Battery module

Abstract

A battery module according to an embodiment of the present application includes: a battery cell stack in which a plurality of battery cells are stacked; a module case in which the battery cell stack is accommodated inside; and a busbar assembly provided between the module case and the battery cell stack to be electrically connected with the battery cells, the busbar assembly including: at least one busbar; and a thermally conductive unit in which the busbar is embedded inside, the thermally conductive unit being formed of a resin material including a thermally conductive filler.

Description

Technical Field

[0001] This invention relates to a battery module with improved heat dissipation performance. Background Technology

[0002] Unlike primary batteries, secondary batteries can be charged and discharged, making them suitable for various applications such as digital cameras, mobile phones, laptops, and hybrid vehicles. Examples of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-metal hydride batteries, and lithium-ion batteries.

[0003] Among these secondary batteries, a great deal of research is being conducted on lithium secondary batteries with high energy density and discharge voltage. In recent years, lithium secondary batteries have been manufactured as flexible pouch-type battery cells and used in modular form by connecting multiple battery cells.

[0004] However, as the energy density of battery modules increases, there is a problem of excessive temperature rise in the busbars located inside the battery modules.

[0005] Therefore, a battery module that can effectively reduce the heat of the busbar is needed. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] The purpose of this invention is to provide a battery module that can effectively reduce the heat generated in the busbar.

[0008] (II) Technical Solution

[0009] A battery module according to an embodiment of the present invention may include: a battery cell stack having a plurality of battery cells stacked thereon; a module housing having the battery cell stack inside; and a busbar assembly disposed between the module housing and the battery cell stack for electrical connection with the battery cells, the busbar assembly including: at least one busbar; and a thermally conductive unit having the busbar embedded therein, the thermally conductive unit being formed of a resin material containing thermally conductive filler.

[0010] In this embodiment, the busbar assembly can be configured to contact at least a portion of the module housing.

[0011] In this embodiment, the thermally conductive filler may include any one of boron nitride, aluminum nitride, silicon carbide, magnesium oxide, and aluminum oxide.

[0012] In this embodiment, the heat-conducting unit may be formed of a material with a thermal conductivity of 2 W / mK or higher.

[0013] In this embodiment, the heat-conducting unit can achieve 1×10⁻⁶ Ω·cm under a 500V voltage and 60-second environment. 10 Volume resistivity above Ω·cm.

[0014] In this embodiment, the heat-conducting unit can achieve 1×10⁻⁶ Ω·cm under a 500V voltage and 60-second environment. 12 Surface resistance above Ω·cm.

[0015] In this embodiment, more than half of the busbar assembly can be embedded inside the heat-conducting unit.

[0016] In this embodiment, the battery module may further include a cooling device attached to the outer surface of the module housing.

[0017] In this embodiment, the cooling device may have a cooling flow path inside it.

[0018] Additionally, a battery module according to an embodiment of the present invention may include: a battery cell stack having a plurality of battery cells stacked thereon; a module housing having the battery cell stack internally housed thereon; and a busbar assembly disposed between the module housing and the battery cell stack for electrical connection with the battery cells. The busbar assembly may include: a busbar having a plurality of through slits incorporating electrode leads of the battery cells; and a heat-conducting unit having the busbar embedded therein, wherein the area between the through slits of the busbar may be embedded within the heat-conducting unit.

[0019] In this embodiment, the thermally conductive unit may be formed of a resin material containing thermally conductive filler.

[0020] In this embodiment, more than half of the busbar assembly can be embedded inside the heat-conducting unit.

[0021] (III) Beneficial Effects

[0022] In the battery module according to an embodiment of the present invention, heat transferred from the battery cell to the busbar is rapidly transferred to the housing via a heat-conducting unit. Therefore, even if the heat generated by the battery cell is concentrated in the busbar, the heat of the busbar can be effectively dissipated. Attached Figure Description

[0023] Figure 1 This is a schematic perspective view of a battery cell according to an embodiment of the present invention.

[0024] Figure 2 yes Figure 1 An exploded 3D diagram.

[0025] Figure 3 It is shown in magnification Figure 2 A three-dimensional view of the busbar assembly shown.

[0026] Figure 4 yes Figure 3 The main view of the busbar component shown.

[0027] Figure 5 It is shown Figure 3 The diagram shown omits the heat-conducting unit in the busbar assembly.

[0028] Figure 6 yes Figure 1 The side view of the battery module shown.

[0029] Explanation of reference numerals in the attached figures

[0030] 1: Battery cell stack 10: Battery cell

[0031] 30: Module housing; 40: Second plate

[0032] 50: First plate 60: Side cover

[0033] 70: Busbar assembly 80: Busbar

[0034] 88: Thermal conductive unit; 100: Battery module Detailed Implementation

[0035] Before providing a detailed description of the invention, the terms or words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that inventors can appropriately define the concepts of terms in order to best interpret their invention, they should be interpreted as meanings and concepts consistent with the technical concept of the invention. Therefore, the configurations shown in the embodiments and drawings described in this specification are merely the most preferred embodiments of the invention and do not represent all the technical concepts of the invention. It should be understood that equivalents and modifications that can replace these configurations may be present at the time of filing this application.

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same components are represented by the same reference numerals wherever possible in the drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the essence of the invention will be omitted. For the same reason, some components in the drawings are enlarged, omitted, or shown schematically, and the dimensions of each component do not perfectly reflect the actual dimensions.

[0037] Figure 1 This is a schematic perspective view of a battery cell according to an embodiment of the present invention. Figure 2 yes Figure 1 The exploded diagram.

[0038] Reference Figure 1 and Figure 2 The battery module 100 in this embodiment may include: a battery cell stack 1, on which multiple battery cells 10 are stacked; a module housing 30; and a busbar assembly 70.

[0039] The battery cell stack 1 can be formed by stacking battery cells 10 in the up-down direction (or vertical direction). However, it can also be configured to be stacked in the left-right direction as needed.

[0040] Each battery cell 10 can be a pouched type secondary battery and can have an electrode lead 15 protruding outwards.

[0041] The battery cell 10 can be configured such that an electrode assembly (not shown) is housed within a pouch 11.

[0042] The electrode assembly includes multiple electrode plates and electrode connectors, and is housed within a bag 11. The electrode plates can be formed by alternately stacking multiple positive and multiple negative electrode plates. In this case, each of the multiple positive and multiple negative electrode plates is provided with an electrode connector and can be connected to the same electrode lead 15 by contacting each other with the same polarity.

[0043] In this embodiment, each battery cell 10 can be configured such that two electrode leads 15 face opposite directions.

[0044] The bag 11 is formed in a container shape to provide internal space for accommodating the electrode assembly and electrolyte (not shown). At this time, a portion of the electrode leads 15 of the electrode assembly is exposed outside the bag 11.

[0045] On the other hand, although not shown in the figure, at least one buffer pad may be provided between the stacked battery cells 10.

[0046] A cushioning pad can be incorporated to suppress the volume expansion of the entire battery cell when a specific battery cell expands. The cushioning pad can be made of polyurethane foam, but is not limited to this.

[0047] When the buffer pads are made of an adhesive material, the battery cells 10 can be joined together to form a battery cell stack 1. However, the invention is not limited to this, and separate fixing members can be added to secure the stacked battery cells 10.

[0048] The battery cell 10 constructed as described above can be a rechargeable and dischargeable nickel-metal hydride (Ni-MH) battery or a lithium-ion (Li-ion) battery.

[0049] The module housing 30 defines the appearance of the battery module 100, and the module housing 30 is disposed outside the plurality of battery cells 10 to protect the battery cells 10 from the influence of the external environment.

[0050] The module housing 30 of this embodiment may include: a first plate 50 disposed on one side of the battery cell stack 1; a second plate 40 disposed on the other side of the battery cell stack 1; and a side cover 60 disposed on the side of the battery cell 10 on which the electrode leads 15 are provided. In addition, the first plate 50 and the second plate 40 can function as cooling components of the battery module 100.

[0051] The first plate 50 may include: a lower plate 52 disposed at the lower part of the battery cell stack 1 to support the bottom surface of the battery cell stack 1; and a side plate 58 to support the side surface of the battery cell stack 1.

[0052] In this embodiment, the lower plate 52 and the side plate 58 can be formed by bending a plate-shaped member. However, the construction of the present invention is not limited to this, and the side plate 58 and the lower plate 52 can also be constructed as independent components as needed.

[0053] The lower plate 52 forms the bottom surface of the battery module 100. Therefore, the lower plate 52 can be constructed flat.

[0054] Side plates 58 can be formed by extending from both sides of the lower plate 52. Heat dissipation components or buffer components can be sandwiched between the side plates 58 and the battery cell stack 1.

[0055] The first plate 50 can be made of a material with high thermal conductivity, such as metal. For example, the first plate 50 can be made of aluminum. However, it is not limited to this; various materials can be used as long as they have similar strength and thermal conductivity, even if they are not metals.

[0056] The second plate 40 can be disposed on the upper part of the battery cell 10 and attached to the upper surface of the battery cell stack 1. In addition, the second plate 40 can be fastened to the upper end of the side plate 58 of the first plate 50. Therefore, when the second plate 40 is fastened to the first plate 50, the second plate 40 and the first plate 50 can have the shape of a hollow tubular member.

[0057] Like the first plate 50, the second plate 40 can be made of a material with high thermal conductivity, such as metal. For example, the second plate 40 can be made of aluminum. However, it is not limited to this; various materials can be used as long as they have similar strength and thermal conductivity, even if they are not metals.

[0058] The first plate 50 and the second plate 40 can be joined by welding or other methods. However, they are not limited to this; various modifications can be made, such as joining by sliding or using fixing components such as bolts or screws.

[0059] The heat transfer component 90 can be disposed at any point between the battery cell stack 1 and the first plate 50, and between the battery cell stack 1 and the second plate 40.

[0060] The heat transfer member 90 transfers the heat generated in the battery cell 10 to the module housing 30. For this purpose, the heat transfer member 90 can be made of a material with high thermal conductivity. For example, the heat transfer member 90 can be formed from any of the following, but is not limited to: thermal grease, thermal adhesive, epoxy resin, and heat dissipation pad.

[0061] The heat transfer component 90 can be disposed on the inner surface of the module housing 30 in the form of a pad, or it can be formed by coating the inner surface of the module housing 30 in a liquid or gel state. The heat transfer component 90 of this embodiment has high insulation properties, for example, it can be made of a material with an insulation strength in the range of 10 to 30 kV / mm.

[0062] Therefore, in the battery module 100 according to this embodiment, even if the insulation in the battery cell 10 is partially damaged, the insulation between the battery cell 10 and the module housing 30 can be maintained by the heat transfer member 90 disposed around the battery cell 10.

[0063] The side covers 60 are respectively attached to the two sides of the battery cell 10 where the electrode leads 15 are provided.

[0064] The side cover 60 is integrated with the first plate 50 and the second plate 40. Therefore, the side cover 60, together with the first plate 50 and the second plate 40, completes the appearance of the battery module 100.

[0065] The side cover 60 may be formed of an insulating material such as resin, and the side cover 60 may have a through hole 62 for exposing the connection terminal 72 to the outside.

[0066] The side cover 60 can be attached to the first plate 50 and the second plate 40 by means of fastening members such as screws or bolts. However, the invention is not limited thereto.

[0067] The busbar 70 can be disposed between the side cover 60 and the battery unit 10.

[0068] Figure 3 It is shown in magnification Figure 2 A perspective view of the busbar assembly shown. Additionally, Figure 4 yes Figure 3 The main view of the busbar component shown is shown. Figure 5 It is shown Figure 3 The diagram shown omits some of the heat-conducting units in the busbar assembly. For ease of understanding, [the following is omitted]. Figure 4 and Figure 5 Circuit units are omitted.

[0069] Reference Figures 3 to 5 The busbar assembly 70 can be disposed on the side of the battery cell 10 where the electrode leads 15 are provided and combined with the battery cell stack 1, and the busbar assembly 70 can include at least one busbar 80 and a heat-conducting unit 88.

[0070] The busbar 80 can be formed in the form of a metal plate and combined with the electrode leads 15 of the battery cell 10. Therefore, the battery cells 10 can be electrically connected to each other through the busbar 80, and can be electrically connected to the outside through the connection terminals 72 connected to the busbar 80.

[0071] In this embodiment, the busbar 80 may be provided with a plurality of through slits 87, and the electrode leads 15 of the battery cell 10 are inserted into and disposed in the plurality of through slits 87. Therefore, after the electrode leads 15 are inserted into the through slits 87 of the busbar 80, they can be joined to the busbar 80 by means of welding or the like, so that the end of the electrode leads 15 can completely penetrate the busbar 80 and protrude to the outside of the busbar 80.

[0072] The busbar assembly 70 may be provided with a connection terminal 72. In addition, the electrode leads 15 of the battery cell 10 can be electrically connected to the connection terminal 72 through the busbar 80 provided in the busbar assembly 70.

[0073] The connection terminal 72 is made of a conductive member and is connected to or coupled to at least one busbar 80 to electrically connect the battery cell 10 to an external source. For example, the connection terminal 72 may be integrally formed with the busbar 80.

[0074] The connection terminal 72 can be exposed to the outside of the module housing 30 through the through hole 62 formed in the side cover 60. Therefore, the through hole 62 of the side cover 60 can be formed in a shape corresponding to the size and shape of the hole of the connection terminal 72.

[0075] The heat-conducting unit 88 is combined with the busbar 80 to form the overall appearance of the busbar assembly 70.

[0076] The heat-conducting unit 88 is formed of an insulating material, and at least a portion of the busbar 80 can be embedded inside the heat-conducting unit 88.

[0077] For example, the busbar 80 can be integrally formed with the heat-conducting unit 88 by insert injection molding.

[0078] Furthermore, the thermally conductive unit 88 in this embodiment can be formed of a thermally conductive resin with high thermal conductivity. For example, the thermally conductive unit 88 can be formed of a resin containing a thermally conductive filler.

[0079] The thermally conductive filler can be a ceramic filler, for example, it can contain any one of boron nitride, aluminum nitride, silicon carbide, magnesium oxide and aluminum oxide.

[0080] In addition, the resin material itself can be a resin component, or the resin material can contain a precursor of the resin component, that is, a component that can become a resin component through a curing reaction, polymerization reaction, or other reactions.

[0081] On the other hand, in this embodiment, the busbar 80 is configured to dissipate heat primarily through the heat-conducting unit 88. Therefore, when the thermal conductivity of the heat-conducting unit 88 is low, it is difficult to dissipate heat from the busbar 80 effectively.

[0082] The applicant has confirmed through various experiments that when the thermal conductivity of the heat-conducting unit 88 is less than 2 W / mK, the heat from the busbar 80 cannot be effectively transferred to the module housing 30 side. Therefore, the heat-conducting unit 88 in this embodiment can be formed to have a thermal conductivity of 2 W / mK or higher.

[0083] In addition, to prevent damage to the insulation, the heat-conducting unit 88 in this embodiment can have a 1×10⁻⁶ characteristic under a 500V voltage and 60-second environment. 10 Volume resistivity above Ω·cm and 1×10 12 Surface resistance above Ω·cm.

[0084] In the busbar assembly 70 constructed as described above, more than half of the busbars 80 can be embedded inside the heat-conducting unit 88. In this embodiment, only the through slit 87 of the busbar 80 and its surrounding area are partially exposed to the outside of the heat-conducting unit 88, while the rest is entirely embedded inside the heat-conducting unit 88. Therefore, heat can be transferred from the entire busbar 80 to the heat-conducting unit 88, thereby improving heat dissipation.

[0085] Additionally, if necessary, the engagement region 86 of the busbar 80 that engages with the circuit unit 78 described later may also be exposed to the outside of the heat-conducting unit 88, but is not limited thereto.

[0086] The busbar assembly 70 can be attached to the module housing 30 such that at least a portion of the busbar assembly 70 contacts the module housing 30.

[0087] Figure 6 yes Figure 1 The image shows a side view of the battery module, omitting the side cover and circuitry.

[0088] like Figure 6 As shown, in this embodiment, the busbar assembly 70 is configured such that its entire two side edges contact the side plates 58 of the module housing 30. Therefore, heat transferred from the busbar assembly 70 can be diffused through the side plates 58 to the entire module housing 30, and can be released by the cooling device 20 attached to the module housing 30.

[0089] For this purpose, thermal interface material (TIM) or thermal adhesive can be applied to the contact surface where the busbar assembly and the side plate meet.

[0090] In the battery module 100 of this embodiment, the heat of the busbar assembly 70 is transferred to the lower plate 52 via the side plate 58. However, it is not limited to this; the busbar assembly 70 may be configured to contact the lower plate 52 to directly transfer heat to the lower plate 52.

[0091] However, as shown in this embodiment, when the cooling device 20 is disposed on the outer surface of the lower plate 52, the movement path of heat from the busbar 80 to the cooling device 20 is very short. Therefore, the busbar assembly 70 may be partially overcooled, or the temperature deviation of the busbar assembly 70 may be too large.

[0092] Therefore, in the battery module 100 of this embodiment, the busbar assembly 70 is configured to contact the side cover 58 of the module housing 30 with the largest possible area. Thus, most of the heat from the busbar assembly 70 is transferred to the cooling device 20 via the side cover 58, thereby minimizing the possibility of the busbar assembly 70 being partially overcooled or experiencing an increase in temperature deviation.

[0093] However, the construction of the present invention is not limited thereto. When the position of the cooling device 20 is changed or the cooling device 20 is added, the contact position or contact area between the busbar assembly 70 and the module housing 30 can be changed.

[0094] The busbar assembly 70 may include a circuit unit 78. The circuit unit may include a circuit board and multiple electronic components packaged in the circuit board, thereby enabling the function of sensing the voltage of the battery unit 10.

[0095] like Figure 3 As shown, the circuit unit 78 can be coupled to the engagement region 86 of the busbar 80 exposed to the outside of the heat-conducting unit 88 for electrical connection with the busbar 80. However, the construction of the present invention is not limited to this, and the circuit unit 78 can be disposed in various locations as long as it can be electrically connected to the battery unit.

[0096] The cooling device 20 can be attached to the outer surface of the module housing 30 to effectively cool the module housing 30. In this embodiment, the cooling device 20 can be attached to the outer surface of the lower plate 52 to directly cool the lower plate 52. However, the construction of the present invention is not limited to this; for example, the cooling device 20 can be additionally and selectively disposed on the outer surface of the side plate 58 or the second plate 40.

[0097] The cooling device 20 in this embodiment can be a water-cooled cooling device 20 with a cooling flow path 22 inside. However, the structure of the present invention is not limited to this, and an air-cooled cooling device can also be used.

[0098] The cooling device 20 can be integrally integrated with the module housing 30 and included in the battery module 100. However, it is not limited to this; the cooling device 20 can also be separately disposed in the device on which the battery module is mounted.

[0099] In addition, for effective heat transfer, a heat transfer component may be additionally disposed between the module housing 30 and the cooling device 20.

[0100] In the battery module 100 constructed as described above, heat transferred from the battery cell 10 to the busbar 80 is rapidly transferred to the module housing 30 via the heat-conducting unit 88. Therefore, even if the heat generated by the battery cell 10 is concentrated in the busbar 80, the heat of the busbar 80 can be effectively dissipated.

[0101] In addition, since most of the busbar 80 is embedded inside the electrically insulating heat-conducting unit 88, the exposure of the busbar 80 can be minimized, thereby improving the insulation reliability between the busbar 80 and other components (e.g., module housing, etc.).

[0102] The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and variations can be made without departing from the technical concept of the present invention as set forth in the claims, which will be obvious to those skilled in the art. Furthermore, the various embodiments can be implemented in combination.

Claims

1.A battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a module case in which the battery cell stack is accommodated inside; a busbar assembly disposed between the module case and the battery cell stack to be electrically connected with the battery cells, and a cooling device coupled to an outer surface of the module case, the busbar assembly comprising: at least one busbar; and a thermally conductive unit in which the busbar is embedded inside, the thermally conductive unit being formed of a resin material containing a thermally conductive filler, the module case comprising: a lower plate supporting a bottom surface of the battery cell stack; and a side plate supporting a side surface of the battery cell stack, a side cover disposed at a side of the battery cell provided with an electrode lead, the cooling device being coupled to an outer surface of the lower plate, the busbar assembly being configured such that both side edges thereof are in contact with the side plate, a majority of heat of the busbar assembly being transferred to the cooling device through the side plate to minimize a case in which the busbar assembly is partially supercooled or temperature deviation is increased. 2.The battery module according to claim 1, wherein the thermally conductive filler contains any one of boron nitride, aluminum nitride, silicon carbide, magnesium oxide, and aluminum oxide. 3.The battery module according to claim 1, wherein the thermally conductive unit is formed of a material having a thermal conductivity of 2 W / mK or more. 4.The battery module according to claim 1, wherein The heat conducting unit is formed of a material having a volume resistivity of 1 x 10 10 Ω·cm or more under an environment of 500 V voltage for 60 seconds. 5.The battery module according to claim 1, wherein The heat conducting unit is formed of a material having a surface resistance of 1 x 10 12 Ω-cm or more under an environment of 500 V voltage for 60 seconds. 6.The battery module according to claim 1, wherein in the busbar assembly, more than half of the busbar is embedded inside the thermally conductive unit. 7.The battery module according to claim 1, wherein the cooling device is provided with a cooling flow path inside thereof. 8.A battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a module case in which the battery cell stack is accommodated inside; a busbar assembly disposed between the module case and the battery cell stack to be electrically connected with the battery cells, and a cooling device coupled to an outer surface of the module case, the busbar assembly comprising: a busbar including a plurality of through slits in which electrode leads of the battery cells are coupled; and a thermally conductive unit in which the busbar is embedded inside, an area between the through slits of the busbar is embedded in the thermally conductive unit, the module case comprising: a lower plate supporting a bottom surface of the battery cell stack; and a side plate supporting a side surface of the battery cell stack, a side cover disposed at a side of the battery cell provided with the electrode lead, the cooling device being coupled to an outer surface of the lower plate, the busbar assembly being configured to be in contact with the side plate with a maximum area, a majority of heat of the busbar assembly being transferred to the cooling device through the side plate to minimize a case in which the busbar assembly is partially supercooled or temperature deviation is increased. 9.The battery module according to claim 8, wherein the thermally conductive unit is formed of a resin material containing a thermally conductive filler. 10.The battery module according to claim 8, wherein In the busbar assembly, more than half of the busbar is embedded inside the heat conduction unit.

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