Battery pack

Abstract

The present invention relates to a battery pack accommodating a plurality of cell assemblies, comprising: a pack case in which the cell assemblies are mounted; an upper case coupled to the pack case to cover an upper portion of the cell assemblies mounted inside the pack case; and at least one spark prevention member having a plurality of mesh holes and provided at a lower end of the upper case, wherein the pack case includes at least one exhaust hole on a side thereof communicating with an internal space, and the spark prevention member is provided at a position corresponding to the exhaust hole of the pack case.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and the battery pack of the present invention is characterized by including a pack case including at least one exhaust hole, and an upper case provided with a spark prevention member having a mesh structure corresponding to the exhaust hole.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0103279, filed on August 8, 2023, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Lithium secondary batteries are typically in the form of a cell, which includes an electrode assembly in which electrodes and separators are alternately stacked, electrode leads connected to the electrodes, and a case that encloses and seals the electrode assembly so that the electrode leads are exposed to the outside. Depending on the shape of the electrode assembly and the case, lithium secondary batteries can be classified into cylindrical cells, prismatic cells, pouch cells, etc.

[0004] The output generated by one cell is not large, so when applied to vehicles, multiple cells are connected together to obtain the desired output.

[0005] FIG. 1 shows a cell assembly A in which a plurality of cells C are stacked and bonded together, and a conventional battery pack 10 in which the cell assembly A is housed.

[0006] Generally, as shown in FIG. 1, a battery pack 10 is composed of a pack case 30 in which a cell assembly A is installed, and an upper case 20 that is coupled to the pack case 30 so as to cover the top of the installed cell assembly A.

[0007] A typical electric vehicle can be equipped with the battery pack 10 shown in FIG. 1, and the electric vehicle equipped with the battery pack 10 can obtain a large output due to the multiple cell assemblies A included in the single battery pack 10.

[0008] Lithium secondary batteries such as the battery pack 10, which can provide a large output as described above, are susceptible to the risk of explosion, fire, etc. due to heat generation, and ensuring safety is an important issue. If an appropriate response is not made in the early stages when such an abnormal phenomenon occurs, the internal temperature of the secondary battery will rise rapidly due to heat generation, and the sudden rise in temperature may cause thermal runaway, which may even lead to an explosion of the secondary battery.

[0009] Each country has set several requirements for secondary battery manufacturers to improve the safety of various electrical products, including electric vehicles. For example, China has proposed GB38031-2020 regulations, which require manufacturers to implement a system that can control thermal runaway of cell C within five minutes of the occurrence of such a condition.

[0010] Not only in China but also in many other countries, there is a demand for a battery pack 10 having a structure that can quickly control an abnormal phenomenon in the contained cell C before it escalates into an explosion and fire of the battery pack 10.

[0011] Meanwhile, in the thermal runaway process of cell assembly A, high-temperature gas g generated by the vaporization of electrolyte inside cell assembly A is released, and spark particles p are released due to short-circuiting of electrodes, etc. A typical battery pack 10 has a gas g exhaust path on the side through which gas g can be released to prevent a sudden increase in internal pressure due to the high-temperature gas g. However, if the generated spark particles p are released outside through the gas g exhaust path where oxygen is concentrated, there is a risk of an explosion.

[0012] Therefore, conventionally, when a thermal runaway situation occurs inside, a method is required to selectively discharge only the gas g and to minimize the situation where the spark particles p come into contact with external oxygen. Summary of the Invention [Problem to be solved by the invention]

[0013] Therefore, the present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery pack having a structure that can selectively release only high-temperature gas in a thermal runaway situation.

[0014] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention, and it is easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as set forth in the claims. [Means for solving the problem]

[0015] In accordance with the present invention, a battery pack is provided that contains a plurality of cell assemblies.

[0016] The battery pack includes a pack case in which a cell assembly is installed, an upper case coupled to the pack case to cover an upper portion of the cell assembly installed inside the pack case, and at least one spark prevention member having a plurality of mesh holes and provided at a lower end of the upper case, wherein the pack case includes at least one exhaust hole in a side portion thereof communicating with an internal space, and the spark prevention member is provided at a position corresponding to the exhaust hole of the pack case.

[0017] The spark arrestor may have a mesh structure.

[0018] The spark prevention member may be provided standing vertically relative to the upper case so that mesh holes can communicate with the exhaust holes of the pack case.

[0019] The pack case can include a base plate that supports the lower portions of the multiple cell assemblies, a center beam that crosses the center of the base plate and is connected to the base plate so as to divide the internal space of the pack case into two, and side beams that are connected to the edges of the base plate so as to support the sides of the cell assemblies.

[0020] The pack case may include at least two or more exhaust holes, and the at least two or more exhaust holes may be formed in the side beams so as to communicate with the internal spaces of the respective pack cases partitioned by the center beam.

[0021] The spark prevention member may be provided at a lower end of the upper case so as to be located inside the side beam.

[0022] The spark prevention member may be provided at a lower end of the upper case so as to be located outside the side beam.

[0023] A pair of spark prevention members may correspond to one exhaust hole, and the pair of spark prevention members may be provided at a lower end of the upper case to face each other with a predetermined gap therebetween.

[0024] One of the pair of spark prevention members may be located inside the side beam, and the other may be located outside the side beam.

[0025] The side beams may include insertion grooves that are open at an upper portion and into which the spark prevention member can be inserted, and the insertion grooves may be formed in correspondence with positions where the exhaust holes are formed so as to intersect with the exhaust holes. The upper case may be coupled to the pack case such that the spark prevention member is inserted into the insertion grooves.

[0026] The spark prevention member may be provided at a lower end of the upper case at a position spaced a predetermined distance horizontally from the side beam.

[0027] The spark arrestor may include an electrically insulating material.

[0028] The spark arrestor may include a flame-resistant material.

[0029] The spark prevention member may have an area larger than an area of ​​the exhaust hole.

[0030] The mesh holes may be formed in any one of a circular shape and a polygonal shape. [Effects of the Invention]

[0031] According to the present invention, it is possible to prevent the explosion of the battery pack and the occurrence of a fire. [Brief explanation of the drawings]

[0032] [Figure 1] 1 shows a conventional battery pack and a cell assembly contained in the battery pack. [Figure 2] 1 is a front perspective view of a battery pack according to a first embodiment of the present invention; [Figure 3] FIG. 3 shows a rear perspective view of the battery pack of FIG. 2. [Figure 4] FIG. 2 is a front view of the spark prevention member. [Figure 5] FIG. 2 is a bottom perspective view of the spark arrestor. [Figure 6] 10 shows the process of joining the upper case and the pack case. [Figure 7] 7 shows a cross section of the pack case where the exhaust hole is located and the upper case where the spark prevention member is located in the battery pack of FIG. 6. [Figure 8] This indicates that gas generated inside the battery pack is discharged to the outside through the exhaust hole. [Figure 9] This shows the movement of spark particles generated inside the battery pack. [Figure 10] 10 illustrates a process of combining an upper case and a pack case included in a battery pack according to a second embodiment of the present invention. [Figure 11] 11 shows a cross section of the pack case where the exhaust hole is located and the upper case where the spark prevention member is located in the battery pack of FIG. 10. [Figure 12] 10 illustrates a process of combining an upper case and a pack case included in a battery pack according to a third embodiment of the present invention. [Figure 13] 13 shows a cross section of the pack case where the exhaust hole is located and the upper case where the spark prevention member is located in the battery pack of FIG. 12. [Figure 14] 10 illustrates a process of combining an upper case and a pack case included in a battery pack according to a fourth embodiment of the present invention. [Figure 15] 15 shows a cross section of the pack case where the exhaust hole is located and the upper case where the spark prevention member is located in the battery pack of FIG. 14. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, it should be noted that the 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 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 concepts of the terms in order to best describe his own invention.

[0034] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments 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.

[0035] Furthermore, 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.

[0036] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0037] The present invention relates to a battery pack that houses a plurality of cell assemblies and has a structure that allows selective release of only high-temperature gas generated in a thermal runaway state of a cell.

[0038] The battery pack of the present invention is characterized by including a pack case having at least one exhaust hole, and an upper case provided with a spark prevention member having a mesh structure corresponding to the exhaust hole.

[0039] The cell assembly includes a plurality of cells stacked in one direction. Specifically, the cell assembly includes a cell stack including a plurality of cells, each having an electrode lead extending from both sides thereof, and bus bar frames, each having a bus bar electrically connected to the electrode leads of the cell stack, coupled to the front and rear surfaces of the cell stack.

[0040] Furthermore, the cell assembly may further include end plates coupled to cover the bus bar frame, and may further include a frame surrounding the cell stack to protect the exposed cell stack from external impacts, etc.

[0041] Figures 2 to 9 relate to a battery pack according to a first embodiment of the present invention, Figures 10 to 11 relate to a battery pack according to a second embodiment of the present invention, Figures 12 to 13 relate to a battery pack according to a third embodiment of the present invention, and Figures 14 to 15 relate to a battery pack according to a fourth embodiment of the present invention.

[0042] Hereinafter, specific embodiments of the battery pack of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front, back, up, down, left, and right used in the following description to designate relative positions are intended to facilitate understanding of the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0043] (First embodiment) FIG. 2 is a front perspective view of the battery pack according to the first embodiment of the present invention, and FIG. 3 is a rear perspective view of the battery pack of FIG.

[0044] The battery pack of the present invention includes a pack case 200 in which a plurality of cell assemblies A are mounted, and an upper case 100 that is coupled to the pack case 200 so as to cover the upper part of the plurality of cell assemblies A mounted inside the pack case 200.

[0045] More specifically, the pack case 200 includes a base plate 210 that supports the lower portions of the multiple cell assemblies A, side beams 220 that are connected to the edges of the base plate 210 to support the sides of the cell assemblies A, and a center beam 230 that is connected to the base plate 210 across the center of the base plate 210 to divide the internal space of the pack case 200 into two.

[0046] In addition, the pack case 200 may further include a cross beam 240, both ends of which are connected to the center beam 230 and the side beams 220, respectively.

[0047] The cross beam 240 serves to re-divide the internal space of the pack case 200, which is divided by the center beam 230, into units of cell assemblies A. However, the cross beam 240 may be omitted if necessary.

[0048] The internal space of the pack case 200 may be partitioned by the center beam 230 and the cross beams 240, and the partitioned spaces may be substantially connected to each other. For example, when gas g is generated in a cell assembly A housed in one of the partitioned spaces, the internal pressure of the internal space of the pack case 200 may rise evenly in any region.

[0049] The pack case 200 includes at least one exhaust hole 221 in communication with the internal space at a side thereof. That is, the pack case 200 may have the exhaust hole 221 formed at one side thereof so that the gas g generated inside can be exhausted to the outside.

[0050] Specifically, the exhaust hole 221 may be formed in the side beam 220 as shown in Fig. 2. Therefore, when any one of the cell assemblies A experiences thermal runaway and generates high-temperature gas g, the gas g can move to the exhaust hole 221 and be exhausted to the outside.

[0051] The pack case 200 of the present invention includes at least two or more discharge holes 221, and the at least two or more discharge holes 221 are formed in the side beams 220 so as to communicate with the internal spaces of the respective pack cases 200 partitioned by the center beam 230.

[0052] The discharge hole 221 may be formed on either the front or rear surface of the pack case 200 .

[0053] Referring to FIG. 2, two exhaust holes 221 are formed on both sides of the joining portion between the center beam 230 and the side beams 220.

[0054] The upper case 100 is coupled to the upper end of the side beam 220 so that the inner space of the pack case 200 can be isolated from the outside.

[0055] The battery pack of the present invention is characterized in that it further includes a spark prevention member 300 provided at the lower end of the upper case 100 and selectively allowing only gas g to pass through.

[0056] FIG. 4 is a front view of spark arrestor 300, and FIG. 5 is a bottom perspective view of spark arrestor 300. As shown in FIG.

[0057] The spark arrestor 300 has a mesh structure and includes a plurality of mesh holes 310 as shown in FIG.

[0058] The mesh holes 310 of the spark prevention member 300 allow gas g to pass through and prevent the movement of spark particles p and the like.

[0059] The spark prevention member 300 preferably includes a flame-resistant material so as not to be damaged by high-temperature gas g, etc. Also, it preferably includes an electrically insulating material so as to be able to block the flow of electricity.

[0060] The shape of the mesh holes 310 may be circular as shown in the figure, but is not limited to this and may be polygonal.

[0061] The upper end of the spark prevention member 300 is coupled to the lower end of the upper case 100. More specifically, the spark prevention member 300 is provided standing vertically relative to the upper case 100 as shown in Fig. 5. Therefore, the gas g moves horizontally and can pass through the mesh holes 310 of the spark prevention member 300.

[0062] The battery pack of the present invention is characterized in that the spark prevention member 300 is provided at a position corresponding to the exhaust hole 221 of the pack case 200.

[0063] FIG. 6 shows the process in which the upper case 100 and the pack case 200 are joined together.

[0064] Referring to FIG. 6, exhaust holes 221 are formed in the side beams 220, and the spark prevention members 300 are provided at the lower end of the upper case 100 at positions corresponding to the exhaust holes 221.

[0065] The spark prevention member 300 included in the battery pack according to the first embodiment is provided at the lower end of the upper case 100 so as to be located inside the side beam 220, as shown in FIG.

[0066] Spark prevention member 300, which is coupled to stand vertically at the lower end of upper case 100, is shaped to cover exhaust hole 221 when upper case 100 is coupled to pack case 200. That is, mesh hole 310 of spark prevention member 300 communicates with exhaust hole 221 of pack case 200 when upper case 100 and pack case 200 are coupled to each other.

[0067] FIG. 7 shows a cross section of the pack case 200 in which the discharge hole 221 is located and the upper case 100 in which the spark prevention member 300 is located in the battery pack of FIG.

[0068] The spark prevention member 300 preferably has an area larger than that of the discharge hole 221 so as to be able to block the spark particles p flying toward the discharge hole 221 .

[0069] As shown in FIG. 7, the spark prevention member 300 is provided at a position where it can cover and close the entire discharge hole 221.

[0070] However, the spark prevention member 300 is provided at a position spaced a predetermined distance from the surface of the side beam 220 so as not to come into contact with the surface of the side beam 220. That is, the spark prevention member 300 is provided at the lower end of the upper case 100 at a position spaced a predetermined distance from the side beam 220 in the horizontal direction.

[0071] Therefore, a gap w may be formed between the spark prevention member 300 and the side beam 220.

[0072] The gap w serves as an auxiliary passage through which the gas g discharged through the mesh holes 310 travels directly to the discharge holes 221 without passing through the spark prevention member 300 .

[0073] When a large amount of gas g is generated inside the battery pack, it may be impossible to quickly exhaust the gas g through the mesh holes 310 of the spark prevention member 300. Therefore, in addition to the mesh holes 310, an additional passage must be secured to allow the internal gas g to move to the exhaust holes 221, and the gap w between the spark prevention member 300 and the side beam 220 serves as the additional passage.

[0074] The size of the gap w may vary depending on the expected amount of gas g and the pressure inside the battery pack.

[0075] FIG. 8 shows that gas g generated inside the battery pack is discharged to the outside through the discharge hole 221, and FIG. 9 shows the movement of spark particles p generated inside the battery pack.

[0076] Referring to FIG. 8, gas g passes through mesh holes 310 of spark prevention member 300 to reach exhaust holes 221, or passes through gaps w between spark prevention member 300 and side beam 220 to reach exhaust holes 221.

[0077] According to FIG. 9 above, the spark particles p cannot pass through the mesh holes 310 of the spark prevention member 300 and are blocked or fly out.

[0078] Therefore, even if a thermal runaway phenomenon occurs in any one of the cell assemblies A housed therein and high-temperature gas g and spark particles p are generated, the battery pack of the present invention can quickly discharge the high-temperature gas g to the outside and minimize contact of the spark particles p with external oxygen.

[0079] (Second embodiment) The battery pack of the present invention allows the positions of the side beams 220 and the spark prevention members 300 to be adjusted more variably.

[0080] FIG. 10 shows a process of combining an upper case 100 and a pack case 200 included in a battery pack according to a second embodiment of the present invention, and FIG. 11 shows a cross section of the pack case 200 where the discharge hole 221 is located and the upper case 100 where the spark prevention member 300 is located in the battery pack of FIG. 10.

[0081] The spark prevention member 300 is provided at the lower end of the upper case 100 so as to be located outside the side beam 220 .

[0082] In this case, the spark particles p that have passed through the discharge holes 221 without any resistance are caught by the spark prevention member 300 located outside the discharge holes 221 and cannot escape to the outside.

[0083] However, the gas g can be smoothly discharged through the gap w between the outer surface of the side beam 220 and the spark prevention member 300 .

[0084] (Third embodiment) In the battery pack of the present invention, the side beam 220 may have an insertion groove 222 into which the spark prevention member 300 can be inserted.

[0085] FIG. 12 shows a process of combining an upper case 100 and a pack case 200 included in a battery pack according to a third embodiment of the present invention, and FIG. 13 shows a cross section of the pack case 200 where the discharge hole 221 is located and the upper case 100 where the spark prevention member 300 is located in the battery pack of FIG. 12.

[0086] 12 and 13, the side beam 220 includes an insertion groove 222 that is open upward so that the spark prevention member 300 can be inserted therein.

[0087] The upper case 100 is coupled to the pack case 200 by inserting the spark prevention member 300 into the insertion groove 222. At this time, it is preferable that the spark prevention member 300 is disposed so as not to come into contact with the side beam 220 in which the insertion groove 222 is formed.

[0088] The insertion groove 222 is formed at a position corresponding to the position where the discharge hole 221 is formed so as to intersect with the discharge hole 221 .

[0089] Therefore, the movement of the spark particles p passing through the discharge hole 221 can be restricted by the spark prevention member 300 inserted into the insertion groove 222 .

[0090] However, in the case of gas g, it can be smoothly discharged to the outside not only through mesh holes 310 of spark prevention member 300 but also through gap w between insertion groove 222 and spark prevention member 300 .

[0091] (Fourth embodiment) In the battery pack of the present invention, a double-designed spark prevention member 300 may be applied to one exhaust hole 221.

[0092] FIG. 14 shows a process of combining an upper case 100 and a pack case 200 included in a battery pack according to a fourth embodiment of the present invention, and FIG. 15 shows a cross section of the pack case 200 where the discharge hole 221 is located and the upper case 100 where the spark prevention member 300 is located in the battery pack of FIG. 14.

[0093] As shown in FIGS. 14 and 15, a pair of spark prevention members 300 are provided in correspondence with each discharge hole 221. As shown in FIG.

[0094] The pair of spark prevention members 300 are provided at the lower end of the upper case 100 to face each other with a predetermined gap therebetween.

[0095] Specifically, one of the pair of spark prevention members 300 is located inside the side beam 220, and the other is located outside the side beam 220. In this case, it is preferable that the pair of spark prevention members 300 are arranged so as not to come into contact with the side beam 220.

[0096] Therefore, the spark particles p generated inside the battery pack are restricted from moving to the outside by the pair of double-designed spark prevention members 300.

[0097] Specifically, the movement of the gas g generated inside the battery pack may be primarily restricted by the spark prevention member 300 located inside the pack case 200, and may be secondarily restricted by the spark prevention member 300 located outside the pack case 200.

[0098] However, gas g generated inside the battery pack can be discharged to the outside through the mesh holes 310 formed in each spark prevention member 300, and can also be additionally discharged to the outside through the gaps w between each spark prevention member 300 and the side beams 220.

[0099] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, at the time of filing this application, there may be various equivalents and modifications that can replace them. [Explanation of symbols]

[0100] 10: (Prior Art) Battery Pack 20: (Prior Art) Upper Case 30: (Conventional technology) Pack case 100: Upper case 200: Pack case 210: Base plate 220: Side beam 221: Discharge hole 222: Insertion groove 230: Center beam 240: Cross beam 300: Spark prevention material 310: Mesh hole A: Cell assembly C: Cell g: Gas (movement) p: Spark particle (movement) w: gap (spacing)

Claims

1. 1. A battery pack containing a plurality of cell assemblies, a pack case in which the plurality of cell assemblies are mounted; an upper case coupled to the pack case so as to cover an upper portion of the plurality of cell assemblies placed inside the pack case; at least one spark prevention member including a plurality of mesh holes and provided at a lower end of the upper case; The pack case includes at least one discharge hole in a side portion thereof that communicates with the internal space, The spark prevention member is provided at a position corresponding to the exhaust hole of the pack case.

2. The battery pack according to claim 1 , wherein the spark prevention member has a mesh structure.

3. The battery pack of claim 1 or 2, wherein the spark prevention member is provided standing vertically relative to the upper case so that the mesh holes can communicate with the exhaust holes of the pack case.

4. The pack case is a base plate supporting a lower portion of the plurality of cell assemblies; a center beam that crosses a center portion of the base plate and is coupled to the base plate so as to divide an internal space of the pack case into two; 3. The battery pack according to claim 1, further comprising: side beams coupled to edges of the base plate to support sides of the cell assemblies.

5. The pack case includes at least two discharge holes, The battery pack according to claim 4 , wherein the at least two or more exhaust holes are formed in the side beams so as to communicate with respective internal spaces of the pack case partitioned by the center beam.

6. The battery pack according to claim 4 , wherein the spark prevention member is provided at a lower end of the upper case so as to be located inside the side beam.

7. The battery pack according to claim 4 , wherein the spark prevention member is provided at a lower end of the upper case so as to be located outside the side beams.

8. A pair of the spark prevention members corresponds to one of the discharge holes, The battery pack according to claim 4 , wherein the pair of spark prevention members are provided at a lower end of the upper case to face each other with a predetermined gap therebetween.

9. The battery pack according to claim 8 , wherein one of the pair of spark prevention members is located inside the side beam, and the other is located outside the side beam.

10. the side beams each include an insertion groove that is open at an upper portion and into which the spark prevention member can be inserted; the insertion groove is formed at a position corresponding to the discharge hole so as to intersect with the discharge hole, The battery pack according to claim 4 , wherein the upper case is coupled to the pack case such that the spark prevention member is inserted into the insertion groove.

11. The battery pack according to claim 4 , wherein the spark prevention member is provided at a lower end of the upper case at a position spaced a predetermined distance horizontally from the side beam.

12. 3. The battery pack according to claim 1, wherein the spark prevention member comprises an electrically insulating material.

13. The battery pack of claim 1 or 2, wherein the spark prevention member comprises a flame-resistant material.

14. The battery pack of claim 1 or 2, wherein the spark prevention member has an area larger than an area of ​​the exhaust hole.

15. The battery pack of claim 1 or 2, wherein the mesh holes are formed in one of a circular shape and a polygonal shape.

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