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 in that it prevents high temperature heat generated due to 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 dated November 14, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Lithium secondary batteries have the risk of explosion, fire, etc. due to heat generation, and ensuring safety is one of the important issues. If such an abnormal phenomenon occurs and an appropriate response is not made in the early stages, the internal temperature of the secondary battery will rise rapidly due to heat generation, and the rapid rise in temperature may cause a thermal runaway phenomenon, which may lead to the explosion of the secondary battery, which may then spread to adjacent secondary batteries and cause serious damage to the battery pack.

[0004] 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 a side wall 40 and a partition wall 50. Thus, 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 wall 40 and partition wall 50 supporting the side parts.

[0005] Generally, the base plate 30 is manufactured to have a large thickness for stability. Specifically, the general base plate 30 is manufactured so as not to be deformed even under the pressure of high-temperature gas generated by thermal runaway of the battery module M. Therefore, the conventional base plate 30 may continuously maintain contact with the thermal runaway battery module M as shown in FIG. 1(b). The conventional battery pack has a fatal problem that the high-temperature heat may be conducted to other normal battery modules M due to such contact. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent No. 10-2170043911 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a battery pack having a structure that can prevent high temperature heat generated due to thermal runaway of some battery modules among a plurality of accommodated battery modules from being transmitted to other normal battery modules.

[0008] Other objects and advantages of the present invention will become apparent from the following description and the embodiments of the present invention. Also, it is easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed in the claims. [Means for solving the problem]

[0009] According to the present invention, there is provided 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.

[0010] The base plate may be deformed by changes in pressure and / or temperature in the module area.

[0011] The pack case further includes a main partition wall that crosses a center of the pack case and is coupled to a base plate, and a sub-partition wall that has both ends coupled to the main partition wall and a side wall, respectively, and is coupled to the base plate at a predetermined interval along a longitudinal direction of the main partition wall, and a plurality of the module regions may be formed by partitions formed by the main partition wall and the sub partition wall.

[0012] The pack case may further include a support block protruding from a boundary between the sub-partition wall and the base plate, and the battery module may further include protrusions protruding from both sides to be supported on upper portions of the support blocks, and the battery module may be fixed to the pack case by bolt members that pass through the protrusions and are screwed into the support blocks.

[0013] The pack case may further include a fixing member that is coupled to the sub-partition and a battery module installed adjacent to the sub-partition, and the battery module may be fixed to the sub-partition by screwing an upper end and an end of the fixing member.

[0014] The fixing members may be screw-coupled to the battery modules located on both sides of the sub-partition across the sub-partition.

[0015] The fixing member may be fixed to an upper end of the sub-partition by being screwed thereto.

[0016] Each of the module regions may be sealed by the main and sub-partition walls.

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

[0018] The base plate may include a plurality of upwardly projecting protrusions.

[0019] The plurality of protrusions may be formed on the upper portion of the base plate in a dot-like distribution, or may be formed on the upper portion of the base plate in a line-like manner in one direction.

[0020] The point-like protrusions may protrude in either a rectangular shape or a columnar shape.

[0021] The linear protrusion may be formed to extend in any one of a straight line and a curved line.

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

[0023] The base plate may expand outwardly due to the pressure of gas generated in the module area. 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 accommodated battery modules, the heat can be prevented from being propagated, thereby improving the stability of the battery pack. [Brief description of the drawings]

[0025] [Figure 1] 1 shows a conventional battery pack. [Diagram 2] 1 is a perspective view of a battery pack according to a first embodiment of the present invention; [Diagram 3] 1 shows a pack case of the present invention and a number of battery modules mounted in the pack case. [Figure 4] 13 is a perspective view showing a modified example of the pack case of the present invention. [Diagram 5] 5 shows a cross section of the pack case and the upper cover of FIG. 4. [Figure 6] 6 shows the combination of the pack case and the top cover of FIG. 5. [Figure 7] This illustrates a phenomenon in which one of the battery modules housed in the battery pack of FIG. 6 experiences thermal runaway. [Figure 8] 11 is a perspective view of a pack case included in a battery pack to which a fixing member is applied according to a second embodiment of the present invention. FIG. [Figure 9] 9 shows a cross section of the pack case and the upper cover of FIG. 8. [Figure 10] 10 shows the pack case of FIG. 9 coupled with an upper cover. [Figure 11] This shows that thermal runaway has occurred in some of the battery modules among the multiple battery modules housed in the battery pack of FIG. 10 above. [Figure 12] 13 shows a cross section of a battery pack according to a third embodiment of the present invention. [Figure 13] This shows that thermal runaway has occurred in some of the battery modules included in the battery pack shown in Figure 12 above. [Figure 14] FIG. 13 is a perspective view of a pack case included in a battery pack according to a fourth embodiment of the present invention. [Figure 15] 15 is a cross-sectional view of the pack case and the upper cover of FIG. 14 joined together. [Figure 16] This shows that thermal runaway occurred in some of the battery modules included in the battery pack of FIG. 15. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to best describe his own invention.

[0027] Therefore, the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0028] In addition, in the description of the present invention, if it is determined that a specific description of related publicly known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0029] Since the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown roughly for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

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

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

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

[0033] (First embodiment) FIG. 2 is a perspective view of the 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 FIG.

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

[0036] As shown in FIG. 2(a), the pack case 100 includes a base plate 110 supporting a lower portion of the battery module M, and a side wall 120 coupled along an edge of the base plate 110.

[0037] The base plate 110 corresponds to the bottom of the pack case 100 and plays a role in supporting and protecting the lower portion of the installed battery module M.

[0038] The side wall 120 supports and protects the sides of the battery modules M mounted on the base plate 110 from the outside.

[0039] FIG. 3 shows a pack case 100 of the present invention and a plurality of battery modules M mounted in the pack case 100. As shown in FIG. 2 and FIG. 3, the pack case 100 of the present invention may further include a main partition 130 that crosses the center of the pack case 100 and is coupled to the base plate 110, and a sub-partition 140 whose both ends are coupled to the main partition 130 and the side wall 120, respectively, and is coupled to the base plate 110 at a predetermined interval along the longitudinal direction of the main partition 130.

[0040] The main partition 130 crosses the internal space of the pack case 100 to divide the space in which the battery modules M are installed into two large spaces, and the sub-partition 140 further divides the space divided by the main partition 130 into a plurality of spaces.

[0041] Various conductors and bus bars used in a battery pack may be inserted or attached inside the main bulkhead 130, or the inside of the main bulkhead 130 may be empty.

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

[0043] The module regions 150 of the present invention are formed in plurality by partitions formed by the main partition walls 130 and the sub-partition walls 140 .

[0044] In each module area 150 formed by the partitions of the main partition 130 and the sub partition 140, one battery module M can be installed.

[0045] The battery module M accommodated in the module area 150 may be fixed to the pack case 100 for more stable mounting.

[0046] FIG. 4 shows an oblique view of a modified pack case 100 of the present invention, FIG. 5 shows a cross section of pack case 100 and upper cover 200 of FIG. 4, and FIG. 6 shows the combination of pack case 100 and upper cover 200 of FIG. 5.

[0047] The battery module M used in the battery pack of the present invention may include protrusions M1 protruding from both sides as shown in Figures 4 and 5. In addition, the pack case 100 to which the battery module M of the above type is mounted may further include a support block 160 protruding from a boundary between the sub-partition wall 140 and the base plate 110. Specifically, the battery module M is installed 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 mounted in the module area 150 may be fixed to the pack case 100 by a bolt member B that penetrates the protrusion M1 and is screwed into the support block 160.

[0049] 2(b), the upper cover 200 is coupled to the pack case 100 to cover the upper portion of each battery module M mounted in the pack case 100. More specifically, the upper cover 200 may be coupled to an upper end of a side wall 120 whose end is coupled along an edge of the base plate 110, and may be screwed to the side wall 120 by a bolt member B or the like so that the inside of the pack case 100 may be sealed.

[0050] 6, the battery pack of the present invention may be sealed such that each module region 150 is independent of each other by combining the pack case 100 and the upper cover 200. More specifically, each module region 150 of the present invention may be sealed by the upper cover 200 combined with the pack case 100 abutting the upper ends of the main partition wall 130, the sub partition wall 140, etc. without any gaps. Therefore, even if thermal runaway occurs in the battery module M included in any one of the module regions 150, high-temperature gas due to the thermal runaway is not directly transferred to the battery modules M of the other module regions 150.

[0051] Generally, the base plate 110 may be made of an aluminum material and is manufactured to have a large thickness so as not to deform even under high temperature and pressure. That is, since the conventional base plate 110 is manufactured to have a larger thickness than the upper cover 200, when high temperature and high pressure gas is generated inside the sealed battery pack, the relatively thin 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 included in the pack case 100 is adjusted to be thinner than the upper cover 200. That is, 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 first by the gas pressure rather than the upper cover 200.

[0053] However, the base plate 110 needs to have a strength capable of withstanding 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 pressure and / or temperature in the module area 150 .

[0055] FIG. 7 illustrates a phenomenon in which one of the battery modules M housed in the battery pack of FIG. 6 experiences thermal runaway.

[0056] When the battery module M experiences thermal runaway, high temperatures and gas are generated, causing gas pressure to fill the sealed module area 150. The gas pressure then pushes out the base plate 110, which is relatively thin and weak, causing the shape of the base plate 110 to change.

[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. Therefore, high-temperature heat generated in the thermally runaway battery module M is not easily transferred to other adjacent battery modules M via the base plate 110, thereby preventing a chain reaction of thermal runaway in the other battery modules M.

[0058] Second embodiment The battery pack of the present invention may further include a fixing member 170 for fixing the battery module M to the sub-partition wall 140.

[0059] FIG. 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 a fixing member 170 is applied, FIG. 9 shows a cross-section of the pack case 100 and upper cover 200 of FIG. 8, and FIG. 10 shows the pack case 100 of FIG. 9 combined with the upper cover 200.

[0060] 8 to 10, the pack case 100 included in the battery pack according to the second embodiment of the present invention further includes a fixing member 170 coupled to the sub-partition 140 and a battery module M installed adjacent to the sub-partition 140. Specifically, the battery module M installed in the pack case 100 is fixed to the sub-partition 140 by a bolt member B that is coupled to an upper end of the battery module M at an end of the fixing member 170 and is additionally fixed to the sub-partition 140 by a bolt member B that penetrates the fixing member 170 and is screwed to an upper end of the battery module M.

[0061] As shown in the figure, the fixing members 170 may be screw-coupled 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 may be fixed to the sub-partition 140 interposed therebetween via one fixing member 170.

[0062] The battery module M is fixed to the sub-partition wall 140 through the fixing member 170 in this manner in order to prevent the battery module M from being depressed together with the base plate 110 when the base plate 110 bulges outward and is depressed downward due to thermal runaway of the battery module M. That is, the fixing member 170 plays a role in minimizing contact between the battery module M and the base plate 110 by continuing to fix the battery module M in which thermal runaway has occurred to the sub-partition wall 140.

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

[0064] The fixing member 170 is also preferably screwed to the sub-partition wall 140 .

[0065] As shown in FIGS. 8 to 10, the fixing member 170 may be fixed to the upper end of the sub-partition wall 140 by being screwed thereto.

[0066] In addition, although not shown, the fixing member 170 may be fixed to the sub-partition wall 140 by a bolt member B which penetrates the upper cover 200 and the fixing member 170 simultaneously and is screwed to the upper end of the sub-partition wall 140 .

[0067] FIG. 11 shows that thermal runaway occurs in some of the battery modules M among the plurality of battery modules M housed in the battery pack of FIG.

[0068] Referring to FIG. 11, it can be seen that the base plate 110 is deformed downward due to gas pressure caused by thermal runaway of the battery module M, but the battery module M does not collapse along with the base plate 110 and remains fixed by the fixing member 170.

[0069] That is, as the base plate 110 is gradually and violently deformed by the gas pressure, the contact area between the thermally runaway battery module M and the recessed base plate 110 decreases.

[0070] Third embodiment The base plate 110 included in the battery pack of the present invention may be formed by combining a plurality of support plates 111 together.

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

[0072] As shown in FIG. 12 above, a single base plate 110 is formed by connecting a plurality of support plates 111 together.

[0073] That is, the base plate 110 is formed by combining a plurality of support plates 111 corresponding to each module region 150, and the support plates 111 are deformed by at least one change in pressure and temperature of the corresponding module region 150.

[0074] Each support plate 111 may be screwed to the lower ends of the side wall 120, the main bulkhead 130, and the sub-bulhead 140, and may also be connected and coupled between each support plate 111.

[0075] In order to suppress heat transfer between the support plates 111 to the maximum extent possible, a heat insulating member may be additionally interposed between the support plates 111 as required.

[0076] FIG. 13 shows that thermal runaway occurs in some of the battery modules M among the plurality of battery modules M included in the battery pack of FIG.

[0077] Referring to FIG. 13, only the support plate 111 corresponding to the module area 150 in which the battery module M in which thermal runaway occurred is accommodated is deformed.

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

[0079] FIG. 14 is a perspective view of a pack case 100 included in a battery pack according to a fourth embodiment of the present invention, and FIG. 15 is a cross-sectional view of the pack case 100 and upper cover 200 of FIG. 14 combined together.

[0080] The base plate 110 includes a plurality of protrusions 112 protruding upward, as shown in FIGS.

[0081] The plurality of protrusions 112 may be formed in a dot-like distribution on the upper part of the base plate 110 as shown in the figure, but is not limited thereto, and may also be formed in a line extending in one direction on the upper part of the base plate 110.

[0082] The point-like protrusions 112 may protrude in various shapes, for example, the protrusions 112 may protrude in any one of a rectangular shape and a columnar shape.

[0083] The linear protrusion 112 may be formed to extend in any one of a straight line and a curved line.

[0084] Therefore, the battery modules M mounted in each module area 150 are supported by the upper ends of the protrusions 112, and therefore the entire area of ​​the battery modules M cannot be in contact with the base plate 110.

[0085] FIG. 16 illustrates the occurrence of thermal runaway in some of the battery modules M among the battery modules M included in the battery pack of FIG.

[0086] 16, the base plate 110 located under the battery module M where thermal runaway has occurred is deformed while maintaining the protrusions 112, thereby further reducing the number of contact points with the battery module M. In addition, even if high temperature heat is transferred through the base plate 110 to the adjacent normal battery modules M, only a small amount of heat is transferred through the protrusions 112.

[0087] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments, etc. in this specification are merely one embodiment of the present invention and do not fully represent the technical ideas of the present invention, and therefore there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

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

Claims

1. A battery pack in which a battery module is housed, a pack case including a module area in which the battery module is installed; an upper cover coupled to the pack case to cover an upper portion of the battery module mounted in the pack case; The pack case includes: A base plate supporting a lower portion of the battery module; a sidewall coupled along an edge of the base plate; The base plate has a thickness smaller than that of the upper cover.

2. The battery pack of claim 1 , wherein the base plate is deformed by at least one of a change in pressure and a change in temperature in the module area.

3. The pack case includes a main partition wall that crosses a center portion of the pack case and is coupled to the base plate; a sub-partition wall, both ends of which are coupled to the main partition wall and the side wall, respectively, and which is coupled to the base plate at a predetermined interval along a longitudinal direction of the main partition wall, The battery pack according to claim 1 , wherein a plurality of module regions are formed by partitions defined by the main partition and the sub partition.

4. The pack case includes: a support block protruding from a boundary between the sub-partition wall and the base plate, the battery module further includes protrusions protruding from both sides of the battery module to be supported by the upper portion 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 protrusion and is screwed into the support block.

5. The pack case includes: a fixing member coupled to the sub-partition and a battery module disposed adjacent to the sub-partition, The battery pack according to claim 3 or 4, wherein the battery module is fixed to the sub-partition by screwing an upper end of the battery module to an end of the fixing member.

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

7. The battery pack according to claim 5 , wherein the fixing member is fixed to an upper end of the sub-partition by being screwed thereto.

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

9. The base plate is formed by combining a plurality of support plates corresponding to each module area; The battery pack according to claim 3 or 4, wherein each of the support plates is deformed by at least one of a change in pressure and a change in temperature of a corresponding module area.

10. The battery pack according to claim 1 , wherein the base plate includes a plurality of protrusions protruding upward.

11. The battery pack of claim 10, wherein the protrusions are formed in a dot-like distribution on the upper portion of the base plate, or are formed in a line-like extension on the upper portion of the base plate in one direction.

12. The battery pack according to claim 11 , wherein the point-like protrusion protrudes in one of a rectangular shape and a columnar shape.

13. The battery pack according to claim 11 , wherein the linear protrusion is formed to extend in one of a straight line and a curved line.

14. The battery pack according to claim 1 , wherein the base plate has a strength sufficient to withstand at least a weight of the battery module.

15. The battery pack according to claim 1 , wherein the base plate expands outward due to pressure of gas generated in the module area.

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