Battery system

Abstract

According to exemplary embodiments of the present invention, a battery system is provided. The battery system comprises: battery packs each having a cooling flow path in the upper portion thereof and venting passages in the lower portion thereof; and a battery pack stack in which the plurality of battery packs are stacked one on top of another. The battery system is capable of efficiently cooling and discharging high-temperature flammable gases, thereby preventing thermal runaway and thermal propagation between battery modules or between the battery packs.

Description

battery system

[0001] The present invention relates to a battery system, and more specifically, to a battery system that simplifies the structure by integrating the cooling channel and the venting channel of a battery pack. This application claims the benefit of Korean application No. 10-2024-0188698 filed on December 17, 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 frame, onto electric vehicles and the like.

[0003] 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.

[0004] 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.

[0005] To effectively counter thermal runaway phenomena in battery packs, various cooling technologies and gas venting technologies are applied to the battery packs. However, in the case of existing battery packs, venting design technology is insufficient, so the venting gas generated by thermal runaway cannot be properly isolated and discharged, which limits the ability to delay thermal propagation to adjacent banks or modules.

[0006] [Prior Art Literature]

[0007] Korean Published Patent Application No. 10-2024-0144841 (Publication Date: Oct. 04, 2024)

[0008] In order to solve the problems of the prior art described above, the present invention aims to provide a battery system having a stacked structure that integrates a cooling system and a safety ventilation system of a battery pack.

[0009] According to exemplary embodiments of the present invention for achieving the above-mentioned purpose, a battery system is provided in which a cooling system and a safety exhaust system are integrated.

[0010] The battery system comprises: a battery pack having a cooling channel at the top and a venting passage at the bottom; and a battery pack stack in which a plurality of the battery packs are stacked vertically.

[0011] In the above battery system, the battery pack comprises: a battery module having a plurality of battery cells; and a pack housing in which the battery module is housed.

[0012] In the above battery system, the battery module includes the plurality of battery cells and a module frame that accommodates the plurality of battery cells.

[0013] In the above battery system, a venting cut line may be further provided on the bottom surface of the module frame.

[0014] In the battery system above, the pack housing may include: a base plate located at the bottom of the pack housing and having a plurality of venting slots; side plates assembled to both ends of the base plate; and end plates assembled to the other ends of the base plate and forming a certain space together with the side plates.

[0015] In the battery system above, the pack housing may include: an upper cover plate located at the top of the pack housing and covering the battery module; and a venting channel plate located at the bottom of the pack housing.

[0016] In the above battery system, the cooling channel may be formed in the upper cover plate.

[0017] In the battery system above, the cooling channel may be connected to a refrigerant inlet and outlet on the outer side of the end plate.

[0018] In the battery system above, the venting channel plate may have a plurality of openings communicating with the venting slots of the base plate.

[0019] In the battery system above, the venting passage may include: a plurality of connecting venting passages formed on one side of the base plate; an internal venting passage of a side plate located in the plurality of connecting venting passages; an internal venting passage of an end plate connected to the side plate; and a venting device communicating with the internal venting passage of a side plate located at the other end of the base plate.

[0020] In the battery system above, the venting passage may be formed on the base plate.

[0021] In the above battery system, the battery pack stack allows the venting passage of the upper battery pack to come into contact with the cooling passage of the lower battery pack immediately below it.

[0022] In the battery system above, the battery pack stack allows the venting channel plate of the upper battery pack to come into contact with the upper cover plate of the lower battery pack immediately below it.

[0023] In the above battery system, the battery pack stack may have a bottom plate disposed on the lowest layer battery pack.

[0024] In the battery system above, the base plate may be thinner than the lower plate.

[0025] A battery system according to exemplary embodiments of the present invention can provide a plurality of battery packs with a simplified structure by applying an integrated cooling system and a safety ventilation system.

[0026] In addition, this battery system can efficiently cool and discharge high-temperature flammable gases, thereby preventing thermal runaway and heat propagation between battery modules or battery packs.

[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 perspective view of a battery pack according to an exemplary embodiment of the present invention.

[0029] Figure 2 shows the state in which the upper cover plate is separated from the battery pack of Figure 1.

[0030] Figure 3 shows the state in which the battery module has been removed from the battery pack of Figure 2.

[0031] Figure 4 is a perspective view of one battery module of Figure 3.

[0032] Figure 5 is an exploded perspective view of the battery module of Figure 4.

[0033] Figure 6 is a plan view showing the state in which the battery cell assembly has been removed from the battery pack of Figure 2.

[0034] Figure 7 is a plan view showing the venting passages within the battery pack.

[0035] FIG. 8 is an exploded perspective view of the pack housing of FIG. 3, showing the gas flow within the venting passage of FIG. 7 in three dimensions.

[0036] FIG. 9 is a perspective view of a battery system having multiple battery packs of FIG. 1 stacked together.

[0037] Figure 10 is a cross-sectional view of line AA of Figure 9.

[0038] FIG. 11 is a perspective view of another battery system in which a plurality of battery packs of FIG. 1 are stacked, viewed from a different direction.

[0039] FIG. 12a is a perspective view taken along line BB of FIG. 11, and FIG. 12b is an enlarged view of part A of FIG. 12a.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044]

[0045] (1st embodiment)

[0046] FIG. 1 is a perspective view of a battery pack according to an exemplary embodiment of the present invention, FIG. 2 shows the state in which the upper cover plate is separated from the battery pack of FIG. 1, and FIG. 3 shows the state in which the battery module is removed from the battery pack of FIG. 2. FIG. 4 is a perspective view of one battery module of FIG. 3, and FIG. 5 is an exploded perspective view of the battery module of FIG. 4. FIG. 6 is a plan view showing the state in which the battery cell assembly is removed from the battery pack of FIG. 2.

[0047] FIG. 7 is a plan view showing a venting passage within a battery pack, and FIG. 8 is an exploded perspective view of the pack housing of FIG. 3, showing the gas flow within the venting passage of FIG. 7 in three dimensions.

[0048] Referring to FIGS. 1 to 8, the battery pack (101) according to the present embodiment includes a battery module (110) having a plurality of battery cells (B) and a pack housing (120) in which the battery module (110) is housed.

[0049] The battery module (110) includes a plurality of battery cells (B) and a module frame (112) that accommodates the plurality of battery cells (B). The module frame (112) can accommodate the plurality of battery cells (B) in the form of an arranged battery cell assembly (10) by stacking or assembling them in one direction.

[0050] A battery cell assembly (10) may include a plurality of battery cells (B). Each individual battery cell (B) is a basic unit of a lithium-ion battery, i.e., a secondary battery. Each individual battery cell (B) 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.

[0051] Multiple battery cells (B) may be connected in series and / or in parallel. For example, multiple battery cells (B) may be connected in series. For example, multiple battery cells (B) may be connected in parallel. For example, when a set of two or more battery cells (B) connected in parallel is defined as a bank, one bank consisting of two or more battery cells (B) connected in parallel and another bank consisting of two or more battery cells (B) connected in parallel may be connected in series.

[0052] The individual battery cells (B) may correspond to pouch-type battery cells, cylindrical battery cells, or prismatic battery cells. The electrode assembly of a pouch-type battery cell is embedded in a pouch case containing an aluminum laminate sheet. The electrode assembly of a cylindrical battery cell is embedded in a cylindrical metal can. The electrode assembly of a prismatic battery cell is embedded in a prismatic metal can.

[0053] In this embodiment, the battery cell (B) may be a pouch-type battery cell. The pouch-type battery cell may be formed by housing an electrode assembly in a pouch case made of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. Such a battery cell (B) may be formed in a rectangular sheet structure.

[0054] The battery cell (B) 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 (B) 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 (B) may be a unidirectional battery cell in which two electrode leads protrude in the same direction.

[0055] A plurality of battery cells (B) may be configured and assembled so as to be electrically connected to each other to form a battery cell assembly (10). A plurality of battery cells (B) may be arranged along a direction parallel to the Y-axis (the thickness direction of the battery cells) in the battery cell assembly (10).

[0056] The module frame (112) accommodates the battery cell assembly (10), and a venting cut line (114) may be provided on the bottom surface of the module frame (112). The module frame (112) may be a module housing that accommodates the battery cell assembly (10). In this case, the module housing may be a structure in which all four sides of the module frame are wrapped with plates. The module frame or the module housing may further be provided with a cover plate on the top.

[0057] The pack housing (120) includes a base plate (121), side plates (123, 125), and end plates (124, 126).

[0058] The base plate (121) is located at the bottom of the pack housing (120) and has a plurality of venting slots (122). The base plate (121) is positioned to face the bottom surface of the module frame (112) and can cover at least partially the bottom surface of the module frame (112).

[0059] The base plate (121) can be joined to the lower end of each of the two side plates (123, 125) positioned on both sides of the pack housing (120). For example, one side of the base plate (121) can be joined to the lower end of the first side plate (123) by welding, and the other side of the base plate (130) can be joined to the lower end of the second side plate (125) by welding.

[0060] The base plate (121) may include a venting slot (122) for exhausting high-temperature gas originating from the battery cell assembly (10) into the space below the battery module (110). A plurality of venting slots (122) may be arranged in the X and Y directions on the base plate (121). Each of the plurality of venting slots (122) may be a rectangular slot formed long in the Y direction. These venting slots (122) may correspond to a venting cut line (114) formed on the bottom surface of the module frame (112).

[0061] Additionally, one side of the base plate (121) has a plurality of connecting venting passages (129) that allow gas present in the lower part of the base plate (121) to pass into the interior of the side plate (123) (see arrow in FIG. 8).

[0062] Each of the side plates (123, 125) may have an internal venting passage (123a, 125a) through which high-temperature gas can pass. For example, the first side plate (123) may have multiple venting passages (123a) formed inside, and the second side plate (125) may also have multiple venting passages (125a) formed inside. Additionally, a venting device (128) for discharging gas to the outside may be provided on one side of the second side plate (125).

[0063] End plates (124, 126) may be located on both ends of the base plate (121). Each of the end plates (124, 126) includes a first end plate (124) and a second end plate (126). A Battery Management System (BMS) may be placed in the space (150) between the first end plate (124) and the battery module (110). The BMS may be configured to perform monitoring, balancing, and control of the battery pack (101). Monitoring of the battery pack (101) may include monitoring the voltage and current of specific nodes within a plurality of battery modules (110) and monitoring the temperature distribution of set locations within the battery pack (101). A venting passage (124a) may be provided inside the first end plate (124).

[0064] A refrigerant inlet (131) and an outlet (132) may be installed in the second end plate (126).

[0065] An upper cover plate (130) may be positioned on the top of the pack housing (120). The upper cover plate (130) may have a cooling channel (133) formed therein as a member for covering the battery module (110). The upper cover plate (130) may be attached to the upper surface of the battery module (110) and may be thermally bonded to the battery module (110). For example, the upper cover plate (130) may be attached to the upper surface of the battery module (110) through a thermally conductive adhesive layer interposed between the upper cover plate (130) and the upper surface of the battery module (110). For example, the thermally conductive adhesive layer may include a thermal interface material (TIM).

[0066] The upper cover plate (130) may have a cooling channel (133) configured to allow fluid to flow, and may cool the battery module (110) by a refrigerant passing through the cooling channel (133). The cooling channel (133) may define a passage for the fluid. The cooling channel (133) may be connected to a refrigerant inlet (131) and an outlet (132) on the outside of the end plates (124, 126). The cooling channel (133) may have a single path extending from the refrigerant inlet (131) to the outlet (132). While the fluid flows along the cooling channel (133), cooling of the battery cell assembly (10) may be performed. For example, the upper cover plate (130) may be manufactured by joining two plates, and the cooling channel (133) may include a space defined between the two plates. That is, the cooling channel (133) may be located inside the upper cover plate (130). The fluid may include cooling water or a refrigerant.

[0067] The upper cover plate (130), base plate (121), side plates (123, 125) and end plates (124, 126) together form a certain space (127) capable of accommodating the battery module (110).

[0068] A venting channel plate (140) may be placed at the bottom of the pack housing (120). The venting channel plate (140) is installed below the base plate (121) of the pack housing (120). The venting channel plate (140) may have a plurality of openings (141) that communicate with the venting slots (122) of the base plate (121). The venting channel plate (140) has a venting channel (142) capable of guiding high-temperature gas in a specific direction. The venting channel plate (140) may be a continuously connected channel having peaks and ridges when viewed from the Y direction.

[0069] Figures 7 and 8 show the gas flow in the venting passages within the battery pack.

[0070] Referring to FIGS. 7 and 8, the venting passage of the vector pack (101) includes a plurality of connecting venting passages (129) formed at one end of the base plate (121), an internal venting passage (123a) of a first side plate (123) located in the plurality of connecting venting passages (129), an internal venting passage (124a) of a first end plate (124) connected to the first side plate (123), an internal venting passage (125a) of a second side plate (125) connected to the first end plate (124), and a venting device (128).

[0071] In the case of the battery pack (101) of the present invention, if heat or flame is generated in any one of the battery cells (B) of the battery modules (110), the venting cut line (114) of the module frame (112) facing the battery cell (B) opens, and as shown in FIG. 8, high-temperature gas, etc. proceeds through the venting slot (122) of the base plate (121) to the opening (141) of the venting channel plate (140) and moves laterally along the channel space (142) of the venting channel plate (140).

[0072] Next, the gas present at the bottom of the base plate (121) can move to the internal venting passage (123a) of the first side plate (123) through the connecting venting passage (129) provided on the side of the base plate (121), and then proceed through the internal venting passage (124a) of the first end plate (124) to the internal venting passage (125a) of the second side plate (125), and finally be discharged to the outside through the venting device (128).

[0073] Accordingly, the battery pack (101) of the present invention can be very useful for preventing heat propagation by extending the venting passage significantly along the circumference of the pack housing (120) to induce a flow of gas in a certain direction.

[0074]

[0075] (2nd Example)

[0076] As seen in the first embodiment, the battery pack (101) of the present invention has a so-called upper cooling lower venting structure, having a cooling channel (133) at the top and a venting passage at the bottom. In the second embodiment, a battery system (100) can be provided by optimizing the upper cooling lower venting technology of such a battery pack (101) to form a battery pack stack (100A).

[0077] The battery system (100) according to the second embodiment includes a battery pack stack (100A) in which a plurality of battery packs (101, 102, 103, 104) are stacked vertically, each having a cooling channel (133) at the top and a venting channel at the bottom, as in the first embodiment. Although the second embodiment illustrates a structure in which four battery packs (101 to 104) are stacked, it goes without saying that the number of battery packs is not limited thereto.

[0078] The basic configuration of the second to fourth battery packs (102 to 104) of the battery pack stack (100A) is the same as that of the first battery pack (101). However, in the lowest layer battery pack (104) of the battery pack stack (100A), a lower plate (160) may be further disposed below the venting channel plate.

[0079] In the battery pack stack (100A), the venting passage of the upper battery pack is in contact with the cooling passage of the lower battery pack immediately below it. For example, the venting passage of the first battery pack (101) on the top layer is in contact with the cooling passage of the second battery pack (102) on the lower layer immediately below it. Similarly, the venting passage of the second battery pack (102) on the middle layer is in contact with the cooling passage of the third battery pack (103) on the lower layer immediately below it. In addition, the venting passage of the third battery pack (103) on the middle layer is in contact with the cooling passage of the fourth battery pack (104) on the lowest layer immediately below it.

[0080] Additionally, in the battery pack stack (100A), the venting channel plate (140) of the upper battery pack (101) is in contact with the upper cover plate (130_2) of the lower battery pack (102) that is adjacent directly below it.

[0081] The base plate of each of the multiple battery packs (101 to 104) may be thinner than the lower plate (160) of the lowest battery pack (104).

[0082] According to the battery system (100) of the present invention, when a thermal runaway occurs in one of the battery packs, such as the second battery pack (102), the high-temperature gas transferred to the lower side of the base plate (121) is in contact with the cooling path of the upper cover plate (130_3) of the third battery pack (103), so it can be rapidly cooled and discharged through long venting passages such as the internal venting passage of the side plate and the internal venting passage of the end plate. Accordingly, the battery system (100) of the present invention has a multi-faceted cooling structure that simultaneously performs cooling on the surfaces of a plurality of battery packs (101 to 104), so heat propagation between battery cells (B) can be effectively delayed and suppressed. Accordingly, the heat generation deviation and temperature deviation of the battery cell (B) and battery module (110) can be reduced, and the temperature can be controlled more uniformly, thereby improving the safety and reliability of the battery pack.

[0083]

[0084] (3rd Example)

[0085] FIG. 11 is a perspective view of another battery system (200) in which a plurality of battery packs of FIG. 1 are stacked, viewed from a different direction. FIG. 12a is a perspective view seen along line BB of FIG. 11, and FIG. 12b is an enlarged view of section A of FIG. 12a.

[0086] Referring to the drawings, the battery system (200) according to the third embodiment is identical to the battery system (100) according to the second embodiment except that five battery packs (201, 202, 203, 204, 205) are stacked, so a redundant description is omitted.

[0087] 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. A battery pack having a cooling channel at the top and a venting passage at the bottom; and A battery system comprising a battery pack stack in which a plurality of the above-mentioned battery packs are stacked vertically.

2. In Paragraph 1, The above battery pack comprises: a battery module having a plurality of battery cells; and A battery system comprising a pack housing in which the above battery module is housed.

3. In Paragraph 2, The above battery module is a battery system comprising a plurality of battery cells and a module frame that accommodates the plurality of battery cells.

4. In Paragraph 3, A battery system having additional venting cut lines on the bottom surface of the above module frame.

5. In Paragraph 2, The above pack housing is, A base plate located at the bottom of the above-mentioned pack housing and having a plurality of venting slots; Side plates assembled to both ends of the base plate; and A battery system comprising: end plates assembled on the other two ends of the base plate to form a certain space together with the side plates.

6. In Paragraph 5, The above pack housing is, An upper cover plate located at the top of the pack housing and for covering the battery module; and A battery system comprising a venting channel plate located at the bottom of the pack housing.

7. In Paragraph 6, A battery system characterized by having the cooling channel formed in the upper cover plate.

8. In Paragraph 6, A battery system characterized in that the above cooling channel is connected to a refrigerant inlet and outlet on the outer side of the end plate.

9. In Paragraph 6, A battery system characterized in that the above-mentioned venting channel plate has a plurality of openings communicating with the venting slots of the above-mentioned base plate.

10. In Paragraph 5, The above venting passage is, A plurality of connecting venting passages formed on one side of the base plate; Internal venting passages of side plates located in the aforementioned plurality of connecting venting passages; An internal venting passage of an end plate connected to the above side plate; and A battery system comprising: a venting device communicating with an internal venting passage of a side plate located at the other end of the base plate.

11. In Paragraph 9, A battery system characterized in that the above venting passage is formed on the base plate.

12. In Paragraph 1, The above battery pack laminate is, A battery system characterized in that the venting passage of the upper battery pack is in contact with the cooling passage of the lower battery pack immediately below it.

13. In Paragraph 6, The above battery pack laminate is, A battery system characterized in that the venting channel plate of the upper battery pack is in contact with the upper cover plate of the lower battery pack immediately below it.

14. In Paragraph 1, A battery system characterized in that the above-described battery pack stack has a lower plate disposed on the lowest layer battery pack.

15. In Paragraph 14, A battery system characterized in that the base plate is thinner than the lower plate.

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