Battery modules, battery packs including battery modules, and vehicles including battery packs

Abstract

A battery module according to an embodiment of the present invention includes: a plurality of cylindrical battery cells, the plurality of cylindrical battery cells being erected such that the positive electrode faces downward and the negative electrode faces upward; a cell housing for accommodating the plurality of battery cells; a top plate covering the entire top side of the cell housing and electrically connected to the positive electrode of a corresponding plurality of battery cells; a bottom plate disposed opposite to the top plate to cover the entire bottom side of the cell housing and electrically connected to the negative electrode of a corresponding plurality of battery cells; and a phase change material filling the cell housing to partially impregnate and cool the plurality of battery cells.

Description

Technical Field

[0001] This disclosure relates to battery modules, battery packs including battery modules, and vehicles including battery packs.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0132071, filed on October 13, 2020, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Secondary batteries, characterized by their ease of use and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric drive sources. These secondary batteries are gaining attention as a new energy source for improving eco-friendliness and energy efficiency, not only because their main advantage lies in significantly reducing fossil fuel consumption but also because they produce no byproducts from energy use.

[0004] Currently widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these individual rechargeable battery cells (i.e., individual battery cells) is approximately 2.5V to approximately 4.5V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to configure a battery pack. Furthermore, multiple battery cells are connected in parallel to configure the battery pack according to the required charge / discharge capacity. Therefore, the number of battery cells included in a battery pack can be set in various ways according to the required output voltage or charge / discharge capacity.

[0005] Furthermore, when configuring a battery pack by connecting multiple battery cells in series / parallel, it is common practice to first configure a battery module that includes at least one battery cell and then add other components using at least one battery module.

[0006] Since multi-module battery packs are manufactured by packing multiple secondary cells into a narrow space, it is important to dissipate the heat generated from each secondary cell effectively. Because the charging or discharging process of the secondary cells is performed through electrochemical reactions, heat buildup occurs if the heat generated during charging / discharging is not effectively removed. This accelerates the degradation of the battery module and, in some cases, may lead to combustion or explosion.

[0007] Therefore, high-output and high-capacity battery modules and the battery packs mounted on them must require cooling devices to cool the battery cells inside.

[0008] Conventional battery modules typically employ a cooling structure in which heat is dissipated through a thermal interface material (TIM) between the battery cell and the heat sink.

[0009] However, this conventional cooling structure has the following problem: it is difficult to improve the performance of battery modules and battery packs, and in addition, electric vehicles that include battery modules or battery packs, due to the low cooling performance. Summary of the Invention

[0010] Technical issues

[0011] This disclosure is designed to address problems in the relevant field, and therefore relates to providing a battery module, a battery pack including the battery module, and a vehicle including the battery pack, the battery module having a structure that maximizes cooling performance and effectively prevents secondary events such as thermal runaway caused by high-temperature exhaust when exhaust is discharged from the battery cells.

[0012] Technical solution

[0013] In one aspect of this disclosure, a battery module is provided, the battery module comprising: a plurality of cylindrical battery cells, the plurality of cylindrical battery cells being erected such that the positive electrode faces downward and the negative electrode faces upward; a cell housing configured to house the plurality of battery cells; a top plate configured to completely cover the upper side of the cell housing and electrically connected to the negative electrode of each of the plurality of battery cells; a bottom plate configured opposite to the top plate to completely cover the lower side of the cell housing and electrically connected to the positive electrode of each of the plurality of battery cells; and a phase change material filling the cell housing such that the plurality of battery cells are partially impregnated, and the phase change material cooling the plurality of battery cells.

[0014] The battery module may also include a heat sink mounted on the upper side of the top plate and configured to cool the plurality of battery cells.

[0015] When the temperature of multiple battery cells rises, the phase change material can be vaporized to move toward the top plate, and can also be liquefied through a heat sink to move toward the bottom plate.

[0016] The battery module may also include guide ribs disposed on the upper side of the inner wall of the cell housing and configured to guide the movement of liquefied phase change material toward the base plate.

[0017] The battery module may further include at least one cell fixing member configured to fix the plurality of battery cells in order to prevent the plurality of battery cells from moving within the cell housing.

[0018] The cell fixing components can be arranged in pairs, and the pair of cell fixing components can include: an upper cell fixing component for inserting and fixing the upper part of a plurality of battery cells to the upper side of the inner part of the cell housing; and a lower cell fixing component for inserting and fixing the lower part of a plurality of battery cells to the lower side of the inner part of the cell housing.

[0019] Multiple cell insertion holes for inserting multiple battery cells can be formed in the upper cell fixing member and the lower cell fixing member.

[0020] The edge of the top plate can be joined to the edge of the cell casing.

[0021] In another aspect of this disclosure, a battery pack is provided, the battery pack including at least one battery module according to the above embodiments and a battery pack housing configured to encapsulate the at least one battery module.

[0022] In another aspect of this disclosure, a vehicle is provided that includes at least one battery pack according to the above-described embodiments.

[0023] Beneficial effects

[0024] According to the various embodiments described above, a battery module, a battery pack including the battery module, and a vehicle including the battery pack are provided. The battery module has a structure that not only maximizes cooling performance but also effectively prevents secondary events such as thermal escape caused by high-temperature exhaust when exhaust is discharged from the battery cells. Attached Figure Description

[0025] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0026] Figure 1 This is a diagram illustrating a battery module according to an embodiment of the present disclosure.

[0027] Figure 2 yes Figure 1 An exploded 3D view of the battery module.

[0028] Figure 3 yes Figure 1 Cross-sectional view of the battery module.

[0029] Figure 4 It is used for explanation Figure 1 A diagram showing the connection between the top plate of the battery module and the cell housing.

[0030] Figure 5It is used for explanation Figure 1 The diagram shows the electrode connections of the battery cells in the battery module.

[0031] Figure 6 It is used for explanation Figure 1 A diagram illustrating the cooling principle of the battery module.

[0032] Figure 7 This is a diagram illustrating a portion of a battery module according to another embodiment of the present disclosure.

[0033] Figure 8 This is a diagram illustrating a portion of a battery module according to another embodiment of the present disclosure.

[0034] Figure 9 This is a diagram illustrating a battery pack according to an embodiment of the present disclosure. Detailed Implementation

[0035] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meanings, but rather is interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure, on the basis of allowing the inventors to appropriately define terms for best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications can be made thereto without departing from the scope of the present disclosure. Furthermore, to aid in understanding the invention, the drawings are not shown to scale, but rather some dimensions of components may be exaggerated.

[0036] Figure 1 This is a diagram illustrating a battery module according to an embodiment of the present disclosure. Figure 2 yes Figure 1 An exploded 3D view of the battery module. Figure 3 yes Figure 1 A cross-sectional view of the battery module. Figure 4 It is used for explanation Figure 1 A diagram showing the connection between the top plate of the battery module and the cell housing. Figure 5 It is used for explanation Figure 1 A diagram showing the electrode connections of the battery cells in the battery module, and Figure 6 It is for the instruction manual. Figure 1 A diagram illustrating the cooling principle of the battery module.

[0037] Reference Figures 1 to 6 The battery module 10 may include a battery cell 100, a cell housing 200, at least one cell fixing member 300 and 400, a heat sink 500, a phase change material 600, a top plate 700, and a bottom plate 800.

[0038] Multiple battery cells 100 can be configured, and multiple battery cells 100 can be configured as cylindrical secondary batteries. Multiple battery cells 100 can be stacked on top of each other and electrically connected to each other.

[0039] When the battery cell 100 is a cylindrical secondary battery, the positive electrode 110 can be disposed in the center of one side surface of the battery cell 100 in the longitudinal direction. The negative electrode 130 can be disposed in the center of the other side surface of the battery cell 100 in the longitudinal direction. A venting portion (not shown) for venting to reduce the internal pressure of the battery cell 100 and thereby ensure safety when the internal pressure of the battery cell 100 increases to a certain level or greater can be disposed on the surface forming the positive electrode 110.

[0040] The cell housing 200 can accommodate multiple battery cells 100. Therefore, a space capable of accommodating multiple battery cells 100 can be provided in the cell housing 200.

[0041] The guide rib 220 can be disposed within the cell housing 200.

[0042] The guide rib 220 can be disposed on the upper side of the inner wall of the cell housing 200 and can guide the phase change material 600 to move downward when it is liquefied (L), as will be described below. Specifically, the guide rib 220 can guide the phase change material 600, which is vaporized (V) and then liquefied (L) again as the internal temperature rises, to move more quickly toward the base plate 800, as will be described below.

[0043] At least one cell fixing member 300 and 400 can fix a plurality of battery cells 100 to prevent the plurality of battery cells 100 from moving in the cell housing 200.

[0044] These cell fixing components 300 and 400 can be provided as a pair. The pair of cell fixing components 300 and 400 may include an upper cell fixing component 300 and a lower cell fixing component 400.

[0045] An upper cell fixing member 300 for inserting multiple battery cells 100 into the upper part can be fixed to the upper side of the inner part of the cell housing 200. For this purpose, multiple cell insertion holes 350 for inserting multiple battery cells 100 into the upper part can be formed in the upper cell fixing member 300.

[0046] A lower cell fixing member 400 for inserting the lower portions of multiple battery cells 100 can be fixed to the lower side of the inner portion of the cell housing 200. For this purpose, multiple cell insertion holes 450 for inserting the lower portions of multiple battery cells 100 can be formed in the lower cell fixing member 400.

[0047] Heat sink 500 is used to cool multiple battery cells 100 and can be mounted on the upper side of top plate 700, as will be described below. Alternatively, heat sink 500 can be mounted on the cell housing 200 instead of the upper side of top plate 700, as will be described below.

[0048] Phase change material 600 is used as an insulating oil for efficiently cooling multiple battery cells 100 and can be partially filled in the cell housing 200. Therefore, multiple battery cells 100 can be partially immersed in phase change material 600 within the cell housing 200.

[0049] The phase change material 600 can be vaporized (V) and moved toward the top plate 700 as the temperature of the multiple battery cells 100 rises, as will be described below, and can be liquefied (L) and moved toward the bottom plate 800 via the heat sink 500, as will be described below. This vaporization (V) and liquefaction (L) can be repeated cyclically, and in this way, cooling of the battery cells 100 can be performed more efficiently.

[0050] Phase change material 600 can be made of fluorine-based materials with low boiling points for more efficient cycling. For example, phase change material 600 can include materials with boiling points between 35 and 50 degrees Celsius. Furthermore, phase change material 600 can include materials with extinguishing capabilities. Therefore, in the event of a fire in battery module 10, the flame can be quickly extinguished by phase change material 600.

[0051] The top plate 700 can be attached to the cell housing 200 to completely cover the upper side of the cell housing 200. Here, the top plate 700 can be attached to the cell housing 200 via a joining structure. This is to maximize the hermeticity of the cell housing 200 and prevent the phase change material 600 from evaporating within the cell housing 200. The joining structure can be formed in the edge of the top plate 700 and the upper edge of the cell housing 200. That is, the edge of the top plate 700 can join with the upper edge of the cell housing 200.

[0052] The top plate 700 is electrically connected to the negative terminal 130 of a plurality of battery cells 100. For this purpose, the top plate 700 can be made of a metallic material and can be welded to the negative terminal 130 of the plurality of battery cells 100. That is, in this embodiment, the top plate 700 can not only be used as a cover for sealing the battery cell housing 200, but also as a busbar for electrical connection of the battery cells 100.

[0053] Therefore, in this embodiment, since these two functions can be achieved by the top plate 700, a separate busbar structure is not required for the electrical connection between the negative terminals 130 of the battery cell 100.

[0054] Furthermore, for insulation between the top plate 700 and the cell housing 200, the top plate 700 may be insulated from the cell housing 200 at the connection portion. In this embodiment, the top plate 700 may be insulated at the joint edge portion and then insulated from the battery cell housing 200. If the cell housing 200 comprises a non-metallic material instead of a metallic material, this insulation can be omitted.

[0055] The base plate 800 can be disposed opposite to the top plate 700 to completely cover the lower side of the cell housing 200. This base plate 800 can be integrally formed with the cell housing 200, or it can be disposed separately and installed on the bottom of the cell housing 200.

[0056] This base plate 800 can be electrically connected to the positive terminal 110 of multiple battery cells 100. In this way, the base plate 800 can not only serve as a cover for sealing the bottom of the cell housing 200, but also, together with the top plate 700, serve as a busbar for electrical connection of the battery cells 100.

[0057] For this purpose, the base plate 800 can be made of a metallic material and can be welded and connected to the positive electrode 110 of the plurality of battery cells 100. Furthermore, when the base plate 800 is integrally formed with the battery cell housing 200, the cell housing 200 can also be made of a metallic material. In this case, to insulate from the top plate 700, as described above, the cell housing 200 can be insulated from the top plate 700 in the connection portion. If the base plate 800 has a structure for separately mounting the cell housing 200, the cell housing 200 can be made of a non-metallic material, and in this case, insulation can be omitted.

[0058] Therefore, in this embodiment, both the sealing of the cell housing 200 and the electrical connection of the positive electrode 110 of the battery cell 100 can be achieved through the base plate 800, so a separate busbar structure for connecting the positive electrode 110 of the battery cell 100 is not required.

[0059] Therefore, in this embodiment, since the top plate 700 and bottom plate 800 used for sealing the cell housing 200 also function as busbars for the electrical connection of the electrodes 110 and 130 of the battery cell 100, a separate additional busbar structure can be omitted, thereby reducing the manufacturing cost of the battery module 10 and improving manufacturing efficiency.

[0060] Furthermore, in this disclosure, the battery cell 100 is disposed upright in the cell housing 200, such that the positive electrode 110 faces downward and the negative electrode 130 faces upward. That is, as described above, the battery cell 100 is configured to be directional, such that the positive electrode 110 is in face-to-face contact with the bottom plate 800 and the negative electrode 130 is in face-to-face contact with the top plate 700.

[0061] In the case of a cylindrical battery cell, a positive electrode 110 and a negative electrode 130 are formed on two side surfaces along the longitudinal direction, and an exhaust portion is formed in the surface where the positive electrode 110 is formed. The exhaust portion is designed to be weaker in rigidity than the surrounding area and to rupture preferentially when the internal pressure of the battery cell 100 increases, so that the gas generated in the battery cell 100 can be discharged.

[0062] The battery module 10 according to this disclosure has a structure in which the surface where the vent portion is formed (i.e., the surface where the positive electrode 110 is formed) faces downward, and thus the positive electrode 110 is immersed in liquefied phase change material 600. Therefore, the battery module 10 according to the embodiment of this disclosure can prevent the temperature inside the battery module 10 from rising rapidly when high-temperature vent gas is ejected due to the increase in internal pressure of the battery cell 100, thereby preventing secondary events caused by gas ejection and ensuring safety in the use of secondary batteries.

[0063] Furthermore, the battery module 10 according to this embodiment can also ensure the capacity of the battery cell 100 through the volume of a separate additional busbar structure, which is even omitted in terms of energy density. In addition, the battery module 10 according to this embodiment can also maximize cooling performance through the phase change material 600.

[0064] Next, we will refer to Figure 7 A battery module according to another embodiment of the present disclosure is described. The battery module according to this disclosure differs from the battery module according to the previous embodiment only in that the contact protrusion 810 is formed on the base plate 800, and other components are substantially the same. Therefore, in describing the battery module according to another embodiment of the present disclosure, descriptions that are repeated in the description of the previous embodiment will be omitted, and only the differences will be described.

[0065] The contact protrusion 810 is formed to protrude upward from the base plate 800. The contact protrusion 810 is formed at a position corresponding to the positive electrode 110 of the battery cell 100 and is in contact with the positive electrode 110. The number of contact protrusions 810 can be the same as the number of battery cells 100.

[0066] Contact protrusion 810 is used to separate a surface of battery cell 100 from a base plate 800, on which a positive electrode 110 is formed in a cell insertion hole 450 formed in a lower cell retaining member 400, and the base plate 800 provides space for filling liquefied phase change material 600. Contact protrusion 810 may be made of a conductive material for electrical connections of multiple battery cells 100.

[0067] Therefore, when a space is formed between the bottom plate 800 and the positive electrode 110 in the cell insertion hole 450 formed in the lower cell fixing member 400, and the phase change material 600 is filled in the space, effective cooling can be achieved when the battery cell 100 is vented, and secondary events such as fire caused by high temperature gas can be effectively prevented.

[0068] Next, we will refer to Figure 8 A battery module according to another embodiment of the present disclosure is described. The battery module according to another embodiment of the present disclosure and... Figure 7 The only difference in the battery module shown is that the flow path P through which the liquefied phase change material 600 can move is formed in the lower cell fixing member 400, and the other members are substantially the same. Therefore, in describing a battery module according to another embodiment of this disclosure, the flow path P will be described in detail, and descriptions that are repeated in the description of the previous embodiment will be omitted.

[0069] A flow path P is formed in the lower cell fixing member 400 and passes between the upper surface of the lower cell fixing member 400 and the inner surface of the cell insertion hole 450 formed in the lower cell fixing member 400. The liquefied phase change material 600 can be smoothly introduced into the space between the positive electrode 110 and the base plate 800 through the flow path P.

[0070] Figure 9 This is a diagram illustrating a battery pack according to an embodiment of the present disclosure.

[0071] Reference Figure 9 The battery pack 1 may include at least one battery module 10 according to the foregoing embodiments and a battery pack housing 50 that encapsulates at least one battery module 10.

[0072] This battery pack 1 can be installed in a vehicle as a fuel source. As an example, the battery pack 1 can be installed in electric vehicles, hybrid vehicles, and other vehicles using other battery packs 1 as a fuel source. Furthermore, besides vehicles, the battery pack 1 can also be installed in other devices, such as energy storage systems, instruments, and facilities using secondary batteries.

[0073] Therefore, the vehicle according to this embodiment and the device such as the vehicle, instrument and facility including the battery pack 1 include the battery module 10 described above, and thus, the battery pack 1 having all the advantages brought about by the battery module 10 and the device such as the vehicle, instrument and facility including such a battery pack 1 can be realized.

[0074] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various changes and modifications within the scope of this disclosure will become apparent to those skilled in the art based on the detailed description.

Claims

1. A battery module comprising: a plurality of cylindrical battery cells disposed upright such that a positive electrode faces downward and a negative electrode faces upward; a cell case configured to accommodate the plurality of battery cells; a top plate configured to completely cover an upper side of the cell case and electrically connected to a negative electrode of each of the plurality of battery cells; a bottom plate disposed opposite the top plate to completely cover a lower side of the cell case and electrically connected to a positive electrode of each of the plurality of battery cells; a lower cell fixing member into which lower portions of the plurality of battery cells are inserted and which is fixed to a lower side of an inner portion of the cell case; and a phase change material filled in the cell case such that the plurality of battery cells are partially impregnated and the phase change material cools the plurality of battery cells, wherein a flow path is formed in the lower cell fixing member, liquefied phase change material moves through the flow path to be introduced into a space between the positive electrode and the bottom plate, and wherein an exhaust portion is provided on a surface of the battery cell on which the positive electrode is formed, which exhausts to reduce an internal pressure of the battery cell when the internal pressure of the battery cell increases to a certain level or more. 2.The battery module of claim 1, further comprising a heat sink mounted on an upper side of the top plate and configured to cool the plurality of battery cells. The phase change material is vaporized to move toward the top plate when a temperature of the plurality of battery cells increases, and the phase change material is liquefied to move toward the bottom plate through the heat sink.

3. The battery module of claim 2, wherein, 4.The battery module of claim 3, further comprising a guide rib provided on an upper side of an inner wall of the cell case and configured to guide liquefied phase change material to move toward the bottom plate. The battery module further comprises:

5. The battery module of claim 1, wherein, an upper cell fixing member into which upper portions of the plurality of battery cells are inserted and which is fixed to an upper side of an inner portion of the cell case. A plurality of cell insertion holes for inserting the plurality of battery cells are formed in the upper cell fixing member and the lower cell fixing member.

6. The battery module of claim 5, wherein, An edge of the top plate is engaged with an upper edge of the cell case.

7. The battery module of claim 1, wherein, The phase change material includes a material having a boiling point between 35 degrees Celsius and 50 degrees Celsius.

8. The battery module of claim 1, wherein, A contact protrusion protruding upward is formed on the bottom plate, and the contact protrusion is formed at a position corresponding to the positive electrode of the battery cell and contacts the positive electrode.

9. The battery module of claim 1, wherein, The number of the contact protrusions is as many as the number of the battery cells.

10. The battery module of claim 9, wherein, 11.A battery pack comprising: at least one battery module according to any one of claims 1 to 10; and a battery pack case configured to package the at least one battery module. ​ ​ 12. A vehicle comprising the battery pack of claim 11.

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