Bag type battery cell

Abstract

The present invention relates to a structure of a battery cell and a battery module including the battery cell, in which heat is prevented from propagating to an adjacent battery cell during fire, and exhaust gas is directed downward. The battery cell comprises: an electrode assembly; a pouch which accommodates the electrode assembly, is folded in half, and is sealed on three side surfaces other than the folded side; and an electrode lead extending from the electrode assembly so as to protrude to the outside of the pouch, and the battery cell further comprises: an insulating, heat-resistant and fire-resistant barrier member having a box-shaped shape having an open side and a slit-type lead hole, the electrode lead protrudes to the outside of the barrier member through the lead hole, and the barrier member covers five side surfaces other than the folded side.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0123603, dated September 28, 2022, and all contents disclosed in the documents of this patent application are included as a part of this specification.

[0002] The present invention relates to a pouch-type battery cell, and more particularly to a pouch-type battery cell capable of blocking the spread of heat and flame and controlling the direction of exhaust gas. Background Art

[0003] Secondary batteries that are easily applied according to product groups and have electrical characteristics such as high energy density are widely used not only in portable devices but also in electric vehicles or hybrid vehicles driven by electric drive sources and power storage devices. These secondary batteries are attracting attention as new energy sources for improving eco-friendliness and energy efficiency, not only because they have the main advantage of being able to significantly reduce the use of fossil fuels, but also because they do not produce any byproducts due to energy use.

[0004] Although small mobile devices use one or two or three battery cells per device, medium to large devices such as vehicles require high output and large capacity. Therefore, medium to large battery modules in which a plurality of battery cells are electrically connected are used.

[0005] Since it is desired to make medium to large battery modules as small and light as possible, rectangular batteries and pouch-type batteries, which are batteries that can be stacked with high integration and have a small weight-to-capacity ratio, are mainly used as battery cells for medium to large battery modules.

[0006] Figure 1 and Figure 2 The figures are a perspective view and an exploded perspective view respectively showing a battery module including a pouch-type battery cell. Figure 1 and Figure 2 The battery module 1 may include a battery cell stack 11 formed by stacking a plurality of battery cells and a case 12 accommodating the battery cell stack 11 .

[0007] Figure 3 is a perspective view showing a pouch-type battery cell. Figure 3, the battery cell 2 may include an electrode assembly, a bag 22 accommodating the electrode assembly, and an electrode lead 21 extending from the electrode assembly and protruding from the bag 22. The bag 22 may be formed by folding a bag sheet made of a metal foil material to surround the electrode assembly and seal three sides except the folded side. Therefore, the bag 22 may include a first sealed portion 221a on the opposite side of the folded side and a second sealed portion 221b on the remaining two sides. The first sealed portion 221a may be sealed again by folding and pasting the end portion of the first sealed portion 221a after the first seal. The bag sheet may be sealed at the second sealed portion 221b with the electrode lead 21 interposed therebetween.

[0008] At the same time, there is a risk of overheating and catching fire of the battery cell 2 due to a short circuit. When the battery cell 2 catches fire, exhaust gas, heat, and flames generated by evaporation of the electrolyte solution injected into the bag 22 may be discharged from the battery cell 2. In addition, the heat and flames generated by the ignition of the battery cell 2 may spread to other adjacent battery cells 2, thereby causing chain fire.

[0009] Figure 4 Schematic diagram showing the degassing that occurs in a pouch-type battery cell. Figure 4 , heat, flames and exhaust gases can be discharged from the battery cell 2 mainly through the sealing portion 221 of the bag 22. At the same time, return to reference Figure 1 and Figure 2 , the battery cells 2 can be accommodated in the housing 12 with the folded sides facing downward, so that heat, flames and exhaust gases can be discharged mainly in the upward direction of the battery module 1.

[0010] However, particularly in electric vehicles, the battery module is generally mounted on the bottom surface of the vehicle in the form of a battery pack having a plurality of integrated batteries. Therefore, when heat, flames, and exhaust gas are discharged from the battery module in an upward direction, it may cause great risks to passengers.

[0011] Therefore, a solution at the battery cell or battery module level is needed that is able to prevent heat propagation between battery cells and direct the discharge of flames and exhaust gases in a downward direction. Summary of the invention

[0012] Technical issues

[0013] In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a structure of a battery cell and a battery module capable of guiding exhaust gas in a downward direction during thermal runaway.

[0014] Another object of the present invention is to provide a structure of a battery cell and a battery module capable of preventing series fire by preventing heat propagation between adjacent battery cells.

[0015] It is a further object of the present invention to provide a structure of a battery cell and a battery module which is capable of maintaining the energy density of a conventional battery module while providing safety measures in the event of thermal runaway as described above, without modifying the design and production equipment of conventional battery cells and battery modules.

[0016] The technical problem to be solved by the present invention is not limited to the above-mentioned purpose, and other purposes and advantages of the present invention that are not described can be understood through the following description, and will be more clearly understood through the examples of the present invention. In addition, it is obvious that the purposes and advantages of the present invention can be embodied by the means indicated in the claims and their combinations.

[0017] Technical Solution

[0018] In order to solve the above problems, the present invention provides a structure of a battery cell, which includes: an electrode assembly; a bag that accommodates the electrode assembly and has a folded side and three sealed sides; and an electrode lead that extends from the electrode assembly and protrudes outward from the bag, the battery cell also including: an insulating, heat-resistant and fire-resistant barrier member having a box shape provided with a slit-type lead hole and an open end; wherein the electrode lead protrudes from the barrier member through the lead hole, and the five sides of the battery cell except the folded side are covered by the barrier member.

[0019] Hereinafter, the length, width and height of the barrier member are referred to as X, Y and Z, respectively.

[0020] The barrier member is manufactured by folding a barrier sheet in the form of a single unfolded pattern into a box shape.

[0021] The barrier sheet may include folds and wings.

[0022] The folded portion may be rectangular with a length and width of X and Y+2Z respectively.

[0023] The folded portion may correspond to one height-direction end surface and both width-direction end surfaces of the battery cell.

[0024] The wing may be a rectangle with a length and width of Y and Z. Alternatively, the wing may be a rectangle with a length and width of Z and Y, respectively.

[0025] The wing portion may protrude from each of both lengthwise ends of the folded portion.

[0026] The wing portions may correspond to both lengthwise end surfaces of the battery cell.

[0027] The barrier member may be formed by folding the barrier sheet to surround the battery cell, and then joining adjacent but unjoined edges to each other by attaching an adhesive tape.

[0028] The adhesive tape may include a heat and fire resistant material.

[0029] The barrier sheet may include an adhesive flap.

[0030] The adhesive tab may protrude from one of the adjacent but unjoined edges of the barrier sheet and be folded to cover the other edge when the barrier sheet may be folded around the battery cell.

[0031] The barrier member may be in the form of a box, all edges of which are joined to each other.

[0032] The barrier member may be manufactured by folding the barrier sheet in the form of a single unfolded pattern and fusing adjacent but unjoined edges to each other.

[0033] The electrode lead may protrude from both lengthwise ends of the battery cell. Here, the lead hole may be provided on each of the two lengthwise end surfaces of the barrier member and extend in the height direction to the lower end of each of the two lengthwise end surfaces of the barrier member.

[0034] The battery cell may be inserted through the open side of the barrier member to be covered by the barrier member. Here, the electrode lead may be inserted along the lead hole from the lower end of each of both lengthwise end surfaces of the barrier member.

[0035] After the battery cell is inserted into the barrier member, an adhesive tape may be attached to a lower end of each of both lengthwise end surfaces of the barrier member.

[0036] The adhesive tape may include a heat and fire resistant material.

[0037] A sealing member may be disposed in a gap between the lead hole and the electrode lead to seal the gap.

[0038] The sealing member may include a heat-resistant and fire-resistant resin.

[0039] The present invention also provides a structure of a battery module including: a battery cell stack manufactured by stacking a plurality of battery cells including a barrier member; and a case accommodating the battery cell stack.

[0040] The barrier member may include a compressible material. Here, the barrier member may be interposed between the battery cells to absorb expansion and tolerance.

[0041] The battery cell stack may be housed in the case in such a manner that the opening portion of the barrier member faces in a downward direction.

[0042] The bottom surface of the housing may be provided with an exhaust hole opened toward a downward direction.

[0043] The exhaust hole opens in response to an increase in the internal pressure of the housing.

[0044] Beneficial Effects

[0045] The present invention can provide a structure of a battery cell capable of: preventing serial fire by surrounding five sides of the battery cell with a barrier member having an open lower end to prevent heat propagation between adjacent battery cells; and guiding exhaust gas in a downward direction.

[0046] The present invention can also provide a structure of a battery cell capable of performing exhaust by maintaining a box shape using an integrally formed barrier member even when the internal pressure increases rapidly when the battery cell catches fire.

[0047] Also advantageously, the present invention can provide a structure of battery cells and battery modules that can maintain the energy density of conventional battery modules by withstanding rapid increases in internal pressure without adding a separate shell member and only utilizing a barrier member made of a thin barrier sheet, without modifying the design and production equipment of conventional battery cells and battery modules.

[0048] The present invention is also advantageous in that tolerances and expansions can be absorbed by using a compressible material for the barrier member.

[0049] In addition, the present invention may have various other effects, and a description thereof will be given in each embodiment, or a description of an effect that can be easily inferred by those skilled in the art will be omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a perspective view showing a battery module including pouch-type battery cells.

[0051] Figure 2 is an exploded perspective view showing a battery module including pouch-type battery cells.

[0052] Figure 3 It is a perspective view showing a pouch-type battery cell.

[0053] Figure 4 is a schematic diagram showing the occurrence of venting in a pouch-type battery cell.

[0054] Figure 5 is a perspective view showing a battery cell including a barrier member according to the present invention.

[0055] Figure 6 is a perspective view showing a barrier sheet according to a first embodiment of the present invention.

[0056] Figure 7 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a first embodiment of the present invention.

[0057] Figure 8 is a perspective view showing a battery cell including the barrier member according to the first embodiment of the present invention.

[0058] Fig. 9 is a perspective view showing a barrier sheet according to a second embodiment of the present invention.

[0059] Fig.10 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a second embodiment of the present invention.

[0060] Fig.11 is a perspective view showing a battery cell including a barrier member according to a second embodiment of the present invention.

[0061] Fig.12 : is a perspective view showing a barrier member according to a third embodiment of the present invention.

[0062] Fig.13 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a third embodiment of the present invention.

[0063] Fig.14 is a perspective view showing a battery cell including a barrier member according to a third embodiment of the present invention.

[0064] Fig.15 : is a perspective view showing a barrier member according to a fourth embodiment of the present invention.

[0065] Fig.16 : is a schematic diagram showing that a battery cell according to a fourth embodiment of the present invention is inserted into a barrier member.

[0066] Fig.17 is a perspective view showing a battery cell including a barrier member according to a fourth embodiment of the present invention.

[0067] Fig.18 is a schematic diagram showing gas exhaust occurring in a battery cell provided with the barrier member according to the present invention.

[0068] Fig.19 is a front sectional view showing a battery module including a battery cell provided with a barrier member according to the present invention.

[0069] Fig. 20 is a transverse sectional view showing a battery module including a battery cell provided with a barrier member according to the present invention.

[0070] Description of Reference Numerals

[0071] 1: Battery module

[0072] 11: Battery cell stack

[0073] 12: Shell

[0074] 121: Top plate

[0075] 122: End plate

[0076] 123: U-shaped frame

[0077] 124: Exhaust hole

[0078] 13: Insulation film

[0079] 14: Thermally conductive resin

[0080] 2: Battery cells

[0081] 21: Electrode lead

[0082] 22: bag

[0083] 221: Sealing part

[0084] 221a: First sealing portion

[0085] 221b: Second sealing part

[0086] 221T: Sealing tape

[0087] 222: The bulge

[0088] 3: Barrier components

[0089] 31: Barrier sheet

[0090] 311: Folding

[0091] 312: Wing

[0092] 313: Adhesive Wing

[0093] 32: Lead hole

[0094] 33: Adhesive tape DETAILED DESCRIPTION

[0095] The above-mentioned objects, features and advantages will be described in detail below with reference to the accompanying drawings so that those skilled in the art will be able to implement the technical concept of the present invention. When describing the present invention, when it is determined that the detailed description of the prior art related to the present invention unnecessarily obscures the main points of the present invention, its detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are used to indicate the same or similar parts.

[0096] Although "first", "second", etc. are used to describe various elements, these elements are certainly not limited by these terms. These terms are only used to distinguish one element from another element, and unless explicitly stated otherwise, the first element may also be the second element.

[0097] Throughout the specification, unless otherwise specified, each element may be in the singular or in the plural.

[0098] Hereinafter, “arranging an element at the upper portion (or lower portion) of an element” or “arranging an element at the top (or bottom) of an element” means not only “arranging the element to be in contact with the upper surface (or lower surface)” but also “arranging the element above the upper surface (or lower surface) with another element interposed therebetween”.

[0099] Additionally, when an element is described as being “connected to,” “coupled to,” or “in contact with” another element, it should be understood that the element may be “directly connected to,” “directly coupled to,” or “directly in contact with” another element, or the element may be “connected to,” “coupled to,” or “in contact with” another element with another element interposed therebetween, or be “connected to,” “coupled to,” or “in contact with” another element via another element.

[0100] Unless the context clearly indicates otherwise, the expressions in the singular form used herein include the expressions in the plural form. The terms such as "consisting of" or "comprising" used herein should not be interpreted as necessarily including all the elements or steps described in the specification, and should be interpreted as excluding some of the elements or steps, or including additional elements or steps.

[0101] In addition, unless the context clearly indicates otherwise, the expressions in the singular form used herein include the expressions in the plural form. Terms such as "consisting of" or "comprising" used herein should not be interpreted as necessarily including all elements or steps described in the specification, and should be interpreted as excluding some of the elements or steps, or including additional elements or steps.

[0102] Throughout the specification, unless explicitly stated otherwise, “A and / or B” means A, B, or A and B, and “C to D” means from equal to or higher than C to equal to or lower than D, unless explicitly stated otherwise.

[0103] For the convenience of description herein, the direction along the longest edge of the battery cell and the battery module is referred to as the "length direction X1" of the battery cell, the direction along the normal line of the longest edge of the battery cell is referred to as the "width direction Y1" of the battery cell, and the direction intersecting both X1 and Y1 is referred to as the "height direction Z1" of the battery cell. The length direction, width direction, and height direction of the battery cell may correspond to the length direction, width direction, and height direction of the battery module, respectively.

[0104] The length X, width Y and height Z of the barrier member refer to dimensions along the X1, Y1 and Z2 directions, respectively. Meanwhile, regarding the dimensions of the barrier sheet, the length direction X2 and the width direction Y2 are directions intersecting each other.

[0105] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0106] Figure 3 is a perspective view showing a pouch-type battery cell. Figure 3 , the battery cell 2 may include: an electrode assembly; a bag 22 accommodating the electrode assembly; and an electrode lead 21 extending from the electrode assembly and protruding outward from the bag 22 .

[0107] The bag 22 can be formed by folding a bag sheet made of a metal foil material to surround the electrode assembly and seal three sides except the folded side. Therefore, the bag 22 can include a first sealing portion 221a on the opposite side of the folded side and a second sealing portion 221b on the remaining two sides.

[0108] The first sealing portion 221 a may be sealed again by folding and attaching the sealing tape 221T to the end portion of the first sealing portion 221 a after the first sealing.

[0109] The pouch sheet may be sealed at the second sealing portion 221 b with the electrode lead 21 interposed therebetween.

[0110] At the same time, there is a risk of overheating and catching fire of the battery cell 2 due to a short circuit. When the battery cell 2 catches fire, exhaust gas, heat, and flames generated by evaporation of the electrolyte solution injected into the bag 22 may be discharged from the battery cell 2. In addition, the heat and flames generated by the ignition of the battery cell 2 may spread to other adjacent battery cells 2, causing a chain fire. The instantaneous increase in the internal pressure of the battery due to the chain of fire and the generation of exhaust gas may cause an explosion.

[0111] Figure 4 Schematic diagram showing the degassing that occurs in a pouch-type battery cell. Figure 4 , heat, flame and exhaust gas can be discharged from the battery cell 2 mainly through the sealing portion 221 of the bag 22. At the same time, the battery cell 2 is usually accommodated in the housing 12, wherein the sealing portion 221 faces the upward direction, the forward direction and the rearward direction. In this case, there is a risk that the heat, flame and exhaust gas generated from the battery cell 2 spread to other adjacent battery modules within one battery pack. In the case of an electric vehicle in particular, there is a risk of explosion toward the passengers.

[0112] Therefore, the present invention provides a structure of a battery cell including a barrier member capable of blocking heat propagation and guiding flame and exhaust gas toward a predetermined direction.

[0113] Figure 5 2 is a perspective view showing a battery cell including a barrier member according to the present invention. Figure 5 , the battery cell 2 according to the present invention may be provided with a barrier member 3 .

[0114] The barrier member 3 may include an insulating, heat-resistant and fire-resistant material. For example, the barrier member 3 may include an insulating, heat-resistant and fire-resistant synthetic resin material.

[0115] The barrier member 3 may have a box shape provided with one open end. Hereinafter, the length, width and height of the barrier member 3 are referred to as X, Y and Z, respectively.

[0116] The barrier member 3 may be provided with a lead hole 32 .

[0117] A plurality of lead holes 32 may be provided.

[0118] The five sides of the battery cell 2 except the folded side may be covered by the barrier member 3 . Here, the electrode lead 21 may protrude from the barrier member 3 through the lead hole 32 .

[0119] [First embodiment]

[0120] Figure 6 2 is a perspective view showing a barrier sheet according to a first embodiment of the present invention. Figure 6 , the barrier member 3 may be manufactured by folding a barrier sheet 31 having a single unfolded pattern into a box shape.

[0121] The barrier sheet 31 may include an insulating, heat-resistant and fire-resistant material. For example, the barrier sheet 31 may include an insulating, heat-resistant and fire-resistant synthetic resin material.

[0122] The barrier sheet 31 may include a folded portion 311 and a wing portion 312 .

[0123] The folding portion 311 according to the first embodiment may be a rectangle having a length and a width of X and Y+2Z, respectively.

[0124] The wing portion 312 according to the first embodiment may be a rectangle having a length and a width of Y and Z.

[0125] The wing portion 312 may protrude from each of both lengthwise end portions of the folded portion 311 .

[0126] The wing portion 312 may include a wire hole 32 .

[0127] Figure 7 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a first embodiment of the present invention. Figure 7 The barrier sheet 31 according to the first embodiment can form the barrier member 3 surrounding five sides of the battery cell 2 by sequentially folding the folded portion 311 and the wing portion 312 .

[0128] The order in which the folding portions 311 and the wing portions 312 are folded is irrelevant. For example, the folding portions 311 and the wing portions 312 may be folded alternately one side at a time.

[0129] The folded portion 311 may correspond to one height-direction end surface and both width-direction end surfaces of the battery cell 2 .

[0130] The wing portions 312 may correspond to two lengthwise end surfaces of the battery cell 2 .

[0131] In the process of folding the wing portion 312, the electrode lead 21 may pass through the lead hole 32. As a result, the electrode lead 21 may protrude outward from the barrier member 3.

[0132] Figure 8 1 is a perspective view showing a battery cell including a barrier member according to a first embodiment of the present invention. Figure 8 , the barrier member 3 can be formed by folding the barrier sheet 31 to surround the battery cell 2, and then joining the adjacent but unjoined edges to each other by attaching the adhesive tape 33. That is, the barrier member 3 according to the first embodiment can be formed by joining four edges where two lengthwise end surfaces and two widthwise end surfaces meet each other using the adhesive tape 33.

[0133] The adhesive tape 33 may include a heat-resistant and fire-resistant material. For example, the adhesive tape 33 may include a heat-resistant and fire-resistant synthetic resin material.

[0134] A sealing member may be provided in a gap between the lead hole 32 and the electrode lead 21 to seal the gap.

[0135] The sealing member may include a heat-resistant and fire-resistant resin.

[0136] Fig.18 Schematic diagram showing the gas exhaust occurring in a battery cell provided with a barrier member according to the present invention. Fig.18 The barrier member 3 according to the first embodiment covers all five sides of the battery cell 2 to prevent heat from propagating from the battery cell 2 and guide flames and exhaust gas to the opening of the barrier member 3 .

[0137] Here, the barrier member 3 according to the first embodiment can be sealed by integrally joining four sides corresponding to the surface of the first sealing portion 221a to each other and integrally joining two sides corresponding to each surface of the second sealing portion 221b to each other by the adhesive tape 33. Therefore, even when the internal pressure increases rapidly due to fire, the portions of the barrier sheet 31 at the front and sides of the battery cell 2 may not fall off the battery cell 2.

[0138] Furthermore, since the wing portion 312 according to the first embodiment is folded in the extending direction of the electrode lead 21 , insertion of the electrode lead 21 into the lead hole 32 is facilitated during the folding process.

[0139] [Second Embodiment]

[0140] Fig. 9 2 is a perspective view showing a barrier sheet according to a second embodiment of the present invention. Fig. 9 , the barrier sheet 31 according to the second embodiment may include a folded portion 311 and a wing portion 312 .

[0141] The folding portion 311 according to the second embodiment may be a rectangle having a length and a width of X and Y+2Z, respectively.

[0142] The wing portion 312 according to the second embodiment may be a rectangle having a length and a width of Z and Y, respectively.

[0143] The wings 312 may be disposed at both longitudinal ends of the folding portion 311 at positions opposite to each other and protrude from both longitudinal ends of the folding portion 311. Alternatively, the wings 312 may be disposed at both longitudinal ends of the folding portion 311 at staggered positions and protrude from both longitudinal ends of the folding portion 311.

[0144] The wing portion 312 may include a wire hole 32 .

[0145] Fig.10 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a second embodiment of the present invention. Fig.10The barrier sheet 31 according to the second embodiment can form the barrier member 3 surrounding five sides of the battery cell 2 by sequentially folding the folded portion 311 and the wing portion 312 .

[0146] The order in which the folding portions 311 and the wing portions 312 are folded is irrelevant. For example, the folding portions 311 and the wing portions 312 may be folded alternately one side at a time.

[0147] The folded portion 311 may correspond to one height-direction end surface and both width-direction end surfaces of the battery cell 2 .

[0148] The wing portions 312 may correspond to two lengthwise end surfaces of the battery cell 2 .

[0149] In the process of folding the wing portion 312, the electrode lead 21 may pass through the lead hole 32. As a result, the electrode lead 21 may protrude outward from the barrier member 3.

[0150] Fig.11 2 is a perspective view showing a battery cell including a barrier member according to a second embodiment of the present invention. Fig.11 , the barrier member 3 can be formed by folding the barrier sheet 31 to surround the battery cell 2, and then joining the adjacent but unjoined edges to each other by attaching the adhesive tape 33. That is, the barrier member 3 according to the second embodiment can be formed by joining four edges where two lengthwise end surfaces, one widthwise end surface, and one heightwise side surface are joined to each other using the adhesive tape 33.

[0151] The adhesive tape 33 may include a heat-resistant and fire-resistant material. For example, the adhesive tape 33 may include a heat-resistant and fire-resistant synthetic resin material.

[0152] A sealing member may be provided in a gap between the lead hole 32 and the electrode lead 21 to seal the gap.

[0153] The sealing member may include a heat-resistant and fire-resistant resin.

[0154] Return to reference Fig.18 The barrier member 3 according to the second embodiment covers all five sides of the battery cell 2 to prevent heat from propagating from the battery cell 2 and guide flames and exhaust gas to the opening of the barrier member 3 .

[0155] Here, the barrier member 3 according to the second embodiment can be sealed by integrally joining four sides corresponding to the surface of the first sealing portion 221a to each other and integrally joining two sides corresponding to each surface of the second sealing portion 221b to each other by the adhesive tape 33. Therefore, even when the internal pressure increases rapidly due to fire, the portions of the barrier sheet 31 at the front and sides of the battery cell 2 may not fall off the battery cell 2.

[0156] In addition, the barrier member 3 according to the second embodiment is advantageous in that a small amount of the adhesive tape 33 is required compared with the first embodiment.

[0157] [Third Embodiment]

[0158] Fig.12 2 is a perspective view showing a barrier member according to a third embodiment of the present invention. Fig.12 , compared with the barrier sheet 31 of the first embodiment, the barrier sheet 31 according to the third embodiment further includes an adhesive wing 313 .

[0159] The adhesive wing 313 may be provided to protrude from at least one edge of the wing portion 312 .

[0160] Although the adhesive wing 313 may be provided at the wing portion 312, the adhesive wing 313 may be provided at the folded portion 311. In addition, the adhesive wing 313 may be provided at both the wing portion 312 and the folded portion 311.

[0161] The adhesive wing 313 may have a quadrilateral shape such as a trapezoid, and is preferably provided to protrude over the entire edge of the wing portion 312 and / or the folded portion 311. However, the adhesive wing 313 may have any shape as long as the adhesive wing 313 protrudes.

[0162] Fig.13 is a schematic diagram showing a barrier sheet folded to surround a battery cell according to a third embodiment of the present invention. Fig.13 , similar to the first embodiment, the barrier sheet 31 according to the third embodiment may be folded to surround the battery cell 2 .

[0163] Here, when the barrier sheet 31 is folded to surround the battery cell 2 , the adhesive tab 313 protruding from one of the adjacent but unjoined edges may be folded and joined to cover the other edge.

[0164] The adhesive wing 313 may be bonded by its adhesiveness or an adhesive applied thereto, and alternatively, the adhesive wing 313 may be bonded using an adhesive tape, which will be described later.

[0165] The adhesive wing 313 may protrude from one of the adjacent edges toward the other edge and be folded, or may protrude from both edges toward the other edge and be folded in a double combination.

[0166] Fig.14 is a perspective view showing a battery cell including a barrier member according to a third embodiment of the present invention. Fig.14, the barrier member 3 according to the third embodiment may be manufactured by incorporating the adhesive wings 313 in the barrier sheet 31 using the adhesive tape 33 after the adhesive wings 313 are folded in such a manner that the barrier sheet 31 forms a box shape.

[0167] The adhesive tape 33 may include a heat-resistant and fire-resistant material. For example, the adhesive tape 33 may include a heat-resistant and fire-resistant synthetic resin material.

[0168] A sealing member may be provided in a gap between the lead hole 32 and the electrode lead 21 to seal the gap.

[0169] The sealing member may include a heat-resistant and fire-resistant resin.

[0170] Return to reference Fig.18 The barrier member 3 according to the third embodiment covers all five sides of the battery cell 2 to prevent heat from propagating from the battery cell 2 and guide flames and exhaust gas to the opening of the barrier member 3 .

[0171] The barrier member 3 according to the third embodiment has advantages in that, compared with the first embodiment, a gap that may exist in the barrier member 3 is minimized due to the adhesive wings 313 and the structural strength thereof is higher.

[0172] [Fourth Embodiment]

[0173] Fig.15 2 is a perspective view showing a barrier member according to a fourth embodiment of the present invention. Fig.15 , the barrier member 3 may have a box shape in which all edges are joined to each other.

[0174] The barrier member 3 can be manufactured by folding the barrier sheet 31 in the form of a single developed pattern and fusing adjacent but unjoined edges to each other. However, various methods such as attaching insulating, heat-resistant and fire-resistant adhesive tapes can be used to join adjacent edges that are not joined to each other.

[0175] The barrier sheet 31 may include an insulating, heat-resistant and fire-resistant material. For example, the barrier sheet 31 may include an insulating, heat-resistant and fire-resistant synthetic resin material.

[0176] The lead holes 32 may be provided at both lengthwise end surfaces of the barrier member 3 .

[0177] The lead hole 32 may be provided on each of the two lengthwise end surfaces of the barrier member 3 , and extend to the lower end of each of the two lengthwise end surfaces of the barrier member 3 in the height direction.

[0178] Fig.16 Schematic diagram showing a battery cell being inserted into a barrier member according to a fourth embodiment of the present invention. Fig.16 , the battery cell 2 can be inserted through the open side of the barrier member 3 to be covered by the barrier member 3 .

[0179] Here, the electrode lead 21 may be inserted along the lead hole 32 from the lower end of each of both lengthwise end surfaces of the barrier member 3 .

[0180] Fig.17 is a perspective view showing a battery cell including a barrier member according to a fourth embodiment of the present invention. Fig.17 , the barrier member 3 can be manufactured by attaching the adhesive tape 33 to the lower end of each of the two lengthwise end surfaces after inserting the battery cell 2 .

[0181] The adhesive tape 33 may include a heat-resistant and fire-resistant material. For example, the adhesive tape 33 may include a heat-resistant and fire-resistant synthetic resin material.

[0182] A sealing member may be provided in a gap between the lead hole 32 and the electrode lead 21 to seal the gap.

[0183] The sealing member may include a heat-resistant and fire-resistant resin.

[0184] Return to reference Fig.18 The barrier member 3 according to the fourth embodiment covers all five sides of the battery cell 2 to prevent heat from propagating from the battery cell 2 and guide flames and exhaust gas to the opening of the barrier member 3 .

[0185] Since the barrier member 3 according to the fourth embodiment surrounds the battery cell 2 in a manner in which all edges of the five sides except the opening side at the bottom are joined and sealed, heat, flames and exhaust gas generated in the battery cell 2 can be guided toward a downward direction without leaking.

[0186] In addition, the barrier member 3 according to the fourth embodiment is advantageous in that a very small amount of the adhesive tape 33 is required compared with the first embodiment.

[0187] The present invention also provides a structure of a battery module including a battery cell having the above-mentioned barrier member. Obviously, the battery cells of the first to fourth embodiments may also constitute a battery module having a structure described later.

[0188] First, the structure of a general battery module will be described with reference to the accompanying drawings.

[0189] Figure 1 and Figure 2 The figures are a perspective view and an exploded perspective view respectively showing a battery module including a pouch-type battery cell. Figure 1 and Figure 2, a battery module including the pouch-type battery cells may include: a battery cell stack formed by stacking a plurality of battery cells 2 ; and a case 12 accommodating the battery cell stack 11 .

[0190] The battery cell stack 11 may be formed by stacking a plurality of battery cells 2 in the width direction.

[0191] The battery cell stack 11 can be formed by stacking a plurality of battery cells 2 in the width direction with a compressible mat interposed therebetween. The compressible mat can absorb tolerance and expansion (a phenomenon in which gas fills the pockets of the battery cells and causes the pockets to expand) by being compression molded to fit the shape of the battery cells 2.

[0192] The shell 12 may include: a U-shaped frame 123, which has a U-shape with an open upper end and two open lengthwise ends (front and rear); an end plate 122, which covers the front and rear of the U-shaped frame 123; and a top plate 121, which covers the open upper end.

[0193] The battery cell stack 11 may be housed in the case with the folded side of the battery cell 2 facing downward (ie, the first sealing portion 221 a facing upward).

[0194] An insulating film may be provided between the case 12 and the battery cell stack 11 to insulate the battery cell stack 11 from the outside.

[0195] A thermally conductive resin capable of transferring heat to the outside may be disposed on the bottom surface of the U-shaped frame 123 to cool heat generated from the battery cell stack 11 .

[0196] Hereinafter, the structure of a battery module according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[0197] [Fifth Embodiment]

[0198] Fig.19 and Fig. 20 The front cross-sectional view and the transverse cross-sectional view respectively show a battery module including a battery cell provided with a barrier member according to the present invention. Fig.19 and Fig. 20 , the battery cells 2 may be stacked on each other in the width direction while being surrounded by the barrier member 3 to form a battery cell stack 11 .

[0199] The battery cells 2 may be stacked with the opening sides of the barrier members 3 facing the same direction to form a battery cell stack 11 .

[0200] The barrier member 3 may include a compressible material. Therefore, the barrier member 3 may have a function of absorbing tolerance and expansion similar to a compressible pad. In this case, the barrier member 3 simply occupies the space occupied by the compressible pad, so that the battery module 1 according to the fifth embodiment can be manufactured by only slightly modifying the manufacturing process of the battery cell stack 11 of the battery module using the compressible pad without changing the design or production equipment.

[0201] This is possible because the barrier member 3 can maintain its box-shaped structure against strong internal pressure even if the barrier member 3 is made of a thin barrier sheet 31 due to the unique integral structure of the barrier member 3. Therefore, advantageously, the present invention can be implemented simply by replacing a conventional compressible pad with the barrier member 3 without adding a separate rigid shell or the like.

[0202] Another advantage of this embodiment is that when the battery module 1 can be manufactured as described above without adding separate components, the number of battery cells 2 that can be accommodated in a single battery module 1 and the energy capacity relative to volume (i.e., energy density) are not reduced compared to conventional battery modules.

[0203] The battery cell stack 11 may be housed in the case 12 with the folded sides of the battery cells 2 and the open sides of the barrier members 3 facing downward.

[0204] The insulating film 13 may be interposed between the battery cell stack 11 and the top plate 121 and between the battery cell stack 11 and both side walls of the case 12 .

[0205] The thermally conductive resin 14 may be interposed between the battery cell stack 11 and the bottom surface of the case 12 .

[0206] The exhaust hole 124 opened toward the downward direction may be provided on the bottom surface of the battery module 1. When the battery cell 2 catches fire, the flame and exhaust gas guided downward by the barrier member 3 may be discharged to the outside of the battery module 1 through the exhaust hole 124. Therefore, from the battery cell level to the battery module level, the flame and exhaust gas caused by the ignition of the battery cell 2 may be guided in the downward direction.

[0207] In this case, since the barrier member 3 can withstand the instantaneous increase in the internal pressure of each battery cell 2 caused by the exhaust gas and the barrier member 3 is made of a compressible material, the pressure applied to the case due to the rapid increase in the internal pressure can be reduced. For example, when the exhaust gas is guided only in the downward direction at the battery module level, the flame generated from the battery cell 2 is likely to damage the insulating film 13 and the thermally conductive resin 14.

[0208] In particular, the end plate 122 may be provided with a terminal mainly for electrically connecting the battery cell stack 11 to the outside, so that the battery module 1 can be connected to other adjacent battery modules to form a battery pack. Since the exhaust gas is directed at the battery module level, causing the end plate 122 to be heated and exposed to flames and exhaust gas, it is very difficult to prevent the heat from propagating to adjacent battery modules. Therefore, there is a risk that a chain fire between battery modules within the battery pack may occur so that the ignition of the battery cell 2 may cause a larger explosion. According to the present invention, a series fire between battery modules as described above can be prevented.

[0209] In addition, since the barrier member 3 can prevent the propagation of heat between the battery cells 2 , excessive thermal runaway due to serial ignition of the battery cells 2 can be fundamentally prevented.

[0210] The exhaust hole 124 may be opened as the internal pressure of the housing 12 increases. In addition, the exhaust hole 124 may be closed as the internal pressure of the housing 12 decreases. That is, the exhaust hole 124 may be opened and closed according to the increase or decrease of the internal pressure of the housing 12.

[0211] The above embodiments are to be understood in all respects as illustrative rather than restrictive, and the scope of the present invention will be represented by the appended claims rather than the detailed description given above. In addition, all changes and modifications derived from equivalent concepts and the meaning and scope of the patent claims to be described later should be interpreted as being included within the scope of the present invention.

[0212] As described above, the present invention has been described with reference to the illustrative drawings, but the present invention is not limited to the embodiments and drawings disclosed herein, and those skilled in the art may make various modifications within the scope of the technical concept of the present invention. Obviously, changes may occur. In addition, although the operational effects of the configuration according to the present invention are not explicitly described and explained while explaining the embodiments of the present invention above, it is natural that the predictable effects caused by the configuration should also be recognized.

Claims

1. A battery cell, comprising: Electrode assembly; a bag containing the electrode assembly, being folded in half and having a folded side and three sealed sides; as well as an electrode lead extending from the electrode assembly and protruding outwardly from the bag, The battery cell also includes: A heat-insulating, heat-resistant and fire-resistant barrier member having a box-like shape provided with slit-type lead holes and one open side, wherein the length, width and height of the box-like shape are X, Y and Z respectively, The electrode lead protrudes from the barrier member through the lead hole, and five side surfaces of the battery cell except the folded side are covered by the barrier member.

2. The battery cell according to claim 1, wherein: The barrier member is manufactured by folding a barrier sheet in the form of a single unfolded pattern.

3. The battery cell according to claim 2, wherein: The barrier sheet comprises: A rectangular folded portion, the horizontal and vertical dimensions of which are X and Y+2Z respectively; and a rectangular wing portion, the wing portion protruding from each of the two horizontal ends of the folded portion, the wing portion being provided with the lead hole and having horizontal and vertical dimensions of Y and Z, respectively, wherein the folded portion corresponds to one end surface in the height direction and two end surfaces in the width direction of the battery cell, and The wing portions correspond to two lengthwise end surfaces of the battery cell.

4. The battery cell according to claim 2, wherein: The barrier sheet comprises: A rectangular folded portion, the horizontal and vertical dimensions of which are X and Y+2Z respectively; and a rectangular wing portion, the wing portion protruding from each of the two horizontal ends of the folded portion, the wing portion being provided with the lead hole and having horizontal and vertical dimensions of Z and Y, respectively, wherein the folded portion corresponds to one end surface in the height direction and two end surfaces in the width direction of the battery cell, and The wing portions correspond to two lengthwise end surfaces of the battery cell.

5. The battery cell according to claim 2, wherein: The barrier member is formed by folding the barrier sheet to surround the battery cell and then joining adjacent but unjoined edges to each other by attaching an adhesive tape.

6. The battery cell according to claim 5, wherein: The adhesive tape comprises a heat-resistant and fire-resistant material.

7. The battery cell according to claim 2, wherein: The barrier sheet includes an adhesive tab that projects from one of the adjacent but unjoined edges of the barrier sheet when the barrier sheet is folded around the battery cell and is folded to cover the other edge. 8 . The battery cell according to claim 2 , further comprising a sealing member sealing a gap between the lead hole and the electrode lead.

9. The battery cell according to claim 8, wherein: The sealing member includes a heat-resistant and fire-resistant resin.

10. The battery cell according to claim 2, wherein: The barrier member has an integral box shape with all edges joined to each other.

11. The battery cell according to claim 10, wherein: The barrier member is manufactured by folding the barrier sheet in the form of a single unfolded pattern and fusing adjacent but unjoined edges to each other.

12. The battery cell according to claim 10, wherein: The electrode leads protrude from both lengthwise end surfaces of the battery cell, and The lead hole is provided on each of the two lengthwise end surfaces of the barrier member, and extends in the height direction to a lower end of each of the two lengthwise end surfaces of the barrier member.

13. The battery cell according to claim 12, wherein: The battery cell is inserted through the open side of the barrier member to be covered by the barrier member, and An adhesive tape is attached to the lower end of each of the two lengthwise end surfaces of the barrier member.

14. The battery cell according to claim 13, wherein: The adhesive tape comprises a heat-resistant and fire-resistant material. 15 . The battery cell according to claim 10 , further comprising a sealing member sealing a gap between the lead hole and the electrode lead.

16. A battery module, comprising: A battery cell stack manufactured by stacking a plurality of battery cells according to any one of claims 1 to 15; and a casing for accommodating the battery cell stack.

17. The battery module according to claim 16, wherein: The barrier member comprises a compressible material.

18. The battery module according to claim 16, wherein: The battery cell stack is accommodated in the case in such a manner that the opening side of the barrier member faces in a downward direction.

19. The battery module according to claim 18, wherein: The bottom surface of the housing is provided with an exhaust hole opened toward the downward direction.

20. The battery module according to claim 19, wherein: The exhaust hole opens according to an increase in the internal pressure of the housing.

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