Battery module with partition walls and insulation for fire suppression

Abstract

The present invention relates to a battery module having partition walls and an insulation layer for preventing thermal runaway, and more specifically, the present invention relates to a battery module in which a cell module assembly including two or more cell stacks is received in an internal space in a protective casing, each cell stack including a plurality of battery cells stacked vertically together, and one or more partition walls are arranged in at least one of the following positions: between the cell stacks positioned adjacent to each other; and between the cell stack and the protective casing.

Description

Technical Field

[0001] This application claims the benefit of priority from Korean Patent Application No. 2020-0079313, filed on Jun. 29, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a battery module having partition walls and an air insulation layer for suppressing fire, and more particularly, to a battery module configured such that partition walls and an air insulation layer are provided between battery cell stacks or between a battery cell stack and a side cover, thereby preventing ignition conditions and thus suppressing the outbreak of a fire, and even when a fire breaks out, preventing the fire from spreading to adjacent battery cell stacks. Background Art

[0003] Secondary batteries with high product applicability and electrical properties (such as high energy density) have been commonly used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) and portable devices that are all driven by electric drive sources. As a new energy source that can increase environmental friendliness and energy efficiency, such secondary batteries have attracted attention because, in addition to the main advantage of significantly reducing the use of fossil fuels, they do not produce byproducts due to the use of energy.

[0004] As secondary batteries, there are lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. A plurality of battery cells can be connected in series or in parallel to form a battery module or a battery pack.

[0005] An energy storage system (ESS) that has drawn attention in recent years is a device that stores generated electricity in a battery to supply the electricity to consumers when needed to thereby maximize electricity usage efficiency.

[0006] In a typical energy storage system (ESS), multiple battery modules form a single battery rack, and dozens to hundreds of battery racks are combined to form a single system. Furthermore, energy storage systems are used in conjunction with an uninterruptible power supply (UPS) that is configured to stably supply power in response to sudden power outages or abnormal conditions, or with a photovoltaic power system that is a power generation device configured to convert sunlight into electrical energy.

[0007] At the same time, although secondary batteries have excellent electrical properties, the components that make up the battery (such as active materials or electrolytes) decompose in abnormal operating conditions such as overcharging, overdischarging, exposure to high temperatures, or electrical short circuits, thereby generating heat and gas. As a result, a swelling phenomenon, i.e., swelling of the secondary battery, occurs. The swelling phenomenon accelerates decomposition, which causes the secondary battery to explode or catch fire due to thermal runaway.

[0008] Specifically, when thermal runaway occurs in a battery cell, it generates flashes of light (flames that erupt from weak seals), sparks (heat-producing particles emitted due to separation of the internal electrodes and melting of the aluminum current collector), and high-temperature exhaust gas. These substances, in particular, do not remain at the point of generation but instead migrate to adjacent modules, including surrounding battery cells, potentially leading to a serious accident.

[0009] In connection with this, the patent document (Korean Patent Application Gazette No. 2020-0011816) discloses a battery pack, comprising: a plurality of battery cells arranged so that the main surfaces of the battery cells face each other; and a partition wall placed between adjacent battery cells in the battery cells, wherein the partition wall is provided with an air bag that is carved to be concave in a direction away from the main surface of each battery cell in a thickness direction of the partition wall.

[0010] In the above-mentioned prior art documents, partition walls and air pockets are formed between adjacent battery cells, thereby being able to interrupt thermal interference between the adjacent battery cells, and thus being able to slightly interrupt thermal runaway from certain deteriorated battery cells to other battery cells adjacent thereto.

[0011] However, the prior art document relates to a battery pack in which prismatic cells are stacked side by side, and therefore, without modification, is not applicable to a battery module composed of pouch-shaped cells (each of which includes a cell housing and an electrode assembly and is configured such that leads protrude outward from the housing). In addition, air is trapped in the thermal insulation layer, so when thermal runaway occurs in a battery cell, the thermal insulation layer does not function properly, whereby heat is easily transferred to adjacent cells, thereby spreading a fire.

[0012] (Prior art literature)

[0013] (Patent Document 1) Korean Patent Application Publication No. 2020-0011816 Summary of the Invention

[0014] Technical issues

[0015] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a battery module that can interrupt the movement of generated flames and sparks when thermal runaway occurs in a battery cell, thereby preventing the outbreak of fire or preventing the fire from spreading to adjacent battery cell stacks.

[0016] Another object of the present invention is to provide a battery module that can quickly discharge air in a module case together with ejected exhaust gas when thermal runaway occurs in a battery cell, thereby preventing the outbreak of fire.

[0017] Yet another object of the present invention is to provide a battery module that, when thermal runaway occurs in a battery cell, can suppress the generated heat from moving to an adjacent battery cell stack and discharge the heat to the outside together with exhaust gas, thereby preventing the outbreak of fire.

[0018] Technical Solution

[0019] To achieve the above-mentioned object, a battery module according to the present invention is constructed such that a battery cell module assembly (200) including two or more battery cell stacks (210) is received in a space portion defined in a protective housing (100), in each of the battery cell stacks, a plurality of battery cells (211) are stacked in a vertical direction, and the battery module is constructed such that one or more partition walls (300) are provided in at least one of the following positions: between adjacent battery cell stacks in the battery cell stacks (210); and between the battery cell stack (210) and the protective housing (100).

[0020] Moreover, in the battery module according to the present invention, a first partition wall (310) may be provided between adjacent battery cell stacks in the battery cell stack (210), and the first partition wall (310) may include: a pair of vertical partition walls (311), the pair of vertical partition walls (311) being positioned to face each other in a state of being spaced apart from each other by a predetermined distance, each of the vertical partition walls (311) having a flat shape; and a connecting wall (312), the connecting wall (312) being configured to connect the upper ends of the vertical partition walls (311) to each other, the connecting wall (312) being provided with one or more opening holes (312').

[0021] Moreover, in the battery module according to the present invention, the protective housing (100) may include: a pair of side covers (110), the pair of side covers (110) being placed to face each other; a lower cover (120), the lower cover (120) being configured to connect the lower ends of the side covers (110) to each other; a front cover (130); a rear cover (140); and an upper cover (150), the upper cover (150) being placed on the side covers (110).

[0022] Moreover, in the battery module according to the present invention, each of the vertical partition walls (311) can be provided with a first bending wall (311') and a second bending wall (311") at its opposite two side ends, and the first bending wall (311') and the second bending wall (311") are bent and / or curved in a direction toward a battery cell stack (210) positioned adjacent to the vertical partition wall.

[0023] Moreover, in the battery module according to the present invention, the first bending wall (311') and the second bending wall (311") can form a fourth space portion (S4) and a fifth space portion (S5), respectively.

[0024] Furthermore, in the battery module according to the present invention, the vertical partition wall (311) and the battery cell stack (210) may be spaced apart from each other by a predetermined distance to form a sixth space portion (S6).

[0025] Moreover, in the battery module according to the present invention, a second partition wall (320) having one open side surface can be arranged near a corner of one side of a battery cell stack adjacent to each of the side covers (110) in the battery cell stack (210), the second partition wall (320) is configured to form a first space portion (S1), and the open surface of the second partition wall (320) can be positioned to face the corner of the other side of the battery cell stack (210).

[0026] Moreover, in the battery module according to the present invention, a third partition wall (330) having an open side surface can be arranged near the corner of the other side of a battery cell stack adjacent to each of the side covers (110) in the battery cell stack (210), the third partition wall (330) is configured to form a second space portion (S2), and the open surface of the third partition wall (330) can be positioned to face the open surface of the second partition wall (320).

[0027] Furthermore, in the battery module according to the present invention, a third space portion (S3) may be provided between the side cover (110) and the battery cell stack (210).

[0028] Moreover, in the battery module according to the present invention, the battery cell stack (210) may include: a plurality of battery cells (211); a first bus bar (213), the first bus bar (213) being configured to allow a negative electrode lead or a positive electrode lead of the battery cell (211) to be connected to the first bus bar (213); and a second bus bar (214), the second bus bar (214) being configured to allow the remaining leads of the battery cell (211) to be connected to the second bus bar (214), and adjacent battery cell stacks in the battery cell stack (210) can be connected to each other via a connecting bus bar (220).

[0029] Moreover, in the battery module according to the present invention, the front cover (130) may include a front plate (131) and a first recessed portion (132), the first recessed portion (132) may be located at each of opposite sides of the front plate (131) in a state of being recessed toward the front surface of the battery cell stack (210) at a predetermined depth, and the first recessed portion (132) may be provided with a first slit (132'), the first slit being configured to allow an electrode lead of the battery cell (211) to extend through the first slit.

[0030] Furthermore, in the battery module according to the present invention, the entire surface of the first recessed portion (132) except for the first slit (132') may be hermetically sealed.

[0031] Furthermore, in the battery module according to the present invention, each of the first slits (132') may be formed by a first inclined plate (132") inclined at a predetermined angle.

[0032] Moreover, in the battery module according to the present invention, the rear cover (140) may include a rear plate (141) and a second recessed portion (142), the second recessed portion (142) may be located at each of opposite sides of the rear plate (141) in a state of being recessed toward the rear surface of the battery cell stack (210) at a predetermined depth, and the second recessed portion (142) may be provided with a second slit (142'), the second slit being configured to allow the electrode lead of the battery cell (211) to extend through the second slit.

[0033] Furthermore, in the battery module according to the present invention, the entire surface of the second recessed portion (142) except for the second slit (142') may be hermetically sealed.

[0034] Furthermore, in the battery module according to the present invention, each of the second slits (142') may be formed by a second inclined plate (142") inclined at a predetermined angle.

[0035] Moreover, in the battery module according to the present invention, each of the pair of side covers (110) can be provided with a fastening recess (111) protruding outward in its upper end, the upper cover (150) can include a main board (151) positioned in a horizontal direction and an auxiliary board (152) bent downward from the main board (151), the main board (151) can be provided with a second perforated portion (151'), and the auxiliary board (152) can be provided with a fastening protrusion (152') on its outer surface, and the fastening protrusion is configured to be received in the fastening recess (111).

[0036] Furthermore, in the battery module according to the present invention, the second perforated portion (151') may be located directly above the connecting wall (312) of the first partition wall (310).

[0037] Moreover, in the battery module according to the present invention, the lower cover (120) may be provided with a first perforated portion (121), and the first perforated portion (121) may be located directly below the connecting wall (312) of the first partition wall (310).

[0038] In addition, the present invention provides a battery pack including the battery module.

[0039] In addition, the present invention provides an energy storage system including the battery module.

[0040] Beneficial effects

[0041] The battery module according to the present invention has the advantage that the vertical partition walls and the bent walls are located between the battery cell stacks, thereby interrupting the movement of flames and sparks generated during thermal runaway to adjacent battery cell stacks or adjacent electrode leads, thereby preventing the outbreak of fire in the battery module.

[0042] In addition, the battery module according to the present invention has an advantage in that the second partition wall and the third partition wall are located between the side cover and the battery cell stack so as to face each other, thereby interrupting the movement of flames and sparks generated during thermal runaway to adjacent battery cell stacks or adjacent electrode leads, thereby preventing the outbreak of fire.

[0043] Furthermore, the battery module according to the present invention has the advantage that exhaust gas ejected during thermal runaway can be quickly discharged to the outside, and air can also be discharged together with the exhaust gas at this time, thereby preventing the occurrence of flames. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1is an external perspective view of a battery module according to a first preferred embodiment of the present invention when viewed in a direction toward one side of the battery module.

[0045] Figure 2 is an external perspective view of the battery module according to the first preferred embodiment of the present invention when viewed in a direction toward the other side of the battery module.

[0046] Figure 3 It shows Figure 1 An exploded perspective view of the coupling structure between the lower cover and the upper cover of the battery module shown in FIG.

[0047] Figure 4 It shows Figure 1 An exploded perspective view of the coupling structure between the front cover and the rear cover of the battery module shown in FIG.

[0048] Figure 5 are views showing the front cover viewed at various angles.

[0049] Figure 6 are views showing the rear cover viewed at various angles.

[0050] Figure 7 It shows Figure 1 An exploded perspective view of the coupling structure between partition walls of the battery module shown in FIG.

[0051] Figure 8 It is an enlarged perspective view of the first partition wall.

[0052] Figure 9 are cross-sectional views showing various modifications of the first partition wall.

[0053] Figure 10 1 and 2 are perspective views showing various modifications of the third partition wall.

[0054] Figure 11 When viewed from the front with the front cover and top cover removed Figure 1 A perspective view of the battery module shown.

[0055] Figure 12 When viewed from above with the top cover removed Figure 1 A plan view of the battery module is shown.

[0056] Figure 13 It is along Figure 1 A cross-sectional view taken along line AA'.

[0057] Figure 14 is a plan view of a battery module according to a second preferred embodiment of the present invention when viewed from above in a state in which an upper cover is removed.

[0058] Figure 15 is a cross-sectional view of a battery module according to a second preferred embodiment of the present invention, taken in a transverse direction. DETAILED DESCRIPTION

[0059] In this application, it should be understood that the terms "include", "have", "include", etc. indicate the existence of the stated features, numbers, steps, operations, elements, parts or their combinations, but do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, parts or their combinations.

[0060] In addition, in all drawings, the same reference numerals will be used to refer to parts that perform similar functions or operations. In the specification, when a part is said to be connected to another part, the part can be directly connected to the other part and the part can also be indirectly connected to the other part via another part. In addition, the inclusion of a specific element does not mean that other elements are excluded, but rather means that such elements may be further included unless otherwise mentioned.

[0061] Hereinafter, a battery module having a partition wall and a heat insulating layer for suppressing fire according to the present invention will be described with reference to the accompanying drawings.

[0062] Figure 1 is an external perspective view of a battery module according to a first preferred embodiment of the present invention when viewed in a direction toward one side of the battery module, Figure 2 is an external perspective view of the battery module according to the first preferred embodiment of the present invention when viewed in a direction toward the other side of the battery module, Figure 3 It shows Figure 1 An exploded perspective view of the coupling structure between the lower cover and the upper cover of the battery module shown in FIG.

[0063] like Figures 1 to 3 As shown in FIG, the battery module according to the first embodiment of the present invention is configured to have a structure in which a battery cell module assembly 200 and a partition wall 300 are received in a protective case 100 having a substantially hexahedral shape, which is made of a metal material.

[0064] In the battery cell module assembly 200 , a plurality of battery cells 211 are stacked in a vertical direction to constitute the battery cell stack 210 , and two battery cell stacks 210 are positioned side by side in a state of being spaced apart from each other by a predetermined distance.

[0065] The partition walls 300 are configured to prevent or inhibit the movement of flames, sparks, exhaust gases, and heat generated when an incident occurs in a particular battery cell to adjacent battery cell stacks, while also guiding the discharge of air within the protective housing 100. Specifically, the first partition wall 310 is located between adjacent battery cell stacks 210, and the second and third partition walls 320 and 330 are provided between the battery cell stacks 210 and the protective housing 100. A detailed description of this will be provided below.

[0066] At the same time, the protective housing 100 is configured to physically protect the battery cell module assembly 200 received therein, and includes: a pair of side covers 110, which are positioned to face each other in a state of being spaced apart from each other by a distance slightly greater than the width (X-axis direction) of the battery cell module assembly 200; a lower cover 120, which is configured to connect the lower ends of the pair of side covers 110 to each other; a front cover 130; a rear cover 140; and an upper cover 150, which is placed on the pair of side covers 110.

[0067] A plurality of fastening recesses 111 protruding outward are provided in the upper end of each side cover 110 , each side cover 110 having a substantially flat shape and configured to protect a corresponding side surface of the battery cell module assembly 200 , and the lower cover 120 is connected to the lower ends of the pair of side covers 110 .

[0068] The pair of side covers 110 and the lower cover 120 may be separately formed and then coupled to each other using a well-known coupling method, or may be manufactured in an integrated state using a well-known method such as molding.

[0069] The upper cover 150 configured to protect the upper portion of the battery cell module assembly 200 includes a main plate 151 positioned horizontally and an auxiliary plate 152 bent from the main plate 151 toward the lower cover 120 .

[0070] Here, a fastening protrusion 152 ′ received in the fastening recess 111 of the side cover 110 is provided on an outer surface of the auxiliary plate 152 .

[0071] Meanwhile, a second perforated portion 151' is formed longitudinally (in the Z-axis direction) in the middle of the main plate 151 of the upper cover 150, more specifically in the portion of the main plate 151 where the first partition wall 310 extends vertically upward. In the event of an accident, the second perforated portion 151' serves as a passage configured to allow exhaust gas and heat to escape. In particular, when high-pressure exhaust gas is discharged, the air within the protective housing 100 is discharged along with the exhaust gas, thereby preventing the outbreak of a fire.

[0072] When all conditions such as combustible materials, oxygen, and a temperature above the ignition point are met, a fire breaks out in the battery module. As described above, the heat and air in the protective housing 100 are discharged to the outside through the second perforated portion 151' of the main board 151, thereby suppressing the outbreak of fire.

[0073] Here, it is preferred that the second perforated portion 151' is formed to alternately arrange slits and circular holes, because the second perforated portion needs to correspond to the opening hole 312' formed in the connecting wall 312 of the first partition wall 310, which will be described later.

[0074] In addition, it is more preferred that the lower cover 120 is also provided with a first perforated portion 121 in the longitudinal direction (Z axis direction), and the first perforated portion 121 is configured to guide the discharge of air and heat, which has the same function as the second perforated portion 151 ′.

[0075] Figure 4 It shows Figure 1 An exploded perspective view of the coupling structure between the front cover and the rear cover of the battery module shown in FIG. Figure 5 are views showing the front cover viewed at various angles, and Figure 6 are views showing the rear cover viewed at various angles.

[0076] refer to Figures 4 to 6 The front cover 130 is positioned in a direction in which electrode leads located on one side of the battery cell stack 210 protrude, and the rear cover 140 is positioned in a direction in which electrode leads located on the other side of the battery cell stack protrude. The front cover 130 and the rear cover 140 secure bus bars, provide electrical insulation between the protective housing 100 and the bus bars, and protect the battery cell stack 210 from external impacts applied from the front and rear.

[0077] First, the front cover 130 made of a thermoplastic material will be described in detail. The front cover 130 includes a front plate 131 and a pair of first recessed portions 132 formed slightly spaced apart from opposite edges of the front plate 131. Each first recessed portion has a predetermined width, height, and depth toward the front surface of the battery cell stack 210.

[0078] Here, the first recessed portions 132 are formed at positions slightly spaced apart from opposite side edges of the front plate 131 because it is necessary to closely contact the front cover 130 with the second partition wall 320. A detailed description will be given below.

[0079] At the same time, each first recessed portion 132 is provided with a first slit 132' through which the electrode leads of the battery cells 211 extend. Preferably, the first slits 132' are formed by a plurality of first inclined plates 132" that are inclined downward at a predetermined angle toward the outer surface of the front cover 130, thereby maximally interrupting the movement of flames generated around the electrode leads of the battery cells through the first slits 132' to the outside. In other words, except for the first slits 132', the entire surface of the first recessed portion 132 is hermetically sealed.

[0080] Next, the rear cover 140 made of a thermoplastic material will be described. The rear cover 140 is similar in construction and function to the front cover 130 described above.

[0081] The rear cover 140 includes a rear plate 141 and a pair of second recessed portions 142 , which are formed at positions slightly spaced apart from opposite side edges of the rear plate 141 , and each second recessed portion 142 has a predetermined width, height, and depth toward the rear surface of the battery cell stack 210 .

[0082] Similar to the front plate 131, the second recessed portions 142 are formed slightly apart from the opposite side edges of the rear plate 141 because the rear cover 140 needs to be in close contact with the third partition wall 330. A detailed description will be given below.

[0083] Each second recessed portion 142 is provided with a second slit 142' through which the electrode leads of the battery cells 211 extend. Preferably, the second slits 142' are formed by a plurality of second inclined plates 142" that are inclined upward at a predetermined angle toward the outer surface of the rear cover 140, thereby minimizing the risk of flames generated around the electrode leads of the battery cells from migrating to the outside through the second slits 142'. Except for the second slits 142', the entire surface of the second recessed portion 142 is also hermetically sealed.

[0084] Meanwhile, the battery cell module assembly 200 includes two battery cell stacks 210 and a connection bus bar 220 configured to electrically connect the battery cell stacks 210 to each other.

[0085] First, the battery cell stack 210 includes: a plurality of battery cells 211, which are stacked in a vertical direction; a gasket 212, which is arranged at each of the upper and lower parts of the stacked battery cells 211; a first bus bar 213, which is configured to electrically connect the leads on one side of the battery cells 211 located at the relatively upper part of a battery cell stack 210; and a second bus bar 214, which is configured to electrically connect the leads on the other side of the battery cells 211.

[0086] The battery cell 211 may be a pouch-shaped battery cell and include a cell case configured to receive an electrode assembly (not shown) therein and a pair of electrode leads.

[0087] Here, the electrode assembly may be a jelly roll assembly having a structure in which a long sheet-type positive electrode and a long sheet-type negative electrode are wound with a separator interposed therebetween; a stacked assembly having a structure in which a rectangular positive electrode and a rectangular negative electrode are stacked with a separator interposed therebetween; a stacked and folded assembly having a structure in which a unit cell is wound using a long separator; or a layered and stacked assembly having a structure in which battery cells are stacked with a separator interposed therebetween and then attached to each other. However, the present invention is not limited thereto.

[0088] Also, it is apparent that, in addition to the generally used liquid electrolyte, the electrolyte may be replaced by a solid electrolyte or a gel-type quasi-solid electrolyte having an intermediate phase between liquid and solid obtained by adding additives to a solid electrolyte.

[0089] The electrode assembly is received in a single housing, and the single housing is generally constructed to have a laminated sheet structure including an inner layer, a metal layer and an outer layer. The inner layer is placed in direct contact with the electrode assembly, so the inner layer should exhibit high insulation properties and electrolyte resistance. In addition, the inner layer should exhibit high sealing properties, thereby hermetically sealing the single housing from the outside, that is, the thermal bond seal between the inner layers should exhibit excellent thermal bonding strength. The inner layer can be made of a material selected from the following: a polyolefin resin, such as polypropylene, polyethylene, polyethylene acrylate or polybutylene; a polyurethane resin; and a polyimide resin, which exhibits excellent chemical resistance and high sealing properties. However, the present invention is not limited thereto, and most preferably, polypropylene is used, which exhibits excellent mechanical and physical properties (such as tensile strength, stiffness, surface hardness and impact resistance) and excellent chemical resistance.

[0090] The metal layer disposed adjacent to the inner layer corresponds to a barrier layer configured to prevent moisture or various gases from penetrating into the battery from the outside. A light and easily formable aluminum thin film can be used as a preferred material for the metal layer.

[0091] The outer layer is provided on the other surface of the metal layer. The outer layer may be made of a heat-resistant polymer exhibiting excellent tensile strength, moisture permeability resistance, and air permeability resistance, so that the outer layer exhibits high heat resistance and chemical resistance while protecting the electrode assembly. As an example, the outer layer may be made of nylon or polyethylene terephthalate. However, the present invention is not limited thereto.

[0092] At the same time, the paired electrode leads are composed of a positive electrode lead and a negative electrode lead, which can be exposed to the outside from the single body shell in a state of being electrically connected to the positive electrode tab and the negative electrode tab of the single body component respectively, or can be directly connected to the single body component in a state where the tab is omitted.

[0093] The gasket 212 allows the stacked battery cells 211 to be in close contact with each other in a normal state and absorbs the expansion volume of the battery cells when they are bulging. Moreover, it is preferred that the gasket is made of a material exhibiting low thermal conductivity, more specifically a material exhibiting high elasticity, high insulation and low thermal conductivity, such as expanded polypropylene (EPP), EDS or EPDM. However, the material used for the gasket is not particularly limited as long as the gasket performs the same function.

[0094] Of course, in order to reliably interrupt heat transfer to adjacent battery cell stacks, a heat insulating layer (not shown) made of a heat insulating material in close contact with the lower cover 120 and the upper cover 150 may be further provided on the lower cover 120 and the upper cover 150 .

[0095] Although a pair of spacers 212 is provided in the figure to cover the lowermost layer and the uppermost layer of the battery cells 211 , this is for illustration only, and the spacers may be provided between the battery cells 211 as needed.

[0096] Each of the first bus bar 213 and the second bus bar 214 configured to electrically connect the leads of the battery cells 211 to each other is a flat metal plate in which a slit through which the leads extend is formed.

[0097] The connecting busbars 220 include a pair of third busbars 221 and a connecting bar 222. Specifically, the third busbar 221 fixes the other leads of one battery cell stack 210 that are not connected by the first busbar 213, and the pair of third busbars 221 can be connected to each other via the connecting bar 222, thereby connecting adjacent battery cell stacks 210 in series or in parallel.

[0098] The assembly process of the battery cell module assembly 200 having the above-described configuration will be briefly described. The battery cell stack 210 is prepared, and the battery cell stack 210 is configured such that a gasket 212, a plurality of battery cells 211, and the gasket 212 are stacked in this order, and the leads of the battery cells 211 (e.g., the leads of the battery cells facing the front direction) extend through the first slit 132' of the front cover 130.

[0099] Subsequently, the upper lead extends through the slit of the first bus bar 213 and is then bent, and the lower lead extends through the slit of the third bus bar 221 of the connection bus bar 220 and is then bent. Subsequently, the leads are fixed by well-known coupling means such as welding.

[0100] At this time, because the first bus bar 213 and the third bus bar 221 are fastened while being seated in the first recessed portion 132 of the front cover 130, it is possible to minimize the increase in volume caused by the first bus bar 213 and the third bus bar 221. In addition, because each of the pair of third bus bars 221 has a structure in which three sides are connected to each other at right angles and one side is open, thereby corresponding to the structure of the outer shape of the front cover 130, and the third bus bars are connected to each other via the connecting bars 222, adjacent battery cell stacks 210 remain electrically connected to each other.

[0101] The leads of the rear-facing battery cells 211 sequentially extend through the second slits 142' of the rear cover 140 and the slits of the second busbars 214 before being bent. The leads are then secured using well-known means, such as welding. Because the second busbars 214 are positioned within the second recessed portion 142 of the rear cover 140, the increase in volume can also be minimized.

[0102] Figure 7 It shows Figure 1 An exploded perspective view of the coupling structure between the partition walls of the battery module shown in FIG. Figure 8 It is an enlarged perspective view of the first partition wall.

[0103] When thermal runaway occurs in a specific battery cell, flames, sparks, high-pressure exhaust gas, and heat are ejected, and when oxygen and combustible materials coexist therewith, a fire outbreak or explosion occurs.

[0104] The partition wall 300 according to the present invention is configured to prevent thermal runaway products (such as flames and sparks) from migrating to adjacent battery cell stacks 210 while simultaneously preventing the protective housing 100 from protruding outward. Furthermore, the partition wall is configured to guide exhaust gas and heat to the second perforated portion 151' of the upper cover 150 and the first perforated portion 121 of the lower cover 120. Because the air inside the protective housing 100 is also exhausted during this process, flames are not generated.

[0105] refer to Figure 3 、 Figure 7 and Figure 8 The partition wall 300 configured to perform the above-mentioned function includes: a first partition wall 310, which is located between the battery cell stacks 210; a second partition wall 320, which is located near the corner of one side of the battery cell stack 210; and a third partition wall 330, which is located near the corner of the other side of the battery cell stack 210.

[0106] First, the first partition wall 310, which is placed between the battery cell stacks 210 adjacent to each other and is positioned slightly apart from the battery cell stacks 210, fundamentally interrupts the movement of flames and sparks to the adjacent battery cell stacks 210, prevents the flames and sparks from being ejected to the front surface or rear surface of the protective housing 100, and guides the movement of exhaust, heat and air in the vertical direction.

[0107] Specifically, the first partition wall 310 includes: a pair of vertical partition walls 311, which are erected so as to face each other while being spaced apart from each other by a predetermined distance; and a connecting wall 312, which is configured to connect the upper ends of the vertical partition walls 311 to each other.

[0108] Here, the length (Z-axis direction) of the vertical partition wall 311 is similar to that of the battery cell 211, and the height of the vertical partition wall is set so that the vertical partition wall is in close contact with the upper cover 150. That is, the vertical partition wall has a substantially flat plate shape.

[0109] The connecting wall 312 is configured to connect the pair of vertical partition walls 311 while supporting the pair of vertical partition walls and quickly guide exhaust gas to the outside. One or more openings 312' are formed in the connecting wall 312. The upper cover 150, which extends vertically upward from the connecting wall 312, is provided with a second perforated portion 151', and the lower cover 120, which extends vertically downward from the connecting wall 312, is provided with a first perforated portion 121.

[0110] Preferably, the first bent wall 311' and the second bent wall 311" are further arranged at opposite side ends of the vertical partition wall 311, that is, near the corners on opposite sides of the battery cell stack 210. Each of the first bent wall 311' and the second bent wall 311" can have a shape with one side surface open and the two sides connected to each other at right angles.

[0111] The vertical partition wall 311 prevents flames and sparks from moving to the adjacent battery cell stack 210. However, the interrupted flames and sparks may move to the vicinity of the front cover 130 or rear cover 140 where the leads of the battery cells 211 are located, so there is still a possibility of fire.

[0112] However, in a case where the first bent wall 311' and the second bent wall 311" each having a shape with both sides connected to each other at right angles are located at opposite ends of the vertical partition wall 311 so as to face each other, the flames and sparks mainly interrupted by the vertical partition wall 311 are captured by the first bent wall 311' and the second bent wall 311", thereby preventing the flames and sparks from moving in the direction toward the electrode lead.

[0113] Next, the second partition wall 320 will be described. The second partition wall 320, located near a corner of one side of the battery cell stack 210, more specifically, near a corner where the side cover 110 and the front cover 130 are coupled to each other, is configured to interrupt the movement of flames and sparks toward the electrode leads after colliding with the side cover 110, while also ensuring a space separating the side cover 110 and the battery cell stack 210 from each other.

[0114] That is, the second partition wall 320 has a shape in which one side surface is open and three sides are connected to each other at right angles, and the open surface is positioned to face the electrode lead located opposite to the open surface.

[0115] At the same time, except that the third partition wall is located near the corner of the other side of the battery cell stack 210 and only the direction of the open surface is different, the third partition wall 330 is the same as the second partition wall 320 in shape, and the third partition wall is the same as the second partition wall in structure and function, so the repeated description will be omitted.

[0116] The movement of the flames and sparks, which are mainly interrupted by the side cover 110, is suppressed by the second partition wall 320 and the third partition wall 330 (the second partition wall 320 and the third partition wall 330 are positioned facing each other while both having a shape in which three sides are connected to each other at right angles and one side is open), thereby being able to interrupt the flames and sparks from forming direct contact with the electrode lead.

[0117] Figure 9 : is a cross-sectional view showing various modifications of the first partition wall. Figure 9 As shown in , the first bent wall 311 ′ and the second bent wall 311 ″ of the first partition wall 310 can be deformed to capture firelight and sparks. That is, each of the first bent wall and the second bent wall can have a shape in which the angle of the bent portion is changed or includes a bent portion, rather than the shape having three sides connected to each other at right angles and one side open according to the first preferred embodiment.

[0118] Of course, in this case, it is obvious that the front cover 130 and the rear cover 140 may also be deformed, thereby corresponding to the outer shapes of the deformed first bending wall 311 ′ and the second bending wall 311 ″.

[0119] Figure 10 : is a perspective view showing various variations of the third partition wall. Figure 10 As shown in , the third partition wall 330 can be deformed to capture flame light and sparks. That is, the third partition wall can have a shape with a changed angle of the bend or a curved portion, rather than the shape of three sides connected at right angles and one side open according to the first preferred embodiment.

[0120] Even in this case, it is apparent that the front cover 130 and the rear cover 140 may be deformed so as to correspond to the outer shape of the deformed third partition wall 330 .

[0121] Figure 11 When viewed from the front with the front cover and top cover removed Figure 1 A perspective view of the battery module shown, Figure 12 When viewed from above with the top cover removed Figure 1 A plan view of the battery module shown, and Figure 13 It is along Figure 1 A cross-sectional view taken along line AA'.

[0122] refer to Figures 11 to 13 , suppressing the ignition of the battery module according to the present invention will be described in detail through a description of the processes of fire, sparks, exhaust, heat, and air movement when an event such as thermal runaway occurs.

[0123] The battery module according to the present invention further includes first to seventh spaces S1 to S7 and the partition wall 300. Specifically, the first space S1 is formed in the second partition wall 320, the second space S2 is formed in the third partition wall 330, and the third space S3 is formed between the vertical side surface of the battery cell stack 210 in the longitudinal direction and the side cover 110.

[0124] In addition, a fourth space portion S4 and a fifth space portion S5 are formed in the first bent wall 311′ and the second bent wall 311″, respectively, a sixth space portion S6 is formed between the vertical partition wall 311 and the vertical side surface of the battery cell stack 210 in the longitudinal direction, and a seventh space portion S7 is formed between the pair of vertical partition walls 311.

[0125] For example, suppose thermal runaway occurs at Figures 11 to 13 In a specific battery cell 211 of the battery cell stack 210 on the right side of the drawing, the light and sparks are collected in one or more of the first to sixth space portions S1 to S6 in an interrupted state, so that the light and sparks cannot move to the battery cell stack 210 on the left side of the drawing.

[0126] Since the protective housing 100 and the partition wall 300 are not maintained in a perfectly airtight state, the generated exhaust gas and air are discharged to the outside through the second perforated portion 151' of the upper cover 150 and the first perforated portion 121 of the lower cover 120 via the front cover 130, the rear cover 140 and the seventh space portion S7.

[0127] Meanwhile, heat transferred to the adjacent battery cell stack 210 is minimized by the sixth and seventh space portions S6 and S7 corresponding to the air insulation layer and the gasket 212 each made of an insulating material, and the heat is discharged to the outside together with the exhaust gas.

[0128] The battery cells 211 (each of which is flat) that constitute the battery cell stack according to the present invention are stacked vertically. This increases the volume of the battery cell stack when bulging occurs, but minimizes bulging in the lateral direction. Consequently, the sixth and seventh space portions S6 and S7 can maintain their function as air insulation layers without being affected by bulging.

[0129] As a result, even if an incident occurs in any one battery cell stack, air is exhausted to the exterior along with the exhaust gas. This reduces the oxygen necessary for fire within the protective housing, preventing combustible materials from reaching adjacent battery cell stacks and being trapped without being exhausted. Furthermore, as the air is exhausted, heat is also exhausted along with it, maintaining the battery cell stack temperature below the ignition point, thereby preventing the outbreak of fire.

[0130] Of course, a fire may break out in a particular battery cell stack due to unexpected surrounding conditions. However, the air insulation layers corresponding to the sixth and seventh space portions S6 and S7 interrupt heat transfer to adjacent battery cell stacks, thereby reliably preventing fires from breaking out in adjacent battery cell stacks.

[0131] Specifically, when the ambient temperature rises to an abnormal range, the separators of the battery cells shrink, causing a short circuit. In the present invention, an air barrier is provided. Even when the air in the air barrier is heated, it is discharged into the second perforated portion of the upper cover by convection, thus limiting heat transfer. As a result, the area near adjacent battery cell stacks is maintained at a relatively safe temperature, preventing separator shrinkage.

[0132] Figure 14 is a plan view of a battery module according to a second preferred embodiment of the present invention when viewed from above in a state where an upper cover is removed, and Figure 15 is a cross-sectional view of a battery module according to a second preferred embodiment of the present invention, taken in a transverse direction.

[0133] The second embodiment is identical in construction to the above-described first embodiment, except that the front and rear covers of the protective housing are modified and the number of battery cell stacks received in the battery module is changed.

[0134] That is, in the second embodiment, each of the front cover 130 and the rear cover 140 is provided with three first recessed portions and three second recessed portions, and two first partition walls are located between the corresponding battery cell stacks.

[0135] In the second embodiment of the present invention, three battery cell stacks are shown; however, it is apparent that four or more battery cell stacks may be continuously arranged while one first partition wall is located between adjacent ones of the battery cell stacks.

[0136] At the same time, the battery module having the above-mentioned structure can be received in a separate housing to constitute a single battery pack, and the battery module or battery pack can be used in various facilities or devices including large-capacity power sources, such as energy storage systems, electric vehicles, hybrid electric vehicles and plug-in hybrid electric vehicles.

[0137] Although the specific details of the present invention have been described in detail, it will be understood by those skilled in the art that the detailed description of the present invention only discloses the preferred embodiments of the present invention and therefore does not limit the scope of the present invention. Accordingly, it will be understood by those skilled in the art that various changes and modifications are possible without departing from the scope and technical ideas of the present invention, and it will be apparent that such changes and modifications fall within the scope of the appended claims.

[0138] Description of Reference Numerals

[0139] 100: Protective housing

[0140] 110: Side cover

[0141] 111: Fastening recess

[0142] 120: Lower cover

[0143] 121: First perforation

[0144] 130: Front cover

[0145] 131: Front panel

[0146] 132: First recessed portion

[0147] 132': first slit 132": first inclined plate

[0148] 140: Back cover

[0149] 141: Back plate

[0150] 142: Second recessed portion

[0151] 142': Second slit 142": Second inclined plate

[0152] 150: Upper cover

[0153] 151: Main board 151': Second perforated portion

[0154] 152: Auxiliary plate 152': Fastening protrusion

[0155] 200: Battery cell module assembly

[0156] 210: Battery cell stack

[0157] 211: Battery Cell

[0158] 212: Gasket

[0159] 213: First bus

[0160] 214: Second bus

[0161] 220: Connecting busbars

[0162] 221: Third bus bar 222: Connecting bar

[0163] 300: Partition wall

[0164] 310: First partition wall

[0165] 311: Vertical partition wall

[0166] 311': first bending wall 311": second bending wall

[0167] 312: Connecting Wall

[0168] 312': Opening hole

[0169] 320: Second partition wall

[0170] 330: Third partition wall

[0171] S1: First space S2: Second space

[0172] S3: third space S4: fourth space

[0173] S5: fifth space S6: sixth space

[0174] S7: Seventh Space Department

Claims

1. A battery module, the battery module being configured such that a battery cell module assembly including two or more battery cell stacks is received in a space portion defined in a protective housing, in each of the battery cell stacks, a plurality of battery cells are stacked in a vertical direction, and the battery module being configured such that one or more partition walls are provided in at least one of the following positions: between adjacent battery cell stacks in the battery cell stacks, and between the battery cell stack and the protective housing, the protective housing including a pair of side covers disposed to face each other; in, A first partition wall is provided between adjacent battery cell stacks in the battery cell stacks, and wherein the first partition wall includes a pair of vertical partition walls disposed to face each other in a state of being spaced apart from each other by a predetermined distance, each of the vertical partition walls having a flat shape, Each of the vertical partition walls is provided with a first bending wall and a second bending wall at opposite end portions thereof, and the first bending wall and the second bending wall are bent and / or curved in a direction toward a battery cell stack located adjacent to the vertical partition wall in the battery cell stack, wherein a second partition wall having one open side surface is provided near a corner of one side of a battery cell stack adjacent to each of the side covers in the battery cell stack, the second partition wall being configured to form a first space portion, and wherein the open side surface of the second partition wall is positioned to face a corner of the other side of the battery cell stack, wherein a third partition wall having one side surface opened is provided near a corner of the other side of one battery cell stack adjacent to each of the side covers in the battery cell stack, the third partition wall being configured to form a second space portion, and Wherein, the open side surface of the third partition wall is positioned to face the open side surface of the second partition wall.

2. The battery module according to claim 1, wherein: The first partition wall further includes a connecting wall configured to connect upper ends of the vertical partition walls to each other, the connecting wall being provided with one or more opening holes.

3. The battery module according to claim 2, wherein: The protective housing further comprises: a lower cover configured to connect lower ends of the side covers to each other; Front cover; rear cover; and An upper cover is arranged on the side cover.

4. The battery module according to claim 1, wherein: The first bent wall and the second bent wall form a fourth space portion and a fifth space portion, respectively.

5. The battery module according to claim 4, wherein: The vertical partition wall and the battery cell stack are spaced apart from each other by a predetermined distance to form a sixth space portion.

6. The battery module according to claim 1, wherein: A third space portion is provided between the side cover and the battery cell stack.

7. The battery module according to claim 3, wherein: The battery cell stack comprises: Multiple battery cells; a first bus bar configured to allow a negative electrode lead or a positive electrode lead of the battery cell to be connected to the first bus bar; and a second bus bar configured to allow the remaining leads of the battery cell to be connected to the second bus bar, and Adjacent battery cell stacks in the battery cell stacks are connected to each other via connecting bus bars.

8. The battery module according to claim 7, wherein: The front cover comprises a front plate and a first recessed portion, wherein the first recessed portion is located at each of opposite sides of the front plate in a state of being recessed toward the front surface of the battery cell stack at a predetermined depth, and The first recessed portion is provided with a first slit, and the first slit is configured to allow the electrode lead of the battery cell to extend through the first slit.

9. The battery module according to claim 8, wherein: The entire surface of the first recessed portion except for the first slit is hermetically sealed.

10. The battery module according to claim 9, wherein: Each of the first slits is formed by a first inclined plate inclined at a predetermined angle.

11. The battery module according to claim 7, wherein: The back cover comprises a back plate and a second recessed portion, wherein the second recessed portion is located at each of opposite sides of the rear plate in a state of being recessed toward a rear surface of the battery cell stack at a predetermined depth, and The second recessed portion is provided with a second slit, and the second slit is configured to allow the electrode lead of the battery cell to extend through the second slit.

12. The battery module according to claim 11, wherein: The entire surface of the second recessed portion except for the second slit is hermetically sealed.

13. The battery module according to claim 12, wherein: Each of the second slits is formed by a second inclined plate inclined at a predetermined angle.

14. The battery module according to claim 3, wherein: Each of the pair of side covers is provided with a fastening recess protruding outward in an upper end thereof, The upper cover includes a main board positioned in a horizontal direction and an auxiliary board bent downward from the main board. Wherein, the main board is provided with a second perforated portion, and Wherein, the auxiliary plate is provided with a fastening protrusion on an outer surface thereof, and the fastening protrusion is configured to be received in the fastening recess.

15. The battery module according to claim 14, wherein: The second perforated portion is located directly above the connecting wall of the first partition wall.

16. The battery module according to claim 3, wherein: The lower cover is provided with a first perforated portion, and Wherein, the first perforated portion is located directly below the connecting wall of the first partition wall.

17. A battery pack comprising the battery module according to any one of claims 1 to 16.

18. An energy storage system comprising the battery module according to any one of claims 1 to 16.

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