High-voltage battery module with excellent cooling efficiency

Abstract

One embodiment of the present application relates to a battery module using a bidirectional cooling device, and provides a battery module including: a module case including an upper cover plate and a lower cover plate; and two or more pouch battery cells included in the module case, a sealing portion in which an electrode lead is not protruded is folded to one side direction, the folded sealing portion is located at the upper cover plate side or the lower cover plate side of the module case, and a heat dissipation adhesive is directly attached to a pouch in a direction opposite to a folding direction of the folded sealing portion of at least one pouch battery cell.

Description

Technical Field

[0001] This invention relates to a high-voltage battery module with excellent cooling efficiency, and more specifically, to a battery module employing a bidirectional cooling device. Background Technology

[0002] Generally speaking, rechargeable batteries can be charged and discharged, so they are used in various fields such as digital cameras, mobile phones, laptops, and hybrid vehicles, and further research is being actively conducted.

[0003] Examples of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-metal hydride batteries, and lithium-ion batteries. Lithium-ion batteries, which have high energy density and discharge voltage, are under extensive research and have been commercialized and widely used.

[0004] Furthermore, the secondary battery module comprises multiple battery cells stacked side-by-side and electrically connected to each other, and the battery cells are configured to be housed within a casing. Additionally, multiple of these secondary battery cells are installed as battery modules in electric vehicles, energy storage systems (ESS), etc.

[0005] On the other hand, increasing the driving range requires increasing the energy density of battery cells, but this leads to increased heat generation. Therefore, there is an increasing demand for modules that can improve cooling efficiency in response to the increased heat generation.

[0006] To address this need, a heat sink has traditionally been installed under the cooling plate of the battery module to improve cooling efficiency.

[0007] The battery module is provided with a cooling plate at the bottom, which is in contact with a one-way heat sink. In addition, the cooling plate is in contact with a thermally conductive material and the bottom of the battery cell inside the module, thereby transferring the heat generated in the battery cell to the outside for cooling.

[0008] The heat sink and module's cooling plate achieve cooling by contacting the battery cells and passing through the lower end of the module, and utilizes an aluminum-based material with high thermal conductivity to improve cooling efficiency. Furthermore, attempts are made to further enhance cooling efficiency by using thermally conductive components such as thermally conductive adhesives or pads to eliminate gaps between the battery cells and the cooling plate.

[0009] In the cooling plate, the thermal conductivity is determined based on the fundamental properties of the materials used. Furthermore, the thermal conductivity of the heat-conducting components is increased by adding ceramic fillers, etc., to improve thermal efficiency. However, this unidirectional cooling is insufficient to cool the heat generated as energy density increases.

[0010] Therefore, in recent years, a two-sided cooling technology has been developed that cools battery cells or battery modules by placing radiators on the lower and upper parts of the module, and it is being applied to some sports cars and advanced platforms.

[0011] In this bidirectional cooling technology, a method has been developed in which a liquid injection hole is formed in the upper part of the module, and a heat dissipation adhesive previously used in the lower part is injected through the liquid injection hole to fill the hollow space of the battery cell, thereby cooling the heat generated in the battery cell from both the top and bottom. This technology has been widely used. Summary of the Invention

[0012] (a) Technical problems to be solved

[0013] An embodiment of the present invention aims to improve the performance of a battery module by improving the cooling performance of the high-voltage battery module.

[0014] Furthermore, an embodiment of the present invention aims to improve the fast charging effect of the battery by improving cooling performance and to provide an effect that improves the long-term lifespan of the battery.

[0015] (II) Technical Solution

[0016] An embodiment of the present invention provides a battery module comprising: a module housing including an upper cover and a lower cover; and two or more pouch battery units included within the module housing, wherein each pouch battery unit has a sealing portion on three sides, wherein the sealing portion in which electrode leads do not protrude is folded to one side, the folded sealing portion being located on the upper cover side or the lower cover side of the module housing, and a heat-dissipating adhesive is directly attached to a pouch in the opposite direction to the folding direction of the folded sealing portion of at least one pouch battery unit.

[0017] The sealing part can be folded to 90°, 180°, 270° or 540°.

[0018] The sealing portions of the pouch cell and the adjacent pouch cell can be folded in opposite directions.

[0019] The heat-dissipating adhesive can be in direct contact with two adjacent pouch cells.

[0020] The heat-dissipating adhesive can come into contact with the upper or lower cover plate of the module housing.

[0021] The upper or lower cover plate in contact with the heat-dissipating adhesive can be formed by intaglio molding to have protrusions that project downward from the upper cover plate or upward from the lower cover plate.

[0022] The heat-dissipating adhesive may be at least one adhesive selected from the group consisting of polyurethane, silicone and epoxy.

[0023] The thermal adhesive can have a thermal conductivity of 1.0 W / mK or higher.

[0024] The heat-dissipating adhesive may include thermally conductive fillers.

[0025] The thermally conductive filler may be at least one selected from the group consisting of alumina, aluminum hydroxide, and silicon dioxide.

[0026] The heat-dissipating adhesive may include a first heat-dissipating adhesive attached to the inner surface of the upper cover and a second heat-dissipating adhesive attached to the lower cover.

[0027] The folded sealing portion can be secured by attaching insulating tape.

[0028] One end of the insulating tape may be present on the surface of the folded sealing portion.

[0029] Preferably, the adhesive force of the insulating tape is 500 gf / in or more, and the shear stress is 30 kgf / in. 2 above.

[0030] The insulating tape may be at least one pressure-sensitive adhesive or hot melt adhesive selected from the group consisting of silicone, acrylic, rubber or epoxy.

[0031] The battery module may include an elastic pad between any one of the pouch cell and the adjacent pouch cell.

[0032] Preferably, the area of ​​the elastic pad is larger than the area of ​​the pouch battery unit.

[0033] The elastic pad may be attached with release paper.

[0034] According to another embodiment of the present invention, a battery module is provided, comprising: a module housing including an upper cover and a lower cover; adjacent pouch battery cells housed within the module housing and each including a sealing portion; sealing portions of adjacent pouch battery cells having no protruding electrode leads and being folded in opposite directions on the upper surfaces of adjacent pouch battery cells; a first thermally insulating adhesive directly connecting the upper surfaces of adjacent pouch battery cells to the upper cover; and a second thermally insulating adhesive connecting the filler material to the lower cover, wherein the first and second thermally insulating adhesives provide bidirectional cooling to the adjacent pouch battery cells.

[0035] The adjacent pouch cell may further include an elastic pad disposed between the cell and the cell.

[0036] (III) Beneficial Effects

[0037] According to one embodiment of the present invention, the heat-dissipating adhesive layer made of heat-dissipating adhesive is in direct contact with the pouch cell and the top cover plate, thus ensuring excellent cooling performance in the upper direction of the battery module, thereby improving bidirectional cooling performance and thus more effectively cooling the heat generated in the battery cell.

[0038] In addition, according to one embodiment of the invention, a high-viscosity heat-dissipating adhesive is coated on the upper part of the bag, instead of injecting the heat-dissipating adhesive through the injection hole as in the prior art. Therefore, the amount and shape of the heat-dissipating adhesive can be adjusted as needed, and its shape can be confirmed, thus allowing for more quantitative prediction of cooling performance.

[0039] Furthermore, according to one embodiment of the invention, since the heat-dissipating adhesive does not seep between the pouch battery cells but is instead applied to the top, damage to the pouch can be minimized. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a pouch cell that shows the structure of an air layer formed between the pouch cell and the thermal adhesive at the top of the battery module by injecting thermal adhesive according to the prior art.

[0041] Figure 2 This is an exploded perspective view schematically showing an example of a battery module.

[0042] Figure 3 The diagram shows an example of the sealing part of a folded bag, where A, B, C, and D represent examples of folding at 90 degrees, 180 degrees, 270 degrees, and 360 degrees, respectively.

[0043] Figure 4 This is a schematic diagram illustrating an example of a pouch battery cell inserted into a battery module according to an embodiment of the present invention, wherein a heat-dissipating adhesive is applied to a pouch battery cell in the direction opposite to the direction in which the sealing portion of the pouch battery cell is folded.

[0044] Figure 5 It is shown schematically in Figure 4 The figure shows an example of a pouch battery cell where the folded sealing portion of the pouch battery cell is secured by insulating tape.

[0045] Figure 6 This is a schematic diagram of a portion of the upper part of a stack of pouch cells in a battery module forming a heat-dissipating adhesive. It schematically illustrates an example in which the folding directions of the seals in adjacent pouch cells are opposite to each other, the heat-dissipating adhesive is applied in two adjacent pouch cells in directions opposite to the folding directions of the seals, and the top cover is formed by intaglio printing.

[0046] Figure 7 The diagram schematically shows the upper part of the module forming the thermal adhesive, where (a) is a plan view and (b) is a perspective view showing only the thermal adhesive.

[0047] Figure 8 The diagram schematically illustrates the structure of the heat-dissipating adhesive formed on the lower cover plate, wherein (a) shows the lower cover plate on which the heat-dissipating adhesive is formed, and (b) shows an exploded perspective view of the lower cover plate.

[0048] Figure 9 This is a schematic diagram showing the lower part of a pouch cell in a battery module where a heat-dissipating adhesive is formed on the lower cover.

[0049] Figure 10 This is a diagram illustrating an example of a heat-dissipating adhesive formed on the inner surface of the lower cover plate and a gap filler material formed at the boundary of the pouch cell.

[0050] Figure 11 This schematically illustrates a front view and an exploded perspective view of a battery module with a bidirectional cooling device according to an embodiment of the present invention.

[0051] Figure 12 This is a graph showing the results of measuring the changes in the highest internal temperature, the upper temperature, and the lower temperature of the battery cell at the same location during the battery driving process of the battery modules manufactured in Example 1, Comparative Example 1, and Comparative Example 2.

[0052] Explanation of reference numerals in the attached figures

[0053] 1, 11: Pouch battery unit; 3, 13: Sealing part

[0054] 5, 15: Insulating tape; 7, 17, 27: Heat dissipation adhesive.

[0055] 19: Elastic pad 20: Front cover plate

[0056] 30: Busbar assembly; 50: Rear cover plate

[0057] 60: Top cover plate; 70: Insulating cover

[0058] 80: Lower cover plate Detailed Implementation

[0059] In conventional bidirectional cooling, a considerable amount of heat-dissipating adhesive is injected, and ceramic fillers are added to the heat-dissipating adhesive to increase its thermal conductivity. As a result, the amount of additives required also increases, leading to a price increase.

[0060] also, Figure 1This schematically illustrates the structure of the thermal adhesive layer formed on top of the pouch cell when thermal adhesive is injected into the battery module using a conventional liquid injection method. However, as... Figure 1 As shown, because the shape of the thermal adhesive cannot be confirmed through this injection method, there is a limitation that more quantitative cooling performance cannot be predicted. Furthermore, as... Figure 1 As shown, the bag seal at the top of the battery cell is folded into shapes such as 90°, 180°, 270°, and 540°, making it difficult to fix the position of the folded portion. Furthermore, the changing position of the folded portion can alter the heat transfer path, such as the formation and thickness of air layers. Therefore, heat transfer efficiency is reduced, leading to limitations in cooling reliability, such as difficulty in maintaining precise module thermal resistance and cooling performance. In addition, there is a problem of the injected thermal adhesive seeping between the battery cells and damaging the bag.

[0061] One embodiment of the present invention is an invention for improving cooling efficiency in high-voltage battery modules, and more specifically, it relates to a battery module including cooling devices for performing lower and upper cooling of the battery module, thereby achieving excellent bidirectional cooling efficiency and solving the problems existing in conventional bidirectional cooling methods.

[0062] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0063] According to one embodiment, a battery module includes: a module housing, including at least an upper cover and a lower cover; and two or more pouch cell units, included inside the module housing and having sealing portions on three sides, wherein a sealing portion in which electrode leads do not protrude is located in the upper part of the module housing.

[0064] The module housing includes at least an upper cover plate and a lower cover plate. Additionally, the module housing includes a front cover plate and a rear cover plate, and also includes side cover plates. In this case, the side cover plates can be separated from the lower cover plate and joined to it, and the side cover plates can also be integrally formed with the lower cover plate, or they can be separated from each other and joined together.

[0065] For example, Figure 2 An example of a battery module is shown, wherein the module housing may include at least: a lower cover plate 80 having a structure covering the lower and sides of the pouch battery cell 11, and being integrally formed. The shape includes: an upper cover 60 covering the upper part of the battery cell; a front cover 20 covering the front part of the pouch battery cell 11; and a rear cover 50 covering the rear part of the pouch battery cell 11. The shape and size of the module housing are not particularly limited and can be appropriately selected according to the application, the shape and number of pouch battery cells 11 housed within the internal space, etc. Figure 2The lower cover plate 80 is shown to have The shape is an example, but the lower cover plate 80 can be separated from the side cover plates. In the following description, for ease of explanation, an example of a structure where the lower cover plate and side cover plates are separated will be described.

[0066] The pouch battery unit 11 is housed within the module housing. The module housing may contain two or more pouch battery units 11, each electrically connected to the others. The number of pouch battery units 11 housed in the module housing can be appropriate depending on the intended use, and therefore there is no particular limitation on the number.

[0067] The pouch battery unit 11 is manufactured by housing an electrode assembly including a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode in a pouch and heat-sealing the pouch. The pouch battery unit 11 has a sealing portion. The sealing portion is present on at least one side of the pouch; there is no particular limitation on this, and it can have three or four sealing portions by three-sided or four-sided sealing. More preferably, it can have three sealing portions by three-sided sealing.

[0068] At this time, the electrode leads protrude from one or both of the sealing portions 3 of the bag battery unit 11. The sealing portion where the electrode leads do not protrude can be set to face the upper surface of the module housing, i.e., the upper cover plate 60. Alternatively, it can be set to face the lower surface of the module housing, i.e., the lower cover plate 80.

[0069] The following description will focus on an embodiment of the invention with reference to a diagram showing the shape of the folded sealing portion located on the upper cover plate, but it is also applicable to the case where the sealing portion is located on the lower cover plate, as will be readily understood by those skilled in the art.

[0070] In the pouch battery unit 11, in order to prevent the metal inside the bag from coming into contact with the top cover plate 60 and causing a short circuit, the sealing part 3 is preferably folded to one side, that is, folded in one direction with the center of the sealing part of the pouch battery unit 11 as a reference, so as to prevent the metal layer inside the bag from being exposed to the outside.

[0071] like Figure 3 As shown, there are no particular restrictions on the folding of the sealing part 13; it can be folded to 90 degrees, 180 degrees, 270 degrees, 360 degrees, or 450 degrees. Figure 3 The folding of the sealing part is schematically shown, where A to D represent folds of 90 degrees, 180 degrees, 270 degrees and 360 degrees respectively.

[0072] When folded at 0 degrees, i.e. without folding, the metal inside the bag may be exposed, leading to a short circuit. Furthermore, the increased length of the sealing part 13 causes a decrease in the length of the battery cell, resulting in a decrease in energy density.

[0073] Two or more pouch battery units 11 are housed in the module housing. In the sealing portion 13 of each pouch battery unit 11, the sealing portion without protruding electrode leads is positioned and housed facing the upper cover plate 60 (upper surface) or the lower cover plate 80 (lower surface) of the module housing. That is, the sealing portion of the pouch can be housed facing either the upper or lower surface of the module housing; there is no particular limitation on this. However, for convenience, an example of housing the sealing portion of the pouch facing the upper surface of the module housing will be described in detail below.

[0074] With the sealing portion of the pouch battery unit 11 folded to one side as described above, as follows: Figure 4 As shown, the heat-dissipating adhesive 17 is attached to the bag in the direction opposite to the folding direction of the sealing portion. Therefore, while protecting the folded sealing portion, the heat-dissipating adhesive can transfer heat generated in the bag's battery cell for heat dissipation. Figure 4 The structure shown can be applied to unidirectional cooling structures, and also to bidirectional cooling structures.

[0075] The material of the heat-dissipating adhesive 17 is not limited to this; polyurethane, silicone, and epoxy resins can be used as the main agent, and the main agent and curing agent can be included simultaneously as needed. The curing agent can be appropriately selected according to the main agent, and therefore there are no particular limitations.

[0076] The main agent and the curing agent, which can be added as needed, can each independently have a viscosity of 300 Pa·s or higher (measured according to ASTM D2196, based on 1 / s at room temperature). If the viscosity of the main agent and the curing agent is less than 300 Pa·s, due to their high fluidity, they can flow between the pouch cell 11 and the pouch cell 11. Especially when coated on the upper part, due to the unevenness of the opposite side of the fold and the upper part of the cell, it may flow to the outside of the cell, which may cause damage to the pouch.

[0077] The heat-dissipating adhesive may include thermally conductive fillers. These fillers, used to provide or improve heat dissipation for the adhesive, may include alumina, aluminum hydroxide, silica, etc. The content of the thermally conductive filler is not particularly limited and may comprise 55 to 80% by weight relative to the total weight of the heat-dissipating adhesive. When the content of the thermally conductive filler exceeds 80% by weight, the viscosity is high, insulation and adhesion may decrease, and it may also adversely affect the cured bag.

[0078] The thermal adhesive 17 can have a strength of 30 kgf / in 2The above (measured according to ASTM D5656, by attachment to a SUS substrate after removal of the release paper at room temperature) shear strength. A higher shear strength of the thermal adhesive 17 is preferred; there is no particular upper limit, for example, it can be 100 kgf / in. 2 The following shear strength values. On the other hand, the thermal adhesive 17 can have a 180° peel strength value of 500 gf / in (ASTM D1000) or higher.

[0079] The folded sealing portion 13 can be secured by attaching insulating tape 15. The insulating tape 15 can be attached such that one end is located on the surface of the folded sealing portion 13 and extends in the folding direction, such that the other end is located on the surface of the pouch battery unit 11.

[0080] That is, such as Figure 1 As shown, when the insulating tape 5 is attached such that one end exists on the opposite side of the folding direction of the sealing portion 13, but not on the surface of the folded sealing portion 13, an air layer can be formed between the surface of the pouch cell 11 and the insulating tape 5.

[0081] When the heat-dissipating adhesive 7 is attached and applied with an air layer formed as described above, the heat-dissipating adhesive 7 is located on the insulating tape 5. Due to the heat insulation effect provided by the air layer formed between the insulating tape 5 and the pouch battery unit 11, the heat transfer efficiency of transferring heat from the pouch battery unit 11 to the heat-dissipating adhesive 7 may be significantly reduced. Furthermore, when the heat-dissipating adhesive 7 is located on the insulating tape 5, a greater number of interfaces are formed from the pouch battery unit 1 to the top cover plate. This increased number of interfaces may become a major factor in reducing heat transfer efficiency.

[0082] On the other hand, such as Figure 5 As shown, when one end of the insulating tape 15 is present on the folded surface of the sealing portion 13, and the heat-dissipating adhesive 17 is attached to the opposite side of the folding direction, the pouch battery unit 11 and the upper cover plate 60 are connected by the heat-dissipating adhesive 17, thereby reducing the number of interfaces. Moreover, since no air layer is formed and no heat insulation effect is provided, the heat generated in the pouch battery unit 11 can be transferred to the upper cover plate 60 more effectively through the heat-dissipating adhesive 17. Figure 5 The structure shown can be applied to unidirectional cooling structures, and also to bidirectional cooling structures.

[0083] The insulating tape 15 is not limited to this; it can be a silicone, acrylic, rubber, or epoxy pressure-sensitive adhesive or hot melt adhesive, and these can be used in combination.

[0084] When two or more pouch cell units are housed within a module housing, such as Figure 6 As shown, any one of the included pouch battery cells 11 and its adjacent pouch battery cell 11 can be configured such that the folding directions of the sealing portion 13 toward the upper surface of the module housing are opposite to each other. The heat-dissipating adhesive is applied to the sealing portions of the pouch battery cells of two adjacent pouch battery cells folded in opposite directions, and the upper cover plate 60 can be a plate having a protrusion projecting downward from the upper cover plate and formed by intaglio printing.

[0085] More specifically, when the sealing portion 13 of any one of the pouch battery units 11 is folded and accommodated to the right, the sealing portions 13 of the adjacent two pouch battery units 11 can be folded to the left. That is, the folding directions of the sealing portions 13 of the pouch battery units 11 can be set to alternately face left, right, and left. In this case, as... Figure 6 As shown, by attaching a heat-dissipating adhesive 17 to the unfolded direction of the sealing portion 13 in the two adjacent pouch battery cells 11, the heat generated in the two pouch battery cells 11 can be transferred more effectively.

[0086] The heat-dissipating adhesive 17 can contact the module housing to easily dissipate heat generated in the pouch battery unit 11 to the outside. Specifically, when the folded sealing portion of the pouch battery unit is positioned facing the upper surface of the module housing, the upper cover plate 60 and the heat-dissipating adhesive 17 are in direct contact; when the folded sealing portion is positioned facing the lower surface of the module housing, the lower cover plate 80 and the heat-dissipating adhesive 17 are in direct contact, which facilitates heat dissipation.

[0087] Therefore, the thickness of the heat-dissipating adhesive 17 is not particularly limited, as long as it has a thickness sufficient to contact the upper cover plate 60 or the lower cover plate 80.

[0088] Furthermore, the upper cover plate 60 or the lower cover plate 80 can be formed by intaglio etching. That is, Figure 6 An example of a cover plate formed by intaglio engraving is shown schematically. (As shown) Figure 6 As shown, the upper cover plate 60 is formed by intaglio printing, which allows for a further reduction in the thickness of the heat-dissipating adhesive 17. This reduces the amount of heat-dissipating adhesive 17 used, thereby lowering costs. Furthermore, since the gap between the pouch battery unit 11 and the upper cover plate 60 can be further reduced, heat generated in the pouch battery unit 11 can be transferred to the upper cover plate 60 more effectively. Figure 6 The structure shown can be applied to unidirectional cooling structures, and also to bidirectional cooling structures.

[0089] like Figure 6As shown, a battery module according to one embodiment may include an elastic pad 19 between any one pouch battery cell 11 and adjacent pouch battery cells 11. The elastic pad 19 can be applied between all pouch battery cells 11 and can be arranged at predetermined intervals without particular limitation. There is no particular limitation on the elastic pad 19; any elastic pad commonly used in battery modules can be applied to one embodiment of the present invention.

[0090] The elastic pad 19 can have an area larger than the main body area of ​​the pouch battery unit 11, and more specifically, larger than the area of ​​the negative electrode. In this case, the heat-dissipating adhesive 17 coated on the pouch battery unit 11 on the upper part of the battery module can be prevented from flowing and seeping into the space between the pouch battery units 11, thus preventing damage to the pouch surface.

[0091] The elastic pad 19 is typically supplied to the battery module manufacturing process with release paper attached. When the elastic pad is applied between pouch battery cells 11, it can be used directly with the release paper attached without removing it. Typically, the elastic pad 19 is a foam pad with pores. When a heat-dissipating adhesive is applied with the release paper removed, the adhesive may penetrate into the pores of the elastic pad 19, leading to a decrease in its performance.

[0092] Figure 7 The upper surface of a battery module obtained according to an embodiment of the invention as described above is schematically shown. Figure 7 (a) shows the upper surface of the battery module with the top cover 60 removed. Figure 7 (b) schematically illustrates a heat-dissipating adhesive 17 formed on the upper part of a battery module according to an embodiment of the invention. Here, the heat-dissipating adhesive 17 may include a strip of the adhesive extending in one direction to cover the elastic pad 19.

[0093] According to one embodiment, the battery module has a bidirectional cooling device and may include an upper cooling device and a lower cooling device. For example, a separate cooling device may be provided on the inner surface of the upper or lower cover plate on the side opposite to the side where the folded sealing portion is located. Hereinafter, an example of a separate cooling device formed on the lower cover plate will be described.

[0094] Specifically, when the cooling device using a heat-dissipating adhesive in the aforementioned pouch cell is applied to the upper surface of the module housing, i.e., the upper cover plate, as follows: Figure 8 As shown, a heat-dissipating adhesive 27, serving as a separate cooling device for the lower cover plate, can be attached to the lower cover plate 80. The heat-dissipating adhesive 27 may be formed only on a portion of the inner surface of the lower cover plate, or it may be formed on the entire surface.

[0095] Figure 8 (a) is a plan view showing the lower cover plate 80 with the thermal adhesive 27 attached. Figure 8 (b) is its exploded stereograph. Furthermore, Figure 9 A partially enlarged view of a battery module including a lower cover plate 80 with the thermally insulating adhesive 27 attached is shown. As described above, downward cooling can be provided by attaching the thermally insulating adhesive 27 to the lower cover plate 80. Figure 9 The structure shown can be applied to unidirectional or bidirectional cooling structures.

[0096] In addition, such as Figure 10 As shown, a filler material may be included in the space formed at the boundary between the heat-dissipating adhesive 27 formed on the inner surface of the lower cover plate 80 and the pouch battery unit 11. The heat-dissipating adhesive 27 is attached to the lower cover plate 80, and a filler material may be included in the space between the heat-dissipating adhesive 27 and the lower surface of the pouch battery unit. Therefore, the pouch battery unit 11 can be tightly attached to the lower cover plate 80 by the heat-dissipating adhesive 27, thereby allowing for more efficient cooling of the heat generated from the pouch battery unit.

[0097] Figure 10 An example of inserting a three-sided sealed pouch battery unit 11 into a module housing is partially shown, with the unsealed side of the pouch battery unit 11 positioned in contact with the lower cover plate 80. A filler made of a thermally conductive material can be used to fill the boundary between the lower cover plate 80 (cooling plate) and the pouch battery unit 11 on the lower surface of the module housing. Figure 10 The structure shown can be applied to unidirectional or bidirectional cooling structures.

[0098] Examples of the thermally conductive materials include, but are not limited to, alumina, aluminum hydroxide, and silicon dioxide. The gap filler may further include an adhesive in addition to the thermally conductive material, as needed.

[0099] According to one embodiment described above, by attaching a heat-dissipating adhesive 17 to the upper surface of the pouch battery unit 11 included in the battery module, the battery module can be cooled in one direction. In addition, the heat-dissipating adhesive 27 can also be applied as a cooling device for the battery module to the lower surface of the pouch battery unit 11 in the opposite direction, thereby enabling bidirectional cooling of the battery module and maximizing cooling efficiency.

[0100] Figure 11 An embodiment of a battery module provided by means of an embodiment as described above is schematically illustrated. Figure 11As shown, one embodiment of the battery module includes a lower cover plate 80 and a heat-dissipating adhesive 27 formed on the lower cover plate 80, and an upper cover plate 60. When accommodating two or more pouch battery units 11, a heat-dissipating adhesive 17 is applied to the upper part of the battery module, directly contacting the pouch battery units 11, and the upper cover plate 60 is in direct contact with the heat-dissipating adhesive 17. Therefore, heat can be easily transferred bidirectionally, that is, heat generated in the pouch battery units 11 can be transferred to the upper cover plate 60 via the heat-dissipating adhesive 17, and to the lower cover plate 80 via the heat-dissipating adhesive 27, thereby maximizing the heat transfer effect.

[0101] As mentioned above, in the prior art, such as Figure 1 As shown, the insulating tape 5 used to prevent venting is attached to the entire width of the upper part of the pouch cell 1. Therefore, due to the thermal resistance of the insulating tape 5 itself and the increased interface due to the insulating tape 5, the thermal resistance increases. Furthermore, due to the heat insulation effect of the air layer formed between the insulating tape 5 and the upper part of the battery cell, the thermal resistance increases further, forming a structure that makes it difficult to transfer heat upwards.

[0102] However, according to the embodiments described above, such as Figure 4 As shown, in the construction of the battery module, the bag sealing part 13 of the bag battery unit 11 is folded in one direction, and a heat dissipation adhesive 17 for cooling is applied to the bag surface on the opposite side of the folding direction, so that the bag battery unit 11 can be in direct contact with the upper cover plate 60 or the lower cover plate 80, thereby minimizing thermal resistance and maximizing heat transfer effect.

[0103] Example

[0104] The present invention will now be described in detail through examples.

[0105] Example 1

[0106] In a three-sided sealed pouch cell where the electrode leads protrude in two directions, the sealed portion of the electrode leads that does not protrude is folded 270° in one direction and then secured with insulating tape.

[0107] At this time, as Figure 5 As shown, one end of the insulating tape is located on the surface of the sealing part, and the other end is located on the electrode surface of the pouch cell on the folding side, so that the insulating tape is only attached to half (1 / 2) of the electrode thickness.

[0108] Ten pouch battery units with the aforementioned insulating tape attached are manufactured. At this time, the sealing portions of five of the pouch battery units are folded to the left, and the sealing portions of the other five pouch battery units are folded to the right.

[0109] The pouch cell units, with their folded sealing sections folded in different directions, are alternately stacked and longitudinally housed within a battery module housing consisting of a front cover, a rear cover, and a lower cover, with a thermally insulating adhesive attached to the entire interior of the lower cover. The folded sealing sections are then accommodated towards the upper cover of the module housing.

[0110] Thermal adhesive is applied to the stack of pouch cell units housed within the battery module housing. For example... Figure 5 As shown, the coating is applied on the opposite side of the folding direction of the seal.

[0111] The battery module is then manufactured by covering it with a top cover.

[0112] Comparative Example 1

[0113] like Figure 1 As shown, one end of the insulating tape is located on the electrode surface of the pouch cell on the folding direction side, and the other end is located on the electrode surface of the pouch cell on the opposite folding direction side, so that the insulating tape is attached to the entire electrode thickness. The battery module is manufactured in the same manner as in Example 1, except that the insulating tape is attached to the entire battery cell thickness.

[0114] Comparative Example 2

[0115] The battery module was performed and manufactured in the same manner as in Example 1, except that no insulating tape was attached and no thermal adhesive was applied to the inner surface of the lower cover.

[0116] Evaluation of heating characteristics

[0117] During the process of driving the battery using the battery modules manufactured in Example 1, Comparative Example 1, and Comparative Example 2, the highest internal temperature of the battery cells housed within the battery modules, as well as the temperature changes at the upper and lower parts of the battery cells, were measured at the same locations, and the results are shown in Table 1 and... Figure 12 middle.

[0118] [Table 1]

[0119] Comparative Example 1 32.7 28.3 0.49 Comparative Example 2 35.8 30.25 0.69 Example 1 31.7 28.1 0.45

[0120] As shown in Table 1, in Comparative Example 1, where a cooling device is provided for bidirectional cooling of the upper and lower cover plates, but insulating tape is attached to the entire thickness of the battery cell after the sealing part is folded, the temperature difference between the highest temperature inside the battery cell and the temperature at the top of the battery cell is 4.4°C. In Comparative Example 2, where a cooling device is provided for cooling in one direction (downward cover plate), and no additional insulating tape is attached after the sealing part is folded, the temperature difference between the highest temperature inside the battery cell and the temperature at the top of the battery cell is 5.6°C.

[0121] On the other hand, in Embodiment 1, where a cooling device is provided for bidirectional cooling of the upper and lower cover plates, and insulating tape is attached only over the entire thickness of the battery cell in the folding direction after the sealing portion is folded, the temperature difference between the highest temperature inside the battery cell and the temperature at the top of the battery cell is 3.6°C.

[0122] In addition, by Figure 12 It can be seen that, when comparing Comparative Example 1 and Embodiment 1, which are equipped with cooling devices in both the upper and lower directions, in the case of Comparative Example 1, there is a temperature difference between the upper and lower parts of the battery cell, therefore, the cooling efficiency of the upper and lower parts differs. On the other hand, in the case of Embodiment 1, there is almost no temperature difference between the upper and lower parts of the battery cell, therefore, the cooling efficiency of the upper and lower parts is the same. Figure 12 In the graphs of Comparative Example 1 and Comparative Example 2, a range of sharp temperature drops appears. This is due to the condition that heating stops at any point in time after temperature convergence. Typically, convergence to a specific temperature occurs after 8000–10000 seconds. Figure 12 The graphs for Comparative Examples 1 and 2, and Example 1, all exhibit the same temperature change pattern after temperature convergence within 8000–10000 seconds. Therefore, the temperature ranges represented in the graphs are different.

[0123] As described above, according to one embodiment of the present invention, the insulating tape is only attached to the folding direction side of the sealing part for upper and lower cooling, and a heat dissipation adhesive is attached to the side opposite to the folding direction, thereby improving the upward cooling efficiency.

Claims

1. A battery module, comprising: The module housing includes an upper cover and a lower cover; and Two or more pouch battery units are included within the module housing, and each pouch battery unit has a sealing portion on three sides. The sealing part in which the electrode lead does not protrude is folded to one side, and the folded sealing part is located on the upper cover plate side or the lower cover plate side of the module housing. The heat-dissipating adhesive is directly attached to the bag in the opposite direction to the folding direction of the folded sealing portion of at least one pouch battery cell. The heat-dissipating adhesive comes into contact with the upper cover plate or the lower cover plate of the module housing. The upper or lower cover plate in contact with the heat-dissipating adhesive is formed by intaglio printing to have protrusions that project downwards from the upper cover plate or upwards from the lower cover plate. When the heat-dissipating adhesive comes into contact with the upper cover plate, the surface of the heat-dissipating adhesive in contact with the upper cover plate is higher than the folded sealing portion; when the heat-dissipating adhesive comes into contact with the lower cover plate, the surface of the heat-dissipating adhesive in contact with the lower cover plate is lower than the folded sealing portion.

2. The battery module according to claim 1, wherein, The folded sealing portion is folded to 90°, 180°, 270° or 540°.

3. The battery module according to claim 1, wherein, The seals of any one pouch cell and its adjacent pouch cell are folded in opposite directions.

4. The battery module according to claim 3, wherein, The thermal adhesive is in direct contact with two adjacent pouch cell units.

5. The battery module according to claim 1, wherein, The heat-dissipating adhesive is at least one adhesive selected from the group consisting of polyurethane, silicone and epoxy.

6. The battery module according to claim 1, wherein, The thermal adhesive has a thermal conductivity of 1.0 W / mK or higher.

7. The battery module according to claim 1, wherein, The heat-dissipating adhesive includes thermally conductive fillers.

8. The battery module according to claim 7, wherein, The thermally conductive filler is at least one selected from the group consisting of alumina, aluminum hydroxide, and silicon dioxide.

9. The battery module according to claim 1, wherein, The heat-dissipating adhesive includes a first heat-dissipating adhesive attached to the inner surface of the upper cover and a second heat-dissipating adhesive attached to the lower cover.

10. The battery module according to any one of claims 1 to 9, wherein, The folded sealing portion is secured by attaching insulating tape.

11. The battery module according to claim 10, wherein, One end of the insulating tape is present on the surface of the folded sealing portion.

12. The battery module according to claim 10, wherein, The adhesive strength of the insulating tape is above 500 gf / in, and the shear stress is 30 kgf / in. 2 above.

13. The battery module according to claim 10, wherein, The insulating tape is at least one pressure-sensitive adhesive or hot melt adhesive selected from the group consisting of silicone, acrylic, rubber or epoxy.

14. The battery module according to any one of claims 1 to 9, comprising an elastic pad between any one of the pouch battery cells and the adjacent pouch battery cells.

15. The battery module according to claim 14, wherein, The area of ​​the elastic pad is larger than the area of ​​the pouch battery unit.

16. The battery module according to claim 14, wherein, The elastic pad is attached with release paper.

17. A battery module, comprising: The module housing includes an upper cover and a lower cover; Adjacent pouch cell units are housed within the module housing and each includes a sealing portion; The sealed portions of adjacent pouch cell units, in which no electrode leads protrude, are folded in opposite directions on the upper surfaces of adjacent pouch cell units. The first heat-dissipating adhesive directly connects the upper surface of the adjacent pouch cell to the top cover plate; as well as The second heat-dissipating adhesive connects a gap filler made of a thermally conductive material to the lower cover plate. The first and second thermal adhesives provide bidirectional cooling to the adjacent pouch cells. The first heat-dissipating adhesive is in contact with the upper cover plate. The second heat-dissipating adhesive comes into contact with the lower cover plate. The top cover plate, which is in contact with the first heat-dissipating adhesive, is formed by intaglio printing to have a protrusion that projects downward from the top cover plate. The lower cover plate, which is in contact with the second thermal adhesive, is etched to have a protrusion that projects upward from the lower cover plate. The surface of the first heat-dissipating adhesive in contact with the upper cover plate is higher than the folded sealing portion, and the surface of the second heat-dissipating adhesive in contact with the lower cover plate is lower than the folded sealing portion.

18. The battery module according to claim 17, wherein, The adjacent pouch cell further includes an elastic pad disposed between the cell and the cell.

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