Battery pack

Abstract

The present invention provides a battery pack in which a battery module is housed, comprising: a pack case including a module area in which a battery module can be installed; and an upper cover coupled to the pack case to cover an upper portion of the battery module installed in the pack case, wherein the pack case includes a base plate supporting a lower portion of the battery module; and a side wall coupled along an edge of the base plate, and the base plate is thinner than the upper cover.

Description

Technical Field

[0001] The present invention relates to a battery pack, and is characterized by preventing high-temperature heat generated by thermal runaway of some of the accommodated battery modules from being transmitted to other normal battery modules through a base plate corresponding to the bottom of the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0151958 filed on November 14, 2022, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

Background Art

[0003] Lithium secondary batteries have risks such as explosion and fire due to heat generation, and ensuring safety is one of the important issues. If an appropriate response cannot be made at the initial stage when such abnormal phenomena occur, the internal temperature of the secondary battery will rapidly increase due to heat generation, and a rapid increase in temperature may cause a thermal runaway phenomenon, leading to explosion of the secondary battery, which may spread to adjacent secondary batteries and cause significant damage to the battery pack.

[0004] FIG. 1 shows a pack case 20 constituting a conventional battery pack and an upper cover 10 coupled to the pack case 20. As shown in (a) of FIG. 1, a plurality of battery modules M are supported at the lower part by a base plate 30 and at the side parts by side walls 40 and partition walls 50. Therefore, each battery module M can be protected in all directions by the base plate 30 supporting the lower part, the upper cover 10 covering the upper part, and the side walls 40 and partition walls 50 supporting the side parts.

[0005] Generally, the base plate 30 is manufactured with a thick thickness for stability. Specifically, a typical base plate 30 is manufactured so as not to deform even under the pressure of high-temperature gas generated by thermal runaway of the battery module M. Therefore, a conventional base plate 30 can maintain continuous contact with a thermally runaway battery module M, as shown in Figure 1(b). Conventional battery packs have a fatal problem in that such contact can conduct high-temperature heat to other normal battery modules M. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Korean Registered Patent No. 10-2170043911 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the present invention was devised to solve the above-mentioned problems, and aims to provide a battery pack with a structure that can prevent high-temperature heat generated by thermal runaway in some of the multiple battery modules housed in it from being transmitted to other normal battery modules.

[0008] Other objects and advantages of the present invention can be understood from the following description and will be more clearly seen from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations set forth in the claims. [Means for solving the problem]

[0009] The present invention provides a battery pack that houses a battery module, comprising: a pack case including a module area in which the battery module can be installed; and an upper cover that is coupled to the pack case so as to cover the upper part of the battery module installed in the pack case, wherein the pack case comprises a base plate that supports the lower part of the battery module and a side wall coupled along the edge of the base plate, and the base plate is thinner than the upper cover.

[0010] The base plate described above can be deformed by changes in at least one of the pressure and temperature in the module region.

[0011] The pack case further includes a main partition wall that crosses the center of the pack case and connects to a base plate, and sub-partition walls whose ends are connected to the main partition wall and side walls, respectively, and which connect to the base plate at predetermined intervals along the longitudinal direction of the main partition wall, and multiple module regions can be formed by the partitions created by the main partition wall and the sub-partition walls.

[0012] The pack case further includes support blocks protruding from the boundary between the sub-bulkhead and the base plate, and the battery module further includes protrusions that protrude on both sides to be supported on the upper part of the support blocks, and the battery module can be fixed to the pack case by bolt members that pass through the protrusions and are screw-connected to the support blocks.

[0013] The pack case further includes a fixing member that is coupled to the sub-bulkhead and a battery module mounted adjacent to the sub-bulkhead, the battery module being fixed to the sub-bulkhead by screw coupling between its upper end and the end of the fixing member.

[0014] The above-mentioned fixing member can be screw-connected to the battery modules located on both sides of the sub-bulkwall, respectively, across the sub-bulkwall.

[0015] The above fixing member can be fixed by being screwed to the upper end of the above sub partition wall.

[0016] Each of the above module regions can be sealed by the above main partition wall and sub partition wall.

[0017] The above base plate is formed by the connection of a plurality of support plates corresponding to each module region, and each of the above support plates can be deformed by at least one change in the pressure and temperature of the corresponding module region.

[0018] The above base plate may include a plurality of protrusions protruding upward.

[0019] The above plurality of protrusions may be formed by being dispersed in a dot shape on the upper part of the above base plate or by extending linearly side by side in one direction on the upper part of the above base plate.

[0020] The above dot-shaped protrusions can protrude in either a square shape or a column shape.

[0021] The above linear protrusions can be formed by extending in either a straight line or a curved line.

[0022] The above base plate may have a strength capable of withstanding at least the weight of the above battery module.

[0023] The above base plate can expand outward due to the pressure of the gas generated in the above module region.

Effect of the Invention

[0024] According to the present invention, even if high-temperature heat and gas are generated due to thermal runaway of some of the plurality of accommodated battery modules, the propagation of the heat can be prevented and the stability of the battery pack can be improved.

Brief Description of the Drawings

[0025] [Figure 1] It shows a conventional battery pack. [Figure 2] It is a perspective view of a battery pack according to the first embodiment of the present invention. [Figure 3] It shows the pack case of the present invention and a plurality of battery modules installed in the pack case. [Figure 4] It is a perspective view showing a modified example of the pack case of the present invention. [Figure 5] It shows a cross section of the pack case and the upper cover in FIG. 4 above. [Figure 6] It shows the connection of the pack case and the upper cover in FIG. 5 above. [Figure 7] It shows the phenomenon that any one of the plurality of battery modules housed in the battery pack in FIG. 6 above undergoes thermal runaway. [Figure 8] It is a perspective view of the pack case included in the battery pack according to the second embodiment of the present invention to which a fixing member is applied. [Figure 9] It shows a cross section of the pack case and the upper cover in FIG. 8 above. [Figure 10] It shows that the pack case in FIG. 9 above is coupled to the upper cover. [Figure 11] It shows that thermal runaway has occurred in some of the plurality of battery modules housed in the battery pack in FIG. 10 above. [Figure 12] It shows a cross section of a battery pack according to the third embodiment of the present invention. [Figure 13] It shows that thermal runaway has occurred in some of the plurality of battery modules included in the battery pack in FIG. 12 above. [Figure 14] It is a perspective view of the pack case included in the battery pack according to the fourth embodiment of the present invention. [Figure 15] The above Figure 14 shows a cross-section of the pack case and the top cover joined together. [Figure 16] Figure 15 above shows that thermal runaway occurred in some of the battery modules included in the battery pack. [Modes for carrying out the invention]

[0026] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Before that, however, the terms and words used herein and in the claims should not be interpreted to be limited to their ordinary or dictionary meanings, but rather to be interpreted as meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that an inventor may appropriately define the concepts of terms in order to best describe his own invention.

[0027] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention; there are various equivalents and modifications that can substitute for them at the time of filing.

[0028] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would likely obscure the gist of the invention, such detailed description will be omitted.

[0029] Since embodiments of the present invention are provided to more fully explain the invention to an ordinary person, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes and proportions.

[0030] The present invention relates to a battery pack in which battery modules M are housed, and is characterized by preventing high-temperature heat generated by thermal runaway in some of the housed battery modules M from being transmitted to other normal battery modules M via a base plate 110 located at the bottom of the battery pack.

[0031] Figures 2 to 6 relate to a battery pack according to the first embodiment of the present invention, Figures 7 to 10 relate to a battery pack according to the second embodiment of the present invention, Figures 11 to 12 relate to a battery pack according to the third embodiment of the present invention, and Figures 13 to 15 relate to a battery pack according to the fourth embodiment of the present invention.

[0032] Hereinafter, each embodiment of the battery pack of the present invention will be described with reference to the drawings.

[0033] (First Embodiment) Figure 2 is a perspective view of a battery pack according to the first embodiment of the present invention.

[0034] The battery pack of the present invention includes a pack case 100 and an upper cover 200, as shown in Figure 2 above.

[0035] The pack case 100 includes a module area 150 in which battery modules M can be installed, and supports the sides and bottom of each installed battery module M, protecting it from the outside.

[0036] The pack case 100, as shown in Figure 2(a), includes a base plate 110 that supports the lower part of the battery module M and a side wall 120 that is coupled along the edge of the base plate 110.

[0037] The base plate 110 described above corresponds to the bottom of the pack case 100 and serves to support and protect the lower part of the installed battery module M.

[0038] The side wall 120 serves to support the sides of the multiple battery modules M mounted on the base plate 110 and protect them from the outside.

[0039] Figure 3 shows the pack case 100 of the present invention and a plurality of battery modules M installed in the pack case 100. The pack case 100 of the present invention may further include, as shown in Figures 2 and 3, a main partition wall 130 that crosses the center of the pack case 100 and connects to a base plate 110, and sub-partition walls 140 whose ends are connected to the main partition wall 130 and side walls 120, respectively, and which connect to the base plate 110 at a predetermined distance along the longitudinal direction of the main partition wall 130.

[0040] The main partition wall 130 divides the internal space of the pack case 100 into two large spaces where the battery module M is installed, and the sub-partition wall 140 further divides the space partitioned by the main partition wall 130 into multiple smaller spaces.

[0041] Various wires and busbars used for the battery pack may be inserted into or installed inside the main bulkhead 130, or the inside of the main bulkhead 130 may be empty.

[0042] The sub-partition 140 partitions the multiple battery modules M located on one side of the main partition 130 so that they can be separated from one another.

[0043] The module region 150 of the present invention is formed in multiple locations by the main partition wall 130 and the sub-partition wall 140 described above.

[0044] Each module area 150 formed by the divisions of the main bulkhead 130 and the sub-bulkhead 140 can be fitted with one battery module M.

[0045] The battery module M housed in module area 150 can also be secured to pack case 100 for more stable mounting.

[0046] Figure 4 is a perspective view showing a modified example of the pack case 100 of the present invention, Figure 5 shows a cross-section of the pack case 100 and upper cover 200 of Figure 4, and Figure 6 shows the connection of the pack case 100 and upper cover 200 of Figure 5.

[0047] The battery module M used in the battery pack of the present invention may include protrusions M1 that protrude on both sides, as shown in Figures 4 and 5. Furthermore, the pack case 100 in which the battery module M of the above form is mounted may further include a support block 160 that protrudes from the boundary between the sub-partition 140 and the base plate 110. Specifically, the battery module M is placed in the module area 150 such that the protrusions M1 are supported on the upper part of the support block 160, as shown in Figures 4 and 5.

[0048] The battery module M, positioned in the module region 150, can be fixed to the pack case 100 by bolt members B that pass through the protruding portion M1 and are screw-connected to the support block 160.

[0049] The upper cover 200 is connected to the pack case 100 so as to cover the top of each battery module M mounted in the pack case 100, as shown in Figure 2(b). More specifically, the upper cover 200 may be connected to the upper end of a side wall 120 whose end is joined along the edge of the base plate 110, and may be screw-connected to the side wall 120 by bolt members B or the like so that the inside of the pack case 100 can be sealed.

[0050] As shown in Figure 6, the battery pack of the present invention can be sealed such that each module region 150 is independent of the others by the coupling of the pack case 100 and the upper cover 200. More specifically, each module region 150 of the present invention can be sealed by the upper cover 200 coupled to the pack case 100 making gapless contact with the upper ends of the main partition 130 and sub-partition 140. Therefore, even if thermal runaway occurs in a battery module M contained in any one module region 150, the high-temperature gas caused by the thermal runaway is not directly transmitted to the battery modules M in the other module regions 150.

[0051] Generally, the base plate 110 can be manufactured from aluminum, but it is made thick enough to prevent deformation under high temperature and pressure. In other words, conventional base plates 110 are manufactured thicker than the upper cover 200, so when high temperature and pressure gas is generated inside the sealed battery pack, the relatively thinner upper cover 200 expands and deforms due to the gas pressure.

[0052] The battery pack of the present invention is characterized in that the thickness of the base plate 110 contained in the pack case 100 is adjusted to be thinner than that of the upper cover 200. In other words, the battery pack of the present invention is characterized in that when high temperature and high pressure gas is generated inside, the base plate 110 is deformed by the gas pressure before the upper cover 200.

[0053] However, the base plate 110 must have sufficient strength to withstand at least the weight of the battery module M.

[0054] Preferably, the base plate 110 of the present invention can be deformed by changes in at least one of pressure and temperature in the module region 150.

[0055] Figure 7 illustrates the phenomenon of thermal runaway in one of the multiple battery modules M housed in the battery pack shown in Figure 6.

[0056] When the battery module M experiences thermal runaway, high temperatures and gases are generated, filling the sealed module area 150 with gas pressure. Subsequently, this gas pressure pushes out the relatively thin and weak base plate 110, deforming its shape.

[0057] The deformation of the base plate 110 reduces the contact area between the battery module M and the base plate 110, thereby reducing the rate at which high-temperature heat is transferred by conduction. Consequently, the high-temperature heat generated in a thermally runaway battery module M is not easily transferred to other adjacent battery modules M via the base plate 110, preventing a chain reaction of thermal runaway in other battery modules M.

[0058] (Second Embodiment) The battery pack of the present invention may be further modified by adding a fixing member 170 that can fix the battery module M to the sub-partition 140.

[0059] Figure 8 is a perspective view of a pack case 100 included in a battery pack according to a second embodiment of the present invention to which the fixing member 170 is applied, Figure 9 shows a cross-section of the pack case 100 and upper cover 200 of Figure 8, and Figure 10 shows the pack case 100 of Figure 9 coupled with the upper cover 200.

[0060] The pack case 100 included in the battery pack according to the second embodiment of the present invention further includes a fixing member 170 which is connected to the sub-partition wall 140 and the battery module M installed adjacent to the sub-partition wall 140, as shown in Figures 8 to 10. Specifically, the battery module M installed in the pack case 100 is fixed to the sub-partition wall 140 by a bolt member B which is connected at the upper end to the fixing member 170 and additionally penetrates the fixing member 170 and is screw-connected to the upper end of the battery module M.

[0061] As shown in the figure, the fixing member 170 can be screw-connected to the battery modules M located on both sides of the sub-partition 140 across the sub-partition 140. That is, a pair of adjacent battery modules M can be fixed to the sub-partition 140 interposed between them via a single fixing member 170.

[0062] The purpose of fixing the battery module M to the sub-partition wall 140 via the fixing member 170 in this manner is to prevent the battery module M from denting together with the base plate 110 when the base plate 110 bulges outward and dents downward due to thermal runaway of the battery module M. In other words, the fixing member 170 plays a role in minimizing contact between the battery module M and the base plate 110 by continuously fixing the battery module M, which has experienced thermal runaway, to the sub-partition wall 140.

[0063] In the battery pack of the present invention, as shown in the figure, four fixing members 170 can be fixed to one battery module M. However, the number and form of fixing members 170 used are not limited to those shown in the figure, as long as each battery module M can be fixed to the sub-partition wall 140.

[0064] It is preferable that the above-mentioned fixing member 170 is also screw-connected to the sub-partition wall 140.

[0065] As shown in Figures 8 to 10, the fixing member 170 can be fixed by screw connection to the upper end of the sub-partition wall 140.

[0066] Although not shown in the figures, the fixing member 170 can also be fixed to the sub-partition wall 140 by a bolt member B that passes through both the upper cover 200 and the fixing member 170 simultaneously and is screw-connected to the upper end of the sub-partition wall 140.

[0067] Figure 11 shows that thermal runaway occurred in some of the battery modules M housed in the battery pack shown in Figure 10.

[0068] Referring to Figure 11 above, it can be seen that the base plate 110 is deformed downwards due to the gas pressure caused by the thermal runaway of the battery module M, but the battery module M itself remains fixed in place by the fixing member 170 without collapsing along with the base plate 110.

[0069] In other words, the more the base plate 110 deforms gradually and violently due to the gas pressure, the smaller the contact area between the thermally runaway battery module M and the indented base plate 110 becomes.

[0070] (Third embodiment) The base plate 110 included in the battery pack of the present invention can also be formed by joining a plurality of support plates 111.

[0071] Figure 12 shows a cross-section of a battery pack according to the third embodiment of the present invention.

[0072] As shown in Figure 12 above, a single base plate 110 is formed by connecting multiple support plates 111.

[0073] In other words, the base plate 110 is formed by the combination of a plurality of support plates 111 corresponding to each module region 150, and the support plates 111 deform in response to changes in at least one of the pressure and temperature of the corresponding module region 150.

[0074] Each support plate 111 can be screw-connected to the lower ends of the side walls 120, the main bulkhead 130, and the sub-bulkhead 140, and can also be connected and joined to each other.

[0075] If necessary, an insulating material may be additionally interposed between each support plate 111 to minimize heat transfer between them.

[0076] Figure 13 shows that thermal runaway occurred in some of the battery modules M included in the battery pack shown in Figure 12.

[0077] Referring to Figure 13 above, only the support plate 111 corresponding to the module region 150 in which the battery module M experiencing thermal runaway is housed is deformed.

[0078] (Fourth Embodiment) In order to minimize the contact area between the battery module M and the base plate 110, the battery pack of the present invention may have protrusions 112 applied to the surface of the base plate 110.

[0079] Figure 14 is a perspective view of a pack case 100 included in a battery pack according to the fourth embodiment of the present invention, and Figure 15 shows a cross-section of the pack case 100 and the upper cover 200 connected in Figure 14.

[0080] The base plate 110 includes a plurality of projections 112 that protrude upward, as shown in Figures 14 and 15.

[0081] The multiple protrusions 112 described above can be formed as points dispersed on the upper part of the base plate 110 as shown in the figure, but are not limited to this, and can also be formed as lines extending in one direction on the upper part of the base plate 110.

[0082] The point-like projections 112 can protrude in a variety of shapes. For example, the projections 112 can protrude in either a square shape or a columnar shape.

[0083] The linear projection 112 described above may be formed by extending in either a straight line or a curved shape.

[0084] Therefore, the battery modules M placed in each module region 150 are supported by the upper end of the projection 112, so that their overall surface area cannot come into contact with the base plate 110.

[0085] Figure 16 shows that thermal runaway occurred in some of the battery modules M included in the battery pack shown in Figure 15.

[0086] Referring to Figure 16 above, the base plate 110 located below the battery module M where thermal runaway has occurred deforms while maintaining the protrusion 112, thus further reducing the contact points with the battery module M. Furthermore, even if high-temperature heat is transferred to multiple adjacent normal battery modules M via the base plate 110, only a small amount of heat is transferred due to the protrusion 112.

[0087] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, at the time of filing, there may be various equivalents and modifications that can substitute for them. [Explanation of symbols]

[0088] 10: (Conventional technology) Top cover 20: (Conventional technology) Pack case 30: (Conventional technology) Base plate 40: (Conventional technology) Side wall 50: (Conventional technology) Partition wall 100: Pack Case 110: Base plate 111: Support plate 112: Protrusion 120: Side wall 130: Main bulkhead 140: Sub-bulk 150: Module area 160: Support Block 170: Fixing member 200: Top cover B: Bolt member M: Battery Module M1:Protrusion

Claims

1. A battery pack that houses a battery module, A pack case including a module area in which the aforementioned battery module is installed, It includes an upper cover that connects to the pack case so as to cover the upper part of the battery module mounted in the pack case, The aforementioned pack case is A base plate supporting the lower part of the battery module, The base plate includes a side wall that is joined along the edge of the base plate, A battery pack in which, by making the thickness of the base plate thinner than the thickness of the upper cover, when high temperature and high pressure gas is generated inside the battery pack, the base plate expands and deforms due to the gas pressure before the upper cover.

2. The battery pack according to claim 1, wherein the base plate is deformed by a change in pressure in the module region.

3. The pack case has a main partition that crosses the center of the pack case and connects to the base plate, The present invention further includes sub-partitions, the sub-partitions whose ends are connected to the main partition and the side walls, respectively, and which are connected to the base plate at a predetermined distance along the longitudinal direction of the main partition, The battery pack according to claim 1, wherein a plurality of module regions are formed by partitions created by the main partition and the sub-partition.

4. The aforementioned pack case is The system further includes support blocks protruding from the boundary between the sub-partition and the base plate, The battery module further includes protrusions that project from both sides of the battery module so as to be supported on the upper part of the support block, The battery pack according to claim 3, wherein the battery module is fixed to the pack case by a bolt member that passes through the protruding portion and is screw-connected to the support block.

5. The aforementioned pack case is The invention further includes a fixing member that is coupled to the sub-partition and a battery module installed adjacent to the sub-partition, The battery pack according to claim 3 or 4, wherein the upper end of the battery module and the end of the fixing member are screw-connected and fixed to the sub-bulkhead.

6. The battery pack according to claim 5, wherein the fixing member is screw-coupled to battery modules located on both sides of the sub-partition wall across the sub-partition wall.

7. The battery pack according to claim 5, wherein the fixing member is fixed to the upper end of the sub-partition wall by screw connection.

8. The battery pack according to claim 3 or 4, wherein each module region is sealed by the main partition and the sub-partition.

9. The base plate is formed by the combination of a plurality of support plates corresponding to each module region. The battery pack according to claim 3 or 4, wherein each of the support plates is deformed by a change in pressure in the corresponding module region.

10. The battery pack according to any one of claims 1 to 4, wherein the base plate includes a plurality of protrusions projecting upward.

11. The battery pack according to claim 10, wherein the plurality of protrusions are formed as points dispersed on the upper part of the base plate, or are formed as lines extending in one direction on the upper part of the base plate.

12. The battery pack according to claim 11, wherein the point-shaped projection protrudes in either an angular or columnar shape.

13. The battery pack according to claim 11, wherein the linear projection is formed to extend in either a straight line or a curved shape.

14. The battery pack according to any one of claims 1 to 4, wherein the base plate has strength to withstand at least the weight of the battery module.

15. The battery pack according to any one of claims 1 to 4, wherein the base plate expands outward due to the pressure of the gas generated in the module region.

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