length side of the edge portion 120 and a second gas exhaust member 180B disposed along a width side of the edge portion 120.

[0132] When the internal pressure of the cup 110 increases, gas passing through the first gas discharging member 180A may be discharged to the discharge channel 140 in the first folded portion 130A, and gas passing through the second gas discharging member 180B may be discharged to the discharge channel 140 in the second folded portion 130B.

[0133] However, a plurality of gas discharging members 180 may be provided on a single folded portion 130. The gas discharging member 180 may be used in place of the gas vent 160 of the aforementioned second and third embodiments.

[0134] The above-disclosed subject matter is to be considered illustrative and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention.

[0135] Therefore, the embodiments of the present invention are to be regarded as illustrative rather than restrictive, and the technical spirit of the present invention is not limited to the aforementioned embodiments.

[0136] Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

[0137] [Description of Reference Signs]

[0138] 10: Pouch-type battery cell 100: Housing

[0139] 110: Cup-shaped portion 120: Edge portion

[0140] 130: Folding portion 131: First facing portion

[0141] 132: Second facing portion 133: Connecting portion

[0142] 140: Discharge channel 150: Sealing part

[0143] 151: First sealing portion 152: Second sealing portion

[0144] 160: Exhaust part 180: Gas exhaust component

[0145] 200: Electrode assembly

Claims

1. A pouch-type battery cell, in which an electrode assembly is accommodated between a first shell and a second shell, the pouch-type battery cell comprising: a cup-shaped portion disposed in at least one of the first shell or the second shell and configured to accommodate the electrode assembly; a folded portion in which an edge portion of the first shell surrounds an edge portion of the second shell so that a discharge passage is provided between the edge portion of the first shell and the edge portion of the second shell; a sealing portion, the sealing portion being provided on the folding portion; as well as A vent portion, wherein the cup portion and the discharge passage communicate with each other through the vent portion when an internal pressure within the cup portion increases.

2. The pouch-type battery cell according to claim 1, wherein: The sealing portion and the vent portion are arranged between the cup portion and the discharge passage.

3. The pouch-type battery cell according to claim 1, wherein: The folding portion includes: a first facing portion configured to face one surface of an edge portion of the second housing; a second facing portion configured to face the other surface of the edge portion of the second housing on an opposite side of the first facing portion; and a connecting portion configured to connect the first facing portion to the second facing portion, the connecting portion being bent or curved to be spaced a predetermined distance from a terminal end portion of the edge portion of the second housing, Wherein, the discharge channel is at least partially defined by the connecting portion.

4. The pouch-type battery cell according to claim 3, wherein: The thickness of the connection portion in a direction parallel to the thickness of the edge portion of the second housing is greater than the sum of the thickness of the first facing portion, the thickness of the edge portion of the second housing, and the thickness of the second facing portion.

5. The pouch-type battery cell according to claim 3, wherein: The width of the discharge passage in a direction parallel to the thickness of the edge portion of the second housing is greater than the thickness of the edge portion of the second housing.

6. The pouch-type battery cell according to claim 3, wherein: The connecting portion includes a curved surface convex outward.

7. The pouch-type battery cell according to claim 3, wherein: The sealing portion includes: a first sealing portion formed by sealing the first facing portion to an edge portion of the second housing; and A second sealing portion is formed by sealing the second facing portion to an edge portion of the second housing.

8. The pouch-type battery cell according to claim 3, wherein: The vent is provided by weakly sealing the first facing portion and the edge portion of the second housing with each other, or by not sealing the first facing portion and the edge portion of the second housing with each other.

9. The pouch-type battery cell according to claim 1, wherein: The discharge channel extends along the entire length or width of the cup-shaped portion and has at least one open end.

10. The pouch-type battery cell according to claim 1, wherein A plurality of exhaust portions are provided along the peripheries of the first shell and the second shell.

11. The pouch-type battery cell according to claim 1, wherein The folding portion and the exhaust portion are provided in plurality, Wherein, the multiple folding parts include: a first folded portion extending along the entire length of the cup-shaped portion; and a second folded portion extending along the full width of the cup-shaped portion, Wherein, the plurality of exhaust parts include: a first vent portion disposed at the first folded portion; and A second vent is disposed at the second folded portion.

12. A pouch-type battery cell, in which an electrode assembly is accommodated between a first case and a second case, the pouch-type battery cell comprising: a cup-shaped portion disposed in at least one of the first shell or the second shell and configured to accommodate the electrode assembly; a folded portion in which an edge portion of the first shell surrounds an edge portion of the second shell so that a discharge passage is provided between the edge portion of the first shell and the edge portion of the second shell; a sealing portion provided on the folded portion; and A gas discharge member is disposed between the cup and the discharge passage, the gas discharge member being formed of a gas-permeable material.

13. The pouch-type battery cell according to claim 12, wherein: The gas permeable material includes a hygroscopic material.

14. The pouch-type battery cell according to claim 12, wherein: The inner end of the gas discharge member is configured to be at least partially disposed within the cup.

15. The pouch-type battery cell according to claim 12, wherein An outer end portion of the gas discharge member is at least partially disposed within the discharge passage.

16. The pouch-type battery cell according to claim 12, wherein: An outer end portion of the gas discharge member protrudes further than an end portion of an edge portion of the second housing.

17. The pouch-type battery cell according to claim 12, wherein: The folding portion includes: a first facing portion configured to face one surface of an edge portion of the second housing; a second facing portion configured to face the other surface of the edge portion of the second housing; and a connecting portion configured to connect the first facing portion to the second facing portion, the connecting portion being bent or curved to be spaced a predetermined distance from a terminal end portion of the edge portion of the second housing, Wherein, the discharge channel is at least partially defined by the connecting portion.

18. The pouch-type battery cell according to claim 17, wherein The gas discharge member is arranged between the first facing portion and an edge portion of the second housing.

19. The pouch-type battery cell according to claim 12, wherein: The gas discharge member is provided in plural numbers along the circumferences of the first and second housings.

20. The pouch-type battery cell according to claim 1, wherein The folding portion includes an auxiliary folding portion, The connection portion of the auxiliary folding portion is in contact with or adjacent to a terminal end portion of an edge portion of the second shell.

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