Battery pack

Abstract

According to exemplary embodiments of the present invention, provided is a battery pack that implements a technical idea of cooling from the upper side and venting gas from the lower side of the battery pack. The battery pack comprises: a pack case having a venting space; at least one battery unit accommodated inside the pack case, above the venting space; and a cooling plate that seals the top surface of the pack case, is coupled to the battery unit in close contact therewith, and has a cooling circulation flow path.

Description

battery pack

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack that implements the technical concept of so-called upper cooling and lower venting, which cools the upper side of the pack and vents the lower side of the pack. The present application claims the benefit of Korean application No. 10-2024-0150038 filed on October 29, 2024, which is incorporated herein by reference in its entirety.

[0002] As technology development and demand for mobile devices and electric vehicles increase, the demand for secondary batteries as an energy source is rapidly growing.

[0003] A secondary battery is a battery capable of repeated charging and discharging, and multiple battery modules, each containing multiple battery cells housed in a module frame, are mounted in electric vehicles or the like to form a battery pack.

[0004] Recently, to increase the energy density of battery packs, Cell-to-Pack (CTP) battery packs are being developed, which eliminate battery modules and configure the battery pack by installing battery cells directly into the battery pack case.

[0005] 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 cell propagate to adjacent cells, can lead to a chain reaction of explosions in the battery pack.

[0006] To effectively counter thermal runaway phenomena in battery packs, various cooling and gas venting technologies are applied to the battery packs.

[0007] For example, Korean Published Patent Application No. 10-2022-0070835 proposes a battery pack that directly injects cooling water into a battery cell ignited from the upper side of the battery pack to prevent the spread of a flame ignited in a battery cell within the battery pack.

[0008] However, in the case of existing battery packs, the venting design technology was insufficient, so the venting gas generated by thermal runaway could not be properly isolated and discharged, which had limitations in delaying thermal propagation to adjacent banks or adjacent modules.

[0009] In order to overcome the limitations of the conventional technology described above, the present invention aims to provide a battery pack having a technical concept of an upper cooling and lower venting structure that delays heat propagation by directly supplying cooling water to the upper side of the battery pack upon the occurrence of an event, and can also suppress damage to normal modules by the cooling water supplied to the battery pack during this process.

[0010] According to exemplary embodiments of the present invention for achieving the above-mentioned purpose, a battery pack is provided that cools on the upper side and vents gas on the lower side of the battery pack.

[0011] The battery pack comprises: a pack case having a venting space; at least one battery unit housed inside the pack case above the venting space; and a cooling plate that seals the upper surface of the pack case and is coupled to the battery unit.

[0012] In the battery pack above, the pack case comprises a base plate, a side plate surrounding the base plate, and a venting plate spaced apart from the base plate, and has a venting space at the bottom of the venting plate.

[0013] In the battery pack above, the venting plate may have a plurality of openings communicating with the battery unit and the venting space.

[0014] In the battery pack above, the opening may be a venting hole.

[0015] In the battery pack above, the venting plate is an uneven plate having an opening formed therein, and a venting channel can be formed by the uneven shape.

[0016] In the battery pack above, a venting device communicating with the venting space may be formed on the side of the pack case at a position higher than the position of the venting space.

[0017] In the battery pack above, the cooling plate has a water supply hole at a position facing the battery unit and includes a meltable plug that closes the water supply hole.

[0018] In the battery pack above, the meltable plug is melted by an abnormal temperature rise of the battery unit, causing the water supply hole to open, and cooling water can flow out from the opened water supply hole and be supplied to the battery unit.

[0019] In the above battery pack, the coolant supplied to the battery unit can flow into the venting space.

[0020] In the battery pack above, a water supply passage may be formed on the upper part of the battery unit at a position corresponding to the meltable plug.

[0021] In the battery pack above, the battery units are provided in a plurality, and the water supply holes may be formed in an equal number for each battery unit.

[0022] In the battery pack above, the cooling plate is provided with an inlet and an outlet through which cooling water flows in and out, and includes a cooling circulation path connected to the inlet and the outlet.

[0023] In the battery pack above, the cooling circulation path is preferably a meandering path that passes through the plurality of battery units at least once.

[0024] In the battery pack above, the battery unit includes a battery module in which a cell assembly is accommodated.

[0025] In the battery pack above, the battery unit includes a cell block of a modular structure in which at least part or all of the upper surface of the cell assembly is open.

[0026] A battery pack according to an exemplary embodiment of the present invention directly introduces cooling water to the upper side of the battery pack upon the occurrence of an event to delay heat propagation, and in this process, damage to the normal module can also be effectively suppressed by the cooling water introduced into the battery pack.

[0027] 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.

[0028] FIG. 1 is a schematic diagram of a battery pack according to an exemplary embodiment of the present invention.

[0029] Figure 2 is a schematic diagram illustrating the thermal propagation (TP) prevention effect in the battery pack of Figure 1.

[0030] FIG. 3 is a schematic diagram of a battery pack according to another exemplary embodiment of the present invention.

[0031] Figure 4 is a schematic diagram illustrating the thermal propagation (TP) prevention effect in the battery pack of Figure 3.

[0032] Figure 5 is a schematic plan view of the cooling plate of the battery pack of Figure 3.

[0033] Figure 6 is a schematic plan view of another cooling plate of the battery pack of Figure 3.

[0034] FIG. 7 is an exploded perspective view of a battery pack according to another exemplary embodiment of the present invention.

[0035] FIG. 8 is a detailed exploded perspective view of the battery module of FIG. 7.

[0036] Figure 9 is a partial cross-sectional view of Figure 7.

[0037] FIG. 10 is a schematic diagram of another battery pack according to an exemplary embodiment of the present invention.

[0038] 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, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0039] 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.

[0040] 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.

[0041]

[0042] (1st embodiment)

[0043] FIG. 1 is a schematic diagram of a battery pack (100) according to an exemplary embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining the heat propagation (TP) prevention effect in the battery pack (100) of FIG. 1.

[0044] In FIG. 1, the battery pack (100) of the present invention schematically shows a lower venting structure in which a venting gas is discharged from a venting space (111) on the lower side, along with upper cooling in which cooling water is directly supplied from the upper side.

[0045] Referring to the drawings, the battery pack (100) according to the present embodiment comprises a pack case (110) having a venting space (111), at least one battery unit (10) housed inside the pack case (110) above the venting space (111), and a cooling plate (120) that seals the upper surface of the pack case (110) and is coupled to the battery unit (10).

[0046] The pack case (110) may include a base plate (112), a side plate (114) surrounding the base plate (112), and a venting plate (116) spaced apart from the base plate (112).

[0047] In the case of the battery pack (100) according to the present embodiment, the pack case (110) forms a venting space (111) at the bottom of the venting plate (116).

[0048] In the battery pack (100) according to the present embodiment, the venting plate (116) may have a plurality of openings (113) communicating with the battery unit (10) and the venting space (111). The openings (113) may have various shapes, such as square holes or slots, and in the present embodiment, venting holes are exemplified.

[0049] A venting device (115) communicating with the venting space (111) may be formed on the side of the pack case (110) at a position higher than the position of the venting space (111). The venting device (115) may include a venting valve. The venting device (115) may be positioned higher than the venting space (111) to facilitate the discharge flow of venting gas.

[0050] In the battery pack (100) according to the present embodiment, the cooling plate (120) is provided with a plurality of water supply holes (121) in a position facing the battery unit (10) and includes a meltable plug (122) that closes the water supply holes (121). The meltable plug (122) may be made of a material that melts by high-temperature gas or a spark emitted from the battery cell (12).

[0051] The above-mentioned meltable stopper may be made of a thermoplastic polymer resin having a melting point of about 200°C or lower, and for example, the thermoplastic polymer resin may be made of materials having a melting point of about 100°C or higher and 200°C or lower, such as polyethylene and polypropylene.

[0052] When the battery unit (10) is in a normal state, the melting plug (122) remains closed to the water supply hole (121), but when an event occurs, the melting plug (122) melts due to an abnormal temperature rise of the battery unit (10), opening the water supply hole (121), and cooling water can flow out from the opened water supply hole (121) and be supplied to the battery unit (10). When the battery unit (10) ignites, some of the cooling water vaporizes and increases in volume, resulting in a high-pressure state; therefore, when the water supply hole (121) is opened, water will be supplied to the ignited battery unit (10) with strong pressure.

[0053] Coolant supplied to the battery unit (10) can flow into the venting space (111) of the pack case (110) by passing through the opening (113) of the venting plate (116).

[0054] Additionally, a water supply passage (14) may be formed on the upper part of the battery unit (10) at a position corresponding to the meltable plug (122) in the battery pack (100) according to the present embodiment. The upper surface of the module frame (13) of the battery unit (10) is in close contact with the lower part of the cooling plate (120), and the water supply passage (14) may be located at a position corresponding to the water supply hole (121) of the cooling plate (120).

[0055] In the battery pack (100) according to the present embodiment, since the battery unit (10) may be provided in multiple numbers, the water supply holes (121) may be formed in an equal number for each battery unit (10).

[0056] In the battery pack (100) according to the present embodiment, the cooling plate (120) is illustrated as if it were a water tank, but for efficient cooling, a cooling channel may be formed inside the cooling plate (120) as in other embodiments described later.

[0057] Meanwhile, the battery pack (100) of the present invention may be a battery pack including a battery module in which a cell assembly is accommodated in a battery unit (10), or a battery pack including a cell block of a modular structure in which at least part or all of the upper surface of the cell assembly is open (see FIG. 10).

[0058] The battery unit (10) may include a plurality of battery cells (12). Each individual battery cell (12) is a basic unit of a secondary battery. Each individual battery cell (12) may include an electrode assembly, an electrolyte, and a cell case.

[0059] A plurality of battery cells (12) may be connected in series and / or in parallel. For example, a plurality of battery cells (12) may be connected in series with each other. For example, a plurality of battery cells (12) may be connected in parallel with each other. For example, when a set of two or more battery cells (12) connected in parallel is defined as a bank, one bank consisting of two or more battery cells (12) connected in parallel with each other and another bank consisting of two or more battery cells (12) connected in parallel with each other may be connected in series.

[0060] The individual battery cells (12) may correspond to pouch-type battery cells, cylindrical-type battery cells, or prismatic-type battery cells.

[0061] In exemplary embodiments, individual battery cells (12) correspond to pouch-type battery cells, and multiple battery cells (12) can be stacked together in one direction within a single cell assembly.

[0062] Hereinafter, a situation in which a thermal runaway (TR) phenomenon occurs in a battery pack (100) according to the present embodiment will be explained with reference to FIG. 2.

[0063] As illustrated in FIG. 2, in the case of the battery pack (100) of the present invention, if heat or flame is generated in any one of the battery cells (12) of the battery unit (10), the meltable plug (122) of the cooling plate (120) facing the battery cell (12) will melt and the water injection hole (121) will open.

[0064] Next, as indicated by the arrow in Fig. 2, cooling water is directly supplied to the battery cell (12) through the open water supply hole (121). Through this selective water supply operation, the ignited battery cell (12) can be rapidly cooled and the spread of flame to adjacent battery cells (12a) can be prevented. Accordingly, the thermal runaway phenomenon of the battery cell (12) can be reliably suppressed by delaying heat propagation to adjacent battery cells (12a).

[0065] Then, the coolant supplied to the battery unit (10) passes through the opening (113) of the venting plate (116) and is discharged into the lower venting space (111), and the remaining coolant (R) accumulates on the base plate (112). At this time, the remaining coolant (R) may include not only the used coolant but also other discharged materials.

[0066] In the present invention, due to the structure forming the lower venting space (111) of the battery pack (100), the cooling water used for water supply does not remain in the ignition battery cell (12), thereby preventing short circuits in the battery cell (12). Furthermore, since the residual cooling water (R) is not used in adjacent battery cells (12a), secondary events caused by residual cooling water (R) can be prevented in advance.

[0067] In addition, in the battery pack (100) of the present invention, gas generated in the battery cell (12) can be guided through the venting space (111) of the base plate (112) and the side plate (114) by a venting device (115) formed higher than the venting space (111) and quickly discharged to the outside.

[0068]

[0069] (2nd Example)

[0070] FIG. 3 is a schematic diagram of a battery pack (200) according to another exemplary embodiment of the present invention, FIG. 4 is a schematic diagram for explaining the heat propagation (TP) prevention effect in the battery pack (200) of FIG. 3, and FIG. 5 is a schematic plan view of the cooling plate (220) of the battery pack (200) of FIG. 3.

[0071] Referring to FIGS. 3 to 5, the battery pack (200) according to the second embodiment includes a pack case (210) having a venting space (211) similar to the battery pack (100) of the first embodiment, at least one battery unit (20) housed inside the pack case (210) above the venting space (211), and a cooling plate (220) that seals the upper surface of the pack case (210) and is closely coupled to the battery unit (20), but a redundant description of these is omitted.

[0072] The cooling plate (220) according to the second embodiment can be combined with the battery pack case (210) in a manner that covers the upper surface of the open battery pack case (210), similar to the cooling plate (120) of the first embodiment.

[0073] In the battery pack (200) according to the second embodiment, the pack case (210) forms a venting space (211) at the bottom of the venting plate (216). The venting plate (216) may have a plurality of openings (213) communicating with the battery unit (20) and the venting space (211).

[0074] A venting device (215) communicating with the venting space (211) may be formed on the side of the pack case (210) at a position higher than the position of the venting space (211).

[0075] Unlike the battery pack (100) according to the first embodiment, the battery pack (200) according to the second embodiment further includes various cooling circulation channels (224) in the upper cooling plate (220).

[0076] In the battery pack (200) according to the second embodiment, the cooling plate (220) is provided with an inlet (223) and an outlet (225) through which cooling water flows in and out, and a cooling circulation path (224) through which cooling water is guided can be connected to the inlet (223) and the outlet (225).

[0077] As shown in FIG. 5, the cooling circulation path (224) can be formed inside the cooling plate (220) as a meandering path that passes through a plurality of battery units (20) at least once.

[0078] FIG. 6 is a schematic plan view of another cooling plate (220A) of the battery pack (200) of FIG. 5, exemplarily showing that it can be installed in a different direction from the cooling circulation path (224) of FIG. 5. The cooling circulation path (224a) may be a meandering path that passes through a plurality of battery units (20) at least once, and the arrangement design is not particularly limited and can be varied.

[0079] The cooling plate (220) includes a melting plug (222) that closes a plurality of water supply holes (221) in a position facing the battery unit (20). As shown in FIG. 3, the melting plug (222) melts due to an abnormal temperature rise of the battery unit (20), causing the water supply holes (221) to open, and cooling water can flow out from the opened water supply holes (221) and be supplied to the battery cell (22). The cooling water supplied to the battery cell (22) can pass through the opening (213) of the venting plate (216) and flow into the venting space (211) of the pack case (210).

[0080] Likewise, in the battery pack (200), gas generated in the battery cell (22) can be guided into the venting space (211) through the base plate (212) and side plate (214) by a venting device (215) formed higher than the venting space (211) and quickly discharged to the outside.

[0081]

[0082] (3rd Example)

[0083] FIG. 7 is an exploded perspective view of a battery pack (300) according to another exemplary embodiment of the present invention, FIG. 8 is a detailed exploded perspective view of a battery module (30) of FIG. 7, and FIG. 9 is a partial front cross-sectional view of FIG. 7.

[0084] Referring to the drawings, the battery pack (300) according to the third embodiment includes a pack case (310) having a venting space (311) similar to the battery pack (200) of the second embodiment, at least one battery unit (30) housed inside the pack case (310) above the venting space (311), and a cooling plate (320) that seals the upper surface of the pack case (310) and is coupled to the battery unit (30), but a redundant description of these is omitted.

[0085] In the battery pack (300) according to the third embodiment, a gasket (318) is positioned on the upper edge of the base plate (312) and the lower edge of the cooling plate (320) to completely seal the battery pack (300). Consequently, the battery pack (300) can be joined so that the cooling plate (320) and the pack case (310) are in close contact.

[0086] In the battery pack (300) according to the third embodiment, the battery unit (30) may be a battery module in which a cell assembly (32) is accommodated in a module frame (33). In the battery module, the upper surface of the module frame (33) is in close contact with the lower surface of the cooling plate (320), and a water supply passage (34) may be located at a position corresponding to the melting plug (322) of the cooling plate (320).

[0087] In the battery pack (300) according to the third embodiment, the pack case (310) forms a venting space (311) at the bottom of the venting plate (316). The venting plate (316) may have a plurality of openings (313) communicating with the battery unit (30) and the venting space (311).

[0088] The venting plate (316) is an uneven plate having an opening (313) formed therein, and as shown in FIGS. 7 and 9, it may be a plate shape formed by repeating several C-shaped or U-shaped channels in reverse. Due to the uneven shape, the venting channel (314) may be formed long in the longitudinal direction (perpendicular to the drawing) of the battery cell (32). Additionally, the venting channel (314) may be connected in a vertical direction to the venting main channel (317) to guide the venting gas in one direction.

[0089] When an event occurs in the battery pack (300) according to the third embodiment, coolant is supplied to the battery cell (32) that has been ignited, and the coolant supplied to the battery cell (32) can pass through the opening (313) of the venting plate (316) and flow into the venting space (311) of the pack case (310).

[0090] And the venting gas passes through the opening (313) of the venting plate (316) and is guided to the venting channel (314) forming the venting space (311), and can be discharged to the venting device (315) through the venting main channel (317) which is connected to each venting channel (314).

[0091]

[0092] (Fourth Example)

[0093] FIG. 10 is a schematic diagram of another battery pack (400) according to an exemplary embodiment of the present invention.

[0094] Referring to the drawings, the battery pack (400) according to the fourth embodiment includes, like the battery pack (200) of the second embodiment, a pack case (410) having a venting space (411), at least one battery unit (40) housed inside the pack case (410) above the venting space (411), and a cooling plate (420) that seals the upper surface of the pack case (410) and is coupled in close contact with the battery unit (40), etc., but a redundant description of these is omitted.

[0095] The battery pack (400) according to the fourth embodiment includes a cooling plate (420) having a cooling circulation channel (424) and a meltable plug (422), similar to the battery pack (200) of the second embodiment.

[0096] Additionally, the battery pack (400) according to the fourth embodiment exemplifies a CTP method comprising a cell block of a modular structure in which at least part or all of the upper surface of the cell assembly (41) is open.

[0097] Therefore, the battery pack of the present invention, which embodies the technical concept of top cooling and bottom venting, can be applied to both battery packs including battery modules and cell-to-pack (CTP) type battery packs that omit battery modules.

[0098]

[0099] 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. Pack case having a venting space; At least one battery unit housed inside the pack case above the venting space; and A battery pack comprising a cooling plate that seals the upper surface of the pack case and is coupled to the battery unit.

2. In Paragraph 1, The above pack case is, base plate and, A side plate surrounding the above base plate, and It includes a venting plate spaced apart from the base plate, and A battery pack having the venting space at the bottom of the venting plate.

3. In Paragraph 2, The above venting plate is a battery pack having a plurality of openings communicating with the battery unit and the venting space.

4. In Paragraph 3, A battery pack characterized in that the above-mentioned opening is a venting hole.

5. In Paragraph 2, A battery pack characterized in that the above-mentioned venting plate is an uneven plate having an opening formed therein, and a venting channel is formed by the uneven shape.

6. In Paragraph 1, The above pack case is a battery pack having a venting device formed on the side of the pack case that communicates with the venting space at a position higher than the position of the venting space.

7. In Paragraph 1, A battery pack comprising a cooling plate having a water injection hole in a position facing the battery unit and a meltable plug that closes the water injection hole.

8. In Paragraph 7, The above-mentioned meltable plug is melted by an abnormal temperature rise of the battery unit, causing the water injection hole to open, and coolant flows out from the opened water injection hole and is supplied to the battery unit.

9. In Paragraph 7, A battery pack characterized in that the coolant supplied to the above battery unit flows into the above venting space.

10. In Paragraph 7, A battery pack characterized by having a water supply passage formed on the upper part of the battery unit at a position corresponding to the above-mentioned meltable plug.

11. In Paragraph 7, The above battery unit is provided in multiple units, and A battery pack characterized in that the above-mentioned water supply holes are formed in an equal number for each battery unit.

12. In Paragraph 1, The above cooling plate is provided with an inlet and an outlet for the inflow and outflow of cooling water, and the battery pack includes a cooling circulation path connected to the inlet and the outlet.

13. In Paragraph 12, A battery pack characterized in that the cooling circulation path is a meandering path that passes through the plurality of battery units at least once.

14. In Paragraph 1, The above battery unit is a battery pack comprising a battery module in which a cell assembly is accommodated.

15. In Paragraph 1, The above battery unit is a battery pack comprising a cell block of a modular structure in which at least part or all of the upper surface of the cell assembly is open.

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