Battery module with improved vent structure

Abstract

The present invention provides a battery module structure that incorporates a battery cell stack in which a plurality of pouch-type battery cells and compressible pads are stacked in the width direction, wherein the battery cells are provided with thinner terrace portions at both ends in the length direction compared to other parts, and the compressible pads are provided with packing portions that protrude to one or both sides in the width direction and face the terrace portions in the width direction at both ends in the length direction.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0060414 filed on May 10, 2023, and the contents disclosed in the documents of the Korean Patent Application are all included as part of this specification.

[0002] The present invention relates to a structure of a battery module in which a plurality of pouch-type battery cells are stacked, and in which a vent structure is improved.

Background Art

[0003] Secondary batteries that are highly applicable according to product groups and have electrical characteristics such as high energy density are widely applied not only to portable devices but also to electric vehicles, hybrid vehicles, or power storage devices driven by an electric drive source. These secondary batteries not only have the primary advantage of being able to significantly reduce the use of fossil fuels, but also attract attention as a new energy source for environmental friendliness and energy efficiency improvement because they do not generate any by-products due to energy use.

[0004] One or two or three battery cells are used per device for small mobile devices, whereas medium- to large-sized devices such as automobiles require high output and large capacity. Therefore, medium- to large-sized battery modules in which a large number of battery cells are electrically connected are used.

[0005] Medium- to large-sized battery modules are preferably manufactured to be small in size and weight if possible, and thus square batteries, pouch-type batteries, etc., which can be stacked with a high degree of integration and have a low weight relative to the capacity, are mainly used as battery cells of medium- to large-sized battery modules.

[0006] Figures 1 and 2 show the structure of a pouch-type battery cell. Referring to these, the battery cell 10 may include an electrode assembly, a pouch 100 that houses the electrode assembly, and electrode leads 101 that extend from the electrode assembly and protrude to the outside of the pouch 100. The electrode leads 101 may include lead films 102 that cover both surfaces in the thickness direction.

[0007] The pouch 100 may be formed by a pouch sheet made of metal foil material surrounding the electrode assembly, folding it, and then fusion sealing three sides of it excluding the folded portion 100c. In this way, the pouch 100 may include a sealing portion 100b at the end opposite the folded portion 100c, and may include terrace portions 100a that are thinner than the other portions at both ends in the longitudinal direction. At the terrace portion 100a, the pouch sheet may be sealed between the electrode lead 101 and the lead film 102 interposed therebetween.

[0008] Figures 3 and 4 show the structure of a battery cell stack in which battery cells are stacked. Referring to these drawings, multiple battery cells 10 can be connected in series and / or parallel to form a battery module in order to increase capacity and / or voltage. The battery module may include a battery cell stack 1 in which multiple battery cells 10 are stacked in the thickness direction (width direction), and a housing that accommodates it.

[0009] On the other hand, the battery cell 10 is at risk of overheating and igniting due to a short circuit or other reasons. If the battery cell 10 ignites, heat, flames, and gas generated by the vaporization of the electrolyte charged inside the pouch 100 may be emitted from the battery cell 10. Furthermore, the flames and high-temperature gases from the ignition of the battery cell 10 may propagate to other adjacent battery cells 10, causing a chain reaction of ignition.

[0010] Furthermore, multiple battery modules can be integrated to form a battery pack. In a battery pack, the battery modules may be arranged so that their longitudinal ends face each other. In this case, flames and high-temperature gases generated from inside the battery modules are mainly discharged through the terrace portion 100a from which the electrode leads 101 protrude. Venting by the terrace portion 100a as described above can cause heat propagation between modules and ignition of the pack as a whole.

[0011] Therefore, a battery module structure is required that can prevent heat transfer between the battery cells and prevent flames and high-temperature gases from being discharged forward or backward. [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention was conceived against the background of the prior art described above, and aims to provide a battery module structure in which the venting direction of the battery cells can be guided in a specific direction. More specifically, the present invention aims to provide a battery module structure in which the venting direction of the battery cells can be guided toward a seal portion provided on one side in the height direction.

[0013] The present invention also aims to provide a battery module structure that can delay or prevent heat transfer between battery cells, thereby minimizing assembly play in the battery cell stack.

[0014] A further technical problem of the present invention is to provide a battery module structure in which the vents of the battery cells are not oriented in the direction in which the electrode leads are provided and / or in the direction of adjacent lateral connections in other battery modules.

[0015] Furthermore, the present invention aims to achieve the above-mentioned objectives without changing the structure of the battery cell itself as much as possible.

[0016] The technical problems of the present invention are not limited to the objectives mentioned above. Other objectives and advantages of the present invention not mentioned can be understood from the following description and more clearly from the embodiments of the present invention. Furthermore, it is readily apparent that the objectives and advantages of the present invention can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0017] To solve the aforementioned problems, the present invention provides a battery module structure that incorporates a battery cell stack in which a plurality of pouch-type battery cells and compressible pads are stacked in the width direction, wherein the battery cells are provided with thinner terrace portions at both ends in the length direction compared to other parts, and the compressible pads are provided with packing portions that protrude to one or both sides in the width direction and face the terrace portions in the width direction at both ends in the length direction.

[0018] The aforementioned battery cell may be made by folding a single pouch sheet containing an electrode assembly in half, with the three sides excluding the folded portion being fusion-sealed. In this way, the terrace portions may be provided at both ends in the longitudinal direction of the battery cell, and a sealing portion may be provided at the end of the battery cell opposite the folded portion.

[0019] The terrace portion may cause electrode leads that electrically connect the electrode assembly to the outside to protrude. The electrode leads may be fused to the pouch sheet with a lead film interposed between them, covering both surfaces in the thickness direction.

[0020] The packing portion may extend in the height direction. Preferably, the packing portion may extend to correspond to the entire height section of the terrace portion.

[0021] In one embodiment of the present invention, at least one compressible pad may be stacked on each side in the width direction of any battery cell. In this case, the packing portion provided on the compressible pad interposed between two battery cells may protrude on both sides in the width direction, and the packing portion provided on the compressible pads located on the outermost edges of both sides in the width direction of the battery cell stack may protrude on one side in the width direction of the battery cell stack.

[0022] In another embodiment of the present invention, any battery cell may have a first compressible pad laminated on one side in the width direction, the packing portion of which protrudes toward the other side in the width direction, and a second compressible pad laminated on the other side in the width direction, the packing portion of which protrudes toward the one side in the width direction.

[0023] The thickness of the packing portion of a compressible pad interposed between two battery cells, before compression, may be greater than the widthwise distance between the terraces of the two battery cells. That is, the compressible pad may be compressed and interposed between the terraces of the two battery cells in the assembled battery module. As a result, the compressible pad may press against the terraces and adhere tightly to them.

[0024] The battery cell stack is compressible in the width direction as a whole, since the compressible pads are compressible in the width direction. In this case, the width of the battery cell stack before compression may be greater than that of the battery module when it is assembled. That is, the battery cell stack can be housed in the housing of the assembled battery module in a state where the compressible pads are compressed in the width direction, and the entire stack is compressed in the width direction.

[0025] The battery module may include pressurizing means for applying pressure inward in the width direction to both sides in the width direction at both ends of the battery cell stack in the longitudinal direction.

[0026] In one embodiment of the present invention, the pressing means may include a clip bus bar frame connected to one end of the battery cell stack in the length direction thereof. The clip bus bar frame may include a main body portion corresponding to the end face in the length direction of the battery cell stack, and a pair of pressing portions provided on both sides in the width direction of the main body portion. The pair of pressing portions may protrude from both sides in the width direction of the main body portion toward the inner side in the length direction of the battery cell stack.

[0027] At this time, the width of the battery cell stack before compression may be larger than the width direction distance between the pair of pressing portions. Thereby, by attaching the clip bus bar frame to the battery cell stack, the packing portion may be compressed between the pair of pressing portions and adhere closely to the terrace portion.

[0028] In another embodiment of the present invention, the pressing means may include a clip housing that houses the battery cell stack. The clip housing may include a pair of side walls provided on both sides in its width direction with one side in its height direction being open. For example, the clip housing may have a U-shaped cross section with one side and the front and rear sides in its height direction being open.

[0029] At this time, the width of the battery cell stack before compression may be larger than the width direction distance between the pair of side walls. Thereby, by housing the battery cell stack in the clip housing, the packing portion may be compressed between the pair of side walls and adhere closely to the terrace portion.

[0030] The compressible pad may include a heat-resistant or fire-resistant material.

[0031] The present invention also provides a battery pack incorporating the battery module and a structure of an automobile incorporating the battery pack.

[0032] The battery module may have predetermined vent holes in the upper plate of its housing. High-temperature gas and flames discharged from the battery cells can be discharged upward through the vent holes to the battery module.

[0033] Multiple battery modules can be connected in series and / or parallel to each other to increase their charge / discharge capacity and / or power, thereby forming a single battery pack. Furthermore, this battery pack can be built into an automobile as a power source.

[0034] The battery pack may include vent passages and vent devices for discharging high-temperature gas and flames discharged upward from the battery module. The vent device may rupture when the internal pressure of the battery pack exceeds a predetermined level, thereby enabling the discharge of the thermal energy and gases. [Effects of the Invention]

[0035] The present invention can provide a battery module structure in which the venting direction of a battery cell can be guided in a specific direction by means of solving the above-mentioned problems. More specifically, the present invention can provide a battery module structure in which the venting direction of a battery cell can be guided toward a seal portion provided on one side in the height direction.

[0036] The present invention can also provide a battery module structure in which heat transfer between battery cells is delayed or prevented, thereby minimizing assembly play in the battery cell stack.

[0037] Another effect of the present invention is that it can provide a battery module structure in which the vents of the battery cells are not oriented in the direction in which the electrode leads are provided and / or in the lateral direction to which other battery modules are adjacent.

[0038] Furthermore, the present invention can achieve the above-mentioned effects without changing the structure of the battery cell itself.

[0039] In addition, the present invention can have various other effects, which will be explained in each embodiment, or effects that can be easily inferred by an ordinary person will not be explained. [Brief explanation of the drawing]

[0040] [Figure 1] This diagram shows the structure of a pouch-type battery cell. [Figure 2] This diagram shows the structure of a pouch-type battery cell. [Figure 3] This figure shows the structure of a battery cell stack, in which battery cells are stacked. [Figure 4] This figure shows the structure of a battery cell stack, in which battery cells are stacked. [Figure 5] This figure shows the structure of a battery cell stack according to one embodiment of the present invention. [Figure 6] This figure shows the structure of a battery cell stack according to one embodiment of the present invention. [Figure 7] This figure shows a cross-section of a battery cell stack according to one embodiment of the present invention. [Figure 8] This figure shows a cross-section of a battery cell stack according to one embodiment of the present invention. [Figure 9] This figure shows a cross-section of a battery cell stack according to one embodiment of the present invention. [Figure 10] This figure shows a cross-section of a battery cell stack according to one embodiment of the present invention. [Figure 11] Figure 5 shows how a clip busbar frame according to one embodiment of the present invention is attached to the battery cell stack shown in Figure 5. [Figure 12] Figure 5 shows how a clip busbar frame according to one embodiment of the present invention is attached to the battery cell stack shown in Figure 5. [Figure 13] Figure 5 shows how a clip busbar frame according to one embodiment of the present invention is attached to the battery cell stack shown in Figure 5. [Figure 14]This figure shows a cross-section of an assembly of a battery cell stack and a clip busbar frame according to one embodiment of the present invention. [Figure 15] This figure shows a cross-section of an assembly of a battery cell stack and a clip busbar frame according to one embodiment of the present invention. [Figure 16] This figure shows the vent path in a battery module according to one embodiment of the present invention. [Figure 17] This figure shows the structure of a battery cell stack according to another embodiment of the present invention. [Figure 18] This figure shows the structure of a battery cell stack according to another embodiment of the present invention. [Figure 19] This figure shows the structure of a battery cell stack according to another embodiment of the present invention. [Figure 20] This figure shows the structure of a battery cell stack according to another embodiment of the present invention. [Figure 21] Figure 17 shows how the battery cell stack is housed in a clip housing according to another embodiment of the present invention. [Figure 22] Figure 17 shows how the battery cell stack is housed in a clip housing according to another embodiment of the present invention. [Figure 23] Figure 17 shows how the battery cell stack is housed in a clip housing according to another embodiment of the present invention. [Figure 24] Figure 17 shows how the battery cell stack is housed in a clip housing according to another embodiment of the present invention. [Figure 25] This figure shows a battery pack incorporating a battery module according to one embodiment of the present invention. [Figure 26] This figure shows the structure of an automobile incorporating a battery pack that includes a battery module according to one embodiment of the present invention. [Modes for carrying out the invention]

[0041] The aforementioned objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, so that a person with ordinary skill in the art to which the present invention pertains can easily implement the technical concept of the present invention. In describing the present invention, if a specific description of known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0042] Although terms like "first," "second," etc., are used to describe various components, these components are, of course, not limited by these terms. These terms are simply used to distinguish one component from another, and unless otherwise stated, the first component may also be the second component.

[0043] In the entire specification, unless otherwise stated, each component may be singular or plural.

[0044] In the following, the placement of any configuration "above (or below)" a component or "above (or below)" a component means not only that the configuration faces the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed on (or below) it.

[0045] Furthermore, where it is stated that one component is “linked,” “joined,” or “connected” to another component, it should be understood that the components may be directly linked or connected to one another, but may also be “interposed” between each component, or each component may be “linked,” “joined,” or “connected” through other components.

[0046] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as “composed of” or “including” in this application should not be interpreted as necessarily including all of the multiple components or stages described in the specification, and some of them may not be included, or they may include further components or stages.

[0047] In the entire specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0048] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

[0049] [Structure of pouch-type battery cells and battery cell stacks] Figures 1 and 2 show the structure of a pouch-type battery cell. Referring to these drawings, the pouch-type battery cell 10 may generally include an electrode assembly and a pouch 100 that surrounds the electrode assembly, is folded in half, and has three sides sealed except for the folded portion 100c. The seal may be a fusion seal.

[0050] The battery cell 10 may substantially have the shape of a rectangular parallelepiped having a length direction (X, front-to-back direction) aligned with its longest side, a thickness direction (Y, width direction, left-to-right direction) aligned with its shortest side, and a height direction (Z, up-and-down direction) that intersects both the length direction and the thickness direction.

[0051] The side opposite to the folding portion 100c, which is one end of the battery cell 10 in the height direction, can form a sealing portion 100b. The sealing portion 100b can be further sealed by folding or by attaching tape.

[0052] Terrace portions 100a, which are thinner in thickness than other parts, may be formed at both ends in the longitudinal direction of the battery cell 10, excluding the folding portion 100c and the sealing portion 100b.

[0053] Electrode leads 101 that electrically connect the electrode assembly to the outside may protrude from the electrode assembly and extend to the outside of the pouch 100. The electrode leads 101 may protrude via the terrace portion 100a.

[0054] The electrode lead 101 may include a fusion-adhesive lead film 102 that surrounds both surfaces in the thickness direction. The lead film 102 can be interposed between the pouch 100 and the electrode lead 101 and fuse together to seal the portion of the terrace 100a through which the electrode lead 101 passes.

[0055] Figures 3 and 4 show the structure of a battery cell stack in which battery cells are stacked. Referring to these drawings, multiple battery cells 10 can be connected in series and / or parallel to each other to form a single battery module in order to increase their capacity and / or voltage.

[0056] The battery module may include a battery cell laminate 1 in which the battery cells 10 are stacked and integrated with each other in the thickness direction.

[0057] On the other hand, since the battery cell stack 1 is formed by stacking multiple battery cells 10, the tolerances between them can accumulate, potentially resulting in large tolerances in the width direction.

[0058] Furthermore, the battery cell 10 is at risk of ignition due to short circuits, impacts, overheating, etc. If the battery cell 10 ignites, it will be heated to a high temperature, and high-temperature gas and flames may be generated from inside the pouch 100. In the battery cell stack 1, the battery cells 10 are stacked with large areas of contact with each other, resulting in a high risk of heat propagation between cells. This can cause a chain reaction of ignition between cells, potentially leading to ignition at the module level.

[0059] Therefore, when constructing the battery cell stack 1, there have been conventional attempts to solve the above-mentioned tolerance and heat propagation problems by interposing a compressible pad containing a heat-resistant and / or fire-resistant material between the battery cells 10.

[0060] <Example 1> [Structure of a battery cell stack including a compressible pad] Figures 5 and 6 show the structure of a battery cell stack according to one embodiment of the present invention, and Figures 7 to 10 show cross-sections of a battery cell stack according to one embodiment of the present invention. Referring to these drawings, the battery cell stack 1 according to one embodiment of the present invention may be formed by stacking a plurality of the battery cells 10 and a compressible pad 11 together.

[0061] The compressible pad 11 may include a compressible material. The compressible material may be a material whose volume shrinks in response to pressure. Alternatively, the compressible material may be a material that elastically restores itself to its original volume when compressed by pressure. By including a compressible material in the compressible pad 11, the battery cell stack 1 may be compressible in its width direction and may have elastic restorative force when compressed. As a result, the battery cell stack 1 according to one embodiment of the present invention can be housed in a compressed state such that its width corresponds to the inner width of a predetermined housing, thereby reducing the assembly tolerance of the battery module.

[0062] Referring to Figure 6, the compressible pads 11 can be interposed between the battery cells 10 and can also constitute the outermost layer of the battery cell stack 1. Preferably, at least one compressible pad 11 may be stacked on each side in the width direction of any battery cell 10. In other words, any battery cell 10 may be interposed between two compressible pads 11. Alternatively, at least one compressible pad 11 may be interposed between any pair of adjacent battery cells 10. In other words, any battery cell 10 can have at least one compressible pad 11 interposed between it and its adjacent battery cells 10.

[0063] The compressible pad 11 preferably contains a heat-resistant and / or fire-resistant material. Furthermore, the compressible pad 11 preferably contains an insulating material. This allows the compressible pad 11 to delay or prevent heat transfer in the width direction between the battery cells 10. Additionally, this allows the compressible pad 11 to delay or prevent heat transfer between the battery cells 10 without melting or burning, even in the event of ignition of any of the battery cells 10.

[0064] The compressible pad 11 may be provided with packing portions 110 that are thicker than other parts at both ends in the longitudinal direction. The packing portions 110 may be formed by a portion of both ends in the longitudinal direction of the compressible pad 11 protruding from one or both sides in the width direction.

[0065] Referring to Figures 7 to 9, the packing portion 110 may be provided in the battery cell stack 1 so as to face the terrace portion 100a in the width direction. Preferably, the packing portion 110 may be provided so as to press and tightly adhere to the terrace portion 100a.

[0066] Referring to Figure 10, the packing portion 110 may extend in the height direction. Preferably, the packing portion 110 may extend to correspond to the entire height section of the terrace portion 100a. This allows the packing portion 110 to delay the propagation of heat in the forward and backward directions when the battery cell 10 ignites.

[0067] According to one embodiment of the present invention, compressible pads 11 may be stacked on each side in the width direction of any battery cell 10, and the compressible pads 11 may have packing portions 110 that protrude from one or both sides in the width direction and extend in the height direction to correspond to the entire height direction of the terrace portion 100a. In this case, the packing portions 110 provided on a compressible pad 11 interposed between two battery cells 10 may protrude from both sides in the width direction, and the packing portions 110 provided on compressible pads 11 located on the outermost edges of both sides in the width direction of the battery cell stack 1 may protrude from one side in the width direction. The compressible pads 11 may include compressible, heat-resistant and fire-resistant materials, and may also include thermal insulation materials.

[0068] Furthermore, according to one embodiment of the present invention, the thickness of the packing portion 110 of the compressible pad 11 interposed between two battery cells 10 before compression may be greater than the widthwise distance between the terrace portions 100a of the two battery cells 10. That is, in the assembled state, the packing portion 110 may be interposed between the terrace portions 100a of the two battery cells 10 in a compressed state, thereby being in close contact with the terrace portions 100a under pressure. In this case, since the compressible pad 11 is compressible in the widthwise direction, the battery cell stack 1 as a whole is compressible in the widthwise direction, and the width of the battery cell stack 1 before compression may be greater than the width of the battery cell stack 1 in the assembled battery module. That is, the battery cell stack 1 in the assembled battery module can be incorporated in a compressed state in the widthwise direction.

[0069] [Pressurized structure of the packing section, including the clip busbar frame] The battery module may include a pressurizing means for applying pressure inward in the width direction to both sides in the width direction of both ends of the battery cell stack 1 in the length direction. The pressurizing means can compress the packing portion 110 and press it tightly against the terrace portion 100a by applying pressure inward in the width direction from both sides of a predetermined section in the width direction of both ends of the battery cell stack 1 in the length direction.

[0070] Figures 11 to 13 show how a clip busbar frame according to one embodiment of the present invention is attached to the battery cell stack shown in Figure 5, and Figures 14 and 15 show cross-sections of the assembly of the battery cell stack and the clip busbar frame according to one embodiment of the present invention. Referring to these drawings, the pressurizing means according to one embodiment of the present invention may include a clip busbar frame 2 connected to one end of the battery cell stack 1 in the longitudinal direction. The clip busbar frame 2 may be provided in a pair, further including one connected to the other end of the battery cell stack 1 in the longitudinal direction.

[0071] Referring to Figure 11, the clip busbar frame 2 may include a main body 21 and a pressurizing section 22. The pressurizing section 22 may be provided in a pair that pressurizes both sides of the battery cell stack 1 in the width direction inwards. In this case, the main body 21 can connect the pair of pressurizing sections 22. That is, the pressurizing sections 22 may be provided in a pair on both sides of the main body 21 in the width direction.

[0072] The main body portion 21 can correspond to the end faces in the longitudinal direction of the battery cell stack 1. In this case, the pressurizing portion 22 may protrude from both sides in the width direction of the main body portion 21 in the longitudinal direction inward of the battery cell stack 1. That is, the clip busbar frame 2 may be box-shaped with substantially open sides in both the height direction and the longitudinal direction inward.

[0073] Referring to Figures 11 and 12, the main body portion 21 may be provided with a slit 210 through which the electrode lead 101 passes. Furthermore, a busbar 20 to which the electrode lead 101 is connected may be provided on the longitudinal outer surface of the main body portion 21. The electrode leads 101 may be electrically connected to each other via the busbar 20, with like poles and / or different poles connected to each other.

[0074] Referring to Figures 14 and 15, the widthwise distance between the pair of pressurizing sections 22, that is, the inner width of the pressurizing section 22, may be smaller than the width of the battery cell stack 1 before compression. This allows the packing section 110 to be compressed in the widthwise direction and to be tightly pressed against the terrace section 100a when the clip busbar frame 2 is connected to the longitudinal end of the battery cell stack 1.

[0075] In one modified example, the compressible pads do not need to be provided on the outermost edges of both sides in the width direction of the battery cell stack. In this case, the pressurizing portion may be provided with a protrusion that is in close contact with the terrace portion of the outermost battery cell, corresponding to the terrace portion of the outermost battery cell. The protrusion may, for example, protrude inward in the width direction from the inner surface of the pressurizing portion and extend in the height direction to correspond to the entire height section of the terrace portion.

[0076] [Effect of inducing venting direction and preventing thermal runaway] Figure 16 shows the vent path in a battery module according to one embodiment of the present invention. Referring to this, when the battery cell 10 ignites, the high-temperature gas and flame generated inside the pouch 100 can be mainly discharged through the terrace portion 100a and / or the seal portion 100b. This is because, unlike the folding portion 100c, the seals of the terrace portion 100a and the seal portion 100b can be released by melting due to heat. However, according to one embodiment of the present invention, by pressurizing and adhering the packing portion 110 to the entire height of the terrace portion 100a, the seal of the terrace portion 100a can be maintained even if the fused seal of the terrace portion 100a melts. As a result, in the battery module according to one embodiment of the present invention, venting due to the ignition of the battery cell 10 can only occur on the side of the seal portion 100b.

[0077] Furthermore, the compressible pad 11 according to one embodiment of the present invention can effectively prevent heat transfer between cells by including an insulating material.

[0078] Therefore, according to one embodiment of the present invention, even if one battery cell 10 ignites, the heat insulation properties of the compressible pad 11 prevent the heat from spreading to other adjacent battery cells 10, and the upward direction of the vent also prevents heat from spreading to other battery modules located in front of, behind, or to the sides of the battery module. Thus, thermal runaway caused by chain reactions of ignition at the module and pack levels can be delayed or prevented.

[0079] <Example 2> [Structure of a battery cell stack including a compressible pad] Figures 17 to 20 show the structure of a battery cell stack according to another embodiment of the present invention. Referring to these drawings, according to another embodiment of the present invention, a first compressible pad 11A, whose packing portion 110 protrudes toward the other side in the width direction, may be stacked on one side in the width direction of any battery cell 10, and a second compressible pad 11B, whose packing portion 110 protrudes toward the other side in the width direction, may be stacked on the other side in the width direction of any battery cell 10. That is, the battery cell stack 1 may be formed by stacking a plurality of units, each unit including one battery cell 10 and a pair of compressible pads 11 stacked on both sides in the width direction, and each pair of compressible pads 11 may have a packing portion 110 that protrudes inward in the width direction.

[0080] According to this embodiment, unlike the above embodiment, there is no need to produce the outermost compressible pad and the intervening compressible pad separately. Regardless of the number of battery cells constituting a single battery cell stack, the battery module according to the present invention can be constructed simply by stacking multiple units of the same structure.

[0081] [Pressurized structure of the packing section, including the clip housing] Figures 21 to 24 show how the battery cell stack of Figure 17 is housed in a clip housing according to another embodiment of the present invention. Referring to these drawings, the pressurizing means according to another embodiment of the present invention may include a clip housing 3 that houses the battery cell stack 1.

[0082] Referring to Figure 21, the clip housing 3 may include a bottom plate 30 and side walls 31. The side walls 31 may be provided in pairs, each pressing inward in the width direction on both sides of the battery cell stack 1. In this case, the bottom plate 30 can connect the pair of side walls 31. That is, the side walls 31 may be provided in pairs on both sides of the bottom plate 30 in the width direction.

[0083] The bottom plate 30 can correspond to the bottom surface of the battery cell stack 1. In this case, the side walls 31 may protrude upward from both sides in the width direction of the bottom plate 30. That is, the clip housing 3 may be a box shape that is substantially open on both sides in the length direction and at the top.

[0084] Referring to Figures 23 and 24, the widthwise distance between the pair of side walls 31, that is, the inner width of the side walls 31, may be smaller than the width of the battery cell stack 1 before compression. As a result, when the clip housing 3 accommodates the battery cell stack 1, the packing portion 110 may be compressed in the widthwise direction and pressurized to adhere tightly to the terrace portion 100a.

[0085] According to this embodiment, there is no need to add a separate pressurizing means, and the pressurizing means according to the present invention can be implemented using a U-frame structure housing, which has been widely used as a housing for battery modules that incorporate battery cell stacks.

[0086] In one modified example, the compressible pads do not need to be provided on the outermost edges of the battery cell stack on both sides in the width direction. In this case, the longitudinal ends of the side walls may be provided with protrusions that are in close contact with the terrace portions of the outermost battery cells. For example, the protrusions may project inward in the width direction from the inner surface of the side wall and extend in the height direction to correspond to the entire height section of the terrace portion.

[0087] <Example 3> [Battery modules, battery packs, and the structure of automobiles including them] The present invention also provides a battery pack including the battery module, and an automobile structure including the battery pack.

[0088] Figures 25 and 26 show a battery pack incorporating a battery module according to one embodiment of the present invention, and the structure of an automobile incorporating the battery pack. Referring to these drawings, the battery module (M) may include predetermined vent holes in the upper plate of its housing. High-temperature gas and flames discharged upward from the battery cell 10 can be discharged upward from the battery module (M) through the vent holes.

[0089] Multiple battery modules (M) can be connected in series and / or parallel to each other to increase their charge / discharge capacity and / or power, thereby forming a single battery pack (P). Furthermore, the battery pack (P) can be built into a vehicle (V) as a power source for the vehicle (V).

[0090] The battery pack (P) may include a vent passage and a vent device for discharging high-temperature gas and flames discharged upward from the battery module (M). The vent device may rupture when the internal pressure of the battery pack (P) exceeds a predetermined level, thereby enabling the discharge of the thermal energy and gases.

[0091] The embodiments described above should be understood to be illustrative and not limiting in all respects, and the scope of the present invention is indicated more by the claims described below than by the detailed description above. Furthermore, the meaning and scope of the claims described below, as well as any modified and transformable forms conceived from their equivalent concepts, should all be interpreted as being included within the scope of the present invention.

[0092] As described above, the present invention has been explained with reference to the illustrative drawings. However, the present invention is not limited to the embodiments and drawings disclosed herein, and it is obvious to an ordinary person skilled in the art that various modifications can be made within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described and explained while embodiments of the present invention are described above, it is natural to acknowledge that predictable effects can be obtained from such configuration. [Explanation of Symbols]

[0093] 1. Battery cell stack 10 battery cells 100 pouches 100a Terrace section 100b Seal section 100c folding section 101 Electrode Leads 102 Lead film 11 Compression pad 11A First Compression Pad 11B Second Compression Pad 110 Packing Section 110a First packing section 110b Second packing section 2 Clip Busbar Frame 20 Bus Bar 21 Main body 210 slits 22 Pressurized section 3 Clip Housing 30 Bottom plate 31 Side wall M Battery Module P Battery Pack V Automobile X Length direction / Front-back direction Y width direction / horizontal direction Z (Height direction / Up and down direction)

Claims

1. In a battery module that incorporates a battery cell stack in which multiple pouch-type battery cells and compressible pads are stacked in the width direction, Terrace portions, which are thinner than other parts, are provided at both ends in the longitudinal direction of the aforementioned battery cell. At both ends in the longitudinal direction of the compressible pad, packing portions are provided that protrude to one or both sides in the width direction and face the width direction of the terrace portion. Battery module.

2. The packing portion extends in the height direction, The battery module according to claim 1.

3. The packing portion extends to correspond to the entire height of the terrace portion. The battery module according to claim 2.

4. On each side of any battery cell in the width direction, at least one compressible pad is stacked. The battery module according to claim 1.

5. The packing portion provided on the compressible pad interposed between two battery cells protrudes on both sides in the width direction, The packing portion provided on the compressible pad located at the outermost edge on both sides in the width direction of the battery cell stack protrudes to one side inward in the width direction of the battery cell stack, The battery module according to claim 4.

6. Any battery cell, A first compressible pad is laminated on one side in the width direction, with its packing portion protruding toward the other side in the width direction. A second compressible pad is laminated on the other side in the width direction, with its packing portion protruding toward one side in the width direction. The battery module according to claim 1.

7. The thickness of the packing portion of a compressible pad interposed between two battery cells, before compression, is greater than the widthwise distance between the terrace portions of the two battery cells. The battery module according to claim 1.

8. Since the compressible pads in the battery cell stack are compressible in the width direction, the stack as a whole is compressible in the width direction. The width of the battery cell stack before compression is greater than that of the battery module when assembled. The battery module according to claim 7.

9. The battery cell stack includes a pressurizing means for applying pressure to both sides in the width direction of both ends in the length direction of the battery cell stack inwards in the width direction, The battery module according to claim 8.

10. The pressurizing means includes a clip busbar frame connected to one end of the battery cell stack in the longitudinal direction, The battery module according to claim 9.

11. The aforementioned clip busbar frame is A main body portion corresponding to the end face in the longitudinal direction of the battery cell stack, A pair of pressurizing parts are provided on both sides in the width direction of the main body, including, The battery module according to claim 10.

12. The pair of pressurizing portions protrude from both sides in the width direction of the main body portion in the direction in the length direction of the battery cell stack, The battery module according to claim 11.

13. The width of the battery cell stack before compression is greater than the widthwise distance between the pair of pressurized portions. The battery module according to claim 12.

14. The pressurizing means includes a clip housing that accommodates the battery cell stack. The battery module according to claim 9.

15. The clip housing is open on one side in the height direction and includes a pair of side walls provided on both sides in the width direction. The battery module according to claim 14.

16. The clip housing is open on one side in the height direction and on the front and rear sides. The battery module according to claim 15.

17. The width of the battery cell stack before compression is greater than the widthwise distance between the pair of side walls. The battery module according to claim 15.

18. The compressible pad includes a heat-resistant or fire-resistant material. The battery module according to claim 1.

19. A battery module comprising the battery module described in any one of claims 1 to 18, Battery pack.

20. Includes the battery pack described in claim 19, car.

Images