Battery module having improved safety and battery pack including same

Abstract

The present invention relates to a battery module having improved safety and a battery pack including same, and specifically, to a battery module having improved safety and a battery pack including same, the battery module comprising: multiple battery cells; a module frame for accommodating the multiple battery cells; end plates located on the front and rear surfaces of the multiple battery cells, respectively; a busbar frame for electrically connecting the multiple battery cells; a terminal part having one side connected to the busbar frame and the other side protruding to the outer side of the end plate; and a blocking member provided at a position adjacent to the terminal part.

Description

Battery module with improved safety and battery pack including the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 2024-0109486, filed August 15, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a battery module with improved safety and a battery pack including the same, and more particularly, to a battery module with improved safety and a battery pack including the same, which can prevent high-temperature flying products generated by an internal short circuit in a battery module from settling on a terminal located near the center of the battery pack, thereby causing an internal short circuit in a battery pack unit.

[0003] Recently, due to the development of alternative energy sources to address air pollution and energy depletion caused by the use of fossil fuels, demand for secondary batteries that can store generated electric energy is increasing.

[0004] Secondary batteries, the energy source for various electronic devices indispensable in modern society, are seeing increased capacity requirements due to the increasing use and complexity of mobile devices and the development of electric vehicles. To meet user demand, small devices are equipped with multiple battery cells. However, automobiles and other devices utilize battery modules, which electrically connect multiple battery cells, or battery packs comprising multiple such modules.

[0005] Meanwhile, the battery modules housed in the battery pack are provided with terminal portions for electrically connecting adjacent battery modules, and these terminal portions can be positioned adjacent to the center of the battery pack.

[0006] In such a battery pack structure, there is a high possibility that an internal short circuit may occur in a specific battery module, and the resulting high-temperature flying products may settle on the terminals of adjacent battery modules, causing secondary damage such as an internal short circuit in the battery pack unit.

[0007] Fig. 1 is an exploded perspective view showing a battery module according to the prior art. Referring to Fig. 1, the battery module according to the prior art is configured to include a plurality of battery cells (10), a module case (20) for storing the plurality of battery cells (10), a separating member (30) for separating the spaces of the plurality of battery cells (10), an insulating block (40) positioned near the electrode leads of the battery cells (10), and a busbar assembly (50) for electrically connecting the plurality of battery cells (10).

[0008] A battery module according to the prior art has a structure in which an electrode lead is wrapped between battery cells (10) and an insulating block (40) made of an insulating material is provided to prevent short circuits, etc. from occurring due to contact between the electrode lead and the separating member (30).

[0009] This structure has a problem in that when a high-temperature fly ash is generated due to an internal short circuit inside the battery module, the high-temperature fly ash may settle and cause secondary damage because the terminal portion protruding outside the module case (20) is not protected.

[0010] (Prior art literature)

[0011] (Patent Document 1) Korean Patent Publication No. 2023-0098020

[0012] In order to solve the above problems, the present invention aims to provide a battery module and a battery pack including the same with improved safety, which can prevent secondary damage by preventing damage to a terminal portion caused by high-temperature flying products or high-temperature discharges resulting from thermal runaway due to an internal short circuit.

[0013] In order to achieve the above-described purpose, a battery module with improved safety according to the present invention is characterized by including a plurality of battery cells (100), a module frame (200) for accommodating the plurality of battery cells (100), an end plate (300) positioned on each of the front and rear sides of the plurality of battery cells (100), a bus bar frame (400) for electrically connecting the plurality of battery cells (100), a terminal portion (500) having one side connected to the bus bar frame (400) and the other side protruding outward from the end plate (300), and a blocking member (600) provided at a position adjacent to the terminal portion (500).

[0014] In addition, in the battery module according to the present invention, the blocking member (600) is characterized by including a receiving portion (610) having one side open and a space formed to receive a foaming agent, an extension portion (620) extending horizontally from the upper side of the receiving portion (610), and a cover portion (630) positioned in the open portion of the receiving portion (610).

[0015] In addition, in the battery module according to the present invention, the foaming agent is characterized in that it is a material whose volume expands above a certain temperature.

[0016] In addition, in the battery module according to the present invention, the material is characterized in that it includes at least one of an epoxy-based resin, a vinyl chloride-based resin, and a fluorine-based resin.

[0017] In addition, in the battery module according to the present invention, the cover part (630) is characterized in that it is broken at a certain temperature or above a certain pressure.

[0018] In addition, in the battery module according to the present invention, the end plate (300) is characterized in that it is provided with a groove (310) having a certain depth that can accommodate the blocking member (600) at a position corresponding to the other side of the terminal portion (500).

[0019] In addition, in the battery module according to the present invention, the home portion (310) is characterized in that it is provided at a position adjacent to the lower surface of the blocking member (600).

[0020] Additionally, in the battery module according to the present invention, a step portion (320) is formed on the upper edge of the groove portion (310) so as to correspond to the extension portion (620).

[0021] In addition, in the battery module according to the present invention, the receiving portion (610) and the extension portion (620) are formed as an integral body.

[0022] In addition, in the battery module according to the present invention, the cover part (630) is characterized by having a flat shape.

[0023] In addition, in the battery module according to the present invention, the edge of the cover portion (630) is characterized in that it is joined to the extension portion (620).

[0024] In addition, the battery pack according to the present invention is characterized by including the above-described battery module.

[0025] As described above, the battery module according to the present invention has an advantage in that a blocking member is provided at a position adjacent to the terminal portion, so that when an internal short circuit occurs, the foaming agent expands to protect the terminal portion, thereby preventing secondary damage from occurring.

[0026] In addition, the battery module according to the present invention has an advantage in that the foaming agent of the blocking member can wrap the terminal portion when a high temperature is generated, thereby preventing damage to an adjacent battery module.

[0027] Figure 1 is an exploded perspective view showing a battery module according to the prior art.

[0028] Figure 2 is a perspective view showing a battery module according to an embodiment of the present invention.

[0029] Figure 3 is an exploded perspective view showing a battery module according to an embodiment of the present invention.

[0030] Fig. 4 is a cross-sectional view showing a cross-section taken along line AA shown in Fig. 2.

[0031] Fig. 5 is a perspective view showing an end plate and a blocking member according to an embodiment of the present invention.

[0032] Fig. 6 is an exploded perspective view showing a blocking member according to an embodiment of the present invention.

[0033] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0034] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0035] Hereinafter, a battery module with improved safety according to the present invention and a battery pack including the same will be described with reference to the attached drawings.

[0036] FIG. 2 is a perspective view showing a battery module according to an embodiment of the present invention, FIG. 3 is an exploded perspective view showing a battery module according to an embodiment of the present invention, FIG. 4 is a cross-sectional view showing a section cut along line AA shown in FIG. 2, FIG. 5 is a perspective view showing an end plate and a blocking member according to an embodiment of the present invention, and FIG. 6 is an exploded perspective view showing a blocking member according to an embodiment of the present invention.

[0037] Referring to FIGS. 2 to 6, a battery module according to the present invention is configured to include a battery cell (100), a module frame (200), an end plate (300), a bus bar frame (400), a terminal portion (500), and a blocking member (600).

[0038] First, the battery cell (100) may be a pouch-type battery cell. This battery cell (100) is configured to include an electrode assembly, a pouch case for storing the electrode assembly, an electrode lead protruding outside the pouch case, and an insulating film positioned between the pouch case and the electrode lead.

[0039] The electrode assembly is a structure in which positive and negative electrodes are alternately laminated multiple times with a separator in between, and a pair of electrode leads consisting of a positive lead and a negative lead are electrically connected to the positive tab and the negative tab and then exposed to the outside of the pouch case.

[0040] The positive electrode is manufactured by applying a positive electrode mixture containing a positive electrode active material onto a positive electrode current collector and then drying the mixture. The positive electrode mixture may optionally further include a binder, a conductive agent, a filler, etc., as needed.

[0041] The positive electrode current collector can generally have a thickness of 3 to 500 ㎛. The positive electrode current collector is not particularly limited as long as it has high conductivity and does not cause chemical changes in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. can be used. In addition, the positive electrode current collector can form fine unevenness on the surface to increase the adhesiveness of the positive electrode active material, and various forms such as a film, sheet, foil, net, porous body, foam, or non-woven fabric can be used.

[0042] The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; chemical formula Li. 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, Cu2V2O7; chemical formula LiNi 1-x M x Ni-site type lithium nickel oxide represented by O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); chemical formula LiMn 2-x M x Lithium manganese composite oxides represented by O2 (wherein, M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (wherein, M = Fe, Co, Ni, Cu or Zn); LiMn2O4 in which a portion of the Li in the chemical formula is replaced by an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, etc., but are not limited thereto.

[0043] The negative electrode is manufactured by applying a negative electrode mixture containing a negative electrode active material onto a negative electrode current collector and then drying the mixture. The negative electrode mixture may include components such as a conductive agent, a binder, and a filler, as needed.

[0044] The negative electrode current collector is generally made with a thickness of 3 to 500 ㎛. The negative electrode current collector is not particularly limited as long as it has high conductivity and does not cause chemical changes in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. In addition, like the positive electrode current collector, the bonding strength of the negative electrode active material can be strengthened by forming fine unevenness on the surface, and it can be used in various forms such as a film, sheet, foil, net, porous body, foam, non-woven fabric, etc.

[0045] The separator prevents short circuits between the aforementioned negative and positive electrodes and allows only the movement of lithium ions, and an insulating thin film with high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 ㎛, and the thickness is generally 5 to 300 ㎛. The material of the separator is preferably one selected from among polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited thereto.

[0046] Meanwhile, the negative current collector and the positive current collector are composed of a portion coated with a slurry containing an active material and a non-coated portion where the slurry is not coated. The non-coated portion is formed by cutting the portion or connecting a separate conductive member to the non-coated portion by ultrasonic welding, etc. to form an electrode tab, and these electrode tabs are gathered to form a tab bundle.

[0047] The pouch case can be formed with a pocket portion capable of accommodating an electrode assembly and an edge portion extended to a certain length on one side of the pocket portion using a laminate sheet composed of an inner covering layer, a metal layer, and an outer covering layer.

[0048] Since the inner covering layer is in direct contact with the electrode assembly, it must have insulation and electrolytic resistance, and in order to seal it from the outside, the sealing area where the inner layers are thermally bonded must have excellent thermal bonding strength.

[0049] Materials for such inner covering layers may be selected from, but are not limited to, polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and good sealing properties, polyurethane resins, and polyimide resins, and polypropylene, which has excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, and excellent chemical resistance, is most preferable.

[0050] The metal layer in contact with the inner covering layer serves as a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside, and a preferred material for this metal layer is an aluminum film that is lightweight and has excellent formability.

[0051] And, an outer covering layer is provided on the other side of the metal layer, and this outer covering layer can use a heat-resistant polymer with excellent tensile strength, moisture permeability, and air permeability to protect the electrode assembly while ensuring heat resistance and chemical resistance. For example, nylon or polyethylene terephthalate can be used, but is not limited thereto.

[0052] And a pair of electrode leads, each consisting of a positive lead and a negative lead, are typically connected to the aforementioned electrode tab bundle, more specifically, the positive tab bundle and the negative tab bundle, by welding or the like, and then protrude outside the pouch case.

[0053] The insulating film is positioned on the upper and lower surfaces of the electrode leads overlapping the heat-sealed pouch case sealing portion, and is configured to prevent electricity generated from the electrode assembly from flowing to the pouch case through the electrode leads and further maintain the sealing of the pouch case.

[0054] Here, it is preferable that the insulating film be a non-conductive material that does not conduct electricity well, and generally, an insulating tape that is easy to attach to the electrode lead and has a relatively thin thickness can be used.

[0055] Specifically, the insulating film may be one or two or more materials selected from the group consisting of polyimide (PI), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), high density polyethylene (HDPE), and epoxy resin, and is thermally bonded to the inner resin layer of the pouch case through heat and pressure.

[0056] Although only a battery cell (100) having a structure in which electrode leads protrude in both directions on one side and the other side is described and illustrated in the drawings, as another embodiment of the present invention, a unidirectional pouch-type battery cell in which electrode leads protrude together in one direction can also be used.

[0057] The battery cell (100) may be configured in multiple units, and the multiple battery cells (100) are stacked along one direction to form a battery cell stack so as to be easily electrically connected to each other. For example, as illustrated in FIG. 3, the multiple battery cells (100) may be stacked along one direction.

[0058] The module frame (200) houses a plurality of battery cells (100) and may be a metal frame with open sides.

[0059] More specifically, based on a battery cell stack formed by stacking multiple battery cells (100), the module frame (200) can be opened in both directions in which the electrode leads (111) protrude. However, the module frame (200) illustrated in FIG. 3 is an exemplary structure, and there is no particular limitation on its shape as long as it can accommodate the battery cell stack.

[0060] In addition, the module frame (200) of FIG. 3 is illustrated as a monoframe in the form of a metal plate in which the upper surface, lower surface, and both sides are integrated, but it may also be in a form in which the upper cover is joined to a U-shaped frame with an open upper surface, or in a form in which a U-shaped frame and an inverted U-shaped frame are mutually connected.

[0061] The end plate (300) is located on both open sides of the module frame (200) to seal the inside of the module frame (200) and protect the plurality of battery cells (100) stored therein from the outside.

[0062] The end plate (300) is provided with a groove (310) that is recessed to a certain depth at a position corresponding to a terminal portion (500) that is connected to the busbar frame (400) on one side and protrudes outward from the end plate (300) on the other side, thereby forming a certain space.

[0063] A stepped portion (320) having a certain low height is formed on the upper edge of the home portion (310).

[0064] Additionally, an opening (330) cut to a certain width is formed in the end plate (300), and a terminal portion (500) described later penetrates the opening (330) and protrudes to the outside of the end plate.

[0065] That is, the other side of the terminal portion (500) protrudes through the opening (330) of the end plate (300), and a groove portion (310) and a step portion (320) are formed at a position adjacent to the terminal portion (500) protruding from the end plate (300), more specifically, on the lower side of the terminal portion (500) as shown in FIG. 5.

[0066] Next, the bus bar frame (400) is for electrically connecting a plurality of battery cells (100), and can be placed on one side and the other side of a battery cell stack in which a plurality of battery cells (100) are stacked.

[0067] At this time, an insulating member (not shown) may be further provided between the end plate (300) and the busbar frame (400) to prevent contact between the end plate (300) and the busbar frame (400) and maintain an insulating state.

[0068] Next, the terminal portion (500) can be formed so that one side is connected to the busbar frame (400) and the other side penetrates the opening (330) of the end plate (300) and protrudes outward from the end plate (300), thereby electrically connecting a plurality of battery cells (100) connected to the busbar frame (400) to the outside.

[0069] The terminal portion (500) can be connected to an adjacent battery module through another connecting member at an externally exposed portion, and can be connected to a BDU (Battery Disconnect Unit) or the like to form an HV (High Voltage) connection.

[0070] Here, the HV connection is a connection that serves as a power source for supplying power, and refers to a connection between battery cells (100) or a connection between battery modules. That is, a battery module can be electrically connected to another neighboring battery module via a terminal portion (500).

[0071] The blocking member (600) is located on the lower side of the terminal portion (500), and includes a foaming agent that expands and wraps the terminal portion (500) when high temperature occurs to protect the terminal portion (500), and is configured to include a receiving portion (610), an extension portion (620), and a cover portion (630).

[0072] The storage section (610) extends in the height direction (Z-axis direction) and has an empty space formed inside. It has a structure in which the upper part is open and is inserted into the groove section (310) of the end plate (300).

[0073] A foaming agent made of a material that expands in volume above a certain temperature is stored in the internal space of the storage unit (610). For example, the material of the foaming agent may be configured to include at least one of an epoxy resin, a vinyl chloride resin, and a fluorine resin.

[0074] These foaming agents have the advantage of expanding when an internal short circuit occurs within the battery module and high temperatures are generated, and wrapping the terminal portion (500) located at the upper portion of the storage portion (610) to prevent damage and secondary damage caused by high-temperature fire, high-temperature flying objects, or high-temperature discharges.

[0075] Here, the length (Z-axis direction) of the storage portion (610) may be formed to be shorter than or equal to the depth (Z-axis direction) of the groove portion (310) of the end plate (300). This is because, if the length (Z-axis direction) of the storage portion (610) is formed to be longer than the depth (Z-axis direction) of the groove portion (310), a portion may be formed in which the upper portion of the storage portion (610) protrudes without being stored in the groove portion (310).

[0076] The extension portion (620) can be formed by extending horizontally (XY axis direction) from the upper open portion of the storage portion (610) and can be mounted on the step portion (320) of the end plate (300).

[0077] The extension (620) can be formed in the same shape as the step (320) and can be formed with a width that can be located within the area of ​​the step (320).

[0078] This extension (620) has the advantage of preventing the storage portion (610) from being inserted deeper than necessary so that it can be positioned at a predetermined position when inserted into the home portion (310).

[0079] At this time, the storage portion (610) and the extension portion (620) can be formed as an integral body as shown in the drawing.

[0080] The cover part (630) is positioned in the open part of the storage part (610) to seal the space in which the foaming agent is stored in the storage part (610) and prevent the foaming agent from leaking out of the storage part (610), and may be formed in a flat shape.

[0081] The cover part (630) may be fixed by joining the edge part to the extension part (620) so as to be positioned on the upper part of the storage part (610).

[0082] For example, there is no particular limitation as long as the contacting portion of the cover portion (630) and the extension portion (620) can be fixed with a certain force, such as by melt bonding or adhesive application.

[0083] The cover part (630) may be made of a material that can be broken at a certain temperature or higher, and may be broken by heat, high-temperature flying objects, or high-temperature discharges caused by thermal runaway due to an internal short circuit, and as a result, the upper part of the storage part (610) is opened so that the foaming agent can easily wrap the terminal part (500) when it expands.

[0084] In addition, the cover part (630) may be made of a material that can be broken when subjected to a certain pressure or more, and this allows the foaming agent of the storage part (610) to expand due to heat caused by thermal runaway due to an internal short circuit, thereby applying pressure to the cover part (630) to wrap the terminal part (500).

[0085] At this time, the cover part (630) is not particularly limited as long as it is a material that can be broken at a certain temperature or a certain pressure.

[0086] Additionally, the present invention may be a battery pack including the above-described battery module, and may be a device including the battery module or battery pack.

[0087] Anyone with ordinary skill in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0088] (Explanation of symbols)

[0089] 100: Battery cell

[0090] 200: Module Frame

[0091] 300: End Plate

[0092] 310: Home

[0093] 320: Step section

[0094] 330: Aperture

[0095] 400: Busbar Frame

[0096] 500: Terminal section

[0097] 600: Blocking member

[0098] 610: Storage compartment

[0099] 620: Extension

[0100] 630: Cover

Claims

1. Multiple battery cells; A module frame for storing the plurality of battery cells; End plates positioned on the front and rear sides of the plurality of battery cells; A busbar frame electrically connecting the plurality of battery cells; A terminal portion having one side connected to the busbar frame and the other side protruding outside the end plate; and A battery module including a blocking member provided at a position adjacent to the terminal portion.

2. In paragraph 1, A battery module comprising a storage portion having one side open and a space formed to store a foaming agent, an extension portion extending horizontally from an upper side of the storage portion, and a cover portion positioned in the open portion of the storage portion.

3. In paragraph 2, The above-mentioned foaming agent is a battery module that is a material that expands in volume above a certain temperature.

4. In paragraph 3, The above material is a battery module including at least one of an epoxy resin, a vinyl chloride resin, and a fluorine resin.

5. In paragraph 2, The above cover part is a battery module that is broken when exposed to a certain temperature or pressure exceeding a certain level.

6. In paragraph 2, A battery module in which the end plate has a recessed portion of a certain depth capable of accommodating the blocking member at a position corresponding to the other side of the terminal portion.

7. In paragraph 6, The above home portion is a battery module provided at a position adjacent to the lower surface of the above blocking member.

8. In paragraph 7, A battery module having a step portion formed on the upper edge of the above-mentioned home portion to correspond to the above-mentioned extension portion.

9. In paragraph 2, A battery module in which the above storage portion and the above extension portion are formed as an integral part.

10. In paragraph 2, The above cover part is a battery module having a flat shape.

11. In paragraph 10, The edge of the above cover portion is a battery module that is joined to the above extension portion.

12. A battery pack comprising a battery module according to any one of claims 1 to 11.

Images