Battery module and battery pack comprising same

Abstract

A battery module is provided according to exemplary embodiments of the present invention. The battery module comprises: a plurality of battery cells; a module housing which accommodates the plurality of battery cells; a first fire-resistant layer which has a plurality of vent holes in the upper portion thereof and surrounds the plurality of battery cells while leaving the lower surfaces of the plurality of battery cells exposed; a thermal insulation pad which is disposed on the first fire-resistant layer and has a plurality of slots at positions corresponding to the plurality of vent holes; a second fire-resistant layer which is positioned on the thermal insulation pad and covers the plurality of slots; an upper plate which is disposed on the second fire-resistant layer and has a plurality of openings at positions corresponding to the plurality of slots; and a flame-retardant cover which is installed on the upper plate and has a plurality of other openings at positions corresponding to the plurality of openings.

Description

Battery module and battery pack including the same

[0001] The present invention relates to a battery module and a battery pack including the same, and specifically to a battery module having a venting structure for preventing heat propagation and a battery pack including the battery module. The present application claims the benefit of Korean application No. 10-2024-0191638 filed on December 19, 2024, which is incorporated herein by reference in its entirety.

[0002] With the increasing technological development and demand for mobile devices and electric vehicles, the demand for secondary batteries as an energy source is rapidly rising. Secondary batteries are batteries capable of repeated charging and discharging; they are installed as battery packs by mounting multiple battery modules, each containing multiple battery cells housed in a module housing, onto electric vehicles and the like.

[0003] Battery cells within a battery pack may be exposed to heat or flames due to the charging and discharging process or external impact. When such events occur, a phenomenon called thermal runaway, in which heat or flames generated in one battery cell propagate to adjacent cells, can lead to a chain reaction of explosions within the battery pack.

[0004] To effectively counter thermal runaway phenomena in battery packs, various cooling and gas venting technologies are applied. However, in the venting structures of conventional battery modules and battery packs, high-pressure, high-temperature discharges emitted from a battery module experiencing thermal runaway are vertically discharged to the top of the battery module, where they strongly strike the upper lid of the battery pack. Afterward, they either flow back into the upper vent hole of the battery module or enter other vent holes of the same heat, thereby accelerating thermal propagation. Additionally, discharges such as high-temperature gases, flames, and sparks (hereinafter referred to simply as "discharges") move between the top of the battery module and the double-side folding portions of the battery cells, spreading in random directions to cause damage to adjacent banks or modules and accelerating thermal propagation indiscriminately. As such, conventional battery packs have inadequate venting design technology, which fails to properly isolate and discharge the venting gases generated by thermal runaway; consequently, they have limitations in delaying thermal propagation to adjacent banks or modules.

[0005] [Prior Art Literature]

[0006] Korean Published Patent Application No. 10-2024-0053258 (Publication Date: April 24, 2024)

[0007] In order to solve the problems of the prior art described above, the present invention aims to provide a battery module capable of preventing heat propagation between battery cells or between battery modules, and a battery pack including such a battery module.

[0008] According to exemplary embodiments of the present invention for achieving the above-mentioned purpose, a battery module with an improved upper venting structure is provided.

[0009] The battery module comprises: a plurality of battery cells; a module housing that accommodates the plurality of battery cells; a first refractory layer that surrounds the plurality of battery cells such that the lower surface of the plurality of battery cells is open and has a plurality of vent holes on its upper surface; an insulating pad disposed on the first refractory layer and having a plurality of slots at positions corresponding to the plurality of vent holes; a second refractory layer disposed on the insulating pad and covering the plurality of slots; an upper plate disposed on the second refractory layer and having a plurality of openings at positions corresponding to the plurality of slots; and a flame-retardant cover installed on the upper plate and having a plurality of other openings at positions corresponding to the plurality of openings.

[0010] In the battery module above, the first refractory layer can wrap the side and top surfaces of the plurality of battery cells by grouping at least two battery cells into one group.

[0011] In the battery module above, the vent holes may be rectangular vent holes formed at regular intervals along the length direction of the battery cell.

[0012] In the battery module above, the first refractory layer may be a mica cover.

[0013] In the battery module above, the slot may be at least larger than the vent hole.

[0014] In the battery module above, the insulation pad may be a Si pad or an aerogel pad.

[0015] In the battery module above, the second refractory layer may be a Flame Retardant Barrier (FRB) material or a High-Performance Insulation (HPI) material.

[0016] In the battery module above, the opening of the upper plate may be the same size as or larger than the slot of the insulation pad.

[0017] In the battery module above, the flame retardant cover may include an upper cover and a left cover and a right cover coupled to the lower left and right sides of the upper cover.

[0018] In the battery module above, another opening of the flame-retardant cover may be substantially the same size as the opening of the upper plate.

[0019] In the battery module above, the flame-retardant cover may be any one of mica, superwool, or silicone material cover.

[0020] Meanwhile, according to an exemplary embodiment of the present invention, a battery pack is provided comprising: the battery module described above; and a pack housing that accommodates the battery module.

[0021] A battery module according to exemplary embodiments of the present invention can prevent thermal runaway and thermal propagation between battery cells or between battery modules by modifying the upper venting structure.

[0022] The effects obtainable from the exemplary embodiments of the present invention are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0023] FIG. 1 is a perspective view of a battery module according to an exemplary embodiment of the present invention.

[0024] Figure 2 is an exploded perspective view of Figure 1.

[0025] Figure 3 is a cross-sectional view of line AA of Figure 1.

[0026] Figure 4 is a schematic diagram illustrating the venting process of Figure 3.

[0027] Fig. 5 is a perspective view of a battery pack equipped with the battery module of Fig. 1.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0029] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the invention and do not represent all of the technical ideas of the invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0030] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0031] Since embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically depicted for clearer explanation. Accordingly, the size or proportion of each component does not entirely reflect the actual size or proportion.

[0032]

[0033] (1st embodiment)

[0034] FIG. 1 is a perspective view of a battery module according to an exemplary embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a cross-sectional view of FIG. 1 along line AA.

[0035] Referring to FIGS. 1 to 3, the battery module (100) according to the present embodiment includes a plurality of battery cells (10A, 10B) and a module housing (110) that accommodates the plurality of battery cells (10A, 10B).

[0036] The module housing (110) can accommodate a plurality of battery cells (10A, 10B) in the form of an arranged battery cell assembly (10) by stacking or assembling them in one direction.

[0037] A battery cell assembly (10) may include a plurality of battery cells (10A, 10B). Each individual battery cell (10A, 10B) is a basic unit of a lithium-ion battery, i.e., a secondary battery. Each individual battery cell (10A, 10B) may include an electrode assembly, an electrolyte, and a cell case. The electrode assembly provided in the cell case may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Depending on the assembly form, the electrode assembly may be either a jelly-roll type or a stack type. A jelly-roll type electrode assembly may include a wound structure of a positive electrode, a negative electrode, and a separator interposed between them. A stack type electrode assembly may include a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed between them, which are stacked sequentially. The positive electrode may include a positive current collector and a positive active material. The negative electrode may include a negative current collector and a negative active material.

[0038] Multiple battery cells (10A, 10B) may be connected in series and / or in parallel. For example, multiple battery cells (10A, 10B) may be connected in series. For example, multiple battery cells (10A, 10B) may be connected in parallel. For example, when a set of two or more battery cells (10A, 10B) connected in parallel is defined as a bank, one bank consisting of two or more battery cells (10A, 10B) connected in parallel and another bank consisting of two or more battery cells (10A, 10B) connected in parallel may be connected in series.

[0039] The individual battery cells (10A, 10B) may correspond to pouch-type battery cells, cylindrical battery cells, or prismatic battery cells. The electrode assembly of the pouch-type battery cell is embedded in a pouch case containing an aluminum laminate sheet. The electrode assembly of the cylindrical battery cell is embedded in a cylindrical metal can. The electrode assembly of the prismatic battery cell is embedded in a prismatic metal can.

[0040] In this embodiment, the battery cells (10A, 10B) may be pouch-type battery cells. The pouch-type battery cells may be formed by housing an electrode assembly in a pouch case of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. These battery cells (10A, 10B) may be formed in a rectangular sheet structure.

[0041] The battery cell (10A, 10B) has a structure in which two electrode leads protrude from one end and the other end of the battery body, respectively, facing each other. The battery cell (10A, 10B) can be manufactured by bonding both ends of the battery case and one side connecting them while the electrode assembly is housed in the battery case. The battery cell (10A, 10B) may be a unidirectional battery cell in which two electrode leads protrude in the same direction.

[0042] The battery cells (10A, 10B) may be composed of multiple cells and assembled to be electrically connected to each other to form a battery cell assembly (10). The battery cell assembly (10) may have multiple battery cells (10A, 10B) arranged along a direction parallel to the Z-axis (the thickness direction of the battery cells). For convenience of explanation, in this specification, when viewed from the battery cells in the drawings, the length direction of the battery cells is defined as the X direction, the width direction of the battery cells as the Y direction, and the thickness direction of the battery cells as the Z direction. The battery cell assembly (10) may have side plates (12) arranged on both sides to protect the battery cell assembly (10).

[0043] A module housing (110) housing a battery cell assembly (10) includes a front frame (111), side frames (112, 114), a rear frame (113), and a bottom frame (116). Additionally, the module housing (110) may be structured such that it encloses multiple battery cells (10A, 10B) using only side frames (112, 114) without the front frame (111) and rear frame (113). The module housing (110) may be combined with an upper plate (150) described later. That is, a fastening member (115) located at the upper end of both side frames (112, 114) of the module housing (110) and a fastening member (155) of the upper plate (150) may be bolted together.

[0044] The first refractory layer (120) surrounds the plurality of battery cells (10A, 10B) so that the lower surface of the plurality of battery cells (10A, 10B) is open. For example, as shown in FIG. 3, it is manufactured in a 'C' shape so that the plurality of battery cells (10A, 10B) can be grouped into at least two battery cells (10A, 10B) to surround the side (122) and the top surface (123). If necessary, it is also possible to group multiple battery cells (10A, 10B, …) into one group and surround the side (122) and the top surface (123), rather than being limited to two battery cells (10A, 10B).

[0045] The first refractory layer (120) may have a plurality of vent holes (121) on its upper surface. These vent holes (121) may be elongated rectangular vent holes formed at regular intervals along the length direction (X direction) of the battery cells (10A, 10B) or rectangular vent holes with arc shapes on both sides. When two battery cells (10A, 10B) are manufactured as a single group, the vent holes (121) may extend across the upper surface of both one battery cell (10A) and the other adjacent battery cell (10B). That is, the vent holes (121) may be formed on the upper surface centered on the boundary line where the two battery cells (10A, 10B) meet.

[0046] The first refractory layer (120) may be a mica cover. Since mica has flexibility, it can be made into a flexible sheet with a sufficiently thin thickness and can maintain its physical and chemical properties even in a high-temperature environment of 800 to 1,000°C. Mica has high insulation resistance and is electrically stable, so it can prevent short circuits between battery cells. That is, mica has low thermal conductivity, so it can delay the transfer of heat into the battery cells or between cells. Accordingly, the first refractory layer (120) acts as a thermal barrier that can reduce heat conduction between battery cells or through the top of the cells and prevent damage to adjacent cells caused by discharge.

[0047] The battery cell assembly (10) wrapped by the first refractory layer (120) can be attached to the bottom frame (116) of the module housing (110) with resin or the like.

[0048] An insulating pad (130) may be placed as a cushioning material over the first refractory layer (120) and the battery cells (10A, 10B). The insulating pad (130) can prevent heat propagation through the top of the battery cells (10A, 10B) and induce venting to the target area through physical pressure on the area other than the vent hole. The insulating pad (130) may be a Si material pad or an aerogel pad.

[0049] The insulation pad (130) may have a plurality of slots (131) at positions corresponding to a plurality of vent holes (121) of the first refractory layer (120). The slots (131) of the insulation pad (130) are preferably larger than the vent holes (121) of the first refractory layer (120). The slots (131) may all extend along the same direction. For example, the slots (121) may extend in the length direction (X direction) and be spaced apart from each other in the length direction and thickness direction (Y direction) and arranged in a grid pattern.

[0050] The second refractory layer (140) is positioned on the insulation pad (130) and covers a plurality of slots (131) of the insulation pad (130). The second refractory layer (140) is placed between the upper plate (150) and the insulation pad (130) and ruptures upon the occurrence of an event, and is discharged through the ruptured hole. The second refractory layer (140) is a barrier sheet that blocks flames and may be made of FRB (Flame Retardant Barrier) material or HPI (High-Performance Insulation) insulating material.

[0051] The upper plate (150) is placed on the second fireproof layer (140) and has a plurality of openings (151) at positions corresponding to a plurality of slots (131) of the insulation pad (130). The openings (151) of the upper plate (150) are preferably equal to or larger than the size of the slots (131) of the insulation pad (130). The upper plate (150) is provided with flanges (154) on both edges so that it can be combined with a flame-retardant cover (160). Additionally, the upper plate (150) may be provided with a fastening member (155) on a part of the flange (154) so ​​that it can be combined with a fastening member (115) of the lower module housing (110). The upper plate (150) may be formed of a plastic or metal material capable of maintaining rigidity.

[0052] The flame-retardant cover (160) includes an upper cover (162) and a left cover (163) and a right cover (164) that are attached to the lower left and right sides of the upper cover (162). A flange (165) is provided on both edges of the upper cover (162) so that it can be attached to the flange (154) of the upper plate (150). The upper cover (162) of the flame-retardant cover (160) is attached to the upper plate (150), while the left cover (163) and the right cover (164) can be attached to the lower side of the flange (165) on the left and right sides of the upper plate (150), respectively.

[0053] On the upper cover (162) of the flame-retardant cover (160), there may be a plurality of other openings (161) at positions corresponding to the plurality of openings (151) of the upper plate (150). The other openings (161) of the upper cover (162) may be substantially the same size as the openings (151) of the upper plate (150). The flame-retardant cover (160) may be made of any one of mica, superwool, or silicone material.

[0054] As such, the battery module (100) according to the present embodiment has a plurality of battery cell assemblies (10) surrounded by a first fireproof layer (120), and an insulating pad (130), a second fireproof layer (140), an upper plate (150), and a flame-retardant cover (160) are sequentially arranged on the first fireproof layer (120). This battery module (100) has a venting structure that allows discharges such as gas to be guided in a specific direction and can block discharges such as gas from flowing into adjacent cells.

[0055] FIG. 4 is a schematic diagram for explaining the venting process of the battery module (100) described above.

[0056] Referring to FIG. 4, when an event occurs in any of the battery cells (10A, 10B) of the battery module (100), the internal pressure of the battery cells (10A, 10B) increases, and the discharge inside the cell can move upward through the vent hole (121) of the first refractory layer (120).

[0057] As the discharge passes through the slot (131) of the insulation pad (130) and the pressure gradually increases, the second refractory layer (140) will eventually rupture. Then, through the ruptured hole, the discharge passes through the opening (151) of the upper plate (150) and another opening (161) of the flame-retardant cover (160) and is discharged upward. The discharge can be discharged to the outside through a venting device by the directional venting structure of the battery module (100). In this process, even if the discharge moves to an adjacent cell, the second refractory layer of the adjacent cell can block the discharge to prevent the discharge from flowing back into the adjacent cell.

[0058] Accordingly, the upper venting structure of the battery module (100) according to the present embodiment can prevent heat propagation between battery cells and delay heat propagation between adjacent battery modules (100) and battery modules.

[0059]

[0060] (2nd Example)

[0061] FIG. 5 is a perspective view of a battery pack (100P) housing a battery module (100) of the present invention.

[0062] Referring to FIG. 5, the battery pack (100P) according to the present embodiment includes the battery module (100) described above and a pack housing (101) in which the battery module (100) is accommodated.

[0063] The pack housing (101) includes a base plate (102), a side plate (103), and an end plate (104).

[0064] The base plate (102) is located at the bottom of the pack housing (101) and is positioned to face the bottom surface of the module housing (110). The base plate (102) can be attached to the bottom of each of the two side plates (103) positioned on both sides of the pack housing (101).

[0065] A venting device for discharging gas to the outside may be provided on one side of the side plate (103).

[0066] End plates (104) may be located on both ends of the base plate (102). A Battery Management System (BMS) may be placed in the space (105) between one end plate (104) and the battery module (110). The BMS may be configured to perform monitoring, balancing, and control of the battery pack (100P). Monitoring of the battery pack (100P) may include monitoring the voltage and current of specific nodes within a plurality of battery modules (100) and monitoring the temperature distribution of set locations within the battery pack (100P).

[0067] An upper cover plate, not shown, may be positioned on the top of the pack housing (101). The upper cover plate may have a cooling channel formed therein as a member for covering the battery module (110). Depending on the battery model, the cooling channel may also be installed on the base plate. The upper cover plate may be attached to the upper surface of the battery module (110) and may be thermally coupled to the battery module (110).

[0068] The upper cover plate, base plate (102), side plate (103), and end plate (104) together form a certain space capable of accommodating a battery module (100).

[0069] In the case of the battery pack (100P) of the present invention, if heat or flame is generated in any one of the battery cells (10A, 10B) of the battery modules (110), the discharge material is not allowed to flow back into the battery module adjacent to the battery cell (10A, 10B) as described above.

[0070] The battery pack (100P) may include a venting passage and a venting device for discharging thermal energy and gas discharged upward from the battery module (100). The discharged material present inside the battery module (100) may pass through the venting passage provided in the base plate (102) and finally be discharged to the outside through the venting device. The venting device will enable the discharge of the thermal energy and gas by breaking when the internal pressure of the battery pack (100P) exceeds a predetermined level. The gas inflow reduction or blocking action of the battery module (100) according to the present invention will be more significant in a situation where the internal pressure of the battery pack (100P) is increasing before the venting device breaks.

[0071] The present invention has been described in more detail above through drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all technical concepts of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

Claims

1. Multiple battery cells; A module housing accommodating the above plurality of battery cells; A first refractory layer that surrounds the plurality of battery cells such that the lower surface of the plurality of battery cells is open, and has a plurality of vent holes on the upper surface; An insulating pad disposed on the first refractory layer and having a plurality of slots at positions corresponding to the plurality of vent holes; A second refractory layer located on the insulation pad and covering the plurality of slots; An upper plate having a plurality of openings at positions corresponding to the plurality of slots and disposed on the second refractory layer; and A battery module comprising: a flame-retardant cover installed on the upper plate, having a plurality of other openings at positions corresponding to the plurality of openings.

2. In Paragraph 1, A battery module characterized by the first refractory layer wrapping the side and top surfaces of at least two battery cells grouped together as one group.

3. In Paragraph 1, A battery module characterized in that the above-mentioned vent holes are rectangular vent holes formed at regular intervals along the length direction of the battery cell.

4. In Paragraph 1, A battery module characterized in that the first refractory layer is a mica cover.

5. In Paragraph 1, A battery module characterized in that the slot is at least larger than the vent hole.

6. In Paragraph 1, A battery module characterized in that the above-mentioned insulation pad is a Si pad or an aerogel pad.

7. In Paragraph 1, A battery module characterized in that the second refractory layer is a Flame Retardant Barrier (FRB) material or a High-Performance Insulation (HPI) insulating material.

8. In Paragraph 1, A battery module characterized in that the opening of the upper plate is the same size as or larger than the slot of the insulation pad.

9. In Paragraph 1, The above flame-retardant cover is a battery module comprising an upper cover and a left cover and a right cover coupled to the lower left and right sides of the upper cover.

10. In Paragraph 1, A battery module characterized in that another opening of the flame-retardant cover is substantially the same size as the opening of the upper plate.

11. In Paragraph 1, A battery module characterized in that the flame-retardant cover is one of mica, superwool, or silicone material.

12. The battery module of claim 1; and A battery pack including a pack housing that accommodates the above battery module.

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